JOHN DEERE CYCLONE AND LIQUIFIRE SNOWMOBILES

Transcription

1 JOHN DEERE CYCLONE AND LIQUIFIRE SNOWMOBILES CONTENTS 1 Servie Manual SM-2108 (Aug-77) SECTION 10 - GENERAL Group 5 - Mahine Identifiation Group 10 - Speifiations Group 15 - Tune-Up and Adjustment Group 20 - Fuel and Lubriants SECTION 20 - ENGINE Group 5 - General Information Group 10 - Engine Analysis and Inspetion Group 15 - Fan Cooled Reed Valve Engine Overhaul Group 20 - Liquid Cooled Reed Valve Engine Overhaul Group 25 - Reoil Starters Group 30 - Liquid Cooling System (Serial No. -80,000) Group 32 - Liquid Cooling System (Serial No. 80,001 - ) Group 35 - Speifiations SECTION 30 - FUEL SYSTEM Group 5 - General Information Group 10 - Mikuni Carburetor Group 15 - Sileners Group 20 - Fuel Pump, Fuel Tank, Sreen and In-Line Fuel Filter SECTION 50 - POWER TRAIN Group 5 - General Information Group 10 - John Deere (Comet) Drive Sheave Group 15 - John Deere Driven Sheave Group 20 - Drive Belt Group 25 - Chain Case, Seondary Shaft and Drive Shaft Group 30 - Mehanial Disk Brake Group 35 - Speifiations SECTION 60 - SUSPENSION Group 5 - General Information Group 10 - Slide Suspension (Serial No. -80,000) Group 12 - Slide Suspension (Serial No. 80,001 - ) Group 15 - John Deere and Goodyear Trak Group 20 - Skis and Steering Group 25 - Speifiations SECTION 70 - SERVICE TOOLS Group 5 - Essential Servie Tools Group 10 - Conveniene Servie Tools Group 15 - Dynamometer Test Proedure SECTION 40 - ELECTRICAL SYSTEM Group 5 - General Information Grouf} 10 - Capaitor Disharge Ignition System (COl) Group 15 - Lighting System Group 20 - Eletri Start Kit Group 25 - Speifiations (All information, illustrations and speifiations ontained in this servie manual are based on the latest information available at the time of publiation. The right is reserved to make hanges at any time without notie.) OOA Copyright 1977 DEERE & COMPANY Moline, Illinois All rights reserved

2 2 SM-2108 (Aug-77) INTRODUCTION A- Setion 30 - Fuel System B-Setion 50 - Brakes C-Setion 50 - Drive Sheave and Driven Sheave D- Setion 40 - Eletrial System E- Setion 20 - Engine F-Setion 30 - Carburetor G-Setion 60 - Trak and Suspension H-Setion 50 - Chain Case and Drive Shaft I-Setion 60 - Skis and Steering Fig. I-Components Covered in this Servie Manual This servie manual ontains servie and maintenane information for John Deere 340 and 440 Cylone and 340 and 440 Liquifire snowmobiles. The manual is divided into setions, with eah setion pertaining to a ertain omponent or operational system. The information is divided into groups within eah setion. Emphasis is plaed on diagnosing malfuntions, analysis and testing. Diagnosing malfuntions lists possible troubles, their auses, and how to orret them. These troubles are analyzed to help you understand what is ausing the problem, so it an be orreted rather than just replae parts. Speifiations are found in the last group of eah setion. Speial servie tools are in Setion 70. Hood, onsole, tunnel and pan repair are not overed in this servie manual. Minor raks and holes in hood, onsole or fiberglass pans an be repaired using plasti pathing kits or fiberglass re pair kits. These kits are available at loal auto supply stores. On snowmobiles with aluminum pans, minor tunnel and pan damage an be repaired by pop-riveting soft inh (1.524 mm) aluminum over the tear, rak or punture. If the pan and tunnel are damaged extensively, a omplete assembly is available. A pan reinforement for aluminum pans is available and an be pop-riveted over the damaged pan. A This safety alert symbol identifies important safety messages in this manual. When you see this symbol, be alert to the possibility of personal injury and arefully read the message that follows. NOTE: Metri equivalents have been inluded, where appliable, throughout this servie manual. This manual may be kept in its own over, or it may be removed and filed in your servie manual rak or Consumer Produts Servie Information Binder. J

3 General 10 Mahine Identifiation 5-1 CONTENTS Setion 10 GENERAL Group 5 MACHINE IDENTIFICATION Page GROUP 5 - MACHINE IDENTIFICATION Serial Numbers Mahine Serial Number Engine Serial Number Vintage Information GROUP 10 - SPECIFICATIONS Mahine Speifiations Engine Speifiations Bolt Torque Chart Page GROUP 15 - TUNE-UP AND ADJUSTMENT Tune-up Guide Adjustments Spark Plug Reommendation.., GROUP 20 - FUEL AND LUBRICANTS Break-In Period Fuel Lubriants Capaities fo-2 Servie Intervals C I

4 J General Mahine Identifiation SERIAL NUMBERS Mahine Serial Number Fig. 1-Snowmobile Serial Number Loation Eah snowmobile is assigned an individual mahine serial number. This serial number is loated on the right-hand side of the tunnel, Fig. 1. Engine Serial Number Eah snowmobile engine is assigned an individual serial number. John Deere (Kioritz) engines have the serial plate on the flywheel housing, Fig. 2. Fig. 3-Liquid-Cooled Engine Serial Number Plate Loation J ) ) Fig. 2-Fan-Cooled Engine Serial Number Plate Loation

5 General 10 Mahine Identifiation 5-3 VINTAGE INFORMATION 1976 Model Year Snowmobile Model 340 Cylone 440 Cylone 340 Liquifire 440 Liquifire Serial No. (55,001-70,000) (55,001-70,000) (55,001-70,000) (55,001-70,000) Code No. (type)* J34FE J44FE J34LE J44LE Engine Manufaturer Kioritz** Kioritz** Kioritz** Kioritz* * Engine Model No. 340/22A 440/22A 340/23LC 440/23LC Reed Valve Reed Valve Reed Valve Reed Valve 1977 Model Year Snowmobile Model 340 Cylone 440 Cylone 340 Liquifire 440 Liquifire Serial No. (70,001-80,000) (70,001-80,000) (70,001-80,000) (70,001-80,000) Code No. (type)* J34FF J44FF J34LF J44LF Engine Manufaturer Kioritz** Kioritz** Kioritz** Kioritz** Engine Model No. 340/22B 440/22B 340/23ALC 440/23ALC Reed Valve Reed Valve Reed Valve Reed Valve 1978 Model Year Snowmobile Model 340 Cylone 440 Cylone 340 Liquifire 440 Liquifire Serial No. (80,001- ) (80,001- ) (80,001- ) (80,001- ) Code No. (Type)* J34FG J44FG J34LG J44LG Engine Manufaturer Kioritz** Kioritz** Kioritz* Kioritz** Engine Model No. 340/22C 440/22C 340/23 BLC 440/23BLC Reed Valve Reed Valve Reed Valve Reed Valve *The first four letters and numbers signify the model number. "J" indiates the snowmobile family and the next three numbers or letters the model number. EXAMPLE: J34FE or J34FF is a 340 Cylone Snowmobile, with a 340 fan-ooled engine. "J34 " indiates engine ; "F" meaning fan-ooled. J44LE or J44LF is a Liquifire Snowmobile, with a 440 liquid-ooled engine. "44L" indiates engine ; "L" meaning liquid-ooled. The last letter signifies year manufatured. EXAMPLE: "E"= 1976, "F"= 1977 et. **Manufatured for John Deere by Kioritz Corp., Japan.

6 J 10 General 5-4 Mahine Identifiation SM-21OB (Aug-77) ) )

7 General 10 Speifiations 10-1 Group 10 SPECIFICATIONS MACHINE SPECIFICATIONS FUEL SYSTEM Capaity ( -80,000) gal. (30.3 I) Capaity (80,001- ) gal. (24.6 I) Mixing Ratio All :1 Filters Two loated in pikup line Fuel Pump: Mikuni Carburetor... Impulse-type loated in the inlet line LIQUID COOLING SYSTEM Capaity ( -80,001) /2 qts. (4.25 I) Capaity (80,001- ) qts. (3.78 I) Type Pressurized system with entrifugal pump Engine Temperature Control..... One thermostat Pump Output U.S. gal. ( engine rpm Coolant Filler Cap psi (1 bar) ELECTRICAL SYSTEM Charge System Flywheel Alternator Capaity Watts Ignition System: 340 and 440 Cylone and Liquifire Capaitor Disharge Ignition Timing: 340 and 440 Cylone and Liquifire (Engine Running) in. BTDC (2.438 mm) Eletri Start, Optional on Liquifires (70,001-80,000) and Cylones (55,001 - ) Volt DC POWER TRAIN 340 and 440 Cylone and Liquifire John Deere (Comet) Final Drive Enlosed hain Standard Ratio: 340 Cylone and Liquifire :1 440 Cylone and Liquifire :1 Optional Ratio: 340 and 440 Cylone and Liquifire :1 2.06:1 Brakes: 340 and 440 Cylone and Liquifire.... Mehanial disk Stop Light Standard Litho in U.S.A

8 10 General 10-2 Speifiations MACHINE SPECIFICATIONS-Continued SUSPENSION CHASSIS AND BODY 340 and 440 Cylone..... Slide rail suspension Tunnel and Pan Aluminum 340 and 440 Liquifire... Slide rail suspension Hood and Console Fiberglass Drive Sprokets Molded polyethelene Windshield Polyarbonate Trak Material: Overall Length: 340 and 440 Cylone Rubber 340 and 440 Cylone and 340 and 440 Liquifire Rubber Liquifire in. (264.2 m) Overall Width: Trak Width in. (39.37 m) 340 and 440 Cylone and Trak Drive Involute Liquifire in. (99.0 m) Overall Height: 340 and 440 Cylone and Liquifire in. (104.1 m) ENGINE SPECIFICATIONS Cylone (Serial No. 55,001-70,000) ) Item 340 Cylone 440 Cylone Engine Model KEC 340/22A Reed Valve KEC 440/22A Reed Valve Manufaturer John Deere (Kioritz)* John Deere (Kioritz)* Type of Engine Two-Stroke, Air-Cooled Two-Stroke, Air-Cooled Number of Cylinders Two Two Cyliner Sleeve Cast-Iron Cast-Iron Bore (mm) Stroke (mm) Displaement () Compression Ratio 7.5:1 7.9:1 Horsepower 6750 rpm 6750 rpm Ignition Type Capaitor Disharge Capaitor Disharge Ignition Manufaturer Wio Wio Lighting Coil Output 120 Watt 120 Watt Carburetor Manufaturer Mikuni Mikuni Carburetor Model No. VM VM Starting System Reoil Start (12-Volt Eletri, Reoil Start (12-Volt Eletri, Optional) Optional) *Manufatured for John Deere by Kioritz Corp., Japan

9 Engine 10 Speifiations 10-3 ENGINE SPECIFICATIONS-Continued Liquifire (Serial No. 55,001-70,000) Item Engine Model Manufaturer Type of Engine Number of Cylinders Cylinder Sleeve Bore (mm) Stroke (mm) Displaement () Compression Ratio Horsepower Ignition Type Ignition Manufaturer Lighting Coil Output Carburetor Manufaturer Carburetor Model No. Starting System 340 Liquifire 440 Liquifire KEC 340/23LC Reed Valve KEC 440/23LC Reed Valve John Deere (Kioritz)* John Deere (Kioritz) * Two-Stroke, Liquid-Cooled Two-Stroke, Liquid-Cooled Two Two Cast-Iron Cast-Iron :1 7.9:1 45 (if) 7250 rpm 55 ([il 7250 rpm Capaitor Disharge Capaitor Disharge Wio Wio 120 Watt 120 Watt Mikuni (Dual) Mikuni (Dual) VM VM Reoil Start (12-Volt Eletri, Reoil Start (1 2-Volt Eletri, Optional) Optional) *Manufatured for John Deere by Kioritz Corp., Japan Cylone (Serial No. 70,001- ) Item 340 Cylone 440 Cylone Engine Model KEC 340/22B Reed Valve KEC 440/22B Reed Valve Manufaturer John Deere (Kioritz) * John Deere (Kioritz) * Type of Engine Two-Stroke, Air-Cooled Two-Stroke, Air-Cooled Number of Cylinders Two Two Cylinder Sleeve Cast-Iron Cast-Iron Bore (mm) Stroke (mm) Displaement () Compression Ratio 6.9:1 7.2:1 Horsepower 6500 rpm 6500 rpm Ignition Type Capaitor Disharge Capaitor Disharge Ignition Manufaturer Wio Wio Lighting Coil Output 120 Watt 120 Watt Carburetor Manufaturer Mikuni Mikuni Carburetor Model No. VM VM Starting System Reoil Start (12-Volt Eletri, Reoil Start (12-Volt Eletri, Optional) Optional) *Manufatured for John Deere by Kioritz Corp., Japan

10 10 General 10-4 Speifiations Liquifire (Serial No. 70,001- ) Item Engine Model Manufaturer Type of Engine Number of Cylinders Cylinder Sleeve Bore (mm) Stroke (mm) Displaement () Compression Ratio Horsepower Ignition Type Ignition Manufaturer Lighting Coil Output Carburetor Manufaturer Carburetor Model No. Starting System 340 Liquifire 440 Liquifire KEC 340/23ALC Reed Valve KEC 440/23ALC Reed Valve John Deere (Kioritz) * John Deere (Kioritz) * Two-Stroke, Liquid-Cooled Two-Stroke, Liquid-Cooled Two Two Cast-Iron Cast-Iron :1 6.7:1 47 ([u 7250 rpm 7250 rpm Capaitor Disharge Capaitor Disharge Wio Wio 120 Watt 120 Watt Mikuni (Dual) Mikuni (Dual) VM VM Reoil Start (12-Volt Reoil Start (12-Volt Eletri Optional [ -80,000]) Eletri Optional [ -80,000]) ) *Manufatured for John Deere by Kioritz Corp., Japan. BOLT TORQUE CHART Grade of Bolt SAE-2 SAE-5 SAE-8 Min. Tensile 64, , ,000 Strength PSI PSI PSI Grade Marking on Bolt Soket or Wrenh U.S. Standard U.S. Regular 0 \ () Bolt U.S. De. TORQUE Bolt Dia. Equiv. IN FOOT POUNDS Head Nut 1/ /16 7/16 5/ /2 1/2 3/ /16 9/16 7/ /8 11/16 1/ /4 3/4 9/ /16 7/8 5/ /16 15/16 3/ /8 1-1/8 7/8.875 * /16 1-5/ /2 1-1/2 Multiply readings by 12 for inh pound values. *"8" Grade bolts larger than 3/4-inh are sometimes formed hot rather than old whih aounts for the lower reommended torque. NOTE: Allow a tolerane of plus or minus 10% on all torques given in this hart.

11 General 10 Tune-Up and Adjustment 15-1 Group 15 TUNE-UP AND ADJUSTMENT TUNE-UP GUIDE Operation Speifiation Referene * Replae Spark Plugs Testing for spark Se. 40, Group 10 Champion QN -1 Time Ignition System Kioritz Engines in. BTDC (2.438 mm) (with engine running) Se. 40, Group 1O Adjust Carburetor Selet main jet Synhronize the arburetors Adjust hoke slide Adjust float height Adjust idle srew Adjust air jet Se. 30, Group 1O Reondition Carburetor Clean arburetor and install arburetor kit Se. 30, Group 1O ADJUSTMENTS Adjustment Speifiation Referene Brake Sheave Alignment Trak Skis Fan Belt Coolant Pump Belt Setion 50, Group Setion 50, Group Setion 60, Group 10 Setion 60, Group Setion 60, Group Setion 20, Group Setion 20, Group 30 SPARK PLUG RECOMMENDATION *The spark plug reommended for use in the 340 and 440 Cylone and Liquifire Snowmobile engines is a Champion QN-1 AM IMPORTANT: For sustained high-speed running, use surfae gap plugs N-19V or QN-19V.

12 General Tune-Up and Adjustment SM-210B (Aug-77J J ) ) )

13 SM-2108 (Aug-77) General Fuels and Lubriants BREAK-IN PERIOD Do not exeed 40 mph for the first 25 miles, or fore the mahine at full throttle in deep snow. An oasional burst of power on hard-paked snow will not be harmful. For the first tank of fuel used in the snowmobile, mix gasoline and oil in a 40 to 1 ratio. After this break-in period, mix gasoline and oil in a 50 to 1 ratio. FUEL The 2-yle snowmobile engines require that oil be mixed with gasoline. It is important that quality gasoline and oil are used and mixed thoroughly in the proper ratio. Too little oil results in engine damage, while too muh oil will ause spark plug fouling and exessive smoking. NOTE: Some gasoline anti-freeze additives ould ause fuel pump diaphragm damage. IMPORTANT: Gasoline must be premium grade with an anti-knok index of 92 or higher on snowmobiles (Serial No. 55,001-70,000). (Serial No. 70,001- ) must use regular or premium grade with an anti-knok index of 88 or higher. DO NOT use non-leaded gasoline. Mix gasoline with John Deere 2-Cyle Oil, whih is an ashless, 2-yle oil without metalli additives. John Deere 2-yle Oil meets Boating Industry Assoiation (BIA) test qualifiation TC-W and test proedure BIA It is available in 1-pint and 1-quart "pop-top" ans. Group 20 FUEL AND LUBRICANTS Mix fuel aording to the following proedure: Pour the required amount of John Deere 2-Cyle Oil into a lean ontainer, add one-half the neessary gasoline and shake vigorously. Add the remainder of the gasoline and agitate the mixture thoroughly. The Snowmobile Gasoline Can, Fig. 1, is ideal for snowmobile use. Mix gasoline and oil in a separate ontainer. Never mix in the snowmobile tank. Fig. 1-Corret Gasoline-to-Oil Mixture Ratio '-...:.,...,) M17829Y (

14 10 General 20-2 Fuels and Lubriants LUBRICANTS Oil used in the hain ase should be a good grade of SAE 90. CAPACITIES Fuel Tank ( -80,000) U.S. gal. (30.3 I) Fuel Tank (80,001- ) U.S. gal. (24.6 I) SERVICE INTERVALS Chain Case (Oil Change) hours, 2 years or 1000 miles. A-Lower Plug 8-Fill Plug Fig. 2-Cheking Oil Level in Chain Case Remove plug (A, Fig. 2) from the lower part of the hain ase. If oil flows from this hole, the oil level is satisfatory. If oil must be added, remove fill plug (8) and add SAE 90 oil until it flows from the lower hole. Remove oil from hain ase with a syringe.

15 SM-2108 (Aug-77) Engine 20 General Information 5-1 CONTENTS Setion 20 ENGINE Group 5 GENERAL INFORMATION Page GROUP 5 - GENERAL INFORMATION Desription Priniple of Reed Valve Engine Operation GROUP 10 - ENGINE ANALYSIS AND INSPECTION Analysis Spark Test Compression Test Analyzing Causes of Engine Failure Diagnosing Malfuntions Inspetion Pressure Testing the Engine Replaing PTO End Bearing Seal GROUP 15 - FAN-COOLED REED VALVE ENGINE OVERHAUL General Information Removing Engine Disassembly Removing Exterior Components Cheking Crankshaft for Twist Disassembling Fan Cover Removing Flywheel Removing Stator Assembly Removing Cylinder Heads Cheking Crankshaft Runout Removing Cylinders Removing Pistons Removing Crankshaft Reed Valve Servie Page Inspetion Assembly Assembling Fan Cover Replaing Crankshaft Bearings Installing Crankshaft Installing Pistons and Piston Rings Installing Cylinders and Cylinder Heads Installing Reed Valve Assembly Installing Flywheel Adjusting Fan Belt Tension Installing Exterior Components Installing Engine Cheking Ignition Timing GROUP 20 - LIQUID-COOLED REED VALVE ENGINE OVERHAUL General Information Removing Engine Disassembly Removing Exterior Components Removing Coolant Pump and Flywheel Housing Cheking Crankshaft for Twist Removing Flywheel Removing Stator Assembly Removing Cylinder Heads Cheking Crankshaft Runout Removing Cylinder Assembly Removing Pistons Removing Crankshaft Reed Valve Servie Litho in U. S.A.

16 J 20 Engine 5-2 General Information SM-21GB (Aug-77) Page GROUP 20 - CONTINUED Inspetion Assembly Replaing Crankshaft Bearings :9 Installing Crankshaft Installing Pistons and Piston Rings Installing Cylinders and Cylinder Heads Installing Reed Valve Assemblies Installing Flywheel Installing Coolant Pump Tensioning Coolant Pump Belt Installing Exterior Components Installing Engine Filling Cooling System Cheking Ignition Timing CONTENTS-Continued Page GROUP 30 - LIQUID-COOLING SYSTEM (Serial No. -80,000) General Information Inspetion and Testing Draining and Filling Cooling System Disassembly and Repair GROUP 32 - LIQUID-COOLING SYSTEM (Serial No. 80,001- ) General Information Testing Draining and Filling System Repair GROUP 35 - SPECIFICATIONS Speifiations GROUP 25 - RECOIL STARTERS Torque for Hardware Priniple of Operation Disassembly Inspetion Assembly J ) ) )

17 Engine General Information DESCRIPTION M18240N The engines used in the John Deere 340 and 440 Cylone are 2-ylinder, 2-yle, airooled engines. Fig. 1-John Deere Fan-Cooled Snowmobile Engine See " Priniple of Reed Valve Engine Operation" on page for basi fundamentals of 2-yle reed valve engine operaiion. The engines used in John Deere 340 and 440 Li quifire are 2-ylinder, 2-yle, liquidooled engines. The 2-yle engine is espeially adaptable for snowmobile use beause it offers a relatively small and lightweight pakage with high power output. The 2-yie engine also an be operated at extreme angles without loss of lubriation. Design simpliity is another paint in favor of the 2-yle engine. No valves, tappets or amshaft are required. The 2-yle engine provides a power stroke for every revolution of the rankshaft as opposed to a power stroke for every other revolution in a onventional 4-yle engine. This aounts for the high horsepower-to-weight ratio of the 2-yle engine. Four sequenes are shown under "Priniple of Operation". Remember, however, that two sequenes must take plae with every stroke of the piston. Example: As the piston moves upward, ompression of the previous harge ours in addition to fuel mixture intake into the rankase. The engines feature ball bearings for rankshaft support and needle bearings at rankpin and piston pin loations. Detailed speifiations for the engines are overed in Setion 10 and in Group 35 of this setion. Litho in U. S.A.

18 20 Engine 5-4 General Information Stroke 1 - Power, Exhaust, Fuel Transfer PRINCIPLE OF REED VALVE ENGINE OPERATION Exhaust J Power M18242N ) M18241N A-Reed Valves B-Exhaust Port C-Transfer Port A-Reed Valves B-Exhaust Port Fig. 2-Power Stroke C- Transfer Port Slightly before top dead enter (TDC), ignition ours, Fig. 2. Pressure on the burning gases, aused by ombl:lstion, pushes the piston downward. This ation provides power to turn the rankshaft through the onneting rod. Fig. 3-Power Stroke and Exhaust The exhaust port (B, Fig. 3) is unovered first. Hot gases, whih are still under pressure from ombustion, esape through the open exhaust port. Before the piston reahes the end of its downward movement, it exposes the exhaust port (B) and the transfer port (C). The reed valves (A) remain losed. The intake (reed valve) and exhaust ports are loated on opposite sides of the ylinder.

19 SM-2108 (Aug-77) Engine General Information r Fuel Transfer PRINCIPLE OF REED VALVE ENGINE OPERATION-Continued Stroke 2 - Compression, Intake Compression and Intake M1824JN A-Reed Valves B-Exhaust Port C-Transfer Port Fig. 4-Power Stroke and Fuel Transfer After unovering the exhaust port (8, Fig. 4), the fuel transfer port (C), is unovered. As the piston moves downward, it exposes the transfer port. The piston moving downward pressurizes the rankase. This pressure holds the reed valves (A) losed and auses the fuel-air mixture in the rankase to move up and out the transfer port (C) into the ombustion hamber. The pressure developed in the rankase is only slight pressure, but it is enough to fore the new harge of fuel and air into the ombustion hamber. This new harge also helps to drive out the remaining exhaust gases. M18244N A-Reed Valves B-Exhaust Port C-Transfer Port Fig. 5-Compression Stroke and Intake As the piston moves upward, it loses the transfer port (e, Fig. 5) and exhaust port (8). Upward movement of the piston reates a partial vauum (low pressure) in the rankase. Atmospheri pressure fores a new harge of fuel and air from the arburetor through the reed valves, Fig. 9, into the rankase. The piston moves upward, ompressing the fuel air mixture. Just before the piston reahes TDe, a spark from the spark plug ignites the mixture, and it starts to burn. This begins another power stroke.

20 20 Engine 5-6 General Information J ) ) ) v

21 SM-2108 (Aug-77) Engine 20 Engine Analysis and Inspetion 10-1 Group 10 ENGINE ANALYSIS AND INSPECTION ANALYSIS Most engine trouble is of a minor, non-hroni nature due to eletrial or fuel system diffiulties. Make the following two heks to help isolate the ause of engine problems. Spark Test If spark is good but engine will not start, hek to see if fuel is getting to arburetor. If fuel is available and engine will not start, make ompression test. See also "Diagnosing Malfuntions," page Compression Test Fig. I-Cheking for Spark at Plug Use JDM-74A-5 Ignition Tester Plug for heking spark. Install JDM-74A-5 tester plug on the plug in the engine. Connet high tension lead to the tester plug, Fig. 1. Start and run the engine. If the eletrial system annot fire the test plug and runs on only the one ylinder not being tested, eletrial system diffiulties exist. See Setion 40. Chek both ylinders. h CAUTION: High energy ignition systems.. an produe injurious eletrial shok. DO NOT hold spark plugs, leads or onnetors in your hand to hek for spark. Fig. 2-Testing Engine Compression Remove spark plugs and plae a ompression gauge in one of the spark plug holes, Fig. 2. With hoke "OFF", hold throttle in open position. Hold ompression gauge firmly in spark plug hole and rank engine vigorously as often as required until maximum reading of gauge is obtained. Test both ylinders for ompression. For (Serial No. 55,001-70,000) pressures should be 120 to 130 psi (8.2 to 8.9 bar) for liquid-ooled engines and 135 to 145 psi (9.3 to 9.9 bar) for air-ooled engines. For (Serial No. 70,001 and up) pressures should be 120 to 130 psi (8.2 to 8.9 bar) for liquidooled engines and 125 to 135 psi (8.6 to 9.3 bar) for air-ooled engines. Pressure should not vary by more than 10 psi (0.68 bar) between ylinders. If ompression pressure is low, hek ylinder head gaskets for leakage. If head gaskets are not leaking it is a good possibility that pressure is leaking by worn or stuk piston rings, damaged pistons or damaged ylinder walls. Litho in U. S.A.

22 Engine Engine Analysis and Inspetion SM-2108 (Aug-77) Analysing Causes of Engine Failure The majority of 2-yle engine failures are due to exessive heat. Following is a list of the primary auses of snowmobile engine failure. Fuel Beause the 2-yle engine relies on a gasoline-oil mixture for lubriation, the mixture ratio and the quality of oil used are very important. The oil must retain its lubriation properties at extremely high temperatures. The oil must have an ashless base so it will not ause deposit build-up from burning with the gasoline. The gasoline must have a minimum anti-knok index rating of 92 (Serial No. 55,001-70,000) and 88 (Serial No. 70,001- ) to prevent "knoking" or "detonation" from high temperatures, high ompression and advaned ignition timing. Fuel-Air Mixture Regardless of the quality of fuel used, the fuel-air mixture must be orret to maintain good, reliable engine performane. The high speed main jet on the arburetor is probably the most ommon ause of engine failure. Often a "too lean" fuel mixture will appear to the inexperiened ustomer as making his 2-yle engine run "better." A lean fuel -air mixture also an be aused by air leakage at the following points: Dirt 1. Between rankase halves 2. Around rankshaft seals 3. Between intake manifold and engine 4. Between arburetor and intake manifold The silener used on the snowmobile is not intended to filter inoming air. The snowmobile is designed to operate on lean snow-overed areas, not in dirty, dusty onditions. Operation in onditions other than snow is not reommended. Pistons oming from a snowmobile engine whih has been run in dirt appear shot-peened. This type of failure is onsidered non-warranty, beause the snowmobile was not designed for use under these onditions. Ignition Timing Overadvaned timing auses ombustion temperatures to rise to the detrimental point. Overadvaned timing also auses "knoking" or "detonation." Retarded timing an ause exessive heat in the exhaust port area of the ylinder. Spark Plugs Champion QN-1 spark plugs are reommended for use in the John Deere snowmobiles with CD ignition. It is an extremely old plug. IMPORTANT: For sustained high-speed running, use surfae gap plugs QN-19V or N-19V. It is important that the spark plug be properly seated with its gasket against the ylinder head. If not, the spark plug an run hot due to improper heat ondution to the ylinder head and ooling fins. Heat Although exessive heat an be attributed to most of the preeding auses of engine'failure, lak of ooling on the engine exterior is also an important fator to onsider when viewing an engine damaged from exessive heat. Lak of engine ooling an be aused by one.of the following: 1. Snow-plugged louvers in the hood 2. Dirty or damaged ylinder or ylinder head ooling fins 3. Damaged ooling fan 4. Slipping fan belt or oolant pump belt 5. Broken fan belt or oolant pump belt 6. Operating in "hot" weather 7. Plugged or restrited exhaust system 8. Liquid ooling system low on oolant. 9. Thermostat inoperative (liquid ooled system). J ) ) )

23 SM-21GB (Aug-77) Engine Engine Analysis and Inspetion The following pitures show engine omponents damaged from exessive heat. The ause of the exessive heat ould be almost any of the preeding, exept dirt damage. With the exeption of a broken defetive fan or oolant pump belt, the onditions aused by exessive heat would be non-warranty items attributed to ustomer misuse or improper adjustments. M10608NY Fig. 4-Piston and Cylinder Suffing M10607NY Fig. 3-Ring Breakage Damage Fig. 3 illustrates a piston damaged from pre-ignition or detonation aused by exessive heat. When part of the piston broke away, a piee of exposed ring also broke away and aused extensive damage to the ylinder head and the head of the piston. The piston pin olor gives an indiation of the exessive heat involved. Ring and piston land breakage as shown in Fig. 3, without the indiation of heat, would be aused by improper assembly of the engine. The arrow on the head of the piston must paint toward the exhaust port side of the engine. If not, ring end gaps will pass over the exhaust port, open slightly and ath, ausing breakage. Fig. 4 illustrates a piston whih beame exessively hot, started to melt and eventually suffed and seized to the ylinder. Notie how the severe melting and suffing ourred on the exhaust port side of the piston and ylinder. Also notie the aluminum throw-off (from melting) adhering to the ylinder head. Fig. 5-Cylinder Suffing Fig. 5 illustrates a lose-up view of a suffed ylinder. Note how the aluminum piston material transferred to and adhered to the ast iron ylinder wall from the exessive heat. NOTE: Damaged ylinders an often be salvaged by sraping aluminum off the ylinder bore with a knife or bearing sraper. Use are in doing this to prevent additional marring of the ylinder. Light honing will remove sore marks. A solution of Causti Soda (Sodium Hydroxide) is exellent for removing aluminum from steel and is available at most pharmaies. Litho in U. S.A.

24 Engine Engine Analysis and Inspetion Analysing Causes of Engine Failure- Continued 2. Over-advaned timing reates exessive ombustion hamber heat. A portion of the unburned fuel mixture an be ompressed in the ombustion hamber and self-ignited due to this exessive heat. 3. Exessive ompression aused by heavy deposit build-up. The ompression exeeds the antiknok apability of the fuel and the fuel mixture ignites prematurely. 4. A lean fuel-air mixture results in high ombustion hamber heat. A portion of the unburned fuel mixture an be ompressed in the ombustion hamber and self-ignited due to this exessive heat. J ) Fig. 6-Me/ted and Suffed Piston Knok damage is indiated by a ratered piston dome and eroded ring lands. Exessive heat due to pre-ignition aused the piston, Fig. 6, to melt away, freeze the rings and suff the ylinder wall. Notie how the top of the piston is starting to melt away in the enter. Continued usage would ause omplete burn-through. Pre-Ignition Pre-ignition is the igniting of the fuel-air mixture in the ombustion hamber before the spark plug fires. The most ommon auses of pre-ignition are: 1. Wrong heat range of spark plugs (too hot). 2. Deposits in the ombustion hamber. M10611/VY Fig. 7-Piston Burn- Through Pre-ignition auses the fuel-air mixture to burn longer than was intended whih reates exessive heat on the piston dome. If the situation is not orreted, the piston dome will start to melt and eventually burn through the dome and/or suff the piston wall. Knok (Detonation) Knok is indiated by a high frequeny "ping" and is very hard to distinguish in high-speed, high-output, 2-yle engines (espeially liquid-ooled engines). It ours when the fuel-air mixture is ompressed to a point where spontaneous ignition of the entire mixture ours. Piston burn-through, Fig. 7, is usually aused by spark plugs with too "hot" a heat range. This is generally referred to as spark plug indued pre-ignition. Always loate and orret the ause of the problem before putting an engine bak into servie. Warn and advise the ustomer of the dangers of tampering with arburetor settings, using poor quality gasoline and oil, and of using spark plugs other than those reommended for use in his mahine. The most ommon auses of knok in a 2-yle engine are: 1. Fuel of too Iowan anti-knok index rating selfignites at too Iowa temperature.

25 SM-21OB (Aug-77) Engine Engine Analysis and Inspetion DIAGNOSING MALFUNCTIONS Engine Engine Will Not Start Carburetor and/or fuel pump faulty. Spark plugs faulty. Fuel lines obstruted. Head gasket leaking. Eletrial onnetions loose. Engine Starts With Diffiulty Carburetor out of adjustment. Choke not funtioning properly. Spark plugs fouled. Ignition oil weak. Fuel mixture inorret. Ignition out of time. Water in fuel system. Faulty reed valve. Engine Won't Crank Piston seized. Crankshaft seized to bearings. Conneting rod broken. Faulty reoil starter. Engine Will Not Idle Properly Carburetor idle adjustments inorret. Air srew on arburetor not adjusted. Head gasket leaking. Fuel mixture inorret. Crankshaft seal leaking. Impulse tube to fuel pump obstruted or leaking. Engine Misses At High Speeds Ignition out of time. Fuel pump faulty. Head gasket leaking. Ignition oil weak. Inorret main jet in arburetor. Impulse tube to fuel ~ump obstruted or leaking. Engine Overheated Wrong main jet in arburetor. Ignition out of time. Air leak in intake system or rankase. Coolant pump drive belt broken or slipping. Coolant pump damaged. Coolant leak in ooling system. Cooling fan drive belt broken or slipping. Cooling fins obstruted or damaged. Cooling fan broken or damaged.

26 Engine Engine Analysis and Inspetion Engine-Continued Engine Runs Rough and Smokes Improper fuel mixture. Choke plunger not seated. DIAGNOSING MALFUNCTIONS-Continued Reoil Starter Pawls Not Extending When Rope Is Pulled Frition spring broken allowing frition plate to rotate. Retaining nut loose. J Muffler obstruted. Water in fuel. Engine Kiks Bak and Bakfires Ignition out of time. Engine Loses Power or Aeleration Carburetor out of adjustment. Engine overheating. Ignition out of time. Ignition oil weak. Fuel mixture inorret. Muffler obstruted. Reed valves not losing properly. Running on one ylinder. Restrited in-line fuel filter. Pawls Not Returning When Rope Is Released Return spring broken. Return spring not assembled properly. Rope Not Returning Main spring broken or unhooked. No lubriation between frition plate and washer. ) )

27 SM-21GB (Aug-77) Engine Engine Analysis and Inspetion INSPECTION NOTE: Normally, "Inspetion" would be loated in eah group after disassembly. To keep from being repetitious in eah of the engine groups, inspetion has been grouped with analysis. Inspeting Coolant Pump and Coolant Pump Belt Clean all parts exept stator assembly with leaning solvent. Inspeting Fan and Fan Belt M18248N A-Coolant Pump Belt B-Coolant Pump C- O-Ring M18247N A-Cooling Fan B-Fan Belt C-Fan Bearings Fig. 8-lnspeting Fan and Fan Belt Inspet fan (A, Fig. 8) for raked, broken or damaged fins. Dress niks or dents with a file. If fins are raked or broken, fan must be replaed. Inspet fan bearings (C) for wear or looseness. Replae if neessary. Replae fan belt (8), if frayed, strethed, or deteriorated. Fig. 9-lnspeting Cooling System Components Inspet O-ring (C, Fig. 9), for damage, raks or breaks. Replae if neessary. Inspet oolant pump (8, Fig. 9), for internal wear aused by ooling system ontamination or dirt. Replae oolant pump belt (A, Fig. 9), if frayed, strethed, or deteriorated. Litho in U. S.A.

28 20 Engine 10-8 Engine Analysis and Inspetion Inspeting Crankase Inspeting Fan-Cooled Cylinder Head A-Lower Crankase B-Sealing Surfaes C-Upper Crankase ) Fig. 10-lnspeting Crankase Halves Visually inspet rankase sealing surfaes, (8, Fig. 10) for deep srathes, soring or pitting. Inspet bearing and oil seal retaining inserts for wear, soring or onditions that ould ause leaks. NOTE: Minor indiation of rankshaft bearing outer rae "rotation " in the rankase halves an be onsidered normal. Replae rankase halves if damaged. Crankase halves are available only in a mathed set. A-Surfae Plate B-Cylinder Head Fig. l1-cheking Cylinder Head Flatness Carefully srape arbon from ylinder head (8) and exhaust ports of ylinders. Use a soft metal (nonferrous) sraper to avoid damage. A wooden spatula works well for leaning exhaust ports. Use a spark plug tap (14 mm) to lean arbon from spark plug threads in ylinder head, if required. Plae ylinder head (8) on a surfae plate (A, Fig. 11) and measure at various points between head (8) and surfae plate (A) with a inh (0.025 mm) feeler gauge. There should be no learane in any area. ) )

29 Engine Engine Analysis and Inspetion Inspeting Fan-Cooled Cylinder Measure ylinders with an inside mirometer, Fig. 13. Measure parallel with the rankshaft and at right angles to rankshaft at both top and bottom of ring travel. If at all possible, salvage ylinder as explained on page Inspeting Liquid-Cooled Cylinder Head Assembly A-Cylinder B-Cylinder Head C-Feeler Gauge Fig. 12-Cheking Cylinder Distortion Install a servieable ylinder head (8, Fig. 12) on ylinders (A). Install without gasket or hold-down nuts. Measure for distortion between studs with a feeler gauge, (C, Fig. 12). Maximum allowable distortion is inh (0.05 mm). M18253N Fig. 14-lnspeting Cylinder Head Assembly Inspet liquid-ooled ylinder head (Fig. 14, for exessive arbon build-up within the ombustion ham ber. Chek that all oolant ports are open to permit adequate oolant flow. Fig. 13-Measuring Cylinders Litho in U. SA

30 20 Engine Engine Analysis and Inspetion SM-2108 (Aug-77) Inspeting Liquid-Cooled Cylinder Assembly Honing Cylinders ) M18254N Fig. 1S-lnspeting Cylinder Assembly Inspet ylinder assembly, Fig. 15, for suffing or soring. Inspet mating surfaes for niks whih ould ause improper sealing of the ylinder head to the ylinder assembly. NOTE: Oamaged ylinders an often be salvaged by sraping aluminum off the ylinder bore with a knife or bearing sraper. Use are in doing this to prevent additional marring of the ylinder. Light honing will remove sore marks. A solution of Causti Soda (Sodium Hydroxide) is exellent for removing aluminum from steel and is available at most pharmaies. A-Cylinder Fig. 16-Honing Cylinders 8-Fine Stone Cylinder Hone If ylinder (A) is within wear tolerane, but lightly sored, hone by running a fine stone ylinder hone (8) lightly in ylinder, Fig. 16. Follow manufaturer's reommendations. IMPORTANT: Use only a fixed four-stone hone. Clean thoroughly with detergent and water to remove all partiles. Reboring Cylinders Measure ylinder bore for wear. Using inside mirometer or bore gauge, hek the area just below top of bore. Wear will be indiated by a "step" worn in the wall. Measure at right angles (90 degrees) to the piston pin axis at the top where most wear ours. - I NOTE: Mahine bore or use a rigid hone for reboring the ylinder. Use a oarse stone (AMMCO- 3952) for removing the first inh ( mm) of material from the bore. Change to a less oarse stone (AMMCO-3954) for finishing the final inh ( mm). Use hones for ast iron. BE SURE the orret stone is used and that stones are not worn. 1. Anhor the ylinder before reboring. 2. Set the drill press to operate from 450 to 700 rpm. Litho in U. S.A.

31 SM-21GB (Aug-77) Engine 20 Engine Analysis and Inspetion / 3. Lower the hone to the point where the lower end extends 1/2 to 3/4 inh (1.2 m to 1.9 m) past the end of the ylinder. 4. Rotate the adjusting nut on the hone until the stones ome in ontat with the ylinder wall at the narrowest point. 5. Turn the hone by hand. If you annot turn it, the hone is too tight. Loosen hone until it an be turned by hand. 8. When the ylinder is approximately inh (0.050 mm) within the desired bore speifiation, hange to a less oarse stone (AMMCO-3954) and finish the bore. Finish should not be smooth, but have a 45-degree ross-hath pattern. M12164N Fig. l8-rounding Edges of Ports 9. After reboring, remove any burrs that may have formed at edges of all ports. Use a penil grinder or emery loth and just round the edges of the ports, Fig. 18. Fig. l7-honing the Cylinder 6. Start the drill. Move the hone up and down in the ylinder approximately 40 yles per minute, Fig. 17. Follow the hone manufaturer's reommendations. NOTE: Some hones require oil and some will not work with even a small amount of oil on the ylinder wall. 7. Chek the diameter of the ylinder regularly during honing. (Stop the drill before measuring and remove the hone from the ylinder.) IMPORTANT: Be areful when rounding the ports. Take off only enough to allow the rings to pass the port freely. If the port is rounded too muh, hot exhaust gases may blow by the rings on the piston down-stroke, burning the rings. 10. Clean the ylinder thoroughly. Use soap, warm water and lean rags. Clean the ylinder wall for a "white glove" inspetion. A lean white rag should not show soil from the ylinder wall. IMPORTANT: DO NOT use solvent or gasoline beause these fluids only wash all the oil from the ylinder wall. They do not remove metal partiles produed during honing. 11. Dry the ylinder and oat it with 2-yle engine oil.

32 20 Engine Engine Analysis and Inspetion SM-21GB (Aug-77) Inspeting Piston and Piston Pin Fig. 21-Measuring Piston Pin M18256N A-Piston Pin Bore B-Top Land C-Piston Skirt Measure piston pin with a mirometer, Fig. 21. Cheking Ring End Gap Fig. 19-Measuring Piston Clean piston ring grooves with a ring groove leaner or the broken setion of an old ring if proper tool is not available. Inspet piston for evidene of soring, pitting, or orrosion. Measure piston at right angles to piston pin for wear at top land (8, Fig. 19) and at skirt (C). Measure piston pin bore (A) with an inside mirometer. M22250 Fig. 22-Cheking Ring End Gap Plae ring in piston bore just below the top of piston travel. Measure the ring end gap with a feeler gauge, Fig. 22. NOTE: Use a piston to position the ring in the bore to insure that the ring is squarely plaed for measurement. A-New Ring B-Feeler Gauge Fig. 20-Measuring Ring Side Clearane Install a new ring (A) into ring groove and measure side learane (1976 engines, lower ring only) with a feeler gauge (8) as shown in Fig. 20. Litho in U. S.A.

33 SM-2108 (Aug-77) Engine Engine Analysis and Inspetion Inspeting Crankshaft and Conneting Rod M 1826 ON Y '--.J< A-Conneting Rod B-Feeler Gauge A-Conneting Rods B-Outer Bearings C-Seals D-Inner Bearings Fig. 23-lnspeting Crankshaft and Conneting Rod Fig. 24-Measuring Conneting Rod Side Clearane Measure onneting rod side learane with a feeler gauge (8, Fig. 24). Inspet threads on eah end of rankshaft, Fig. 23. Inspet keyway on flywheel end and taper on eah end of rankshaft for soring or wear. ( Inspet ball bearings for wear, free movement, and seurity. The outer bearings (8) are replaeable. If inner bearings (D) are worn, the rankshaft assembly must be replaed. Inspet seals (C) for wear or damage. Outer seals (8) are replaeable, while inner seals (D) are available only with the omplete rankshaft assembly. M18261NY A-Inside Mirometer B-Crankpin Bearing Fig. 25-Measuring Conneting Rod Small End Inspet rankpin, and piston pin needle bearings (8, Fig. 25) for wear or looseness. Piston pin bearings are available for servie while rankpin bearings are available with the omplete rankshaft assembly only. Measure onneting rod small end diameter with an inside mirometer, (A, Fig. 25). Replae rankshaft assembly if not within tolerane, or if badly sored or disolored.

34 20 Engine Engine Analysis and Inspetion SM-21GB (Aug-77) Removing Crankshaft Outer Bearings J A-Air Supply B-JOM-44 Pressure Regulator C-Rubber Sheets A-Outer Bearing B-JOM-8-3 C-JOM-8-3 Puller Fig. 26-Removing Crankshaft Outer Bearings If inspetion reveals outer seals and bearings (A) are defetive, they an be replaed. Remove Woodruff key from flywheel end of rankshaft and slide seals off rankshaft. Remove outer bearings (A) as shown in Fig. 26 using rankshaft bearing tool (8). Thread other end of puller (C) into PTO end of rankshaft to remove PTO end bearings. PRESSURE TESTING THE ENGINE If detonation-type piston failures have been experiened and a fuel lean-out is suspeted, the following preedure should be performed: JDM-44 Pressure Regulator omes omplete with the neessary items to seal the intake and exhaust system and pressure test the rankase on both liquid-ooled and fan-ooled engines. Pressure test the engine as follows. Fig. 27-Pressure Testing the Engine 2. Seal intake system by plaing rubber sheet (C) between arburetor and intake manifold. Use arburetor gasket as a template to ut stud holes in rubber sheet. 3. Install and torque spark plugs to 15 to 20 ft-ibs (20 to 27 Nm). 4. Connet pressure regulator (8) to impulse fitting. Close valve (lokwise) on regulator. 5. Connet shop air (A) to pressure regulator. Open valve until gauge reads 7 psi (0.48 bar). Close valve. 6. Gauge needle should not drop below 5 psi (0.34 bar) for at least 10 seonds. 7. If needle drops too rapidly, open valve on regulator (8) to maintain 7 psi (0.48 bar). A water and liquid soap solution applied to seals and seams will help to loate leakage. Corret leakage before putting engine bak in servie. 1. Seal the exhaust system by plaing a rubber sheet (C, Fig. 27) (supplied with JDM-44) between exhaust manifold and ylinders. Use manifold gaskets as templates to ut stud holes in rubber sheet.

35 SM-21GB (Aug-77) Engine 20 Engine Analysis and Inspetion REPLACING PTO END BEARING SEAL A-Wooden Blok B- PTO End Bearing Seal C-Srewdriver Fig. 28-Replaing PTO End Bearing Seal To replae PTO end bearing seal, proeed as follows: 1. Remove luth. 2. Remove PTO end seal guard. 3. Use a old hisel to make a slot in old seal. Pry old seal out with a long srewdriver blade (C, Fig. 28). M18265N Fig. 29-PTO End Seal Guard NOTE: Some engines have a PTO end seal guard, Fig. 29, whih prevents a failed drive belt from damaging the PTO end sea/. When installing seal guard, enter hole in guard around rankshaft before tightening srews. This will prevent guard from ontating rankshaft. IMPORTANT: Use are not to hisel too deep or damage to rankshaft and/or bearing may result. 4. Clean rankshaft surfae. 5. Coat inner and outer seal surfaes with STP or equivalent for ease of installation. Do not use snowmobile oil as a lubriant. 6. Install new seal by using a 4 x 4-inh (10.1 x 10.1 m) blok of hard wood, 12 inhes (30.5 m) long with a 1-1/4-inh (3.14 m) diameter hole drilled 3 inhes (7.6 m) deep in end of blok. Plae tool over rankshaft, align seal, and drive seal into plae until flush with rankshaft. Be areful not to ok seal. Litho in U. S.A.

36 ) 20 Engines Engine Analysis and Inspetion SM-210B (Aug-77J ) )

37 SM-21GB (Aug-77) Engine 20 Fan-Cooled Reed Valve Engine Overhaul 15-1 Group 15 FAN-COOLED REED VALVE ENGINE OVERHAUL GENERAL INFORMATION r Fan-ooled reed valve engines, Fig. 1, have five ball bearings; two between rank-throws, one on the flywheel end, and two on the PTO end of the rankshaft. Needle bearings are used at both rankpin and piston pin loations. Fig. 1-Fan-Cooled Reed Valve Engine assembly must be installed. The omplete assembly also inludes outer seals and bearings whih may, however, be purhased separately. The rankase upper and lower halves are available only as a mathed set. - - The rankshaft, inner ball bearings and seals, onneting rods and rankpin bearings are available only as a omplete assembly. If any of these parts are worn or damaged an entire rankshaft The reed valve engine has metri handware. Always use proper tools when serviing the engine. See Group 5 for " Priniple of Reed Valve Engine Operation".

38 Engine Fan-Cooled Reed Valve Engine Overhaul SM-21GB (Aug-77) REMOVING ENGINE A-Air Silener B-Expansion Chamber C-Reoil Starter Rope D-Fuel Line E-Engine Coupler F-Choke Plunger and Cable Fig. 2-0isonneting Engine from Snowmobile Remove hood. Remove spring on air silener strap, loosen lamps on arburetor boots and remove air silener (A, Fig. 2). Remove springs seuring expansion hamber (8) to exhaust manifold and supporting braket and remove expansion hamber (8). Untie knot in starter handle and allow the starter rope (C), to rewind into the starter housing. Tie a slip knot in the starter rope (C), to prevent rope from winding all the way into the starter housing. Close fuel shut-off valve (Serial No. -80,000) and disonnet fuel line (D), to fuel pump. Disonnet eletrial oupler (E), by removing plasti strap lok. Remove hoke plunger and able (F). A- Drive Belt B-Throttle Valve and Cable Fig. 3-0isonneting Engine from Snowmobile Remove drive belt (A, Fig. 3). Remove throttle valve and able (8, Fig. 3). Fig. 4-Removing Engine Remove four lok nuts seuring engine base assembly to rubber mounts. Lift engine and base from snowmobile. a Litho in U. S.A.

39 8M-21GB (Aug-77) Engine 20 Fan-Cooled Reed Valve Engine Overhaul 15-3 DISASSEMBL V n M18270N 1-Piston 2-Rings 3-Cylinder Base Gasket 4-Cylinder S-Head Gasket 6-Cylinder Head 7- Nut 8-Speial Long Nut 9-Upper Crankase Half 10-Dowel 11-Bearing Retaining Clip 12- Cirlip 13-Conneting Rod Needle Bearings 14-Piston Pin 1S-Crankshaft Assembly 16-Woodruff Key 17-Crankshaft Bearing (fan end) 18-0il Seal (fan end) 19-Washer 20-Lok Washer 21-Nut 22-Lower Crankase Half 23-Crankshaft Bearing (PTO end) 24-0il Seal (PTO end) 2S-PTO Seal Guard Fig. 5-Exploded View of Fan-Cooled Reed Valve Engine Litho in U. S.A.

40 20 Engine 15-4 Fan-Cooled Reed Valve Engine Overhaul Removing Exterior Components NOTE: To prevent loss and to aid in assembly, keep attahing hardware with eah part as it is removed. Cheking Crankshaft for Twist A-Carburetor B- Eletroni Pak C-Ignition Leads D-Spark Plug Cables E-Coil Braket F-Cylinder Cover G-Fan Guard H-Reoil Starter Assembly Fig. 6-Removing Exterior Components Remove arburetor (A, Fig. 6). Disonnet ignition leads (C) from oils. Disonnet eletroni pak oupler and remove eletroni pak (8). Remove spark plug ables (D) and oil braket (E). Remove bolts seuring ylinder over (F) to engine and remove ylinder over. A- Dial Indiator B-Pointer Fig. 7-Cheking Crankshaft for Twist C-Marks on Flywheel Set up dial indiator (A, Fig. 7) in No. 1 ylinder to determine TDC (Top Dead Center). With piston at TDC, fasten a brass pointer (8) on the intake manifold stud and diret it to a mark (C) on a tooth of the ring gear on the flywheel. Set up dial indiator (A) in No. 2 ylinder. Rotate flywheel 180 degrees to align with a mark (C) on flywheel ring gear with pointer (8). With pointer (8) aligned to mark, dial indiator (A) should indiate No.2 piston is at TDC or within inh ( mm) either way of TDC. Remove bolts seuring fan guard (G) to engine and remove fan guard. Remove reoil starter assembly (H).

41 Engine Fan-Cooled Reed Valve Engine Overhaul Disassembling Fan Cover If inspetion reveals damaged oaling fan blades or worn fan shaft bearings, further disassembly is neessary to replae parts. Removing Flywheel Fig. 10-JOM-64-1 Flywheel Holding Tool Fig. 8-Removing Retaining Nut Use JDM-30 Spanner Wrenh to remove retaining nut, Fig. 8. Install JDM-64-1 Flywheel Holding Tool, Fig. 10. Remove retaining nut, lok washer and flat washer seuring flywheel to rankshaft. A- Fan Shaft B-Bearings (2 used) C-Snap Ring (2 used) D- Spaer E-Thik Washer J - Plain Washer F-Thin Washer K-Lok Washer G- Sheave Halves L -Retaining Nut H- Fan M-Spaing Washers I -Spaer N-Pulley Fig. 11-Removing Flywheel NOTE: Flywheel housing must be removed before flywheel an be removed. Install JDM-9, Flywheel Puller, Fig. 11, using the three tapped holes in the flywheel. Hold flywheel with JDM-64-1 Holding Tool and tighten puller enter bolt to 35 to 40 ft-ibs (47 to 54 Nm). - - Fig. 9-Fan Assembly Remove retaining nut (L, Fig. 9), washers (E, F, I, J, K and M), sheave halves (G) and spaers (D) from fan shaft (A). Drive fan assembly out of bearings by tapping it lightly with a soft mallet. Inner bearing should remain on shaft, and an be pulled off shaft. Carefully drive outer bearing out of fan over with a soft drift. Replae parts as neessary. NOTE: Do not overtorque enter bolt of flywheel puller. Do not hammer on end of puller bolt beause damage to rankshaft or bearings may result. If flywheel does not break loose, leave puller in plae and strike flywheel with a plasti or wood mallet in line with flywheel keyway. IMPORTANT: Do not strike flywheel with a steel mallet, beause this an ause permanent damage to the flywheel.

42 20 Engine 15-6 Fan-Cooled Reed Valve Engine Overhaul Removing Stator Assem~ly Cheking Crankshaft Runout Before proeeding further with engine disassembly, hek rankshaft runout. A-Stator Assembly 8- Trigger Ring Fig. 12-Removing Stator Assembly I -I Remove stator assembly (A, Fig. 12) by removing four attahing srews. Remove the four srews seuring trigger ring (B) to the rankase and remove trigger ring. See Setion 40 - Eletrial System to test ignition omponents. Removing Cylinder Heads A-Dial Indiator 8-JDM-10 Mounting Braket Fig. 14-Cheking Crankshaft Runout Set up a dial indiator (A) against rankshaft using the JDM-10 Dial Indiator Mounting Braket (B, Fig. 14). Rotate rankshaft. Maximum permissible runout is to inh (0.020 to mm). Replae rankshaft assembly if not within limits. Chek both ends of rankshaft. Removing Cylinders Remove ylinder assembly by lifting the ylinders upward. A slight tap with a rubber hammer may be neessary to loosen ylinders from the upper rankase. Remove and disard ylinder base gaskets. M182?8N Fig. 13-Removing Cylinder Heads Remove eight ylinder head retaining nuts, Fig. 13. Remove ylinder heads and disard gaskets.

43 Engine Fan-Cooled Reed Valve Engine Overhaul Removing Pistons Removing Crankshaft Remove reed valve assembly. A-Cirlip B-Mark C-No. 1 Piston O-No. 2 Piston Fig. 15-Mark on Piston Crown Exhaust Port Side Before removing pistons, be sure piston rowns are marked (B) on the exhaust port side, Fig. 15. If no mark is legible, insribe pistons aordingly. Mark pistons "1" and "2" and sribe mark on piston toward the exhaust port side. NOTE: Pistons " 1" and "2" are not interhangeable. Install orretly during reassembly. Remove irlips (A) from eah end of piston pin. M18282N! A- Nuts on Bottom of Crankase B-Starter Motor Cover Plate C- Cap Srew Fig. 17-Removing Nuts from Bottom of Crankase Remove eight nuts (A) and washers from bottom of rankase, Fig. 17. Remove starter motor over plate (B), ap srew (C) by over plate before separating rankase halves. Use a soft hammer and lightly tap the halves to separate. IMPORTANT: Do not pry rankase halves apart with a srewdriver. This will damage rankase sealing surfaes. Remove rankshaft by lifting upward. Note the four bearing retaining lips loated in the UPPER or TOP half of the rankase. - - Fig. 16-Removing Pistons Use the piston pin tool and guide furnished with the JDM-7 Tool Set to remove piston pins, Fig. 16. NOTE: Beause 340 and 440 Liquifire Snowmobile engines have larger piston pins, use the piston guide from the JOM-7 Tool Set only for removal. IMPORTANT: Do not damage onneting rod needle bearings when removing piston pins. Remove needle bearings from onneting rods. Leave old rings on pistons to protet ring grooves.

44 20 Engine 15-8 Fan-Cooled Reed Valve Engine Overhaul Reed Valve Servie INSPECTION Prior to inspetion, lean all parts exept rankshaft assembly and ignition parts in a suitable leaning solvent. For analysis and inspetion of parts refer to Group 10 of this setion. M12194N, Fig. 18-Reed Valve Assembly Disassemble and lean reed valve assembly, Fig. 18. A faulty reed valve an usually be deteted by exessive fuel "spit-bak" through the arburetor, ausing a "popping" noise. Inspet reeds for raking or warpage. Inspet reed seating surfaes for damage or wear. IMPORTANT: Prolonged running of an engine with a faulty reed valve ould ause a seized piston. This is due to the lean fuel mixture aused by improper fuel transfer on the pistons downstroke. Litho in U. S.A.

45 Engine 20 Fan-Cooled Reed Valve Engine Overhaul 15-9 Assembling Fan Cover Assemble fan as shown in Fig. 9 if previously disassembled to replae worn parts. Torque retaining nut to 28 to 31 ft-ibs (38 to 42 Nm). Replaing Crankshaft Bearings Removing Crankshaft Outer Bearings NOTE: Refer to page for proper proedure for removing outer bearings. Installing Outer Crankshaft Bearings and Seals Apply a light film of 2-yle engine oil to rankshaft and inner rae of ball bearing. ASSEMBLY NOTE: Reed valve engines use two ball bearings on PTO end of rankshaft. Lubriate and install seals, lip inward, on eah end of rankshaft. IMPORTANT: Cover keyway on flywheel end of rankshaft with tape to prevent damage to new seal. Installing Crankshaft Fig. 20-Bearing Retaining Clips M18283fiY A-JOM-8-2 Tool B-JOM-8-3 Tool Fig. 19-1nstalling Outer Crankshaft Bearing Assemble JDM-8-2 and JDM-8-3 Tool as shown in Fig. 19 to install outer bearings. Press bearings onto rankshaft until bearing is firmly seated against ounterweight. Be sure bearing is started true and is not oked on shaft. Thread other end of rankshaft bearing tool into PTO end of rankshaft for installing PTO end bearings. Stand upper rankase half on studs and install bearing retaining lips, Fig. 20. Liberally oat rankshaft and bearings with 2-yle oil and install in upper rankase half. Chek to be sure bearing retaining lips do not beome dislodged. IMPORTANT: Apply an even oat of M64850 (Silione Rubber Adhesive) to sealing surfaes of both rankase halves. NOTE: DO NOT permit sealer to run into interior of rankase halves. Install stator assembly over rankshaft. Be sure rubber grommet on stator assembly wiring leads is positioned in the reess between upper and lower rankase halves. Install the lower rankase half to the upper half. Be sure the two dowel pins are properly engaged with mating holes in opposite half of rankase.

46 20 Engine Fan-Cooled Reed Valve Engine Overhaul If neessary, remove old rings and install new piston rings as follows: Use your fingers or a ring expander tool and install a HALF-KEYSTONE ring in top groove. When using your fingers, spread rings with thumbs. Install halfkeystone rings in both grooves on some snowmobiles (Serial No. 70,001- ) M18285N CD o Fig. 21-Nuts on Lower Crankase Half Install flat washers, lok washers and nuts. Torque nuts to 15 to 18 ft-ibs (20 to 24 Nm) in sequene shown in Fig. 21. Installing Pistons and Piston Rings NOTE: Chek ring end gap. Lubriate onneting rod needle bearings with 2- yle engine oil and install in onneting rods. Plae piston over onneting rod. Be sure port areas of piston skirt and rankase align. No. 1 and No. 2 pistons are not interhangeable. M1828?N A- Top of Piston C-Flat Side of Piston Ring 8-Slant Side of Piston Ring Fig. 23-Proper Installation of a Half-Keystone Ring Fig. 23 shows the proper installation of a HALF KEYSTONE ring. Installing. Cylinders and Cylinder Heads Install new base gaskets over ylinder studs. Be sure sribe mark (marked during disassembly) on piston rown is toward the exhaust port side. ) Fig. 24-lnstalling Cylinders A-Piston Pin Fig. 22-lnstalling Piston Pin 8-JDM-7 Tool Use the piston pin tool and guide furnished with the JOM-7 Tool Set and pull piston pin into position, Fig. 22. Install four new piston pin irlips. Be sure lips have adequate tension to remain in plae during engine operation. Lubriate pistons, rings and ylinders with 2-yle engine oil. Plae a suitable wood blok between piston and rankase to steady piston, Fig. 24. Compress rings with fingers and gently slide ylinder over eah ring. IMPORTANT: Be sure rings are entered on loating pins to prevent ring breakage. Install exhaust manifold with new gaskets. Use M64850 Silione Rubber Adhesive on the exhaust manifold gaskets. Install exhaust manifold and tighten seurely. This aligns ylinders.

47 Engine Fan-Cooled Reed Valve Engine Overhaul Installing Flywheel NOTE: Be sure stator plate is seurely in plae before installing flywheel. Wipe rankshaft lean and install Woodruff key. Position flywheel and install flat washer, lok washer and nut. Install fan over and seure with four ap srews, lok washers and flat washers. Fig. 25-Cylinder Head Torquing Sequene Install NEW ylinder head gaskets (no sealant) and ylinder heads. Use flat washers under nuts and install nuts. Use speial long nuts in loations shown in Fig. 25. Torque ylinder stud nuts A, B, C, and D in sequene to 11.5 to 14.5 ft-ibs (15.6 to 19.7 Nm). Complete torquing sequene by tightening ylinder head stud nuts E, F, G, and H in sequene shown, to 5.0 to 6.5 ft-ibs (6.8 to 8.8 Nm). Installing Reed Valve Assembly Fig. 27-lnstalling Flywheel Using JDM-64-1 Holding Tool and a torque wrenh, tighten flywheel nut, Fig. 27, to 45 to 50 ft Ibs (61 to 67 Nm). Fig. 26-lnstalling Reed Valves Assemble reed valves arefully, Fig. 26 Maximum allowable "hang open" between reed valve and body is inh (1.524 mm). Reed valve and body should form a "light-tight" seal when pinhed together with finger pressure. If reeds are warped beyond allowable learane or raked, they must be replaed. Use new gaskets and install reed valve assembly on rankase. Tighten nuts seurely.

48 Engine Fan-Cooled Reed Valve Engine Overhaul Adjusting Fan Belt Tension Install fan belt, belt sheave and starter up. Seure to flywheel with three 6 x 15 mm ap srews and lok washers. Installing Exterior Components Fig. 28-Cheking Fan Belt Tension Chek fan belt for proper tension, Fig. 28. A properly adjusted fan belt should deflet approximately 3/8-inh (9 mm) when flexed by hand at a point near enter of belt span. To adjust belt, remove fan retaining nut, using JOM-30 Spanner Wrenh to keep fan from turning. Remove fan, belt and outer sheave half. Remove one of the larger spaers from between pulley halves and plae it outside outer pulley half. Reassemble and torque retaining nut to 28 to 31 ft-ibs (38 to 42 Nm). A-Carburetor B- Eletroni Pak C- Ignition Leads D- Spark Plug Cables E-Coil Braket F -Cylinder Cover G- Fan Guard H- Reoil Starter Fig. 29-lnstalling Exterior Components Install reoil starter assembly (H, Fig. 29.) Loate fan guard (G) and install bolts to seure it. Install oil braket (E) and sttah spark plug ables (0), to spark plugs. Install ylinder over (F) to engine. Install eletroni pak (8) to oil mounting braket (E) and ground to engine. Connet eletroni pak oupler to oupler oming from stator. Connet high tension ignition leads (C) to oils. Install arburetor (A) to intake manifold. ) )

49 Engine Fan-Cooled Reed Valve Engine Overhaul INSTALLING ENGINE Fig. 30-lnstalling Engine Install engine with base on rubber mounts and seure with four lok nuts Fig. 30. A-Air Silener B-Expansion Chamber C-Reoil Starter Rope D-Fuel Line E-Engine Coupler F-Choke Plunger and Cable Fig. 32-Making Connetions to Snowmobile Install hoke plunger and able (F, Fig. 32). Connet engine oupler (E) and install plasti strap lok. Connet fuel line (0) to fuel pump and open fuel shut-off valve. (Serial No. -80,000). Route reoil starter rope (C) through firewall and attah starter handle. A-Drive Belt B-Throttle Valve and Cable Install springs seuring expansion hamber (8) to supporting braket and springs seuring expansion hamber to exhaust manifold. Fig. 31-lnstalling Engine Install throttle valve able and throttle valve (8, Fig. 31). Install intake air silener (A) with boot over arburetor and seure with springs. Install and tighten lamp seuring boot to arburetor bore. Install and align snowmobile hood by attahing it with two ap srews on hinge plate. Install hood support. r Litho in U. S.A.

50 Engine Fan-Cooled Reed Valve Engine Overhaul CHECKING IGNITION TIMING Chek Ignition Timing as Follows: ) A-Dial Indiator B-Brass Pointer Fig. 33-Cheking Ignition Timing C-Mark on Flywheel Sheave 1. Remove reoil starter. Bend a loop in a brass rod and seure pointer (B, Fig. 33), to flywheel housing with srew. Pointer should just miss flywheel sheave. 2. Install dial indiator (A, Fig. 33), in No. 1 spark plug hole. 3. Rotate rankshaft to loate TDC (Top Dead Center), and "zero" dial indiator. 4. Rotate rankshaft ounterlokwise (opposite normal rotation) until dial indiator reads inh (2.44 mm) BTDC (before top dead enter). 5. With flywheel in this position, plae a mark (C) with a felt-tip pin on sheave rim orresponding with pointer (B). 6. Remove dial indiator (A) and reinstall spark plug. A- Timing Light B- Clamp-on Pik-up C-Pointer D-Mark on Flywheel Fig. 34-Cheking Ignition Timing 7. Connet a timing light (A, Fig. 34), to No. 1 spark plug lead and to a 12-volt battery. 8. Raise snowmobile so trak is lear of the ground. Start and run engine at approximately 4000 rpm. 9. Aim timing light (A) at pointer (C) and mark on flywheel (D) sheave. Mark on flywheel sheave should align with pointer. 10. If not, remove flywheel housing, flywheel and alternator-stator. Loosen four srews seuring timing ring and rotate it as neessary to advane or retard timing. Turning ring ounterlokwise advanes tim ing-turning ring lokwise retards timing. Re-tighten srews seurely. Reassemble parts and rehek timing. )

51 r SM-21GB (Aug-77) Engine 20 Liquid-Cooled Reed Valve Engine Overhaul 20-1 Group 20 LIQUID-COOLED REED VALVE ENGINE OVERHAUL GENERAL INFORMATION M1B296N The liquid-ooled engines, Fig. 1, feature ball bearing supported rankshafts. These engines have five ball bearings; two between rankthrows, one on the flywheel end, and two on the PTO end of the rankshaft. Needle bearings are used at both rankpin and piston pin loations. Fig. 1-Liquid-Cooled Engine are worn or damaged, an entire rankshaft assembly must be installed. The omplete assembly also inludes outer seals and bearings, whih may, however, be purhased separately. The rankase upper and lower halves are available only as a mathed set. The rankshaft, inner ball bearings and seals, onneting rods and rankpin bearings are available only as a omplete assembly. If any of these parts The ooling system is pressurized and thermostatially ontrolled. Coolant is irulated by a entrifugal pump mounted on the engine. Oversize pistons of (0.254 mm) inh are available.

52 Engine Liquid-Cooled Reed Valve Engine Overhaul REMOVING ENGINE Untie knot in starter handle and allow the starter rope (D) to rewind into the starter housing. Tie a slip knot in the starter rope (D) to prevent rope from winding all the way into the starter housing. Close fuel shut-off valve (Serial No. -80,000) and disonnet fuel line (E) from fuel pump. Disonnet eletrial oupler (F) by removing plasti strap lok. Untape and disonnet kill swith lead. A-Cylinder Head Vent Srew B- Drain Srew ) Fig. 2-Draining Coo/ant Prior to removing the engine from the snowmobile, drain the oolant from the engine blok into a suitable ontainer. Do so by removing drain srew (8, Fig. 2) and ylinder head vent srew (A, Fig. 2). This will allow the oolant to drain from the drain srew opening. A-Drive Belt C-Carburetors B-Water Temperature Sender ) Fig. 4-Disonneting Engine from Snowmobile Mark diretion of drive belt so that it an be reinstalled in same diretion. Remove drive belt (A, Fig. 4). Remove water temperature sender (8) from ylinder head. Loosen lamps seuring arburetors (C) to mounts and remove arburetors. A-Air Silener B- Hose Clamps C-Expansion Chamber D-Rewind Starter Rope E-Fuel Line F-Eletrial Coupler Fig. 3-Disonneting Engine from Snowmobile Remove hood by removing hood support and two attahing ap srews on hinge plate. Remove spring on air silener strap, loosen lamps on arburetor boots and remove air silener (A, Fig. 3). Loosen hose lamps (8) on oolant hoses. Remove springs seuring expansion hamber (C) to exhaust manifold and supporting braket and remove expansion hamber (C). Fig. 5-Removing Engine Remove four lok nuts, Fig. 5, seuring engine base assembly to rubber mounts. Lift engine and base from snowmobile.

53 SM-21OB (Aug-77) Engine 20 Liquid-Cooled Reed Valve Engine Overhaul 20-3 OISASSEMBL Y M2091J A-Lower Crankase Half B-Dowel C-Nut D-Lok Washer E-Washer F -Oil Seal (pump end) G-Bearing Retaining Clip H-Crankshaft Bearing (pump end) I -Woodruff Key J -Crankshaft Assembly K-Cirlip L -Piston Pin M-Conneting Rod Needle Bearings N-Crankshaft Bearing (PTO end) O-Shim P-Oil Seal (PTO end) Q-Upper Crankase Half R-Filler Cap S -Filler Cap Paking Fig. 6-Exploded View of Liquid-Cooled Engine T -Top Tank U -Gasket V -Thermostat W -Gasket X -Cylinder Head Y -Cylinder Head Gasket Z -Cylinder AA-Cylinder Base Gasket BB-Piston Rings CC-Piston DO-Oil Seal Protetor

54 20 Engine 20-4 Liquid-Cooled Reed Valve Engine Overhaul Removing Exterior Components Plae engine on a workbenh and thoroughly lean exterior surfaes, using leaning solvent. The JDM-16 Benh-Mounted Servie Fixture is ideal for serviing snowmobile engines. Removing Coolant Pump and Flywheel Housing NOTE: To prevent loss and to speed assembly, keep attahing hardware with eah part as it is re moved. A-Starter Cup B-Pump Pulley C-Bleed Hose D-Coolant Pump E-Head-to-Pump Hose F- Flywheel Housing Fig. 8-Removing Coolant Pump and Flywheel Housing A-Eletroni Pak B-Coupler C-Fuel Pump O-Intake Manifold E-Coil Cover and Coils F -Spark Plug Cables G-Pump Cover H-Exhaust Manifold I -Reoil Starter Fig. 7-Removing Exterior Components Disonnet oupler (B, Fig. 7) and remove eletroni pak (A). Remove oil over (E), (Serial No. -80,000), disonnet ignition leads, and remove oils along with the spark plug ables (F). Remove oolant pump over (G). Remove the six nuts seuring the exhaust manifold (H) to the ylinder assembly and remove exhaust manifold. Remove reoil starter (I). Remove intake manifold (0) and fuel pump (C). Fuel pump is seured to intake manifold and is removed with manifold as an assembly. Remove the three srews seuring the starter up (A, Fig. 8) and lower pulley to the flywheel. Remove starter up (A), lower pulley and drive belt. Remove four srews seuring oolant pump drive pulley (B) and remove pulley. Remove bleed hose (C, Fig. 8) and head-to-pump hose (E). Remove the three nuts seuring the oolant pump (0, Fig. 8) and remove oolant pump. Remove flywheel housing (F, Fig. 8). )

55 SM-21GB (Aug-77) Engine 20 Liquid-Cooled Reed Valve Engine Overhaul 20-5 Cheking Crankshaft for Twist Loosen flywheel retaining nut using JOM-64-1 Flywheel Holding Tool (A, Fig. 10) and a breaker bar (8) with soket. A-Dial Indiator B-Pointer C-Marks on Flywheel Fig. 9-Cheking Crankshaft Twist Set up dial indiator (A, Fig. 9) in No. 1 ylinder to determine TOC (Top Oead Center). With piston at TOC, fasten a brass pointer (8) on the intake manifold stud and diret it to a mark (C) on a tooth of the flywheel ring gear. Set up dial indiator (A) in No. 2 ylinder. Rotate flywheel 180 degrees to align mark (C) on flywheel ring gear with pointer (8). With pointer (8) aligned to mark (C), dial indiator (A) should indiate No. 2 piston is at TOC or within inh (0.762 mm) either way of TOC. A~DM-64-1 Flywheel Holding Tool B-JDM-9 Flywheel Puller Fig. 11-Using Flywheel Puller Remove flywheel using JOM-9 Flywheel Puller (8, Fig. 11) in onjuntion with the JOM-64-1 Flywheel Holding Tool (A). IMPORTANT: Do not strike flywheel with mallet beause this an ause permanent damage. Removing Flywheel A~DM-64-1 Flywheel Holding Tool B-Breaker Bar Fig. 10-Loosening Flywheel Nut

56 20 Engine 20-6 Liquid-Cooled Reed Valve Engine Overhaul SM-2108 (Aug-77) Removing Stator Assembly Remove eleven head bolts (A, Fig. 13). Remove eight ylinder stud nuts (B, Fig. 13) and remove ylinder head. A slight tap with a rubber mallet may be neessary to loosen head from ylinder assembly. Disard ylinder head gaskets. Cheking Crankshaft Runout Before proeeding further with engine disassembly, make the following hek to determine rankshaft ondition. ) A-Stator Assembly B-Trigger Ring Fig. 12-Removing Stator Assembly Remove stator assembly (A, Fig. 12) by removing four attahing srews. Remove the four srews seuring trigger ring (B) to the rankase and remove trigger ring. See Setion 40 Eletrial System to test ignition omponents. Removing Cylinder Heads A-Dial Indiator B-JDM-10 Mounting Braket Fig. 14-Cheking Crankshaft Runout Set up a Dial Indiator (A, Fig. 14) against the rankshaft using the JDM-10 Dial Indiator Mounting Braket (B). Rotate rankshaft. Maximum permissible runout is to inh (0.020 to mm). Replae rankshaft assembly if not within limits. Chek both ends of rankshaft. ) A-Head Bolts B-Cylinder Stud Nuts Fig. 13-Removing Cylinder Head

57 SM-21GB (Aug-77) Engine 20 Liquid-Cooled Reed Valve Engine Overhaul 20-7 Removing Cylinder Assembly Fig. l7-removing Pistons Use the piston pin tool and guide furnished with the JDM-7 Tool Set to remove piston pins, Fig. 17. fig. IS-Removing Cylinder Assembly Remove ylinder assembly Fig. 15, and disard base gaskets. It may be neessary to loosen ylinder assembly with a slight tap with a rubber mallet. Removing Pistons NOTE: Beause 340 and 44Q Liquifire Snowmobile Engines have larger piston pins, use the piston guide from the JOM-7 Tool Set only for removal. IMPORTANT: Do not damage onneting rod needle bearings when removing piston pins. Remove needle bearings from onneting rods. Leave old rings on pistons to protet ring grooves. Removing Crankshaft Remove reed valve assembly. A- Cirlip 8-Mark C- No. 1 Piston O-No. 2 Piston Fig. 16-Mark on Piston Crown Exhaust Port Side Before removing pistons, be sure piston rowns are marked on the exhaust port side (B, Fig. 16). If no mark is legible, sribe pistons aordingly. Mark pistons (C and D) " 1" and "2" with sribe mark on piston toward the exhaust port side. NOTE: Pistons "1 " and "2" are not interhangeable. Install them orretly during reassembly. Remove irlips (A) from eah end of piston pin. A-Crankase Nuts B-Starter Motor Cover Plate C-Cap Srew Fig. l8-removing Crankshaft Remove eight nuts (A, Fig. 18) and washers from bottom of rankase. Remove starter motor over plate (B), ap srew (C) by over plate, and two srews seuring stator plate, before separating rankase halves. Use a soft hammer and lightly tap the halves to separate. IMPORTANT: Do not pry rankase halves apart with a srewdriver. This will ause damage to the rankase sealing surfaes.

58 20 Engine 20-8 Liquid-Cooled Reed Valve Engine Overhaul Removing Crankshaft-Continued Remove rankshaft by lifting upward. Note the four bearing retaining lips loated in the upper half of the rankase. Reed Valve Servie Disassemble and lean reed valve assembly. INSPECTION Prior to inspetion, lean all parts exept rankshaft assembly and ignition parts in a suitable leaning solvent. For analysis and inspetion of parts refer, to Group 10 of this setion. J M12194N Fig. 19-Reed Valve Assembly A faulty reed valve, Fig. 19, an usually be deteted by exessive fuel "spit-bak" through the arburetor, ausing a "popping" noise. Inspet reeds for raking or warpage. Inspet reed seating surfaes for damage or wear. IMPORTANT: Prolonged running of an engine with a faulty reed valve ould ause a seized piston. This is due to the lean fuel mixture, aused by improper fuel transfer, on the pistons down stroke. ) ~) {

59 Engine 20 Liquid-Cooled Reed Valve Engine Overhaul 20-9 Replaing Crankshaft Bearings Removing Crankshaft Outer Bearings NOTE: Refer to page for proper proedure for removing outer bearings. ASSEMBLY Lubriate and install seals, lip inward, on eah end of rankshaft. IMPORTANT: Cover keyway on flywheel end of rankshaft with tape to prevent damage to new seal. Installing Outer Crankshaft Bearings and Seals Apply a light film of 2-yle engine oil to rankshaft and inner rae of ball bearing. Installing Crankshaft M18314NY A-JDM-8-2 Tool B-JDM-8-3 Tool Fig. 20-Replaing Outer Crankshaft Bearing Assemble JOM -8-2 and JOM-8-3 Tools as shown in Fig. 20 to install outer bearings. Press bearings onto rankshaft until bearing is firmly seated against ounterweight. Be sure bearing is started true and is not oked on shaft. Thread other end of rankshaft bearing tool into PTO end of rankshaft for installing PTO end bearings. Fig. 21-Bearing Retaining Clips Stand upper rankase half on studs and install bearing retaining lips, Fig. 21. Liberally oat rankshaft and bearings with 2-yle oil and install in upper rankase half. Chek to be sure bearing retaining lips do not beome dislodged. IMPORTANT: Apply an even oat of M64850 (Silione Rubber Adhesive) to sealing surfaes of both rankase halves. NOTE: DO NOT permit sealer to run into interior of rankase halves. Install stator assembly over rankshaft. Be sure rubber grommet on stator assembly wiring leads is positioned in the reess between upper and lower rankase halves. Install the lower rankase haif to the upper half. Be sure the two dowel pins are properly engaged with mating holes in opposite half of rankase. Litho in U. SA

60 20 Engine Liquid-Cooled Reed Valve Engine Overhaul If neessary, remove old rings and install new piston rings as follows: Use your fingers or a ring expander tool and install a HALF-KEYSTONE ring in the top groove. When using your fingers, spread rings with thumbs. M18285N CD o Fig. 22-Nuts on Lower Crankase Half Install flat washers, lok washers and nuts. Torque nuts to 15 to 18 ft-ibs (20 to 24 Nm) in sequene shown in Fig. 22. Installing Pistons and Piston Rings NOTE: Chek ring end gap. Lubriate onneting rod needle bearings with 2-yle engine oil and install in onneting rods. Plae piston over onneting rod. Be sure port areas of piston skirt and rankase align. No. 1 and No. 2 pistons are not interhangeable. Be sure sribe mark (marked during disassembly) on piston rown is toward the exhaust port side. M1 828?N A- Top of Piston C-Flat Side of Piston Ring 8- Slant Side of Piston Ring Fig. 24-Proper Installation of a Half-Keystone Ring Fig. 24 shows the proper installation of a HALF KEYSTONE ring. Installing Cylinders and Cylinder Heads Install new base gaskets over ylinder studs. ) ) A-Piston Pin 8-JOM-7 Tool Set Fig. 23-lnstalling Piston Pin Use the piston pin tool and guide (B) furnished with the JOM-7 Tool Set and pull piston pin (A) into position, Fig. 23. Install four new piston pin irlips. Be sure lips have adequate tension to remain in plae during engine operation. Fig. 25-lnstalling Cylinder Assembly Lubriate pistons, rings and ylinders with 2-yle engine oil. Compress rings with fingers and gently slide ylinder over eah ring Fig. 25. IMPORTANT: Be sure rings are entered on loating pins to prevent ring breakage. Install exhaust manifold with new gaskets. Use M64850 Silione Rubber Adhesive on the exhaust manifold gaskets. Install exhaust manifold and tighten seurely. This aligns ylinders. )

61 Engine 20 Liquid-Cooled Reed Valve Engine Overhaul Use new gaskets and install reed valve assembly on rankase. Tighten nuts seurely. Installing Flywheel NOTE: Be sure stator plate is seurely in plae before installing flywheel. Wipe rankshaft lean and install Woodruff key. Position flywheel and install flat washer, lok washer and nut. ( Fig. 26-Cylinder Head Torquing Sequene IMPORTANT: Measure the ylinder head size to make sure it mathes the size of the ylinder bore. Install NEW ylinder head gaskets (no sealant) and ylinder heads. Use flat washers under nuts and install nuts. Torque nuts A, B, C, D, E, F, G, and H in sequene to 21 to 23 ft-ibs (28 to 31 Nm), I, J, K, L, M, N, and 0 to 14 to 16 ft-ibs (18 to 21 Nm) and P, Q, R, and S to 13 to 14 ft-ibs (17 to 18 Nm). Installing Reed Valve Assemblies, KD /' ~. fj- J~~-~ ~~ % M18290N A-JDM Torque Wrenh Fig. 28-lnstalling Flywheel Use JDM-64-1 holding tool (A, Fig. 28) and a torque wrenh (B) to tighten flywheel nut. Torque nut to 45 to 50 ft-ibs (61 to 67 Nm). r Fig. 27-lnstalling Reed Valves Assemble reed valves arefully, Fig. 27. Maximum allowable "hang open" between reed valve and body is inh (1.524 mm). Reed valve and body should form a "light-tight" seal when pinhed together with finger pressure. If reeds are warped beyond allowable learane or raked, they must be replaed.

62 20 Engine Liquid-Cooled Reed Valve Engine Overhaul Installing Coolant Pump Adjust oolant pump belt, Fig. 30, for proper tension. A properly adjusted pump belt should deflet approximately 3/8 inh (9 mm) when flexed by hand at a point near enter of belt. To adjust belt, tighten three nuts on pump one proper tension is obtained. NOTE: It may be neessary to use a one wrenh or a wrenh that has been ground down thin enough to tighten nuts behind upper pump sheave. Installing Exterior Components J ) A- Starter Cup B- Pump Pulley C- Bleed Hose D-Head-to-Pump Hose E-Coolant Pump F-Flywheel Housing Fig. 29-lnstalling Coolant Pump and Flywheel Housing Install flywheel housing (F, Fig. 29) and seure it with four ap srews. Attah starter over plate with two nuts. With O-ring in plae, loate oolant pump (E) on studs and tighten nuts. Install bleed hose (C) from pump to top tank and head-to-pump hose (D). Install pump pulley (8) and starter up (A) with lower pulley and bakup plate to flywheel. Tensioning Coolant Pump Belt A-Eletroni Pak B-Coupler C-Fuel Pump D-Intake Manifold E-Coil Cover and Coils F -Spark Plug Cables G-Pump Cover H- Exhaust Manifold I -Reoil Starter ) Fig. 31-lnstalling Exterior Components Install reoil starter (I, Fig. 31). Install oolant pump over (G). Install exhaust manifold (H) to the ylinder assembly. Install oils (E) and onnet ignition leads and spark plug ables (F) and install oil over (E) (Serial No. -80,000). Connet oupler (8) and install eletroni pak (A). Install intake manifold (D) to engine and attah fuel pump (C). Connet impulse line from engine rankase to fuel pump. Fig. 30-Tensioning Coolant Pump Belt

63 SM-21GB (Aug-77) Engine 20 Liquid-Cooled Reed Valve Engine Overhaul r INSTALLING ENGINE Fig. 32-lnstalling Engine Lift engine and base into snowmobile. Install four lok nuts, Fig. 32, to seure engine base assembly to rubber mounts. A-Air Silener B-Hose Clamps C-Expansion Chamber D-Rewind Starter Rope E-Fuel Line F-Eletrial Coupler Fig. 34-Conneting Engine to Snowmobile Connet and tape kill swith lead. Connet eletrial oupler (F, Fig. 34) to engine and install plasti strap lok to prevent oupler from vibrating loose. Connet fuel line (E) to fuel pump and open fuel shut-off valve (Serial No. -80,000) I I Untie slip knot in starter rope (D) and route starter rope through rope guide and install starter rope handle. A-Drive Belt B-Water Temperature Sender C-Carburetors Position expansion hamber (C) and seure with springs to exhaust manifold and supporting braket. Fig. 33-Making Connetions to Snowmobile Install arburetors (C, Fig. 33) to rubber intake mounts and seure lamps. Connet fuel lines to fuel pump. Install water temperature sender (8) to ylinder head. Install drive belt (A). IMPORTANT: Always install drive belt so it operates in same diretion as it did before being removed. Tighten hose lamps (8) on oolant hoses. Position air silener (A) and tighten lamps on arburetor boots. Install spring on silener strap. Install hood support and hood with two attahing ap srews on hinge plate.

64 J 20 Engine Liquid-Cooled Reed Valve Engine Overhaul SM-21GB (Aug-77) Filling Cooling System Fill ooling system to bottom of filler nek with a 50/50 mixture of ethylene glyol base anti-freeze and water. Plae ap on filler nek and run engine until it reahes operating temperature. Shut off engine. See Group 30 of this Setion for proper method of filling ooling system. Cheking Ignition Timing Chek ignition timing as follows : 5. With flywheel in this position, plae a mark (C) with a felt-tip pen on sheave rim orresponding with pointer (B). 6. Remove dial indiator (A) and reinstall spark plug. J ) A-Timing Light C-Pointer B-Clamp on Pik-up D-Mark on Flywheel Sheave Fig. 36-Cheking Ignition Timing A-Dial Indiator B-Brass Pointer C- Mark on Flywheel Sheave 7. Connet a timing light (A, Fig. 36), to No. 1 spark plug lead and to a 12-volt battery. Fig. 35-Cheking Ignition Timing 1. Remove reoil starter. Bend a loop in a brass rod and seure pointer (B, Fig. 35) to flywheel housing with srew. Pointer should just miss flywheel sheave. 2. Install dial indiator (A, Fig. 35) in No. 1 spark plug hole. 3. Rotate rankshaft to loate TDC (Top Dead Center), and "zero" dial indiator. 4. Rotate rankshaft ounterlokwise (opposite normal rotation) until dial indiator reads inh (2.44 mm) BTDC (before top dead enter). 8. Start and run engine at approximately 4000 rpm. 9. Aim timing light (A) at pointer (C) and mark (D) on flywheel sheave. Mark (D) on flywheel sheave should align with pointer (C). 10. If not, remove flywheel housing, flywheel and alternator-stator. Loosen four srews seuring timing ring and rotate ring as neessary to advane or retard timing. Rotating ring ounterlokwise advanes timing-rotating ring lokwise retards timing. Retighten srews seurely. Reassemble and rehek timing. )

65 Engine Reoil Starters PRINCIPLE OF OPERATION Group 25 RECOIL STARTERS DISASSEMBL Y A-Starter Cup B-Reoil Starter C-Frition Plate D-Pawls E-Reel Fig. 1-Reoil Starter When the starter rope is pulled, the frition plate (C, Fig. 1) does not turn, thus foring the pawls (D) out and into ontat with the starter up (A). After the pawls are extended, the frition plate rotates with the reel (E). When the rope is released, the reoil spring retrats the rope bak onto the reel (E). The return spring (G, Fig. 2) rotates the frition plate to retrat the pawls (D) when the rope is retrated. Pull handle slowly until pawls engage with starter up ; then pull vigorously. Hold handle during reoil. Do not let rope snap bak on reoil. In the event of reoil starter failure, it is possible to start the engine by removing the reoil starter and winding a rope around the starter up. Refer to "Diagnosing Malfuntions" in Group 5 of this setion for trouble-shooting hints. A-Starter Cup B-Nut C-Lok Washer D-Washer E-Frition Plate F -Pawl (3 used) G- Return Spring H- Frition Spring I -Cup Washer J-Reel K-Reoil Spring L-Case M-Rope Guide N- Rope O-Handle P-End Piee Q-Cap Srew Fig. 2-Exploded View of Reoil Starter Litho in U. S.A.

66 Engine Reoil Starters INSPECTION Thoroughly lean all parts exept rope in leaning solvent prior to inspetion. J M18327N ) A-Handle B-Rope Guides Fig. 3-Removing Handle and Rope Guides C-Case Untie knot in reoil starter handle (A, Fig. 3) and let rope reoil into ase (C). Thread rope guides out of ase. A-Starter Cup Fig. 5-lnspeting Starter Cup B-Worn Slots Inspet the reoil starter up (A, Fig. 5) on engine for exessively worn retangular slots (8). Replae if neessary. ) A- Reel B- Frition Plate C-Retaining Nut D-Return Spring E-Pawls Fig. 4-Disassembling Reoil Starter Remove the retaining nut, (C, Fig. 4), and the lok washer, and washer from the reel shaft. Remove frition plate (8), return spring (0), frition spring and upped washer. Remove the three pawls (E). Lift reel (A), with rope, out of ase. Remove reoil spring from ase. Remove rope from reel if rope replaement is neessary. M18330NY A-Pawls B-Frition Plate C-Return Spring Fig. 6-lnspeting Pawls. Frition Plate and Return Spring Inspet the three pawls (A, Fig. 6) and frition plate (8) for wear. Inspet the return spring (C) and frition spring and replae if raked, broken, or distorted...j J

67 Engine Reoil Starters ( Installing Rope ASSEMBLY ( A-Reel Hub B-Exessive Clearane C- Reel Shaft Fig. 7-lnspeting Reel and Reel Shaft Inspet reel hub (A; Fig. 7) and reel shaft (C) for exessive learane. Replae parts if neessary. Fig. 9-lnstalling Rope into Reel ( Install rope through hole in reel. Loop and tie knot as shown, Fig. 9. A-Rope B-Frayed C-Reoil Spring Fig. 8-lnspeting Rope and Reoil Spring Replae rope (A, Fig. 8) if frayed (8), or broken. Replae reoil spring (C) if it is broken or distorted. Inspet ondition of spring ends, and bend them if neessary, so spring properly engages the tabs on reel and ase when installed. M18JJ4NY A-Reel Hub B-Loop Fig. 10-lnstalling Rope Around Reel Hub r Plae loop (8, Fig. 10) around reel hub (A) and pull tight. Wind rope ounterlokwise around reel when viewed as shown.

68 Engine Reoil Starters Installing Reoil Spring I )1 I )' A-Spring Winding Tool B-Spring Pin C-Reoil Spring Fig. 11-lnstalling Reoil Spring Into Winding Tool Plae reoil spring (C, Fig. 11) into spring winding tool (A) as shown, so spring will be wound into tool by winding lokwise. A-Reoil Spring B-Case C-Oowel Pin D-Spring Winding Tool Fig. 13-lnstalling Reoil Spring Into Case Set spring winding tool (D, Fig. 13) with spring (A) into plae in ase (8) with loop on spring end positioned as shown, around dowel pin (C). C~refully pull winding tool (D) off reoil spring (A), leaving spring in position in ase (8). Lightly oat spring with low temperature grease. ) A-Reoil Spring B-Handle C-Plate Fig. 12-Winding Reoil Spring Into Winding Tool Assemble winding tool and wind plate, with handle, lokwise to wind spring (A, Fig. 12) into tool. Let plate (C) with handle (8) unwind and remove bolt and plate. Litho in U. S.A.

69 Engine 20 Reoil Starters 25-5 ( Installing Reel Assembly A-Noth B-Washer C-Nut D-Return Spring Eye E-Slot F-Pawl G-Frition Plate ( A-Reel B-Noth C-Reel Shaft D-End of Return Spring in Retaining Hole E -Return Spring F -Frition Spring G-Pawl H-Cupped Washer Fig. 14-lnstalling Reel, Pawls, and Springs Apply a light film of low-temperature grease to the reel shaft (C, Fig. 14). Plae end of rope through noth (B) in reel (A) and plae reel in position on reel shaft (C). NOTE: Position inner end of reoil spring away from reel shaft (C) or reel (A) will not drop into position properly. Plae upped washer (H). up up, onto reel shaft (C). Plae frition spring (F) and return spring (E) into plae, Fig. 14. IMPORTANT: End of return spring must be plaed into retaining hole (D) in reel, Fig. 14, or pawls (G) will not retrat properly. Fig. 15-lnstalling Frition Plate Slip eye of return spring (D, Fig. 15), through slot in frition plate (G) and position frition plate so nothes (A) line up with pawls (F). Install washer (B), lok washer and nut (C) and tighten seurely. Lubriate washer with PT569 Never-Seez between the washer and the frition plate. Apply a light film of low-temperature grease to the three pawls (G) and position them as shown, Fig. 14. M18340NY A-3 Turns B-Reel C-Rope Guide D-Slip Knot Fig. 16-lnstalling Rope Guide and Handle Tension reel by winding it three turns (A, Fig. 16) ounterlokwise. Insert rope through eye of ase and rope guide (C) and tie a slip knot (D). Thread rope guide into ase.

70 Engine Reoil Starters NOTE: It may be neessary to heat end of rope with a math to fuse strands (see inset, Fig. 16). This will enable rope to be threaded easily through rope guide and handle. Insert end of rope through rope guide in firewall and handle. Tie a knot in rope and pull knot into handle. Chek operation of reoil starter. Pawls should extend when rope is pulled and retrat when rope is released. Rope should reoil sharply bak into ase. )

71 SM-2108 (Aug-77) Engine 20 Liquid-Cooling System ( -80,000) 30-1 GENERAL INFORMATION Group 30 LIQUID-COOLING SYSTEM (Serial No. -80,000) ( E A-Heat Exhangers B-To Coolant Temperature Gauge C-Thermostat O-Bypass Hose E-Coolant Pump F-Coolant Reovery Container Fig. 1-Shemati View of Liquid-Cooling System r The liquid-ooling system, Fig. 1, is a pressurized, thermostatially ontrolled system, having a entrifugal pump (E) and one thermostat (C). Capaity of the ooling system is approximately quarts (4.25 I). Temperature is ontrolled by the thermostat (C) loated in the engine top filler tank. A bypass hose (D) from the engine top filler tank to the entrifugal pump insures fast engine warm-up and provides more uniform ooling temperature through-out the engine during the warm-up period. The filler ap is equipped with a pressure valve that is set to release when ooling system pressure reahes 15 pounds-per-square-inh (psi). A CAUTION: Do not remove the filler ap.. until the system has had suffiient time to ool. Then, loosen ap to relieve pressure before removing it. The entrifugal-type oolant pump is attahed to the engine and is driven by a belt. Pump output is 12 gpm (gallons-per-minute) at 7250 engine rpm. The thermostat used in onjuntion with the entrifugal pump and fixed bypass, regulates the flow of oolant through the ooling system. During the warm-up period, the thermostat emains losed and direts the oolant through the bypass system whih reirulates oolant in the engine, thus resulting in a uniform and quiker warm-up period. When the engine reahes operating temperature (approximately 144 F [61 C]) the thermostat opens, admitting heated oolant to the heat exhangers in the tunnel. The system relies on snow against the exhangers for ooling. Proper engine operating temperature is then maintained by the thermostat.

72 20 Engine 30-2 Liquid-Cooling System ( -80,000) SM-2108 (Aug-77) GENERAL INFORMATION-Continued IMPORTANT: Running the 340 and 440 Liquifire on hard paked snow or ie or pulling loads may ause a heating ondition. If the oolant temperature gauge goes into the red zone, redue load and immediately run snowmobile in loose snow or shut off the engine. If the engine should overheat slightly, oolant will run out the overflow tube into a oolant reovery ontainer (F, Fig. 1). This ontainer prevents loss of oolant from the system and as the engine ools, a siphoning takes plae and oolant is redrawn from the ontainer bak into the system. The oolant in the liquid-ooling system is a solution of ethylene glyol anti-freeze and water. DO NOT exeed the reommended solution. Never add anti-freeze to fill the system until heking the solution with a hydrometer. A solution should give approximately a - 40 F (- 40 C) reading. Chek solution when engine is ompletely warmed up. IMPORTANT: DO NOT use anti-freeze ontaining a radiator stop leak. NEVER add radiator stop-leak to the ooling system. INSPECTION AND TESTING NOTE: Remove seat before inspeting and testing system. This allows visual inspetion of heat exhangers and all onnetions. Testing Filler Cap IMPORTANT: Set JDM-73-3 Adapter in JDM-73-1 Tester (flat side down) before onneting filler ap on snowmobiles (Serial No. 70,001- ). Remove filler ap. Tighten filler ap (A, Fig. 2) to JOM-73-1 Cooling System Tester (B). Connet JOM- 44 Pressure Testing Tool (C) to JOM Connet shop air supply (E) to JOM-44 and open ontrol valve (0). Pressure should rise to 15 psi and remain onstant. If pressure drops off, filler ap is bad and should be replaed. Testing Cooling System A-JOM-73-2 Tester 8-JOM-44 Testing Tool C- Control Valve O- Shop Air Supply Fig. 3-Pressure Testing Cooling System Remove filler ap. Install JOM-73-2 Cooling System Tester (A, Fig. 3) to top filler tank. Install JOM- 44 Pressure Testing Tool (B) to ooling system tester. Connet shop air supply (0) to pressure testing tool. Open ontrol valve (C) until 20 psi registers on the gauge. Close ontrol valve and observe gauge. Pressure should hold steady. If pressure falls off there is a leak in the system. Open ontrol valve as neessary to maintain 20 psi on the system. Coolant leaks should be visible with 20 psi on the system. ) f.11866?lly NOTE: Use soapy water around the filler nek of the top tank. Air is sometimes present at this point in the system and soapy water will help detet leaks in this area. A-Filler Cap 8-JOM-73-1 Tester C-JOM-44 Testing Tool O-Control Valve E-Shop Air Supply Litho in U. S.A. Fig. 2-Pressure Testing Filler Cap

73 SM-2108 (Aug-77) Engine 20 Liquid-Cooling System ( -80,000) 30-3 DRAINING AND FILLING COOLING SYSTEM Draining Cooling System NOTE: Normally the system needs to be drained and refilled every two years only. 5. Continue filling system until top tank is full. System apaity is approximately U.S. quarts (4.25 I). Cr.ek oolant reovery ontainer. Add solutions as neessary until ontainer is half full. 6. Remove seat. Chek hose fittings (A) and heat exhangers for leaks. 7. Install filler ap (B). Blok up trak so engine an be run safely. Start the engine and again hek system for leaks. 8. Shut off engine and replae seat. Thermostat DISASSEMBLY AND REPAIR A-Hoses to Heat Exhangers D-Cylinder Head Air B-Filler Cap Vent Srew C-Thermostat E- Drain Srew Fig. 4-Draining and Filling Cooling System 1. Remove drain srew (E, Fig. 4) and filler ap (B). 2. Remove hoses (A) from engine. 3. Raise rear of snowmobile to ompletely drain system. 4. Wash engine and ompartment with lean water. Filling Cooling System 1. Position snowmobile on a level surfae. 2. Remove air vent srew (0) from engine ylinder head. 00 not lose srew. 3. Remove filler ap (B). 4. Start filling the system with a solution of ethylene glyol anti-freeze and water until solution flows from the ylinder head air vent (0). Install air vent srew (0) and washer. A-Top Tank B-Thermostat Fig. 5-Removing Thermostat If the engine has been running too old or has been overheating, remove and hek thermostat, (B, Fig. 5). Remove drain srew and filler ap and allow oolant to drain out until top tank (A) is empty. Remove top tank and thermostat. If visual inspetion of the thermostat fails to dislose any defets, test thermostat in hot water to make sure it opens and loses at the proper temperatures. Thermostat should open at 144 F. (61 C.). Litho in U. SA

74 Engine Liquid-Cooling System ( -80,000) SM-2108 (Aug-77) Heat Exhangers Drain the system as explained on page To replae heat exhangers, proeed as follows: 1. Tip the ~nowmobile on its side and remove slide suspension. Cooling System Pump Removal 1. Remove drain plug and filler ap and drain oolant from engine. NOTE: It is not neessary to drain heat exhangers for pump removal. 2. Remove drive belt over. Loosen pump adjusting srews and remove drive belt. 3. Remove bypass hose from pump to top filler tank, hose from pump to ylinder head, and hose from heat exhanger to the pump. 4. Remove pump pulley from pulley braket. ) 5. Remove pump from engine. Disassembling Pump A-Hoses B-Heat Exhanger C-Rivets Fig. 6-Heat Exhangers 2. Disonnet hoses (A, Fig. 6) from heat exhangers (8). 3. Use a old hisel and ut off rivets (C). Remove heat exhangers. 4. Install new heat exhangers to tunnel with pop rivets. Rivets should be installed from bottom of tunnel. 5. Connet hoses to heat exhangers. Reinstall slide suspension and trak. 6. Fill and bleed the ooling system. See page A-Puller B-Pulley Braket Fig. 7-Removing Pulley Braket Use a puller (A, Fig. 7) and press to remove pulley braket (8).

75 SM-2108 (Aug-77) Liquid-Cooling System ( Engine -80,000) Assembling Pump A-Pipe B-Housing Fig. 8-Removing Bearing. Seal and Impeller Use a piee of tubing or pipe (A, Fig. 8) the exat diameter of the bearing. The pipe or tubing should ontat the outer rae of bearing only. Press the bearing, seal and impeller from the housing. Fig. 10-lnstalling Seal Use a piee of tubing or pipe the exat diameter of the seal and press seal in plae, Fig. 10. r ( Fig. 9-Removing Bearing From Impeller Press the bearing from the impeller, Fig. 9. Fig. 11-lnstalling Bearing Coat bearing with a light oat of lean SAE 10W engine oil and press bearing into housing, Fig. 11, until bearing outer rae is flush with (not below) edge of housing. Use a piee of tubing or pipe that ontats outer bearing rae only. Litho in U. S.A.

76 Engine Liquid-Cooling System ( -BO,OOO) Installing Pump and Adjusting Belt Tension Install pump on engine. Do not tighten nuts at this time. j ) lr--~~ 1", ~~ Fig. 12-lnstalling Pulley Braket Support bearing shaft (not the housing) and press pulley braket on bearing shaft, Fig. 12, until the braket is flush with end of shaft. Fig. 14-Adjusting Belt Tension Install pulley on pulley braket. Plae drive belt on pulley. Install bypass hose from top tank to pump, hose from heat exhanger to pump and hose from ylinder head to pump. Pry up gently on pump until drive belt has about 3/8-inh (9.52 mm) defletion, Fig. 14, then tighten nuts seurely. Install pump drive belt over. Fill and bleed the ooling system as reommended on page ,.' '-- ~ ~'fj-"",..,.3],$ ;&;4. d "M., ~ Coolant Temperature Gauge If oolant temperature gauge is faulty it must be replaed. Remove gauge from instrument panel and sender from ylinder head. Replae as a omplete unit. Fig. 13-lnstalling Impeller Press the impeller into plae with the pump resting on pulley braket, Fig. 13. Cerami insert of impeller should be toward seal. Press impeller into plae until it is flush with end of bearing shaft. NOTE: After impeller is orretly installed, there should be approximately inh (0.22B mm) learane between the impeller and housing. J Litho in US.A.

77 SM-21G8 (Aug-77) Engine Liquid-Cooling System (80,001- ) Group LIQUID-COOLING SYSTEM (Serial No. 80,001- GENERAL INFORMATION 32 ) ( M22251 A-Heat Exhanger C-Thermostat E-Coolant Pump G-Radiator B-Temperature Gauge Lead D-By-pass Hose F-Coolant Reovery Tank Fig. 1-Shemati View of Liquid-Cooling System ( The liquid-ooling system, Fig. 1, is a pressurized thermostatially-ontrolled system, having a entrifugal pump (E) and one thermostat (C). Capaity of the system is approximately 4 quarts (3.781). Temperature is ontrolled by the thermostat (C). The filler ap has a pressure relief valve that releases when ooling system pressure reahes 15 psi. The pump (E) is attahed to the engine and driven by a belt. Pump output is 12 gallons-per-minute at 7250 engine rpm. During the warm-up period, the thermostat remains losed to divert oolant through the by-pass hose (D) and reirulate the oolant in the engine. This provides a uniform and quiker warm-up period. When the engine reahes operating temperature (approximately 144 F (61 C) ), the thermostat opens to allow oolant through the radiator and heat exhanger. Cool air passing through the radiator and snow against the heat exhanger ools the oolant. Proper engine operating temperature is maintained by the thermostat. IMPORTANT: Running on hard-paked snow or ie or pulling loads may ause overheating. If oolant temperature gauge goes into the red zone, redue load and immediately run in loose snow or shut off engine. If the engine overheats slightly, oolant will run out through the overflow tube to the oolant reovery tank (F). It will be redrawn bak into the ooling system when the engine ools down. r

78 Engine Liquid-Cooling System (80,001- ) SM-2108 (Aug-77) GENERAL INFORMATION-Continued The oolant in the liquid-ooling system is a mixture of ethylene glyol anti-freeze and water. Do. not exeed the mixture. Chek the solution with a hydrometer before adding anti-freeze to the system. A mixture should give approximately a -40 F (- 40 C) reading. Chek only when the engine is ompletely warmed-up. Testing Cooling System IMPORTANT: Do not use anti-freeze ontaining a radiator stop leak or add stop leak to the ooling system. Testing Filler Cap TESTING A-JOM-73-2 Tester B-JOM-44 Testing Tool C-Control Valve D-Shop Air Supply Fig. 3-Pressure Testing Cooling System M1866?NY A- Filler Cap 8-JOM-73-1 Tester C-JOM-44 Testing Tool D-Control Valve E-Shop Air Supply Connet JOM-73-2 Tester (A), Fig. 3, to top filler tank. Connet JOM-44 Testing Tool (8) to JOM-73-2 Tester. Connet shop air supply (D) to JOM-44. Open ontrol valve (C) until gauge reahes 20 psi, then lose valve. Pressure should hold steady. If pressure falls there is a leak in the system. Use the ontrol valve to maintain 20 psi on the system while you look for leaks. NOTE: Use soapy water around the filler nek to detet leaks in that area. Fig. 2-Pressure Testing Filler Cap A. CAUTION: Allow system time to ool... Then, loosen filler ap to relieve pressure before removing it. IMPORTANT: Set JOM-73-3 Adapter (flat side down) in JOM-73-1 Tester before onneting filler ap. Tighten filler ap (A), Fig. 2 on JOM-73-1 Tester. Connet JOM-44 Testing Tool to JOM-73-1 Tester. Connet shop air supply (E) to JOM-44 and open ontrol valve (D). Pressure should rise to 15 psi and remain onstant. If pressure drops off, filler ap must be replaed.

79 SM-2108 (Aug-77) Engine Liquid-Cooling System (80,001- ) DRAINING AND FILLING COOLING SYSTEM NOTE: Normally the system needs to be drained and refilled every two years only. Thermostat REPAIR ( Fig. 5-Removing Thermostat ( r Fig. 4-0raining and Filling Cooling System Draining System 1. Remove drain srew. 2. Remove filler ap. 3. Disonnet bottom hose from heat exhanger. 4. Raise rear of snowmobile to ompletely drain system. Reinstall drain srew. 5. Wash engine and ompartment with lean water. Filling System 6. Level snowmobile. 7. Connet hose to engine. 8. Remove vent srew and washer. IMPORTANT: Use a solution of ethylene glyol anti-freeze and water. 9. Add oolant until it flows from vent srew hole, then install vent srew and washer. 10. Continue to add oolant until system is full to bottom of filler nek and approximately one inh of oolant is in oolant reovery ontainer. 11. Chek ooling system for leaks. 12. Install filler ap. 13. Start engine and idle it until outlet hose is warm. Then, rehek oolant level. 1. Remove drain srew and filler ap. Allow oolant to drain out until top tank is empty. Tighten drain srew. 2. Remove top tank. 3. Remove thermostat. 4. Visually inspet thermostat. 5. Suspend thermostat in a pan of water. Heat water and observe thermostat. It should open at 144 F (61 C). 6. Install thermostat and top tank. 7. Follow Steps 10 through 13 at left. Temperature Gauge If temperature gauge is faulty, replae gauge and sender as a unit. Cooling System Pump and Belt Follow proedure on pages through for pump and belt servie. Litho in U. S.A.

80 20 Engine 32-4 Liquid Cooling System (80,001- ) SM-2108 (Aug-77) Radiator NOTE: Repairs should not be attempted exept by an experiened radiator repair person. Fig. 8-Rep/aing Heat Exhanger ) 2. Replae heat exhanger, Fig. 8. Fig. 6-Rep/aing Radiator 1. Drain system as instruted on page Disonnet hoses from radiator. 3. Remove radiator. 4. Install radiator. 5. Connet hoses to radiator. 6. Fill ooling system as instruted on page Connet hoses, Fig Fill ooling system as instruted on page Cooling System Pump Follow proedure on page for pump repair. Heat Exhanger Replaing Heat Exhanger Drain the ooling system as instruted on page Fig. 7-Disonneting Hoses 1. Disonnet hoses, Fig. 7.

81 SM-21GB (Aug-77) Engine 20 Speifiations 35-1 SPECIFICATIONS Group 35 SPECIFICATIONS New Part Dimension Item Cylinder Bore Conneting Rod Small End Conneting Rod Side Clearane Crankshaft Runout Crankshaft Twist Crankshaft End Play Piston at Top Land Piston at Skirt (0.255 in. * [6.5 mm] up from bottom) Piston Pin Bore Piston Pin Ring Groove Clearane (Top) Ring Groove Clearane (Bottom) Crankshaft 0.0. (PTa) End 340 Cylone 440 Cylone Wear Tolerane in. to in in. to in in. (58.00 to mm) (66.03 to mm) (0.127 mm) in. to in in. to in in. (22.00 to mm) (22.00 to mm) ( mm) in. to in in. to in (0.198 to mm) (0.198 to mm) in. to in in. to in (0.020 to mm) (0.020 to mm) in. (0.076 mm) off TOC in. to in in. to in (0.249 to mm) (0.249 to mm) in. to in in. to in (57.65 to mm) (65.66 to mm) in. to in in. to in in. (57.86 to mm) (65.86 to mm) (0.203 mm) in. to in in. to in (17.00 to mm) (17.99 to mm) in. to in in. to in (17.99 to mm) (17.99 to mm) in. to in in. to in in. (0.030 to mm) (0.030 to mm) (0.102 mm) in. to in in. to in in. (0.030 to mm) (0.030 to mm) (0.102 mm) 30 mm 30 mm ---- I *0.001 inh ( mm) oversize pistons are available for servie.

82 20 Engine 35-2 Speifiations SPECIFICATIONS-Continued New Part Dimension Item 340 Liquifire 440 Liquifire Wear Tolerane J, Cylinder Bore in. to in in. to in. (58.02 to mm) (66.02 to mm) in. (0.127 mm) Conneting Rod Small End in. to in in. to in. (23.00 to mm) (23.00 to mm) in. ( mm) Conneting Rod Side Clearane Crankshaft Runout in. to in in. to in. (0.198 to mm) (0.198 to mm) in. to in in. to in. (0.020 to mm) (0.020 to mm) ) Crankshaft Twist in. (0.076 mm) off TOC Crankshaft End Play in. to in in. to in. (0.201 to mm) (0.201 to mm) ---- Piston at Top Land in. to in in. to in. (57.65 to mm) (65.66 to mm) ---- Piston at Skirt (0.020 in. [6.5 mm] from bottom) in. to in in. to in. (57.86 to mm) (65.86 to mm) in. (0.203 mm) Piston Pin Bore in. to in in. to in. (17.99 to mm) (17.99 to mm) ---- Piston Pin in. to in in. to in. (17.99 to mm) (17.99 to mm) ---- Ring Groove Clearane (Top) in. to in in. to in. (0.030 to mm) (0.030 to mm) in. (0.102 mm) Ring Groove Clearane (Bottom) in. to in in. to in. (0.030 to mm) (0.030 to mm) in. (0.102 mm) Ring End Gap in. to in in. to in. (0.305 mm to mm) (0.305 mm to mm) Crankshaft 0.0. (PTa) End 30 mm 30 mm ----

83 Engine 20 Speifiations 35-3 TORQUE FOR HARDWARE Torque Loation Cylone Liquifire Crankase to 18 ft-ibs (20 to 24 Nm) 15 to 18 ft-ibs (20 to 24 Nm) Cylinder-to-Crankase to 18 ft-ibs (20 to 24 Nm) 15 to 18 ft-ibs (20 to 24 Nm) Cylinder Head to 14.5 ft-ibs (15.6 to 19.7 Nm) 21 to 23 ft-ibs (28 to 31 Nm) (, 5.5 to 6.5 ft-ibs (6.8 to 8.8 Nm) 14 to 16 ft-ibs (18 to 21 Nm) See page to 14 ft-ibs (17 to 18 Nm) See page Intake and Exhaust Manifold to 12 ft-ibs (13 to 16 Nm) 10 to 12 ft-ibs (13 to 16 Nm) Flywheel-to-Crankshaft ft-ibs (81 Nm) 60 ft-ibs (81 Nm) Fan Pulley Retaining Nut to 31 ft-ibs (38 to 42 Nm) Spark Plug ft-ibs (19 Nm) 14 ft-ibs (19 Nm) Litho in U. S.A.

84 20 Engine 35-4 Speifiations ) J J

85 Fuel System 30 General Information 5-1 CONTENTS Setion 30 FUEL SYSTEM Group 5 GENERAL INFORMATION Page GROUP 5 - GENERAL INFORMATION Priniple of Operation Diagnosing Malfuntions Carburetor Too Rih Carburetor Too Lean Identifying Lean or Rih Carburetor Mixtures GROUP 10 - MIKUNI CARBURETOR General Information Priniple of Operation Choke System Float System Pilot System (Idle and Slow Speed) Main System Removal Disassembly Inspetion and Repair Cleaning Carburetor Assembly Installing Pilot Jet Installing Baffle Plate, Needle Valve and Float Arm Float Level Adjustment Installing Needle Jet Installing Floats Installation Installing Throttle Valve Installing Choke Plunger Adjustments Choke System Adjusting Throttle Cable Synhronizing The Carburetors Seleting Main Jets Sea Level and Altitude Charts Page GROUP 15 - SILENCERS 340 and 440 Cylone and 440 Liquifire GROUP 20 - FUEL PUMP, FUEL TANK, SCREEN AND IN-LINE FUEL FILTER General Information Servie Sreen Fuel Tank In-Line Fuel Filter Fuel Pump (

86 30 Fuel System 5-2 General Information PRINCIPLE OF OPERATION - M18207N A-Impulse Line B-Engine Crankase C-Fuel Pump-To-Carburetor Line D-Carburetor E-Silener F-Vent Line G-Fuel Tank H- Sreen I -Fuel Line to Fuel Pump J -Fuel Shut-Off Valve ( -80,000) K- In-Line Fuel Filter L-Fuel Pump ) Fig. 1-Fuel System The fuel system, Fig. 1, onsists of a fuel tank, fuel lines, fuel shut-off valve (Serial No. -80,000), in-line fuel filter, fuel pump and arburetor. Gasoline must be mixed with a good quality oil that is suitable for use in 2-yle, air ooled, snowmobile engines. See page for gasoline and fuel speifiations. The oil in the fuel is the only lubriation the engine reeives. IMPORTANT: Too lean a fuel mixture starves the engine of lubriation and auses severe engine damage. The plasti fuel tank has a fuel gauge-type ap. A spill ledge prevents fuel from spilling onto the seat. The fuel pikup line in the tank has a sreen. The nylon sreen in the in-line filter has a selfleaning ation. Pulsation of the sreen shakes loose ontamination suh as dirt, rust and small fibers. Loose ontamination ollets at the base of the one. The hart below shows the Serial No., Snowmobile Model and arburetor number used. Serial No. (55,001 to 70,000) SNOWMOBILE MIKUNI JOHN DEERE MODEL CARBURETOR PART NO. 340 Cylone VM34-83 AM Cylone VM34-84 AM Liquifire VM34-79 (2 used) AM Liquifire VM34-80 (2 used) AM53808 Serial No. (70,001 and up) SNOWMOBILE MIKUNI JOHN DEERE MODEL CARBURETOR PART NO. 340 Cylone VM AM Cylone VM AM Liquifire VM (2 used) AM Liquifire VM (2 used) AM54245 J

87 Fuel System 30 General Information 5-3 Carburetor Too Rih Float level inorret. Dirt under inlet needle valve. Silener restrited. Wrong main jet. DIAGNOSING MALFUNCTIONS Carburetor Too Lean In-line fuel filter plugged or restrited. Dirty fuel pikup strainer in fuel tank. Debris on top of needle valve. Fuel pump impulse lined plugged. Choke system adjusted inorretly. Jet needle lip positioned inorretly. Air jet restrited. Hole in fuel impulse line. Jet needle lip positioned inorretly. Wrong main jet. Faulty fuel pump. Pinhed fuel lines. Hole in intake silener boot. Head gasket leaking. Operating with air intake silener removed. Air leakage at arburetor mounting gasket, heat spaer gasket or intake manifold gaskets. Air leakage at rankshaft seals or rankase mating surfaes. Litho in U. SA

88 30 Fuel System 5-4 General Information IDENTIFYING LEAN OR RICH CARBURETOR MIXTURES There is no substitute for experiene in reognizing whether an engine is running rih or lean. The following list of symptoms will aid in determining rih and lean onditions. When the fuel mixture is lean, the following onditions may be present: 1. The engine heats rapidly and overheating is ommon under load. 2. Performane improves when the hoke is applied. 3. Aeleration is slow; "flat spots" are also noted. 4. Inside exhaust ball joints are pale or white in olor. 5. Engine rpm flutuates at full throttle running. 6. Lak of power is evident. NOTE: When the main jet is just slightly lean, the engine will run better when old and lose power as it heats up. When the fuel mixture is too rih, the following onditions may be present: 1. Exhaust noise is dull or muted and intermittent. 2. Exessive exhaust smoke is more visible as throttle is advaned. 3. Spark plug fouling. 4. Engine misses under load. 5. Gondition should worsen when the hoke is applied. 6. As engine heats up, ondition beomes worse.

89 Fuel System 30 Mikuni Carburetor 10-1 \" Group 10 MIKUNI CARBURETOR GENERAL INFORMATION M Mixing Chamber Cap 2-Throttle Valve Spring 3-Plate 4-E-Ring 5-Jet Needle 6-Throttle Valve 7-Choke Plunger Cap 8-Choke Plunger Spring 9-Washer 1O-Choke Plunger 11-Needle Jet 12-Air Srew 13-Air Srew Spring 14-Vent Tube 15-Throttle Stop Srew 16-Stop Srew Spring 17-Gasket 18-8affle Plate 19- Mount 20-Pilot Jet 21-Washer 22- Needle Valve 23-Float Arm Pin 24-Float Arm 25-Float (2 used) 26-Ring 27-Main Jet 28-Washer 29-Drain Plug 30-Plate 31-Srew 32- Air Jet Fig. 1-Exp/oded View of Mikuni Carburetor The Mikuni Carburetor, Fig. 1, is a twin-float, fixedjet, throttle-valve arburetor. It onsists of four systems: The hoke system, float system, pilot system and main system. Choke System The hoke system onsists of the starter jet and hoke plunger. This system eliminates the need for a hoke apparatus in the arburetor bore, thereby inreasing effiieny and making rapid aeleration possible. Float System The float system onsists of two independent floats and a needle valve. This system maintains fuel at a onstant level in the float hamber. A baffle plate is used to prevent rippling of the fuel during varying engine speeds or when traveling over rough terrain.

90 Fuel System Mikuni Carburetor Pilot System (Idle and Slow Speed) The pilot system onsists of the pilot jet, air srew, pilot outlet and bypass. The ratio of fuel-air mixture for idling and slow speed is ontrolled by the pilot jet and air srew. Main System The main system onsists of the jet needle, needle jet, main jet, air jet and throttle valve. The fuel -air mixture ratio is ontrolled by a ombination of these omponents of whih the main jet is very important. Float System PRINCIPLE OF OPERATION Choke System 0& M1820 9N A-Fuel B-Fuel Inlet C-Air D-Needle Valve Fig. 3-Float System A-Fuel B-Fuel-Air Mixture Fig. 2-Choke System C-Choke Plunger D-Air NOTE: The throttle valve must be losed. The hoke system requires negative pressure in the inlet pipe in order to funtion. The hoke system, Fig. 2, is opened and losed by the hoke plunger (C). Moving the hoke lever on the dash up lifts the hoke plunger (C) and opens the hoke system. Fuel is metered through the starter jet and mixed with air (8) in the emulsion tube. This mixture flows into the plunger area, mixes with more air from the air intake (0) and is then drawn into the engine through the arburetor throat. The funtion of the float system, Fig. 3, is to maintain the orret level of fuel in the float hamber under all operating onditions. The float system onsists of two floats. This design aids in maintaining the proper fuel level under high-angle operating onditions. When the fuel level drops in the float hamber, the floats and float arm with atuating tab drop. Fuel under pressure from the fuel pump is fored through the needle valve seat, around the needle valve (0) and into the float hamber. As fuel (A) in the float hamber approahes the orret level, the floats raise ontating the float arm with atuating tab whih in turn ontats the needle valve (0). The needle valve is seated against the valve seat, stopping fuel flow (8) into the float hamber. Under atual operating onditions, the fuel level and floats automatially position themselves so that the inward flow of fuel to the arburetor is equal to the outward flow of fuel to the engine.

91 SM-21GB (Aug-77) Fuel System 30 Mikuni Carburetor 10-3 Pilot System (Idle and Slow Speed) Main System (' M18210N M18211N A-Fuel B-Needle Jet C- Throttle Valve O-Jet Needle E-Metered Here F-Air ( A-Fuel B-Pilot Bypass C-Pilot Outlet D-Jet Needle E-Air Fig. 4-Pilot System (Idle and Slow Speed) The pilot system, Fig. 4, ontrols the fuel-air mixture from idle or losed throttle position until the throttle valve is opened sufficiently to allow the main metering system to funtion. At idle speed the throttle valve is losed and the veloity of air flowing through the needle jet is low. This low negative pressure is not strong enough to draw fuel from the needle jet of the main system. Fuel during idle is supplied by the pilot outlet (C) and bypass (8 ). Fuel metered by the pilot jet is mixed with air (E) from the air intake and bypass before the fuel enters the arburetor bore. As the throttle valve is opened wider for low-speed operation, the pilot outlet (C) annot supply the required fuel. The fuel then enters the arburetor bore through the bypass (8) as well as the pilot outlet (C). Fig. 5-Main Metering System The main metering system, Fig. 5, starts to funtion when the throttle valve (C) is opened about 1/4 of the way. Opening the throttle valve also auses the jet needle (0) to move up. This auses the air flowing through the needle jet (8) to inrease, thereby inreasing negative pressure whih auses a suking ation to take plae. From 1/4 to 3/4 open throttle, the fuel passes through the main jet and is metered in the learane between the needle jet (8) and jet needle (D). The fuel is then mixed with air that is metered through the air intake (E), thereby atomizing the fuel. This mixture is then mixed with air flowing through the main bore before entering the engine. During this operation the utaway (slant) of the throttle valve (C) ontrols the negative pressure on the needle jet (8), thereby regulating the amount of fuel that is injeted into the engine. When the throttle valve is fully opened for highspeed operation, fuel is metered entirely by the main jet.

92 Fuel System Mikuni Carburetor SM-210B (Aug-77J REMOVAL J Fig. 8-Removing Mixing Chamber Cap ) A-Spring B-Top Half C-Clamp D-Fuel Line E-Clamp F-Carburetor Fig. 6-Removing Carburetor G-Lower Half 1. Remove air silener springs (A, Fig. 6) and silener top half (8). 2. Loosen lamp (C) on rubber boot seuring air silener to arburetor (F) and remove silener lower half (G). 3. Remove fuel line (0) from arburetor. 4. Loosen lamp (E) seuring arburetor to mount and remove arburetor. 6. Remove mixing hamber ap, throttle valve spring, plate, E-ring, jet needle and throttle valve. These omponents ome out as an assembly, Fig. 8. DISASSEMBL V Remove drain plug and drain the fuel from the float hamber. A CAUTION: Use are when draining fuel from the arburetor. Gasoline is dangerous, even when mixed with oil. Avoid fires due to smoking or areless maintenane praties. Remove throttle stop srew with spring and air srew with spring., M18215N A-Ring B-Main Jet C-Mixing Chamber Body D-Float Chamber E-Floats Fig. 7-Removing Choke Plunger Fig. 9-Removing Float Chamber and Floats 5. Loosen lok nut on hoke able and remove hoke plunger assembly from mixing hamber body, Fig. 7.

93 Fuel System 30 Mikuni Carburetor 10-5 ( Remove float hamber (0, Fig. 9) with floats (E) from mixing hamber body (C). Remove main jet (8) and ring (A). Use a 6 mm (15/64-inh) soket or box end wrenh to remove main jet (8). A-Gaskets 8-lnlet Needle Valve Assembly C-8affle Plate D-Float Air Pin E-Float Arm Fig. 10-Removing Float Arm Assembly and Baffle Plate Remove float arm pin (D, Fig. 10), float arm (E), baffle plate (C), gaskets (A) and inlet needle valve assembly (8). A-Needle Jet 8-Awl Fig. 11-Removing Needle Jet From Mixing Chamber Remove needle jet (A, Fig. 11) arefully from the mixing hamber by pushing from the bottom with an awl (8). INSPECTION AND REPAIR Cleaning Carburetor IMPORTANT: Never lean jets or passages with small drills or wire. A slight enlargement or burring of jets or passages will hange the performane of the arburetor. Plae arburetor parts in arburetor leaner (PT503) or its equivalent. Do not plae gaskets in leaner. Allow parts to remain in leaner for one to two hours. Remove and rinse parts with solvent. Dry parts with ompressed air, making sure all holes are open and free of dirt. Never use rags or paper to dry the parts. Lint may plug jets or passages and affet operating effiieny of the arburetor. NOTE: Rinse mixing hamber body and float hamber in hot water. This will neutralize the orrosive ation of the arburetor leaner on the aluminum of these parts. Inspeting Carburetor Inspet mixing hamber body and float hamber for raks or damage that might ause fuel leaks. Chek all springs for damage or distortion. Inspet throttle stop srew and air srew for seating surfae damage or stripped threads. Inspet main jet and pilot jet for damage or stripped threads. NOTE: Main jet and pilot jet should be lean and shiny. Any abrasions will ause a lean fuel-air mixture and possible engine damage. Remove retainer and inlet valve from inlet valve seat. Inspet seating surfae on inlet valve and seat for damage. 8e sure retainer is not binding or hindering movement of inlet valve. Inspet needle jet and jet needle for damage. Jet needle should slide freely within the needle jet. NOTE: The E-ring on the jet needle should be installed in the following grooves depending on snowmobile model and serial number. JET NEEDLE POSITION CHART Model 340 Cylone 440 Cylone 340 Liquifire 440 Liquifire (Serial No. 55,001-70,000) 2nd Groove 2nd Groove 4th Groove 4th Groove (Serial No. 70,001-80,000) 3rd Groove 3rd Groove 4th Groove 3rd Groove (Serial No. 80,001- ) 3rd Groove 3rd Groove 4th Groove 4th Groove

94 Fuel System Mikuni Carburetor Install floats in float hamber. Move floats up and down to be sure they are not binding on guides. Floats must work freely to maintain a onstant fuel level in the float hamber. Inspet float pin and float arm. Float arm should not bind on pin. Chek hoke plunger. Plunger should move freely in passage of mixing hamber. Plae throttle valve in mixing hamber body and move it up and down to hek for stiking or wear. Be sure guide pin in mixing hamber body is not broken off. This would allow throttle valve to rotate, ausing errati arburetor operation. ASSEMBLY Installing Baffle Plate, Needle Valve and Float Arm J Installing Pilot Jet A- Float Arm B-Inlet Valve C-8affle Plate and Gaskets Fig. 13-lnstalling Baffle Plate, Needle Valve and Float Arm Install gaskets and baffle plate (C) on mixing hamber. Install the seond gasket on top of baffle plate, Fig. 13. Install new washer on inlet needle valve seat and install seat in mixing hamber body. Install inlet valve (B) (point down) and retainer, Fig. 13. J Fig. 12-lnstalling Pilot Jet Use a small srewdriver and install pilot jet, Fig. 12. Tighten jet by turning it lokwise. Install float arm (A) and seure with float arm pin, Fig. 13. Float Level Adjustment A-Mixing Chamber B-Float Arm Fig. 14-Float Level Adjustment

95 Fuel System 30 Mikuni Carburetor 10-7 With the arburetor inverted, the edge of the mixing hamber (A, Fig. 14) should be parallel with the float arm (8). If adjustment is neessary, bend only the float arm atuating tab. Installing Needle Jet Refer to Fig. 1 and install air srew spring (13) and air srew (12). Turn the srew in until it just seats. DO NOT fore it. As a preliminary adjustment, refer to harts on page and bak srew out aordingly. Install throttle stop srew (15) and spring (16), Fig. 1, until srew is just flush with the inside of the bore. INSTALLATION Position arburetor in rubber mount and seure with lamp. Install fuel line from pump to arburetor. Installing Throttle Valve A-Pin B-Noth C-Needle Jet Fig. 15-lnstalling Needle Jet Install needle Jet (C) making sure noth (8) on needle jet is orretly aligned with pin (A) in bore in mixing hamber, Fig. 15. Plae ring over needle jet bore, (reess in ring next to bore) and srew main jet into needle jet. Installing Floats Fig. 17-lnstalling Throttle Valve See page and install E-ring in the proper groove of the jet needle, Fig. 17 (Inset). NOTE: Groove No. 1 provides leaner midrange operation; groove No. 5 provides riher midrange operation. Guide throttle able end button through ap, spring and slot in throttle valve, Fig. 17. Slide able into narrow part of slot in throttle valve. Install plate between spring and throttle valve with tab on plate in the slot of the throttle valve. This loks the able to the throttle valve. Fig. 16-Positioning Pins When Installing Floats in Float Chamber Install floats over float pins. Pins on floats must be down and pointing to the inside of float hamber, Fig. 16. Attah float hamber to mixing hamber with four srews. Compress throttle valve spring and tighten ap to mixing hamber. IMPORTANT: Move throttle lever and observe throttle valve travel. Throttle valve must have full travel up and down. If not, hek to insure that guide pin and slot in throttle valve are properly aligned. Litho in U. S.A.

96 Fuel System Mikuni Carburetor Installing Choke Plunger Adjust the hoke plunger as follows: M182 HNY... Fig. 18-lnstalling Choke Plunger Be sure hoke lever on instrument panel is down. Guide hoke able end button through ap and spring. Hook end button in hoke plunger, Fig. 18. Plae washer on mixing hamber body. Install the assembly and tighten ap. Adjust and synhronize arburetor as explained below. ADJUSTMENTS Choke System (All ) The hoke system is opened and losed by the hoke plunger and operates by negative inlet pipe pressure. The throttle valve must be losed when starting the engine; otherwise, the fuel-air mixture will be too lean for starting. The fuel-air mixture for starting is metered through independent jets. A-JOM-7S Carburetor Choke Gauge B-Adjusting Sleeve Fig. 19-Adiusting Choke Plunger C-Jam Nut 1. Plae the hoke lever on the dash in the " UP" position. 2. Loosen jam nut (C) and turn adjusting sleeve (B) lokwise to fully seat hoke plunger. 3. Insert JDM-75 Carburetor Choke Gauge (A, Fig. 19), with the flat "UP" into the plunger air hole as shown. 4. Turn adjusting sleeve (B) ounterlokwise to bring the hoke plunger "UP". Continue to do so until the arburetor hoke gauge slides further into the plunger air hole indiating that the hoke plunger has raised approximately one half the diameter of the plunger air hole. 5. Tighten jam nut (C). NOTE: When the hoke lever on the dash is down, the hoke plunger should be all the way down in the bore. There should be slight freep/ay between the lever and the dash. IMPORTANT: If the hoke plunger is not down tight in the bore, the arburetor will run "RICH" and will affet the main jet system. This ould ause a problem when attempting to find the orret main jet for top engine performane.

97 Fuel System Mikuni Carburetor Adjusting Throttle Cable (All ) 4. Turn throttle stop srew (A) ounterlokwise until the srew tip is flush with the inside of the bore. 5. Remove rubber band or lamp from the throttle lever and allow the throttle valve to fully seat in the bore. 6. Turn throttle stop srew (A) lokwise until the srew ontats the throttle valve. When the srew ontats the valve, the valve will begin to rise. Turn throttle stop srew two additional turns lokwise. This will give preliminary idle speed. 7. Look into the throat of the arburetor and slowly ompress the throttle lever on the handgrip. The throttle valve should begin to rise. A-Throttle Stop Srew B-Jam Nut C-Adjusting Sleeve D-Pilot Air Srew Fig. 20-Adjusting Throttle Cable 1. Use a strong rubber band or lamp and lok the throttle lever tightly against the handgrip. Remove air silener. 2. Plae your finger in the throat of the arburetor. Loosen jam nut (8, Fig. 20) and turn adjusting sleeve (C) lokwise (in) until the ut-out portion of the throttle valve an be felt flush with the inside of the bore. 3. After the ut-out portion of the throttle valve is flush with the bore, turn the adjusting sleeve (C) ounterlokwise as follows: 3-1/2 turns on 340 Liquifire, 4 turns on 340 Cylone and 440 Liquifire and 5 turns on the 440 Cylone. This will move the throttle valve " UP" making the bakside of the valve flush with the bore. Tighten jam nut (8). IMPORTANT: After adjustment on the 340 and 440 Cylone (Serial No. 50,001-70,000) hek for a learane of inh (2.54 mm) between throttle lever and handgrip. Exess learane ould allow the throttle able retainer to ome loose from the throttle lever, inreasing idle speed. Bak out throttle adjusting sleeve as neessary to prevent retainer from oming loose. NOTE: On the Liquifire, both throttle valves should begin to rise at exatly the same time. If throttle valve movement does not our as speified, repeat Steps 2 through Carefully turn pilot air srew (0) lokwise (in) until a slight seating resistane is felt. 9. Turn pilot air srew (0) ounterlokwise (out). See harts on page and The idle speed may not be orret for normal operation. To hek engine for proper idle, proeed as follows: a. Install air intake silener and run the engine until operating temperature is reahed. b. If engine will not idle or if inreased idle rpm is desired, turn throttle stop srew (A). lokwise until idle speed of 1800 to 2200 rpm is obtained. NOTE: On 340 and 440 Liquifire, set both throttle stop srews equally. IMPORTANT: DO NOT use the pilot air srews (D) at any time to set engine idle. Be sure the pilot air srews are adjusted as explained in Step 9. NOTE: When the throttle valve is adjusted orretly, the bakside of the valve will be flush with or above the bore. No part of the valve will restrit air flow through the arburetor throat.

98 30 Fuel System Mikuni Carburetor Synhronizing Carburetors (340 and 440 Liquifire) 7. Remove wedge from the throttle lever and allow the engine to idle. Repeat Steps 3, 4 and 5. Adjust throttle stop srews as neessary to give proper idle. Seleting Main Jets The main jet meters fuel through the arburetor when operating in the one-half-to-full throttle range. Temperature and altitude affet the density of air. In order to maintain a onstant air-fuel ratio, whih results in peak performane, the arburetors must be jetted riher or leaner for varying onditions. A-Idle Adjusting Srew 8-JOM-64-2 Air Flow Meter C-Tube in Vertial Position O-Float E-Air Flow Control Fig. 21 -Synhronizing Carburetors 1. Raise and support the rear of the snowmobile so trak is lear of the ground. 2. Start and run the engine at 4000 rpm. Use a wedge in the throttle lever to maintain engine speed at 4000 rpm. 3. Open air flow ontrol (E, Fig. 21) of the JDM-64-2 Air Flow Meter and plae meter over right-hand arburetor throat. Tube on meter must be in vertial position (C). 4. Slowly lose air flow ontrol (E) until the float (D) in tube lines up with a graduated mark on tube. 5. Plae Air Flow Meter (8) on left-hand arburetor without hanging adjustment of air flow ontrol (E). If arburetors are equal, all settings are orret. NOTE: Air flow meter should be plaed on arburetor for only 1 to 5 seonds at a time. 6. If adjustment is neessary, loosen jam nut on arburetor with lowest float level and turn adjusting sleeve ounterlokwise until float level mathes the other arburetor. h CAUTION: BE VERY CAREFUL when "making slide adjustment. DO NOT allow your arm to ontat drive belt. DO NOT wear loose lothing that may be aught in the drive belt. 1. Operate the snowmobile at wide open throttle for several minutes on a flat, well-paked surfae. Failure to ahieve maximum rpm or laboring at high rpm indiates the main jet should be hanged. Try to determine if operating problems are aused by too rih or too lean a fuel mixture. 2. Continue to operate at wide open throttle and shut off the ignition before releasing the throttle. This will enable you to determine if the fuel mixture is too rih or too lean by examining the exhaust manifold and spark plugs. 3. If the exhaust manifold or spark plug insulator is dark brown or blak, the fuel/air mixture is too rih. Derease the jet size. NOTE: Do not hange jet sizes more than one inrement (step) at a time. 4. If the exhaust manifold or spark plug insulator is very light in olor, the fuel/air mixture is too lean; inrease the jet size. 5. If you annot determine the olor, proeed as though it is too lean and inrease the jet size. If operation improves, ontinue to inrease the jet size to obtain peak performane. If operation beomes worse, derease the jet size to obtain peak performane. 6. After the proper main jet is seleted, rehek the jet needle and needle jet. ) J Litho in U. S.A.

99 Fuel System 30 Mikuni Carburetor ( ITEM Altitude SEA LEVEL AND ALTITUDE CHARTS Cylone and Liquifire (Serial No. 55,001-70,000) 340 CYCLONE 440 CYCLONE 340 LlaUIFIRE Sea Level 8,000 to Sea Level 8,000 to Sea Level 8,000 to to 12,000 ft. to 12,000 ft. to 12,000 ft ft. ( to 2000 ft. ( to 2000 ft. ( to (609.6 m) m) (609.6 m) m) (609.6 m) m) 440 LlaUIFIRE Sea Level 8,000 to to 12,000 ft ft. ( to (609.6 m) m) Main Jet No. Jet Needle Needle Jet Throttle Valve Pilot Jet No. Air Srew (turns) Idle Speed (rpm) 370* * * 170 6FL 14-2** 6FL 14-2** 6FL14-2** 6FL14-2** 6DH3-4** 6DH3-4** 0-0 P Open 2 Open 1 Open 1 Open 2 Open 10ptm DH3-3** 6DH3-3** P-o p-o /2 Open 1-1/2 Open *Fatory Installed. **Example 6FL The last number (2) indiates the E-ring position on the jet needle, that is, the 2nd groove down from the top. 340 Cylone Snowmobile (Serial No. 70,001- ) Sea Level 2000 to 4000 to 6000 to 8000 Item to 4000 ft ft ft ft ft. (609.6 to ( to ( to ( to (609.6 m) m) m) m) 3048 m) Main Jet Jet Needle 6FL 14-3* 6FL14-3* 6FL 14-4* 6FL14-3* 6DH7-5* NeeCfle Jet P-6 Throttle Valve Pilot Jet Air Srew (turns) Idle Speed (rpm) Cylone Snowmobile (Serial No. 70,001- ) ( Sea Level 2000 to 4000 to 6000 to Item to 4000 ft ft ft ft ft. (609.6 to ( to ( to ( to (609.6 m) m) m) m) 3048 m) Main Jet Jet Needle 6FL 14-3* 6FL14-3* 6FL 14-4* 6FL 14-4* 6FL 14-4* Needle Jet P-2 P-2 P-2 P-2 P-2 Throttle Valve Pilot Jet Air Srew (turns) Idle Speed (rpm) *Last number indiates position of E-ring on the jet needle.

100 Fuel System Mikuni Carburetor 340 Liquifire Snowmobile (Serial No. 70,001- ) Item Sea Level 2000 to 4000 to 6000 to to 4000 ft ft ft ft. (609.6 to ( to ( to (609.6 m) m) m) m) Main Jet Jet Needle SDH3-4* SDH3-4* SDH3-4* SDH3-4* Needle Jet O-S O-S O-S O-S Throttle Valve Pilot Jet Air Srew (turns) Idle Speed (rpm) ft. ( to 3048 m) 1S0 SDP1-4* O-S Liquifire Snowmobile (Serial No. 70,001- ) Sea Level 2000 to 4000 to 6000 to Item to 4000 ft ft ft ft. (609.6 to ( to ( to (609.6 m) m) m) m) Main Jet Jet Needle SDH4-4* SDH4-3* SDH8-2* SDH8-2* Needle Jet p-o p-o P-O P-o Throttle Valve Pilot Jet Air Srew (turns) Idle Speed (rpm) ft. ( to 3048 m) 200 SDH7-3* P *Last number indiates position of E-ring on the jet needle.

101 Fuel System 30 Mikuni Carburetor MAIN JETS TUNING COMPONENTS JET NEEDLES* THROTTLE VALVES - 36 MM MIKUNI JOHN 4/042- DEERE NO. MIKUNI NO. JOHN DEERE NO. MIKUNI VM36/39 JOHN DEERE NO. ( LEAN 70 M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M M66911 RICH 6DH3 6DH2 6FL14 6DP1 6DH7 6DH4 60P5 NEEDLE JETS MIKUNI VM34/ P-O P-2 P-4 P-6 P-8 LEAN M65354 M66656 M66422 M66926 M66927 M66928 M66941 JOHN DEERE NO. M66890 M66891 M66892 M66893 M66739 M65340 M66845 M66894 M66741 M MIKUNI VM22/210 #15 #17.5 #20 #25- #30 #35 #40 #45 #50 #55 #60 RICH LEAN LEAN 0-0 M66740 RICH 0-2 M M M66898 AIR JETS 0-8 M66916 M66884 M66885 M66886 M66887 M66658 M66888 M66889 JOHN DEERE NO. M66912 M66913 M66745 M66929 M66844 M66914 M65355 M66746 M66663 M66672 M66915 RICH MIKUNI JOHN 8S30/97 DEERE NO. THROTTLE VALVES - 34 MM MIKUNI VM34/110 JOHN DEERE NO. RICH 0.5 M M M M M M M66883 LEAN LEAN RICH M66499 M669~7 M66033 M66918 M66919 M66920 M66921 M66922 M66923 M66924 M66925 *Lean to Rih information not available at this time.

102 Fuel System Mikuni Carburetor TUNING COMPONENTS-Continued MAIN JET NEEDLE JET ~ AMBIENT JET TEMP ALTITUDE SIZE HOT HIGH ALT M COLD SEA LEVEL THROTTLE VALVE THROTTLE AMBIENT VALVE TEMP ALTITUDE CUTAWAY COLD HIGH ALT FUEL MIXTURE ~ F=~ LEAN... RICH FUEL MIXTURE RICH ~ M22343 AMBIENT JET TEMP ALTITUDE SIZE HOT HIGH ALT P-2 P-4 P-6 P-8 COLD SEA LEVEL 0-0 JET NEEDLE NEEDLE AMBIENT CLIP TEMP ALTITUDE POSITION HOT HIGH ALT. FUEL MIXTURE LEAN RICH FUEL MIXTURE LEAN M22341 HOT M22344 COLD SEA LEVEL M22345 RICH AIR SCREW ~ AMBIENT, TURNS TEMP. ALTITUDE OPEN HOT HIGH ALT. 2-1/ /2 1 COLD SEA LEVEL 1/2 M22342, FUEL MIXTURE LEAN 1 RICH M22346 PILOT JET AMBIENT TEMP ALTITUDE HOT HIGH ALT. COLD SEA LEVEL JET SIZE FUEL MIXTURE LEAN RICH

103 Fuel System Sileners AND 440 CYCLONE SNOWMOBILE (Serial No. 55,001-70,000) Group 15 SILENCERS l ~ " o f '- ~. if M18225N A-Spring (2 used) B- Pads (4 used) C- Straps (4 used) D-Lower Half E-Boot F-Sreen G-Upper Half H-Rubber Ring I -Hose J-Clamp K- Tube L-Washer M-Nut N-Clamp Fig. 1-Cy/one Silener Components (Serial No. 55,001-70,000) General Information The funtion of the silener, Fig. 1, is to quiet the sound of rushing air, and to ath fuel that spits bak out of the arburetor throat. The silener is not intended to filter inoming air beause the snowmobile should be operated only on lean, snow-overed areas. Installing Tube When installing tube (K) in upper half (G) of silener, be sure "This Side Up" on tube is toward the top of the upper half. Chamfered part of rubber ring (H) must fae inside of box. Servie There is no servie for the upper (G) and lower (D) half of the silener. If these two parts are raked or damaged in any way, they must be replaed. IMPORTANT: NEVER run the snowmobile with the silener removed. Lean mixtures, loss of power and engine damage will result if the engine is run without the silener.

104 30 Fuel System 15-2 Sileners SM-2108 (Aug-77) 340 AND 440 CYCLONE SNOWMOBILE (Serial No. 70,001 and up) A-Straps (4 used) B-Spring (2 used) C-Lower Half D-Boot E-Clamp (2 used) F-Sreen G- Upper Half H-Rubber Ring I -Hose Fig. 2-Cylone Silener Components (Serial No. 70,001 and up) M20934 J-Sreen K- Washer L-Nut General Information The funtion of the silener, Fig. 2, is to quiet the sound of rushing air, and to ath fuel that spits bak out of the arburetor throat. The silener is not intended to filter inoming air beause the snowmobile should be operated only on lean, snow-overed areas. Servie There is no servie on the upper and lower half of the silener. If these two parts are raked or damaged in any way, they must be replaed. IMPORTANT: NEVER run the snowmobile with the silener removed. Lean mixtures, loss of power and engine damage will result if the engine is run without the silener. Installing Hose When installing hose, hamfered part of rubber ring (H) must fae inside of box.

105 Fuel System Sileners AND 440 UaUIFIRE SNOWMOBILE (Serial No. 55,001-70,000) ( J>J18226N A-Springs (2 used) B-Pads (2 used) C-Straps (2 used) D-Lower Half E-Sreen F-Upper Half G-Rubber Ring H-Hose I-Clamp J - Tube K- Washer L-Nut M-Clamps (2 used) N-Boots (2 used) Fig. 3-Liquifire Silener Components (Serial No. 55,001-70,000) ( General Information The funtion of the silener, Fig. 3, is to quiet the sound of rushing air, and to ath fuel that spits bak out of the arburetor throat. The silener is not intended to filter inoming air beause the snowmobile should be operated only on lean, snow-overed areas. Servie There is no servie on the upper (F) and lower (D) half of the silener. If these two parts are raked or damaged in any way, they must be replaed. IMPORTANT: NEVER run the snowmobile with the silener removed. Lean mixtures, loss of power and engine damage will result if the engine is run without the silener. Installing Tube When installing tube (J) in upper half (F) of silener, be sure "This Side Up" on tube is toward the top of the upper half. Chamfered part of rubber ring (G) must fae inside of box.

106 Fuel System Sileners 340 AND 440 LlaUIFIRE SNOWMOBILE (Serial No. 70,001 and up) ) A-Straps (2 used) B-Spring C-Clamp (3 used) D-Boots (2 used) E-Lower Half F-Upper Half G-Rubber Ring H-Hose I -Sreen Fig. 4-Liquifire Silener Components (Serial No. 70,001 and up) J-Washer K-Nut General Information The funtion of the silener, Fig. 4, is to quiet the sound of rushing air, and to ath fuel that spits bak out of the arburetor throat. The silener is not intended to filter inoming air beause the snowmobile should be operated only on lean, snow-overed areas. Servie There is no servie on the upper and lower half of the silener. If these two parts are raked or damaged in any way, they must be replaed. IMPORTANT: NEVER run the snowmobile with the silener removed. Lean mixtures, loss of power and engine damage will result if the engine is run without the silener. Installing Hose When installing hose, hamfered part of rubber ring (G) must fae inside of box. ) -

107 Fuel System 30 SM-2108 (Aug-77) Fuel Pump, Fuel Tank, Sreen and In-line Fuel Filter 20-1 r Group 20 FUEL PUMP, FUEL TANK, SCREEN AND IN-LINE FUEL FILTER ( M18227NY A-Fuel Tank Fig. 1-Fuel Tank Assembly B-Fuel Cap and Gauge GENERAL INFORMATION The fuel tank (A, Fig. 1), features a fuel gauge in the ap (8) and a spill ledge. The spill ledge prevents spilled fuel from spilling onto the seat. The tank has a apaity of 8 U.S. gallons (30.3 I). The fuel tank ap is sealed and the tank is vented by the vent line (E, Fig. 2) at the top of the tank. The fuel pik-up line (A, Fig. 2) in the tank is onneted to a sreen (8). The fuel shut-off valve (C) (Serial No. -80,000) and in-line fuel filter (0) are loated in the fuel line between the fuel tank and fuel pump (F). The nylon sreen in the in-line fuel filter (0) has a self-leaning ation. Pulsation of the sreen shakes loose ontamination suh as dirt, rust and small fibers. Loose ontamination ollets at the base of the one. NOTE: If snowmobile (Serial No. -80,000) has been transported on a trailer and the fuel shut-off valve (e) was not losed, the engine may be "flooded". M18)l28NY A-Fuel Pik-Up Line B-Sreen C-Shut-Off Valve ( -80,000) Sreen D-Fuel Filter E-Vent Line F-Fuel Pump Fig. 2-Fuel Tank Fitting, Lines and Sreen SERVICE To remove pikup sreen, disonnet fuel lines from fitting, and remove fitting from fuel tank, Fig. 2. Remove pikup sreen (8) from end of line, Fig. 2. Clean sreen with gasoline and ompressed air. Replae sreen if it is damaged. Replae gasket on fuel line fitting, if neessary. Fuel Tank Clean fuel tank if dirt deposits have been deteted in tank. Remove tank by disonneting fuel lines and vent lines. Remove the seat and tank hold-down lips. Slide tank rearward to remove. If tank has major damage, it should be replaed. Minor damage or leaks an be pathed, if pratial. In-line Fuel Filter Change the filter annually or when paked ontamination starts to build up at the base of the one.

108 30 Fuel System 20-2 Fuel Pump, Fuel Tank, Sreen and In-line Fuel Filter Fuel Pump Testing Fuel Pump 1. Disonnet impulse line from fuel pump. 2. Use a short piee of fuel line to onnet a pressure gauge to the impulse side of fuel pump. 3. Pressurize to 5 or 6 psi (0.34 or 0.41 bar) (0.35 or 0.42 kg/m2) and observe gauge. Pressure should not drop. 4. If the pressure drops, replae the fuel pump. Inspeting Fuel Pump To inspet fuel pump, separate the astings shown, Fig. 3 or Fig. 4. Chek valves (A) should not be bent or have foreign matter holding them off their seat. There should be no liquid in the impulse avity (8). All parts must be lean and not disolored. If any omponents are damaged, the entire fuel pump must be replaed. IMPORTANT: Do not use arburetor leaner or strong solvents on fuel pump omponents. A-Chek Valves 8-lmpulse Cavity Fig. 3-lnspeting Retangular Fuel Pump ) A-Chek Valves B-Impulse Cavity Fig. 4-lnspeting Round Fuel Pump

109 Eletrial System 40 General Information 5-1 Setion 40 ELECTRICAL SYSTEM Group 5 GENERAL INFORMATION CONTENTS ( r l Page GROUP 5 - GENERAL INFORMATION Priniple of Operation Wiring Diagrams Testing Diagnosing Malfuntions GROUP 10 - CAPACITOR DISCHARGE IGNITION (COl) Priniple of Operation Eletroni Pak Spark Plugs Testing Preliminary Chek Testing Ignition With JDM-74 Tester Trouble Shooting Guide Testing Trigger Assembly With JDM-74 Tester Testing Stator Assembly With JDM-74 Tester Testing Trigger and Stator With JDM-74 Tester Testing Trigger Testing Stator Testing The Eletroni Pak Testing The Alternator Testing Ignition Coils With JDM-74A-5 Ignition Tester Testing The Coils With Mer-O-Troni Analyzer Testing Ignition Coil Power Testing Ignition Coil Insulation Testing Primary Resistane Testing Seondary Resistane Testing COl System-Pull Method Repair Removing Flywheel, Stator and Trigger Assemblies Installing Flywheel, Stator and Trigger Assemblies Cheking Ignition Timing Page GROUP 15 - LIGHTING SYSTEM Priniple of Operation Testing Testing Alternator System with an AC Voltmeter Testing Headlight Dimmer Swith Testing Light Swith Testing Brake Light Swith Testing Engine Kill Swith (1976).... : Testing Ignition Swith (1976) Testing Ignition and Kill Swithes (1977) Replaing Alternator Sfator Aiming Headlight Adjusting Headlight GROUP 20 - ELECTRIC START KIT Priniple of Operation Battery Testing Testing Battery Testing Starter Testing Starter Solenoid Testing Ciruit Breaker Testing Ignition Swith Testing Diode (Retifier) Testing Charging System Repair Battery Starter GROUP 25 - SPECIFICATIONS Speifiations Torque for Hardware Light Bulb Chart

110 40 Eletrial System 5-2 General Information PRINCIPLE OF OPERATION J SPEEDOMETER ) M18341N TAILLIGHT FLYWHEEL ALTERNATOR STATOR ELECTRONIC PACK. Fig. 1-John Deere Snowmobile Eletrial System with Eletri Start Option John Deere 340 and 440 Cylone and Liquifire have an alternator whih provides power for the lighting system. On models equipped with the eletri start option, the alternator also harges the battery through a diode, Fig. 1, whih hanges the AC urrent to DC urrent for harging the battery. A voltage regulator in the system limits the average AC voltage, allowing only the voltage needed in the system at a given time. A CDI ignition system is used with dual ignition oils and eletroni pak. Of the twelve poles on the alternator stator, nine supply power for the lighting system and three supply power for the ignition system. An "ON-OFF" swith on the instrument panel, swithes the headlight and taillight "on" and "off". A brake light swith turns the brake light on when the brakes are applied. The three-position ignition swith has "OFF", "ON" and "START" positions. "OFF" position grounds out the eletroni pak. ("ON" position opens the ignition iruit. However, on the eletri start equipped snowmobiles, "ON" position also loses a iruit making it possible for the alternator to harge the battery.) "START" position energizes the starter solenoid ranking the engine (eletri start). An emergeny stop swith also grounds out the eletroni pak when depressed. The eletri start option inludes battery box, solenoid, starter motor, iruit breaker and diode. A 12-volt manifold-vented battery is used with the eletri start kit. Refer to "Wiring Diagram" and " Diagnosing Malfuntions" in this group, to aid in understanding the eletrial system and diagnosing malfuntions. ) Litho in U. S.A.

111 ( ), ~ ( ') r- : o s ~ (f) ):. WIRING DIAGRAM Cylones and Liquifire (Serial No. 55,001-70,000) AL HRNATOR STATOR 81 a k STOP/TA IL ffi LIGHT J 11 BRAKE TIL LEAD HEAOLI GH T. VN... HlmLOIl (f)(f) ~:::J I 0 I\)~... 3 ~o :r ~ ~C/) ~ I 'J ~ B1 ak Bro wn MAIN WIRI NG HARNESS Tan Ye llow Pi nk Green 81 ak B1 ak ~ ed Yellow M20942 Fig. 2-Wiring Diagram POS I T lo ri -CLOSED-OPEN HEADLIGHT DIMMER SWITCH PO SIT I ON- CLOSED OPE' I g~f I A&B I A.:! 1 I g~f I A&B I ~B I I ~6 I ~ ~ ~ I ~ I G) t!j (!) (!) ~ () ~~ -- o :::J III (3'- :s(f) ~~... eng' :3 Cf~ wo

112 \. ) r- ~ s ~ C/) ):. AL TERNATOR STATOR WIRING DIAGRAM Cylones and Liquifire (Serial No. 70,001-80,000) Blak ef:l STOP/TAIL LIGHT 111 BRAK E TIL LEAD HEADLIGHT!IN HlffiLOW.n~ ~o G)!:!J (!) (!) :::! () (!) ~ g ~. 5" O'~ ~ (/j ;;;"l <i) ~3 o :::! 81 ak Brow n MAIN WIRING HARNE SS Tan Yell ow Pi nk VOL TAGE RE GU LATOR Green ELECTRtN Ie PACK TER MINAL BLOCK Wh i te Brown Bl ak Bl ak! Red Ye 11 ow M20943 Fig. 3-Wiring Diagram _A_ BRAKE LIGHT SWITCH SWI TCH POS I T I 011 CLOSED-OPEN HEADL IGHT DIMMER SW ITCH POS IT I ON- CLOSEO - OPEN Ig~F I A&BIA~ 1 I g~fia&b I A.!..B I I ~~ 1! ~ I ~ 1 ~... ~g> C ~~ g. I _. "'Cir -:::::!n

113 () r- S o s ~ C/) ):. ALTERNATOR STATOR WIRING DIAGRAM Liquifire (Serial No. 80,001- STOP/TAIL LIGHT,m, ) HEAOLIGH~T HI LOW C/)C/) s::j I 0 ~~... 3 ~o 0- ~ ~(Jl < I '-I ~ BLACK BRAKE T /L LEAD BLACK BROWN TAN YELLOW MAIN WIRING HARNESS ~~~mor rtj GREEN l ~ TERMINAL BLOCK WHI BLACK YELLOW W/RED STRIPE ELECTRONIC PACK BLACK ~ "" M22252 [&;' ~ ~ji7"j Fig. 4-Wiring Diagram YELLOW BRAKE LIGHT SWITCH POS 1TI0N-C~OSEP-O~EN Lg~F ~ BJ~ HEADLIGHT DIi'I'IER SWITCH POSJT!QnL~SEDrEN I ~I A & 81 i (j) ~rn <D(j) ~ C) -~ - (=). :J III 0'- 3 (J) Q)~ g'<n" :J :3 Cf~ U'IO

114 \ r- S <:) :So ~ C/) ~ AL TERNATOR STATOR WIRING DIAGRAM Cylone (Serial No. 80,001- ) 81 ak STOP/TAIL ~ LIGHT JI1 HEAOLIGHT lin HlmLOW U1~ 0,0 G)!!! C1l C1l ::J () C1l ~.., -. ~2 ~~ 3 ~ IU C1l g. :3 ::J BRAKE TIL LEAD B1 ak Brown Tan Ye 11 ow MAIN WIRING HARNESS VOL TAGE... Pi nk '";t:l J i=j =Gre=en ====~l IF===F======--_+ REGULATOR rf? j ~ ~! ~ TERM I NAL BLOCK Whi te ELECTRO! IC PACK Brown Blak 81 ak ~ M22253 Fig. 5-Wiring Diagram Yellow POS IT IOll CLOSE O OPEN I g~f IA & B I A~B I HEADLIGHT DIMMER SW IT CH POS IT [ ON-CLOSEO-OP EN I ~~ I ::~I~I ~... ~C/) ::J <:) ~~ :: :3 (Q <:),0- "J::::":.::::!m

115 SM-21GB (Aug-77) Eletrial System 40 General Information 5-7 TESTING Instrutions are provided in eah group for testing eletrial omponents. The purpose of the tests is to isolate the ause of trouble in the ignition system, lighting system, or eletri start system. High quality test equipment is a must for aurate diagnosis of eletrial malfuntions. Always follow the proedures outlined by the manufaturer of the test equipment to supplement instrutions ontained in this manual. NOTE: Beause there are many manufaturers of test equipment, eah with its own speifi operating instrutions, it is important to follow the manufaturer's reommendations if the proedures in this manual should ontradit those of the manufaturer. DIAGNOSING MALFUNCTIONS Ignition System Engine Hard to Start Lights Will Not Light Spark plugs fouled, or defetive. Eletri onnetions loose or wires damaged. Engine not timed properly. Eletrial onnetions loose or orroded. High tension lead(s) aring. Alternator faulty. Light swith faulty ( Bulbs burned out. -80,000). r Engine Misfires Spark plugs fouled, or defetive. Eletrial onnetions loose or orroded. Engine not timed properly. High tension lead(s) aring. Engine Overheating Engine not timed properly. Engine Kiks Bak and Bakfires Spark plug wires reversed. Engine not timed properly. Voltage regulator faulty. Brake Light Will Not Light Brake light swith faulty. Eletrial onnetions loose or wires damaged. Bulb burned out. Bulbs Burn Out Often Wrong type bulbs used. Voltage regulator faulty. Lights Too Bright or Too Dim Voltage regulator faulty. Defetive alternator.

116 40 Eletrial System 5-8 General Information Litho in U.S.A

117 Eletrial System Capaitor Disharge Ignition (COl) Group 10 CAPACITOR DISCHARGE IGNITION (COl) PRINCIPLE OF OPERATION r A-Magneti Flywheel Rotor B-Ignition Timing Rotor C-Alternator Stator O-Ignition Timing Ring E-Eletroni Pak F-Ignition Coils G-Surfae Gap Spark Plugs H-Triggering Slot Fig. 1-Exploded View of Capaitor Disharge Ignition (COl) The Capaitor Disharge Ignition (COl) System, Fig. 1, onsists of a permanent magnet flywheel, alternator and solid-state apaitor. This supplies high voltage for ignition and generates urrent required for the lighting system. The flywheel (A, Fig. 1) inorporates a speial flexible magnet and is mounted on the engine rankshaft. The flywheel and magnet revolve around the stator assembly (C), whih is fixed to the engine. Current is generated in the twelve pole windings of the stator. Nine poles supply power for the lighting system and three poles supply power for the ignition. Litho in U. S.A.

118 Eletrial System Capaitor Disharge Ignition (COl) Eletroni Pak -=-- IGlHTIOI~ COIL #1 TRIGGER r t-i Ar~p.CKT. #1 ~-TRIGGER I =0 POWER SCR. RECTIFIER I ;(SWITCH) I FILl! CAPACITORS /~I- STORAGE_ \ _ Cr-A_PA_C_IT_O_RS --L..j YELLOW! HI~PEEO - CHG. LO SPEEDWHWmG CHG. WINDING )... POWER SCR. #2 (SWITCH) I I ---.J I M20944 Fig. 2-EJetroni Pak Shemati Wiring Diagram The eletroni pak, Fig. 2, inorporates a retifier, two storage apaitors (ondenser), two power SCR (silion ontrol retifier) swithes, two trigger iruits and two filter apaitors (ondensers). The flywheel and magnets revolve around the stator produing AC urrent. The AC urrent is fed to the eletroni pak and hanged by the retifier to DC urrent. This DC urrent is put into and stored by the two storage apaitors (ondensers). The timing rotor of the flywheel revolving within the timing ring triggers an eletrial voltage disharge to one of the trigger iruits of the eletroni pak. The trigger iruit amplifies the signal to the power SCR swithes. This voltage opens the gate of the power SCR swith allowing the voltage stored in the apaitor to be released to the ignition oils. The ignition oils, "step-up", the eletrial voltage to a level high enough to insure firing of the spark plugs.

119 SM-2108 (Aug-77) Eletrial System Capaitor Disharge Ignition (COl) [ Spark Plugs Use Champion QN-1 spark plugs. No additional plugs or heat ranges are required. Do not regap plugs, replae them when gap reahes 0.060" (1.52 mm). A TESTING CAUTION: High energy ignition systems an produe injurious eletrial shok. Always stop engine before touhing or working on any ignition omponents. DO NOT hold, spark plugs, leads or onnetors in hand to hek for spark. Preliminary Chek Be sure all onnetions are lean and tight and that no leads are broken or grounded out. Chek key swith and emergeny stop swith. IMPORTANT: Do not hek the COl system for ontinuity with a 12-volt test light. To do so will destroy the system. Do not attempt tests unless the system is ompletely and properly grounded. Testing Ignition With JOM-74 Tester ---- ',;;;;.-=-:....,.. ~.,. ;.. " -~----- Fig, 3-JDM-74 Capaitor Disharge Ignition Tester M20945 The JDM-74 CD Ignition Tester, Fig, 3, is an eletrial energy measuring devie apable of measuring the peak energy output of apaitor disharge ignition units, trigger, stator and eletroni pak, Capaitor disharge ignition energy output pulses our at a speed of miroseond duration and annot be aurately measured by a voltmeter. The tester is of solid state onstrution and is apable of measuring energy peaks of less than one miroseond in duration. It performs as a omparator. The orret value of energy output is determined by using speifiations from fatory-orret ignition systems, The value limits of these speifiations are determined and provided to the servie tehniian, These values are then ompared with the values taken from the engine being tested, The ignition energy output is referened against a sale on the tester. The greater the energy output, the greater the value indiation on the sale. The indiation is in the form of an inandesent lamp that lights when the sale knob is set at the position orresponding to the energy output. After eah test where indiator lamp lights, the "RESET" button must be pushed to turn off the lamp in preparation for the next test. The tester has two input iruits seleted by a toggle swith, The "LOW" iruit is sensitive to AC or DC voltages from 0.5 to 27 volts, The "HIGH" iruit is senstitive to AC or DC voltages of approximately 75 to 500 volts. A test simulator is provided with eah tester as a means to test the lamp, detetor iruits and batteries, Chek the tester as follows: 1, Plug the test simulator into a wall plug outlet ( volt AC) for ten seonds. 2, Plae toggle swith of tester to "HIGH" iruit. 3, Turn sale knob of tester to 50 on the sale, 4, Hook yellow lead of tester to "N" post of simulator and red lead of tester to "P" post of simulator. 5, Push button on bottom of simulator. The tester light should light. If light does not light, put new batteries in the tester and test again, 6, If tester does not funtion after installing new batteries, return to: Eletro-Speialties, In, W, Bluemound Rd, Wauwatosa, Wis, 53226

120 40 Eletrial System 10-4 Capaitor Disharge Ignition (COl) Trouble Shooting Guide TEST NO. 1 - Trigger Signal sr~ Run Engine at 3000 rpm. NO Remove and inspet fly- Flywheel OK - Replae. trigger Tester onneted one at a wheel trigger. Gap should time to eah trigger lead. attrat srewdriver. Chek Tester on low sale. 48 to see that puk has not Flywheel defetive - Replae Reading 75 or more. rotated. flywheel TEST NO.2 - Stator Output Run engine at 3000 rpm. NO Remove and inspet fly- Flywheel OK - Replae stator Tester onneted to blue wheel. Magnet should lead, tester on high sale attrat srewdriver - same reading 50 or more. Repeat as a new flywheel. Flywheel defetive - Replae for yellow lead. Reading 50 flywheel or more. CAUTION: Shok hazard volts. 48 TEST NO.3 - Eletroni Pak Run engine at 3000 rpm. NO Eletroni pak defetive. Test eletroni pak output Replae pak. with load oil. Disonnet wire from oils one at a time. Reading 60 or more on Test ignition oils. eah output lead. YES See Test No.6. Problem Cause Component to Chek First 1. Engine Fails to Start Any Component of Ele- Eletroni Pak - Test No. 3 trial System 2. Random Firing Any Component of Ele- Trigger Assembly - Test No. 1 trial System 3. Loses Fire on One Cylinder Any Component of Ele- Ignition Coil - Test No.6 trial System 4. One Cylinder Fires Many ITT Cannon Connetors Chek Connetors and Eletroni Times Per Revolution or Eletroni Pak Pak, Test No.3 5. Engine Starts Hard Any Component of Ele- Ignition Coil - Test No.6 and Fouls Plugs trial System 6. No Spark on One Cylinder Any Component of Ele- Ignition Coil - Test No.6 trial System ) 7. Bakfires in Exhaust System Eletroni Pak - Crank- Eletroni Pak - Test No. 3 ase Loaded With Fuel Crankase

121 Eletrial System Capaitor Disharge Ignition (COl) IMPORTANT: Install new spark plugs and perform the following tests in the sequene listed. If the engine an't be started, use the pull-method, page Testing Trigger Assembly with JOM-74 Tester NOTE: The following test is written to aommodate snowmobiles with CD ignition and ITT annon onnetors between the engine and eletroni pak. See Test No. 3 for snowmobiles with 6-wire plasti onnetors between the engine and eletroni pak. /). CAUTION: Raise and support the rear of.. the snowmobile so trak is lear of the ground before onduting test. TRIGGER RING JDM-74 TESTER,,"moM TUTU 0 "LOW" ~IFX. ~'X:::!!, /, Disonnet the red, white and green wiring harness between the engine and eletroni pak. 2. Install JDM-74A-2 Wiring Harness between the engine and eletroni pak, Fig Plae toggle swith of JDM-74 Tester on the "LOW" iruit. Turn dial knob of tester lokwise to 100 on sale. 4. Connet red wires of JDM-74A-2 Wiring Harness together. Separate the white wire of JDM-74A-2 Wiring Harness. 5. Connet "P" lead of the tester to male terminal of the white wire. 6. Connet "N" lead of the tester to ring of green wire of the JDM-74A-2 Wiring Harness. 7. Start and run the engine at 3000 rpm. Run on one ylinder, the one not being tested. 8. Turn the dial knob of the tester slowly ounterlokwise. Light should light before 75 is reahed on the sale. 9. Stop the engine. Disonnet " P" lead of the tester from white wire of JDM-74A-2 Wiring Harness. Leave the "N" lead attahed to the green wire. 1 O. Reonnet the white wire and separate the red wire of JDM-74A-2 Wiring Harness. 11. Connet " P" lead of tester to male terminal of the red wire. Turn dial knob of tester lokwise to 100 on the sale. 12. Start and run the engine at 3000 rpm. Run on one ylinder, the one not being tested. 13. Turn the dial knob of the tester slowly ounterlokwise. Light should light before 75 is reahed on the sale. NOTE: In Steps Band 13, the light should light before 75 is reahed on the sale. If the light lights at a number under 75, the trigger is bad and should be replaed. 14. Stop the engine. Disonnet the tester "P" and "N" leads. Reonnet the red wire of JDM-74A-2 Wiring Harness and remove harness. 15. Reonnet the wiring between the engine and the eletroni pak. IMPORTANT: Engine must be run at 3000 rpm for the trigger test. Engine rpm above or below 3000 rpm will alter the dial reading as reommended. Fig. 4-Testing Trigger Assembly Litho in U. S.A.

122 Eletrial System Capaitor Disharge Ignition (COl) 2. Testing Stator Assembly with JDM-74 Tester NOTE: The following test is written to aommodate snowmobiles with CD ignition and ITT annon onnetors between the engine and eletroni pak. See Test NO.3 for snowmobiles with 6-wire plasti onnetors between the engine and eletroni pak. A CAUTION: Raise and support the rear of the snowmobile so trak is lear of the ground before onduting test. Fig. 5-Testing Stator Assembly JDM- 74 TESTER IGNlnoN TUTU. TO EN GINE GROUND :@; /, "HIGH" 1. Disonnet the yellow and blue wiring harness between the engine and eletroni pak. 3. Plae toggle swith of JDM-74 Tester on the "HIGH" iruit. Turn dial knob of tester lokwise to 100 on the sale. 4. Connet " P" lead of tester to blue wire of JDM- 74A-3 Wiring Harness and "N" lead of tester to engine ground. 5. Start and run the engine at 3000 rpm. 6. Turn the dial knob of the tester slowly ounterlokwise. Light should light before 50 is reahed on the sale. 7. Stop the engine. Leave the "N" lead of the tester Ori'neted to engine ground. Move the "P" lead of the tester from the blue wire to the yellow wire of JDM- 74A-3 Wiring Harness. 8. Start and run the engine at 3000 rpm. NOTE: Use a wedge between the throttle and handgrip to obtain and hold the 3000 rpm. 9. Grasp the swith in the yellow wire with your index and middle finger and push in and hold swith "ON" with your thumb. NOTE: Swith in yellow wire must not be pushed in when starting engine. If swith is pushed in, the tester will "load" the start system and engine will not start. A CAUTION: 300 volts is possible at either the yellow or blue leads when engine is running. DO NOT touh leads when engine is running. Make ertain lead not being tested does not touh mahine metal. 10. Use the other hand to slowly turn the dial knob ounterlokwise. Light should light before 50 is reahed on the sale. NOTE: In Steps 6 and 10, the light should light before 50 is reahed on the sale. If the light lights at a number less than 50, the stator is defetive and should be replaed. 11. Stop the engine. Disonnet "P" and " N" leads of the tester. Remove JDM-74A-3 Wiring Harness. 12. Reonnet the wiring between the engine and the eletroni pak. IMPORTANT: Engine must be run at 3000 rpm for the stator test. Engine rpm above or below 3000 rpm will alter the dial reading as reommended. 2. Install JDM-74A-3 Wiring Harness between the engine and eletroni pak, Fig. 5.

123 SM-21GB (Aug-77) Eletrial System Capaitor Disharge Ignition (COl) Testing Trigger and Stator with JDM-74 Tester NOTE: The following test is written to aommodate snowmobiles equipped with apaitor disharge ignition and 6-wire plasti onnetors between the engine and the eletroni pak. Il.. CAUTION: Raise and support the rear of.. the snowmobile so trak is lear of the ground before onduting test. Testing Trigger 1. Disonnet the wiring harness between the engine and eletroni pak. TRI GGER RIN G IiNITION nm. o 0 ELECTRONIC PACK, I I ~@~,, -4>-. "LOW" 2. Install JDM-74A-4 Wiring Harness between the engine and eletroni pak, Fig Plae toggle swith of JDM-74 Tester on the "LOW" iruit. Turn dial knob of tester lokwise to 100 on the sale. 4. Connet red wires of JDM-74A-4 Wiring Harness together. Separate the white wire of JDM-74A-4 Wiring Harness. 5. Connet "P" lead of the tester to male terminal of the white wire, Fig Connet "N" lead of the tester to ring of green wire of the JDM-74A-4 Wiring Harness, Fig Start and run the engine at 3000 rpm. Run on one ylinder, the one not being tested. 8. Turn the dial knob of the tester slowly ounterlokwise. Light should light before 75 is reahed on. the sale. 9. Stop the engine. Disonnet "P" lead of tester from white wire of JDM-74A-4 Wiring Harness. Leave the "N" lead attahed to the green wire. 1 O. Reonnet the white wire and separate the red wire of JDM-74A-4 Wiring Harness. 11. Connet "P" lead of tester to male terminal of the red wire. Turn dial knob of tester lokwise to 100 on the sale. 12. Start and run the engine at 3000 rpm. Run on one ylinder, the one not being tested. 13. Turn the dial knob on the tester slowly ounterlokwise. Light should light before 75 is reahed on the sale. NOTE: In Steps Band 13, the light should light before 75 is reahed on the sale. If light lights at a number less than 75, the trigger is bad and should be replaed. 14. Stop the engine. Disonnet tester "P" and "N" leads. 15. Reonnet the red wire. Leave the JDM-74A-4 Wiring Harness in plae and proeed with the stator test. M20948 Fig. 6-Testing Trigger Assembly - Litho in U.S.A

124 Eletrial System Capaitor Disharge Ignition (COl) Testing Stator 16. Plae toggle swith of the JDM-74 Tester on the "HIGH" iruit. Turn dial knob of tester lokwise to 1 00 on the sale. JDM-74 TESTER 1IH1Ti0N TUTU 0 ELECTRON IC PACK Fig. 7-Testing Stator Assembly M20949 ~ ;~gt /, ~(.... ~ "HIGH" 17. Connet "P" lead of the tester to the blue wire of JDM-74A-4 Wiring Harness and "N" lead of the tester to engine ground, Fig Start and run the engine at 3000 rpm. 19. Turn the dial knob of the tester slowly ounterlokwise. Light should light before 50 is reahed on the sale. 20. Leave the "N" lead of the tester onneted to ground. Move the "P" lead of the tester from the blue wire to the yellow wire of JDM-74A-4 Wiring Harness. 21. Start and run the engine at 3000 rpm. NOTE: Use a wedge between the throttle and handgrip to obtain and hold the 3000 rpm. 22. Grasp the swith in the yellow wire with your index and middle finger and push in and hold swith "ON" with your thumb. NOTE: Swith in yellow wire must not be pushed in when starting engine. If swith is pushed in the tester will "load" the start system and engine will not start. A CAUTION: 300 volts is possible at either the yellow or blue leads when engine is running. DO NOT touh leads when engine is running. Make ertain lead not being tested does not touh mahine metal. 23. Use the other hand to slowly turn the dial knob ounterlokwise. Light should light before 50 is reahed on the dial. NOTE: In Steps 19 and 23, the light should light before 50 is reahed on the sale. If the light lights at a number under 50, the stator is defetive and should be replaed. 24. Stop the engine. Disonnet the tester "P" and "N" leads and remove the JDM-74A-4 Wiring Harness. 25. Reonnet the wiring between the engine and eletroni pak. IMPORTANT: Engine must be run at 3000 rpm for the trigger and stator tests. Engine rpm above or below 3000 rpm will alter the dial reading as reommended. ) ) Litho in U.S.A

125 Eletrial System Capaitor Disharge Ignition (COl) Testing the Eletroni Pak IMPORTANT: Before testing the eletroni pak, be sure the pak is reeiving the orret input signals by performing Tests 1, 2 or 3. A "GOOD" eletroni pak will not funtion orretly with defetive inputs from the trigger or stator. A CAUTION: Raise and support the rear of.. the snowmobile so trak is lear of the ground before onduting test. 1. Plae toggle swith of JDM-74 Tester on the "HIGH" iruit. Turn dial knob of tester lokwise to 100 on the sale. JOM-74 TESTER l -. "HIGH" 2. Disonnet the red wire from the left oil. 3. Connet "P" lead of the tester to red wire and "N" lead of tester to engine ground. 4. Connet load oil (omes with JDM-74 Tester) to the red wire and to engine ground, Fig. 8. NOTE: Load oil now takes the plae of the engine oil and loads the eletroni pak to a speifi resistane. 5. Start and run engine at 3000 rpm. Run on one ylinder, the one not being tested. 6. Turn dial knob of the tester slowly ounterlokwise. Light should light before 55 is reahed on the dial. 7. Stop the engine. Disonnet " P" lead from tester and the lead from the load oil from the red wire. Leave "N" lead from tester and load oil attahed to engine ground. 8. Reonnet red wire to left oil. 9. Disonnet white wire from the right oil. 1 O. Connet "P" lead from the tester and lead from the load oil to the white wire. Turn dial knob of the tester lokwise to 1 00 on the sale. 11. Start and run engine at 3000 rpm. Run on one ylinder, the one not being tested. 12. Turn dial knob of the tester slowly ounterlokwise. Light should light before 55 is reahed on the dial. EL ECTRIll IC PACK M20950 NOTE: In Steps 6 and 12, the light should light before 55 is reahed on the sale. If the light lights at a number under 55, the eletroni pak is defetive and should be replaed. Fig. 8-Testing The Eletroni Pak 13. Disonnet "P" and "N" leads of the tester and both leads of the load oil. 14. Reonnet white wire to the right oil. IMPORTANT: Engine must be run at 3000 rpm for the eletroni pak test. Engine rpm above or below 3000 rpm will alter the dial reading as reommended.

126 40 Eletrial System Capaitor Disharge Ignition (COl) 5. Testing The Alternator IMPORTANT: DO NOT run the engine for this test. Crank the engine with the start rope. 1. Plae toggle swith of the JDM-74 Tester on the "LOW" sale. Turn dial knob of tester to 90 on the sale. 2. Disonnet wiring harness oupler from the engine. 3. Use eletrial wiring male terminals and install terminals in yellow/green wire onnetions of the engine oupler. 6. Testing Ignition Coils with JDM-74A-5 Ignition Tester NOTE: The JDM-74A-Slgnition Tester an be used to determine ignition oil output on all John Deere without removing the oils. 1. Install new spark plugs in the engine. NOTE: New spark plugs must be installed beause if one of the spark plugs is fouled, that plug will go to ground and the ignition tester will still show spark. J ) Fig. to-testing Ignition Coils With JDM-74A-5 Ignition Tester 2. Remove high tension lead from one plug. Clamp ignition tester to this plug and onnet high tension lead to the ignition tester, Fig Start and run the engine at 3000 rpm. Fig. 9-Testing The Alternator 4. Connet "P" lead and "N" lead to the male terminals, Fig. 9. NOTE: Leads from tester an be onneted in any manner as long as they do not ontat eah other when onneted. 5. Crank the engine with the start rope. Light should light. If light lights at a number less than 90, the stator is defetive. 6. Disonnet tester leads and remove terminals. 7. Reonnet wiring harness oupler to engine. 4. The ignition oil should be able to fire the ignition tester and the spark plug under ompression in the engine. 5. Low ignition oil output will not fire the ignition tester or the spark plug under ompression. Consequently the engine will run on only one ylinder, the one not being tested. 6. Test both oils in the same manner. IMPORTANT: DO NOT ground the ignition tester to the engine to determine oil output. This does not require the ignition oil to put out maximum voltage. Ignition tester must be lamped to the spark plug under ompression in the engine. 7. Chek for higher voltage leaks in high tension leads. Look for spark aring to nearby metal. Replae oil if spark is present.

127 Eletrial System Capaitor Disharge Ignition (COl) Testing The Coils With Mer-O-Troni Analyzer The Model 98A Mer-O-Troni Analyzer, Fig. 11, is one of the most preise and versatile testers available for heking apaitor disharge ignition oils. The following tests are made using the Mer-O Troni analyzer. If different equipment is used, the same tests should be made, but follow the test equipment manufaturers reommendations for proedures. Analyzer Test Prior to testing the oils, test the operation of the battery power of the analyzer. Testing Ignition Coil Power IMPORTANT: Capaitor Disharge Adapter (55-980) must be used with the Model 98 or Model 98A Analyzer when onduting the oil power test. 1. Connet the small red lead of the analyzer to the red post of the adapter. 2. Connet the small blak lead of the analyzer to the blak post of the adapter. M20954 Fig. 12-Testing Ignition Coil Power _M20953 A-Negative Post B-Positive Post _.~ C-Volt Sale Swith Fig. 11-Testing Mer-O-Troni Analyzer 1. Turn the adjustment srew on the front of the analyzer meter so that needle aligns with "0" reading on Sale No. 1, Fig Remove two srews and tip over to the rear to allow aess to the battery. 3. Connet the blak test lead of analyzer to the negative post (A) of the battery. 4. Connet the red test lead of analyzer to the positive post (8) of the battery. 5. Turn volt sale swith to the "ON" position. 6. Read red figures on top of Sale No.1. Reading should show 6 volts. If less, replae analyzer battery. A CAUTiON: Perform tests with analyzer and.. omponents on an insulated or wooden table top to prevent any leakage or shok hazard. 3. Connet large lead from the analyzer to the spark plug wire of the oil, Fig Connet red lead of the adapter to the primary post of the oil, Fig Connet blak lead of the adapter to blak wire and oil laminations, Fig. 12. NOTE: DO NOT onnet the blak lead of the adapter to the blak wire or oil laminations only. Both must be onneted together for the oil power test. 6. Turn the analyzer urrent ontrol knob to "La". 7. Plae seletor swith of analyzer to No. 1 Coil Power Test. 8. Turn urrent ontrol knob lokwise (slowly). Spark gap indiator on the right side of the analyzer should fire steadily before needle reahes 1.9 on Sale No If steady spark ours after 1.9 is reahed on Sale No.1, the oil is defetive and must be replaed. NOTE: When test is ompleted, disonnet adapter from oil and the analyzer leads from the adapter. Adapter is used only for the oil power tests and SHOULD NOT be used for any of the additional tests.

128 Eletrial System Capaitor Disharge Ignition (COl) Testing Ignition Coil Insulation Testing Primary Resistane J M20955 Fig. 13-Testing Ignition Coil Insulation 1. Connet the small blak lead of the analyzer to the blak wire and oil laminations, Fig. 13. NOTE: DO NOT onnet the blak lead of the analyzer to the blak wire or oil laminations ONL Y. Both must be onneted together for the ignition oil insulation test. 2. Connet small red lead of the analyzer to the primary post of the oil, Fig Install test probe in the analyzer. 4. Turn analyzer urrent ontrol knob to "LO". 5. Plae seletor swith of analyzer to No. 1-"Coil Power test. " 6. Pass probe over oil and spark plug wire. Spark disharge will be noted if damage is present. NOTE: If spark disharge is noted, replae oil. M20956 Fig. 14-Testing Primary Resistane 1. Plae seletor swith of analyzer to No. 2 Distributor Resistane. 2. "Zero" meter on right-hand side of Sale No Connet small blak lead of the analyzer to the blak wire of the oil, Fig. 14. NOTE: Connet only to the blak wire, not the oil laminations. 4. Connet small red lead of the analyzer to the primary post of the oil, Fig Needle should move to the left and be in the "OK" zone of Sale No If needle is not in the "OK" zone, the primary iruit of the oil is defetive and oil must be replaed. J

129 Testing Seondary Resistane Eletrial System 40 Capaitor Disharge Ignition (COl) Plae seletor swith of analyzer to No. 3-"Coil Continuity." 2. Touh the small red and blak leads of the analyzer together and "Zero" meter on right-hand side of Sale No Connet small blak lead of the analyzer to the blak wire of the oil, Fig. 15. NOTE: Connet only to the blak wire, not the oil laminations. 4. Connet the small red lead of the analyzer to the spark plug wire of the oil, Fig Needle should move between 0 and.5 on the right-hand side of Sale NO.3. Fig. 15-Testing Seondary Resistane M If needle does not register between 0 and.5, the seondary iruit of the oil is defetive and oil must be replaed.

130 40 Eletrial System Capaitor Disharge Ignition (COl) Testing COl System with JDM-74 Tester (Pull Method) NOTE: The pull method is reommended ONL Y if the engine will not start. AL WA YS use the running method for heking the COl system when possible. Trigger 1. Plae toggle swith of tester on "LOW" sale. 2. Install wiring harness between engine and eletroni pak. 3. Connet red wires of wiring harness together. Separate white wire of harness. Connet "P" lead of tester to male terminal of white wire. 4. Connet "N" lead of tester to green wire of wiring harness. 5. Set tester dial at 20 - rank engine - light should light. 6. Connet white wire. Separate red wire. Connet "P" lead of tester to male terminal of red wire. 7. Connet "N" lead of tester to green wire of wiring harness.. 8. Set tester dial at 20 - rank engine - light should light. 9. Remove wiring harness. Stator 1. Plae toggle swith of tester on "LOW" sale. 2. Install wiring harness between engine and eletroni pak. 3. Connet "P" lead of tester to blue wire. 4. Connet "N" lead of tester to engine ground. 5. Set tester dial at 90 - rank engine - light should light. 6. Plae toggle swith of tester on "HIGH" sale. 7. Connet "N" lead of tester to engine ground. 8. Connet "P" lead of tester to yellow wire. 9. Push in and hold swith in yellow wire. 1 O. Set tester dial at 10 - rank engine - light should light. Eletroni Pak SM-2108 (Aug-77) 1. Plae toggle swith of tester on "HIGH" sale. 2. Disonnet red wire from left oil. 3. Connet "N" lead of tester to engine ground. 4. Connet "P" lead of tester to red wire. 5. Connet load oil between red wire and engine ground. 6. Set tester dial at 55 - rank engine - light should light. 7. Reonnet red wire to left oil. 8. Disonnet white wire from right oil. 9. Connet "N" lead of tester to engine ground. 1 O. Connet "P" lead of tester to white wire. 11. Connet load oil between white wire and engine ground. 12. Set tester dial at 55 - rank engine - light' sbould light. 13. Reonnet white wire to right oil. Alternator 1. Plae toggle swith of tester on "LOW" sale. 2. Connet "P" lead of tester to one of the yellowgreen wires of terminal blok on the engine. 3. Connet "N" lead of tester to the other yellowgreen wire of terminal blok on engine. 4. Set tester dial at 90 - rank engine - light should light.

131 SM-2108 (Aug-77) Eletrial System Capaitor Disharge Ignition (COl) Removing Flywheel, Stator and Trigger Assemblies NOTE: Engine has been removed from snowmobile for photographi purposes. Remove reoil start, flywheel housing and lower fan sheave. IMPORTANT: Do not strike flywheel with a steel mallet beause this an ause permanent damage to the flywheel. REPAIR NOTE: Srews seuring stator and trigger assembly are held with Lotite. Use an L-shaped Phillipshead srewdriver to break Lotite loose, making srew removal easier. Installing Flywheel, Stator and Trigger Assemblies Install trigger and stator assemblies. Use Lotite on eah srew and tighten seurely. Fig. l6-removing Flywheel Retaining Nut Use two of the bolts that seure lower fan sheave to attah JDM-64-1 Flywheel Holding Tool to the flywheel, Fig. 16. Remove retaining nut and remove JDM-64-1 Flywheel Holding Tool. Fig. l8-lnstalling Trigger Assembly When installing trigger assembly, Fig. 18, position all four srews in the enter of their slots. In most ases this will be the orret timing position for the trigger assembly. Fig. l7-removing Flywheel Install JDM-9 Puller assembly as shown in Fig. 17. Two of the puller bolts should be installed through JDM-64-1 Flywheel Holding Tool. This provides a method of holding the flywheel while tightening the puller bolt. Remove stator and trigger assembly. Fig. 19-1nstalling Flywheel Retaining Nut Install flywheel and torque retaining nut to 60 ft-ibs (81.34 Nm), Fig. 19. Remove JDM-64-1 Flywheel Holding Tool and install lower fan sheave, flywheel housing and reoil start.

132 40 Eletrial System Capaitor Disharge Ignition (COl) Cheking Ignition Timing (Without Timing Deal) NOTE: For a quik hek, loate a pointer on an intake manifold bolt and mark reommended timing on fixed fae of primary luth. J A-Timing Light B-Clamp on Pik-up C-Pointer D-Mark on Sheave Fig. 21-Cheking Ignition Timing A-Dial Indiator B-Brass Pointer C-Mark on Flywheel Sheave Fig. 20-Cheking Ignition Timing 1. Remove reoil starter. Bend a loop in a brass rod (B, Fig. 19) and seure it to flywheel housing with srew. Pointer (B) should just miss flywheel sheave. 2. Install dial indiator (A, Fig. 20) in No. 1 spark plug hole. 3. Rotate rankshaft to loate TDC (Top Dead Center), and "zero" dial indiator (A). 4. Rotate rankshaft ounterlokwise (opposite normal rotation) until dial indiator reads inh BTDC (before top dead enter). 7. Connet a timing light (A, Fig. 21) to No.1 spark plug lead and to a 12-volt battery. 8. Start and run engine at approximately 4000 rpm. 9. Aim timing light (A) at pointer (C) and mark (D) on flywheel sheave. Mark on flywheel sheave should align with pointer. 10. If not, remove flywheel housing, flywheel and alternator-stator. Loosen four srews seuring timing ring and rotate ring as neessary to advane or retard timing. Rotating ring ounterlokwise advanes timing - rotating ring lokwise retards timing. Retighten srews seurely. Reassemble and rehek timing. 5. With flywheel in this position, plae a mark (C) (with a felt-tip pen) on sheave rim orresponding with pointer (B). 6. Remove dial indiator (A) and reinstall spark plug. J

133 SM-2108 (Aug-77) Eletrial System 40 Capaitor Disharge Ignition (COl) Cheking Ignition Timing (With Timing Deal) 1. Remove drive belt and spark plugs. Fig. 23-lnstalling Timing Deal Fig. 22-Marking Primary Sheave 2. Install JDM-15 Dial Indiator in No. 1 ylinder spark plug hole, Fig Form a piee of inh (2.032 mm) wire and attah it with an intake manifold nut as shown, Fig Rotate primary sheave until dial indiator shows the No. 1 piston is at top-dead-enter (TDC). 8. Install JDM-1 08 Timing Deal on sheave so that the 0 degree line on timing deal is diretly over TDC mark on the sheave. NOTE: Lined edge of deal should be even with the edge of the sheave and the 20 degree advane mark on the deal should be over the inh (2.438 mm) BTDC mark. 9. Repeat Steps 2 through 8 for the No. 2 ylinder, using another deal. 5. Use a fine~point, felt-tip pen to make a mark that is in line with the wire pointer. 6. Rotate primary sheave lokwise until dial indiator shows that the piston is inh (2.438 mm) BTDC before-top-dead-enter (BTDC). 7. Make a seond mark in line with the wire pointer. I f'

134 40 Eletrial System Capaitor Disharge Ignition (COl) 10. Install spark plugs. 11. Connet timing light to No.1 ylinder spark plug lead. 12. Start and run engine at 3000 rpm. Timing light should indiate 20 degrees ± 1 degree BTDC. A CAUTION: Do not overspeed engine with.. drive belt removed. 13. Repeat Steps 11 and 12 on No.2 ylinder. IMPORTANT: Timing variane should not exeed ± 1 degree between ylinders. Rehek dial indiator readings (Steps 4, 5, 6 and 7) if it varies more than 1 degree. 14. If timing is inorret, remove reoil starter, flywheel housing, flywheel and alternator-stator. Loosen four srews seuring timing ring and rotate ring as neessary to advane or retard timing. Rotating ring ounterlokwise advanes timing, lokwise retards timing. Re-tighten srews seurely. 15. Reassemble and rehek timing. 16. Install drive belt. Cheking Ignition Timing (With Timing Oeal)-Continued Fig. 24-Cheking Timing ) J

135 Eletrial System 40 Lighting System 15-1 PRINCIPLE OF OPERATION Group 15 LIGHTING SYSTEM ( A-Alternator Stator '---, ~Llght Swith ( -80,000) C-Dimmer Swith D-Brake Light Swith E-Headlight F -Speedometer Light G-Tahometer Light H-Coolant Gauge Light I -Brake and Taillight Fig. 1-Components of Snowmobile Lighting System If The lighting system on John Deere 340 and 440 Cylone and Uquifire onsists of an alternator-stator (A, Fig. 1), light swith (8), dimmer swith (C), brake light swith (D), headlight(e), speedometer light (F), tahometer light (G), oolant gauge light (H), (Uquifire only) and a ombination brake and taillight (I). The flywheel ontains a speial flexible magnet whih revolves around the alternator-stator. Current is generated in the twelve poles of the stator plate, nine of whih supply power for the lighting system and battery harging and three supply power for the ignition system. On equipped with eletri start, the AC urrent generated by the alternator-stator is retified to DC urrent by a diode to make batter~ harging possible. A light swith mounted on the instrument panel (Serial No. -80,000) swithes the lights "on" and "oft". A brake light swith swithes the brake light "on" when the brake is applied. See Group 20 of this setion for testing and repair of battery harging system.

136 40 Eletrial System 15-2 Lighting System TESTING Testing Alternator With a Voltmeter All (Serial No. 55,001- ) Blak WIRING HARNESS TO ENGINE M18363N WIRING HARNESS TO TAILLIGHT Fig. 2-Testing Alternator With A Voltmeter The following tests are designed to isolate the ause of trouble in the lighting system. A omplete guide for diagnosing malfuntions appears in Group 5 of this setion. Visually inspet all wiring, ouplers and terminals prior to testing to be ertain they are not at fault. Also, hek for burned out light bulbs. Testing Alternator System With an AC Voltmeter 1. Connet AC voltmeter to the brown and blak leads at the terminal blok, Fig. 2. Disonnet yellow voltage regulator lead from terminal blok. 2. Start and run the engine at approximately 4000 rpm. The AC voltmeter should indiate 40 to 70 volts. If the stator does not produe the voltage indiated, then it must be replaed. IMPORTANT: The wiring harness oupler must be onneted to the engine oupler when testing at the terminal blok. The engine will run with the harness plug disonneted but CANNOT BE STOPPED. With the wiring harness oupled to the engine, the engine an be stopped with the key swith or emergeny stop swith.

137 Eletrial System Lighting System ( Testing Headlight Dimmer Swith All (Serial No. 55,001- ) VOLTAGE REGULATOR Blak --=::::::::~~ WIRING HARNESS TO ENGINE M18J64 N Fig. 3-Testing Headlight Dimmer Swith WIRING HARNESS TO TAILLIGHT Test headlight dimmer swith as follows: 1. Disonnet the green, pink, and yellow lead from the terminal blok as shown in Fig Connet the leads of a ontinuity test light to the green and yellow wires. 3. With the swith in the low beam position, test light should light. 4. With the lead from the test light still onneted to the yellow wire, onnet the other lead of the test light to the pink wire. 5. With the swith in the high beam position, ontinuity light should light. If swith does not funtion properly, replae it.

138 40 Eletrial System 15-4 Lighting System Testing Light Swith All (Serial No. 55,001-80,000) CONTINUITY WITH LIGHT SWITCH " ON" NO CONTINUITY WITH LIGHT SWITCH "OFF" VOLTAGE REGULATOR B1ak --=~~\\\) WIRING HARNESS TO ENGINE M18365N WIRING HARNESS TO TAILLIGHT Fig. 4-Testing Light Swith Test the light swith as follows: 1. Disonnet the yellow and brown wire from the terminal blok as shown in Fig Connet the leads of the ontinuity test light aross the two wires. 3. With light swith in the "ON" position, test light should light. With swith "OFF", test light should not light. Replae swith if determined faulty. Litho in U. S.A.

139 SM-21GB (Aug-77) Eletrial System Lighting System r Testing Brake Light Swith All (Serial No. 55,001- ) CONTINU ITY WITH BRA KE IION ti 'N O CONTINUITY WITH BRAKE "OFF" VOLTAGE REGULATOR Blak --=:~ij)~ WIRING HARNESS TO ENGINE M18366N WIRING HARNESS TO TAILLIGHT Fig. 5-Testing Brake Light Swith Test the brake light swith as follows: 1. Disonnet the tan and brown wires from terminal blok, Fig Connet leads of ontinuity test light to the tan and brown wires. 3. With brake "ON ", test light should light. With brake "OFF" test light should not light. Replae brake swith if it does not funtion properly. Litho in U. SA

140 Eletrial System Lighting System SM-2108 (Aug-77) Testing Engine Kill Swith 1976 (Serial No. 55,001-70,000) ) WITH IGNITION SWITCH "ON" CONTI NU ITY WITH KILL SWITCH "OFF" WITH IGNITION SWITCH "ON" - NO CONTINUITY WITH KILL SWITCH "ON" VOLTAGE REGULATOR Blak --=:~foj\~ WIRING HARNESS TO ENGINE M18367N WIRING HARNESS TO TAILLIGHT 1. Disonnet the white and blak wires leading to the terminal blok, Fig Connet the test leads of a ontinuity light to the white and blak wires. Fig. 6-Testing Engine Kill Swith 3. Turn the ignition swith to the "ON" position. 4. With the kill swith in the "OFF" position test light should light. Test light should not light with the kill swith in the "ON" position....j NOTE: Both white wires have been removed from the terminal board on 1977 (Serial No. 70,001- ). This is also true on all 1976 (Serial No. 55,001-70,000) that have been modified under Modifiation Program 280. See kill swith and ignition swith tests on page Replae kill swith if defetive. --- Litho in U.S.A

141 , I Testing Ignition Swith 1976 (Serial No. 55,001-70,000) Eletrial System Lighting System WITH KILL SWITCH "OFF" - CONTINUITY WITH IGNITION SWITCH "OFF" WITH KILL SWITCH "OFF" - NO CONTINUITY WITH IGNITION SWITCH VOLTAGE REGULATOR Blak WIRING HARNESS TO ENGINE M18 J 68N WIRING HARNES S TO TAILLIGHT Fig. 7- Testing Ignition Swith 1. Disonnet the white and blak wires leading to the terminal blok, Fig Connet the test leads of a ontinuity light to the white and blak wires. 3. Plae the engine kill swith in the "OFF" position. 4. With the ignition swith in the "OFF" position, test light should light. NOTE: Both white wires have been removed from the terminal board on 1977 (Serial No. 70,001- ). This is also true on all 1976 (Serial No. 55,001-70,000) that have been modified under Modifiation Program 280. See kill swith and ignition swith tests on page

142 40 Eletrial System 15-8 Lighting System Testing Ignition and Kill Swithes 1977 (Serial No. 70,001- ) J -... Fig. 8-Testing Ignition and Kill Swithes 1. Disonnet the white and blak wires between the eletroni pak and the ignition and kill swithes. These are the two wires that are taped together. 2. Connet the test leads of a ontinuity light to the white wire and ground, Fig Turn the ignition swith to the "ON" position. 4. With the kill swith in the "OFF" position, test light should light. Test light should not light with the kill swith in the "ON" position. 5. Plae the kill swith in the "OFF" position. 6. With the ignition swith in the "OFF" position, test light should light. Litho in U.S.A

143 Eletrial System 40 Lighting System 15-9 REPLACING ALTERNATOR STATOR Remove flywheel retaining nut, and flywheel using JDM-64-1 Flywheel Holding Tool and JDM-9 Flywheel Puller. Remove four srews seuring alternator stator (A, Fig. 9), to trigger assembly (8). Disonnet alternator stator leads from engine oupler so that the wires will pass through the rubber grommet loated between the rankase halves. A- Alternator Stator B-Trigger Assembly Fig. 9-Replaing Alternator Stator AIMING HEADLIGHT 25' (7.6 m) F 27-1/4" (69.2 em) M17621 Fig. 1 a-aiming Snowmobile Headlight Position snowmobile on a flat surfae with the headlight 25 feet (7.6 m) from a vertial surfae. With an operator on the seat and the headlight on high beam, the light beam enterline should be straight ahead of the mahine and inhes (69.2 m) above the ground level, Fig. 10.

144 40 Eletrial System Lighting System ADJUSTING HEADLIGHT Adjust headlight to the above speifiations by turning the srews 1, 2, or 3, Fig. 10, loated around the headlight either lokwise or ounterlokwise. 1. Turning these two srews, Fig. 11, lokwise lowers the light beam and turning them ounterlokwise raises the light beam. 2. Turning this srew lokwise moves the light beam to the left (viewed from operator's position). 3. Turning this srew lokwise moves the light beam to the right (viewed from operator's position). NOTE: When making adjustments in Steps 2 and 3, it will be neessary to adjust the opposite srew by turning it ounterlokwise. Fig. 11-Adjusting Headlight

145 Eletrial System 40 Eletri Start Kit 20-1 r PRINCIPLE OF OPERATION Group 20 ELECTRIC START KIT ( f A-Battery B-Solenoid C-Starter Motor D-Diode (Retifier) The eletri start kit, Fig. 1, onsists of a 12-volt battery (A), starter solenoid (B), startet motor (C), diode (D) and iruit breaker (E). Battery box (F), wiring harness (G), and battery ables (H) are also inluded. When the ignition swith is turned to the "START" position, battery urrent is direted to the starter solenoid. This ativates the solenoid whih onnets the battery diretly to the starter motor. As the starter motor begins to rotate, the Bendix type drive moves into mesh with the flywheel ring gear and rotates the rankshaft. Fig. 1-Eletri Start Components E-Ciruit Breaker F -Battery Box G-Wiring Harness H-Battery Cables One the engine is started, the alternator-stator within the flywheel generates alternating urrent. This alternating urrent is hanged to diret urrent through a diode. The diret urrent reharges the battery. A iruit breaker protets the system from short iruits or eletrial overloads. The iruit breaker resets automatially after opening. See "Wiring Diagram" and "Diagnosing Malfuntions" in Group 5 of this setion.

146 40 Eletrial System 20-2 Eletri Start Kit PRINCIPLE OF OPERATION-Continued AL TER NATOR STATOR DIODE (RECTIFIER) VOLTAGE REGULATOR '--..,..--' LIGHT SWITCH BATTERY LIGHTS I M18J72N The voltage regulator, Fig. 2, limits the amount of voltage available for either harging the battery (on eletri start models) or operating the lights. The lighting system operates entirely on AC urrent supplied by the 9 poles of the alternator stator. The battery is harged with DC urrent (AC voltage retified by one diode). On 1975 models the lights ould be operated without the engine running. On 1976 and 1977 models the engine must be running for the lights to operate. Fig. 2-Snowmobile Lighting and Charging System

147 Eletrial System 40 Eletri Start Kit 20-3 Battery All plates of like harge are interonneted so that the aumulative harges are present at the positive and negative battery terminals. (.. r A-Manifold Vent B-Disharge Tube Connetion Fig. 3-John Deere Snowmobile Battery The 12-volt, 32-amp-hr. storage battery, Fig. 3, is of the lead-aid variety. Lead is used in the onstrution of the ell plates and a sulfuri aid solution serves as the eletrolyte. The 12-volt battery has a hard rubber ase with six individual ells. Eah ell ontains a speifi number of sets of negative and positive plates. As a battery disharges and the energy is not replenished, the sulfuri aid is withdrawn from the eletrolyte and the lead sulfate deposits build up on the plates. This auses the speifi gravity of the eletrolyte to diminish. Charging the battery reverses the hemial reation, restoring the eletrolyte to its original potential. IMPORTANT: A disharged battery will freeze and damage the battery. Always keep battery fully harged when used in sub-zero weather. John Deere snowmobile batteries feature a manifold vent system, (A, Fig. 3). This system vents all six ells into a disharge tube (8) whih extends below the snowmobile pan. The six fill aps are not vented as in a onventional battery. The battery base also has a tube extending below the pan to disharge water or aid whih might aumulate in this area. Litho in U. SA

148 40 Eletrial System 20-4 Eletri Start Kit TESTING Testing Battery Cheking Battery Voltage With a battery in good ondition, eah ell ontributes approximately 1.95 to 2.0B volts. If battery harge is low and less than 0.05 volt differene is noted between the highest and lowest ells, the battery may be reharged. If the differene is more than 0.05 volts, this ould indiate a raked plate or other damage whih ould all for replaement of the battery. There are two methods of testing battery apaity. Battery eletrolyte temperature should be at or near BO F for these tests. ) Before making either of the two following tests, first hek eletrolyte level in battery. Add water if neessary. If water is added, be sure it is thoroughly mixed with the underlying eletrolyte by harging. Battery voltage should be 11.5 to 12.6 volts before testing. A-Float Must Be Free B-Take a Reading at Eye Level Fig. 4-Testing Speifi Gravity Cheking Speifi Gravity To determine whether the battery is apable of meeting the requirements of the starter motor, it is neessary to dupliate operating onditions by subjeting the battery to a load test. To obtain a true test, the battery should be at least 75 perent harged. This an be determined by taking a hydrometer reading, Fig. 4. The following table illustrates typial ranges of speifi gravity (amount of unused sulfuri aid remaining in the solution) for a ell in various states of harge, with respet to its ability to rank the engine at BO F. Initial full -harge speifi gravity is either or 1.2BO. Using the first method, rank the engine for 15 seonds with the starter motor and measure the battery voltage. If voltage is less than 9.6 volts at the end of 15 seonds, replae battery. As a seond method, use high-rate disharge test equipment, Fig. 5. Disharge the battery (A, Fig. 5) by means of a heavy-duty arbon pile (B) at a rate of 3 times the ampere-hour apaity. Follow equipment manufaturer's reommendations for testing. If after 15 seonds the battery voltage is less than 9.0 volts, the battery fails to meet the load test, indiating loss of apaity or internal short iruits. Any battery that passes the load test is a good battery and an be relied upon to fulfill the requirements of the starter motor under normal onditions. - Speifi Gravity to 1.2BO to to to to to Capaity 100% 75% 50% 25% Very little useful apaity Disharged A-Battery B-Carbon Pile Fig. 5-Testing Battery Capaity

149 Eletrial System 40 Eletri Start Kit 20-5 ( Testing Starter If starter fails to rank engine or ranks very slowly, make the following heks: 1. Inspet ranking iruit wiring for loose or badly orroded onnetions or damaged wiring. 2. Chek ondition of battery to be ertain battery is harged and not defetive. 3. Crank engine with reoil starter to determine if engine turns freely and is not seized. If starter still will not rank engine, starter is defetive and must be removed and disassembled for further testing. Servie on the starter motor is limited to three assemblies. These are: the armature; the end ap assembly, whih inludes the brushes and springs; and the pinion drive assembly, whih inludes the drive gear, anti-drift spring, spring up and nut. Testing Starter Magnets Chek to make sure the magnets are bonded to the housing. Chek magnets for magnetism. Testing Armature If the trouble has not yet been loated, test the armature for opens, shorts, and grounds as follows: ( A-Positive (+ ) Battery Terminal B-Heavy Jumper C-Starter Cable ( A Fig. 6-Testing Starter Operation CAUTION: Remove spark plug wires prior to making the following test. If the above heks revealed no defets and the starter still will not rank engine, remove starter able (C, Fig. 6) from the solenoid and plae a heavy jumper lead (8) from the positive (+) battery terminal (A) to the starter able end. This eliminates the ignition swith, iruit breaker and starter solenoid from the iruit. If starter ranks engine, then one of these items is defetive. A-Haksaw Blade B-Growler Fig. 7-Cheking Armature for Short Ciruits 1. SHORTS-A burned ommutator bar indiates a shorted armature. Short iruits are loated by rotating the armature in a growler (8) with a steel strip (haksaw blade) (A) held on the armature, Fig. 7. The steel strip will vibrate on the area of the short iruit. Shorts between bars are sometimes aused by brush dirt or opper between bars. Inspet for this ondition. Underut ommutator insulation 1/32-inh to eliminate these shorts. Litho in U. S.A.

150 Eletrial System Eletri Start Kit A-Flashlight Tester C-Armature Core B-Commutator Fig. B-Cheking Armature for Grounds 2. GROUNDS-Grounds in the armature an be deteted by use of a test light (A) and prods. If the lamp lights when one test prod is plaed on the ommutator (8) and the other prod on the armature ore (C) or shaft, the armature is grounded, Fig OPENS-Inspet for loose onnnetions at the points where the ondutors are joined to the ommutator (8). Poor onnetions ause aring and burning of the ommutator. If bars are not badly burned, resolder leads in riser bars. If armature (C) heks good on the above test, but the ommutator (8) is worn, dirty, out of round, or has high insulation, turn down the ommutator and underut insulation 1/32-inh. If armature is defetive, replae armature. Testing Starter Solenoid The solenoid is a sealed magnet swith and annot be repaired. If testing reveals a defetive unit, it must be replaed. Remove and insulate able from starter terminal. Connet test light aross two large terminals, Fig. 9, of starter solenoid. With a jumper lead (8), onnet positive (+ ) battery post (A) to small term inal (C) on solenoid, Fig. 9. If in good ondition, the solenoid plunger will snap in, light the test lamp, and hold until the jumper is removed. A-Positive Battery Terminal B-Heavy Jumper Lead Fig. 9-Testing Starter Solenoid Testing Ciruit Breaker A-Ciruit Breaker Fig. 10- Testing Ciruit Breaker C-Small Terminal D-Large Terminals B-Flashlight Tester Test light (8, Fig. 10) must light when onneted aross iruit breaker (A) terminals. If iruit breaker is found defetive, it must be replaed. The iruit breaker terminals are designated "8A T" and "AUX". Short red lead from starter solenoid must be onneted to the "BAT" terminal of iruit breaker. The iruit breaker should reset automatially after opening due to eletrial overload. ) -

151 SM-2108 (Aug-77) Eletrial System 40 Eletri Start Kit 20-7 Testing Ignition Swith OFF START POSITIONS Fig. 11-Testing Ignition Swith M18381N Lift hood and remove oupler from ignition swith. The ignition swith, Fig. 11, an be tested with a test light. Chek for ontinuity between terminals with swith plaed in eah of three positions. See Fig. 11 and hart below for orret urrent flow diagram. If swith is defetive it must be replaed. Position Closed Open OFF A & B D,C,E ON C&D A,B,E START D & E A,C,B Testing Diode (Retifier) Connet the blak test lead (C, Fig. 12) from the flashlight tester to the brown wire side of the diode (A). Connet the red lead (B) from the flashlight tester to the orange wire side of the diode. Test light should light. With the flashlight leads reversed, test light should not light. A-Diode B-Red Lead Fig. 12-Testing Diode (Retifier) Testing Charging System C-Blak Lead The alternator, whih is used to provide urrent for the lighting system, is also used to harge the battery when the snowmobile is equipped with eletri start. Refer to Group 15 of this setion for testing the AC voltage output of the alternator. If battery is not being harged properly, make the DC amperage test. h CAUTION: Blok up snowmobile trak se.. urely so engine an be run at operating speeds without danger. IMPORTANT: Do not operate engine with drive belt removed. Engine ould overspeed and ause engine and drive sheave failure. IMPORTANT: Start engine using reoil starter. 00 not start engine with eletri starter when meter is attahed or meter will be damaged. Litho in U. S.A.

152 Eletrial System Eletri Start Kit SM-2108 (Aug-77) A-Ammeter B-Leads From Ciruit Breaker Fig. 13-Testing Charging System Disonnet the two leads from the iruit breaker and attah them to a 140 Trator Ammeter (AM32296) as shown in Fig. 13. Run the engine at 6000 to 7000 rpm. DC output should be 2 to 3 amps with lights "OFF" or "ON." If not, test retifier, iruit breaker, voltage regulator, and ignition swith. Also hek ondition of wiring and onnetions.

153 Eletrial System 40 Eletri Start Kit 20-9 REPAIR Battery Removing Battery To avoid injury from a spark or short iruit, disonnet negative (-) battery able first (8, Fig. 14). Then remove rubber boot and disonnet positive (+) able (C). Ativating New Battery Ativate a new battery before installing it in snowmobile. This will prevent damage to mahine in ase eletrolyte spills. Add eletrolyte until plates are just overed. Leave ell aps off while harging. Charge at 7 amps for 30 minutes. After initial harge, do not harge battery at more than 5 amps. Charging the battery will inrease battery temperature and raise the eletrolyte level. If eletrolyte is still below the ring in the battery nek, add enough eletrolyte to fill to the bottom of the ring. Advise ustomers to add water as required. A healthy battery will on'sume about one teaspoon of water per ell eah month. A CAUTION: While harging battery, hydrogen and oxygen gases are emitted whih are very explosive. Therefore, keep open flames and sparks away from battery. A-Battery Box B-Negatlve Terminal C-Posltlve Terminal D-Hold-Down E-Hold-Down Bolt Fig. 14-Removing Battery Loosen two hold-down bolts (E, Fig. 14), unhook bolts from box and remove hold-down (D). Disonnet vent tube from battery and lift battery from box. Serviing Battery and Battery Box Good battery serviing should inlude the following items: 1. Clean battery and battery box. 2. Inspet ables and ground strap. 3. Clean terminals and ground strap onnetion. 4. Inspet hold-downs. 5. Inspet battery ase for leaks. 6. Make hydrometer test. 7. Add water if neessary. Use aution to protet snowmobile from eletrolyte damage. 8. Reharge battery if less than 75% harged. 9. Inspet ondition of battery vent tube and battery box drain tube. Litho in U. S.A.

154 40 Eletrial System Eletri Start Kit Cleaning Battery Corrosion around the battery terminals is normal. However. an aumulation of orrosion over a long period an shorten the life of the battery. Therefore. keep battery terminals as lean as possible. To lean terminals. remove battery from snowmobile. Remove all orrosion using a wire brush. Wash terminals using a solution of one part ordinary baking soda to four parts water. Do not permit leaning solution to enter battery ells. Wash entire battery. battery box and hold-down omponents with lear water. Do not get water in eletrial ouplers. Installing Battery Cheking Battery Eletrolyte Level Periodially hek the level of the eletrolyte in the battery ells. This should be done at least one a week during peak operating periods. Proper level is to the bottom of the ring (filler nek) so that the tops of the battery plates are overed. IMPORTANT: Do not overfill. Add only distilled water to the battery. If not available. be sure to use lean. soft water. Avoid water with a high mineral ontent. Never add aid to the battery unless eletrolyte is lost by spilling. To add aid to the battery will unbalane the 10 to 1 sulfuri aid-to-water ratio. Always wait until after heking speifi gravity before adding water to the battery. This will assure a true reading. If level is too low to hek speifi gravity. add water and operate system for a few minutes to mix water and eletrolyte; then hek. In freezing weather. never add water to the battery unless snowmobile will be operated for a period of time to allow mixing of the water and eletrolyte. IMPORTANT: A disharged battery will freeze and break battery ase. Always keep battery fully harged... A-Battery Box B-Negative Terminal C-Positive Terminal D-Hold-Down E-Hold-Down Bolt Fig. 15-lnstalling Battery Clean and dry battery exterior. Chek ondition of battery box rubber pads and replae if neessary. Plae battery in box (A. Fig. 15). Clean and install battery hold-down (D) and bolts (E). Tighten seurely. but not so tight rubber pads under battery are ompletely ompressed. Attah vent tube to battery. Attah positive (+ ) battery able (C) first and install rubber boot; then attah negative (- ) able (8). IMPORTANT: Be areful when attahing battery ables to prevent breaking or loosening battery terminals.

155 SM-2108 (Aug-77) Eletrial System 40 Eletri Start Kit Starter Motor (Permanent Magnet Field) ---[) " N I I I I I I I r- ----_ F M II M18386 r A-Nut B-Lok Washer C-Plain Washer D-Insulating Washer E-Thru Bolt F-Armature G-Retaining Nut H-Gear Stop Spaer I -Anti-Drift Spring J -Drive Assembly K-Mounting Braket L-Thrust Washer M-Brush and Spring Set N-Srew O-Brush Holder I P -Insulating Bushing Q-Commutator End Cap Assembly Fig. 16-Permanent Magnet Starting Motor ( r Repair to the starter is limited to the brushes (M), end ap (Q), mounting braket, armature and starter drive assembly (F). Fig. 16. Any of these parts an be replaed if found to be defetive. Fields in this starter are permanent magnets and no servie is required or possible. Any serious defet in the magnets will require a omplete starter replaement. Removing Starter Disonnet ground able from the battery. Disonnet solenoid-to-starter able from starter terminal. Remove mounting bolts seuring starter to engine and mounting braket to engine, remove starter and mounting braket. Remove mounting braket from starter. Disassembling Starter Drive N18387N'y A-Lok Nut B-Anti-Orift Spring C-Starter Assembly Fig. 17-Starter Drive D-Armature Shaft E-Orive Gear F-Spring Cap Hold drive gear (E) and unsrew lok nut (A), Fig. 17. Remove drive parts (B,C,D,F) from armature shaft.

156 Eletrial System Eletri Start Kit Disassembling Starter Replaing Brushes J '*-'>:: ~ M18388NY M18389NY, A-Ground Brush B-Insulating Brush Holder C-Input Brush D-Input Terminal A-Commutator B-Thru Bolts Fig. 18-Disassembling Starter C-Brush Springs Remove the two thru bolts (B, Fig. 18) whih hold the end ap and mounting braket to starter housing. Remove end ap arefully to avoid losing brush springs (C) whih will pop out when end ap is removed. Tap moljnting braket lightly with a hammer to free it from the housing. NOTE: Take are not to lose the thrust washer when removing mounting braket. Inspetion Clean and inspet starter drive omponents for exessive wear. Replae parts as neessary. Fig. 19-Replaing Brushes Replae brushes whenever they show any appreiable amount of wear. To replae input brush (C, Fig. 19) assembly, remove nuts and washers from terminal (D) and pull the brushes out through the inside of the ap. When assembling, plae the input brush (C) into the insulated brush holders (B). The leads from the ground brushes (A) are attahed to the metal srews whih seure the insulated brush holders to the end ap, Fig. 19. Plae these brushes in the non-insulated brush holders. Assembling Starter Inspet bearings in end ap and mounting braket. Also inspet armature shaft. If armature shaft has exessive play in bearings, replae end ap and mounting braket. It may be neessary to replae armature if bearing surfaes are worn badly. Exessive bearing play will allow armature to rub against fields. ) Clean and inspet ommutator (A, Fig. 18). If surfaes are badly grooved, true up on a lathe and underut mia. Brushes must make good ontat with ommutator. A-Retaining Clips Fig. 20-lnstalling Brushes B-Brushes The preparation of the starter end ap is the first step in the assembly of the starter. First, plae brush springs into brush holders. Then, in suession, plae eah brush (B, Fig. 20) in its respetive holder with the beveled side up. J

157 Eletrial System 40 Eletri Start Kit r Compress brush spring and plae a U-shaped retaining lip (A, Fig. 20) made of banding steel onto eah brush. ( Wipe ommutator lean with a dry loth and lubriate armature shaft with a small amount of light grease. Plae armature into end ap, Fig. 20, and remove U-shaped brush retaining lips. Plae starter housing over armature while exerting down pressure on the armature. This prevents brush springs from pushing armature up and away from end ap. If this ours, reload brushes into end ap and reassemble. A-Index Marks B- Housing C-Mounting Braket Fig. 22-Mounting Braket Index Marks M18392NY Plae steel spaer washer (A, Fig. 21) onto armature shaft (8) and install mounting braket (C) over armature shaft. NOTE: Align marks (A) on mounting braket (e) with mark on housing (B). Insert thru bolts and tighten them to 70 in-ibs (7.9 Nm) torque. r A-Steel Spaer Washer B-Armature C-Housing D-Index Marks E-End Caps Fig. 21-Aligning Index Marks Align housing (C, Fig. 21) with end ap (E) using the index marks (D) on ap and housing. NOTE: The starter housing has a mark and an indentation on the inside whih must fit into the two indentures on the drive end ap. A-Anti-Drift Spring B-Lok Nut C-Spring Cup D-Drive Gear E-Thru Bolt Fig. 23-lnstal/ing Drive Assembly Install starter drive gear (0, Fig. 23), anti-drift spring (A), spring up (C), and lok nut on armature shaft. Torque lok nut to 45 to 50 in-ibs (5 to 5.6 Nm). Install starter in snowmobile, attah solenoid to starter wire, and onnet battery ground able to the battery.

158 Eletrial System Eletri Start Kit J -)

159 Eletrial System 40 Speifiations 25-1 SPECIFICATIONS Group 25 SPECIFICATIONS Item Spark Plug* Ignition Timing Dimension Ignition Coils: Primary Resistane Seondary Resistane Alternator: Alternator Resistane Alternator Output Starter Motor: Armature End Play Speifiation Champion ON-1 ** Wio CDI inh 20 BTDC 0.2 ohms 225 to 275 ohms 0.1 to 0.3 ohms 120 Watts to inh (0.127 to mm) *Spark plugs are gapped at 0.020" (0.508 mm) at the fatory. Do not regap plugs. When plug gap reahes 0.060" (1.52 mm) replae them. **For sustained high-speed running. use a surfae-gap plug ON-19V or N-19V. TORQUE FOR HARDWARE Item Torque - Starter Thru Bolts in-ibs (7.90 Nm)

160 40 Eletrial System 25-2 Speifiations LIGHT BULB CHART John Deere Loation Size Part Number Headlight 12-volt AM53887 J Brake-Taillight 12-volt AM52619 Speedometer Light 12-volt AM52847 Tahometer Light 12-volt AM52847 Coolant Gauge Light 12-volt AT22970 ~

161 Power Train 50 General Information 5-1 CONTENTS Setion 50 POWER TRAIN Group 5 GENERAL INFORMATION '.. r Page GROUP 5 - GENERAL INFORMATION Priniple of Operation Drive Sheave Driven Sheave Chain Case and Drive Chain Brakes Cluthing Reommendations Diagnosing Malfuntions GROUP 10 - JOHN DEERE (COMET) DRIVE SHEAVE General Information Disassembly and Repair Removing Drive Sheave Disassembling Drive Sheave Inspetion Inspeting Bushings Inspeting Guide Buttons and Rollers Inspeting Roller Arms Inspeting Fixed and Movable Faes Assembly Lubriating Drive Sheave Assembling Drive Sheave Installing Drive Sheave GROUP 15 - JOHN DEERE DRIVEN SHEAVE General Information Disassembly and Repair Removing Driven Sheave Disassembling Driven Sheave... : Inspetion and Repair Assembly Pretensioning Driven Sheave Assembling Driven Sheave Installing Driven Sheave GROUP 20 - DRIVE BELT General Information Removing and Installing Drive Belt Aligning Drive Belt Analysis Page GROUP 25 - CHAIN' CASE, SECONDARY SHAFT, AND DRIVE SHAFT General Information Final Drive Ratios Disassembly Removing Drive Chain and Sprokets Removing Seondary Shaft and Brake Disk Removing Drive Shaft Removing Chain Case Inspetion Inspeting Seondary Shaft ~6 Inspeting Drive Chain, Sprokets and Chain Tensioners Inspeting Drive Shaft Assembly Inspeting Chain Case Assembly Installing Chain Case Installing Drive Shaft Aligning Drive Chain and Sprokets Installing Seondary Shaft and Brake Disk GROUP MECHANICAL DISK BRAKE General Information Disassembly and Repair Removing Brake Disk Inspetion Assembly Adjustment GROUP 35 - SPECIFICATIONS Speifiations Torque for Hardware

162 Train General Information SM-21GB (Aug-77) PRINCIPLE OF OPERATION John Deere (Comet) 102C Drive Sheave The drive sheave is mounted on the engine rankshaft and funtions as a entrifugally-operated luth and variator. J A-Oil Level B-Chain Case C-Trak Drive Shaft D-Drive Chain E-Drive Sheave F -Drive Belt (Low-Speed Position) G-Drive Belt (High-Speed Position) H-Driven Sheave I -Seondary Shaft J-Trak When stopped or at idle speed, the sides of the sheave do not ontat the drive belt, thus providing a de-luthed position. Inreasing engine speed auses the entrifugallyatuated arms, Fig. 2, in the movable fae to swing out against the rollers of the spider on the fixed fae. \ This ation fores the sheave halves together, en- J gaging the drive belt with the sheave and starts the snowmobile moving. When the engine reahes top rpm, the sheave halves are as lose together as possible. The drive belt ontinues to ride out as engine speed inreases and the sheave halves ome together. This ation provides a smooth transition from slow to fast snowmobile travel speed. Fig. 1-Power Train The power train for 340 and 440 Cylone and Liquifire onsists of a drive sheave (E), Fig. 1, drive belt (F), driven sheave (H), disk brake, seondary shaft (I), hain ase (8), sprokets, drive hain (0), and drive shaft (C). ) 1' A-Idle Speed B-Moderate Speed C-High Speed D-Drive Belt Fig. 2-John Deere (Comet) 102C Drive Sheave Operation J Litho in U. S.A.

163 Power Train General Information John Deere Driven Sheave M19245N! : ( r A-Low-Speed Position B-High-Speed Position C-Drive Sheave D-Drive Belt E-Driven Sheave Fig. 3-Driven Sheave Operation The drive sheave (C, Fig. 3) is spring-loaded in the low-speed position (A). As the speed of the drive sheave (C) inreases and the drive belt (D) rides out on the drive sheave (C), the driven sheave (E) opens against spring tension, allowing the drive belt to ride deeper in the driven sheave (E). The driven sheave works with the drive sheave to provide a smooth transition from a low speed ratio to a high speed ratio as engine speed inreases. The driven sheave (A, Fig. 4) does more than at as a take-up for the ation of the drive sheave (8). The driven sheave is also "torque-sensitive". The driven sheave rides on the am braket (H) as it opens to obtain high speed position. Normal rotational fore on the am braket (H) works to keep the driven sheave (E, Fig. 3) in the low speed position. If an inreased load or high torque requirement ours (suh as limbing a steep hill) after the snowmobile is up to speed, the am braket (H, Fig. 4) in the driven sheave (E, Fig. 3) fores the sheave halves together, thus obtaining a slower travel speed while maintaining high engine rpm for inreased torque. A-Driven Sheave B-Drive Sheave C-High Engine RPM D-High Engine RPM E-Low Engine RPM M20984 F -Low Output Speed G-High Output Speed H-Cam Braket I -Medium Output Speed Fig. 4-Torque Sensitive Driven Sheave In Fig. 4, the top and bottom drawings have the same drive belt position. However, inreased speed of the engine in the lower drawing, auses a differene in the output speed of the driven sheave. The drive and driven sheaves are mathed to the engine and to eah other to provide smooth luthing speed and torque-sensitive operation. Chain Case and Drive Chain The fully-enlosed hain ase onsists of a silent hain, two sprokets and spring-loaded tensioners. The hain and sprokets are oil-bath lubriated. NOTE: 1976 (Serial No. 50,001-70,000) have two spring-loaded hain tensioners (Serial No. 70,001 and up) have a single spring-loaded tensioner. The spring-loaded tensioners maintain proper hain tension when both aelerating and deelerating. No hain tension adjustment is neessary.

164 50 Power Train 5-4 General Information Brakes CLUTCHING RECOMMENDATIONS To obtain and provide proper governed engine speed proeed as follows: 1. Be sure proper gear ratios and luthing is being used for the altitude at whih the snowmobile will operate. See harts on page , through Change arburetor as required. See page Add shorter spaer between 39-tooth gear and shaft on 440 Cylone and Liquifire. J A-Disk 8--Seondary Shaft C-Brake Arm D-Brake Cable E-Puk F-Puk G-Chain Case Fig. 5-Mehanial Disk Brake The mehanial disk brake (A, Fig. 5) operates on the seondary shaft (B) and is atuated by the brake able (D). When the brake is applied the am on the brake arm (C) moves two pins in against the brake puk (E). The puk moves the brake disk (A) against a seond puk (F) in the hain ase (G), providing positive braking. 4. For altitudes above 6000 feet ( m), install 38 degree am in seondary sheave on 440 Cylone and Liquifire (Serial No. 70,001 and up). 5. On 440 Cylone (Serial No. 55,001 to 70,000) hange the spring in the primary drive sheave from blak (M65684) to silver (M66541)..J

165 SM-2108 (Aug-77) Power Train 50 General Information 5-5 Cluthing Reommendations - Cylone and Liquifire (Serial No. 55,001-70,000) ALTITUDE - SEA LEVEL TO 6,000 FEET Snowmobile Model Cluth Engagement (rpm) Governed Speed (rpm) Spaers in Primary *Gearing Primary Cluth Sprokets Cluth Spring Primary Cluth Arm Kit Spring and Position in Seondary Seondary Cluth Cluth Cam **Chain 340 Cylone tooth Two Silver 39 tooth AM53949 Blue Pith No. 2 M Cylone tooth Two Blak 40 tooth AM53949 Blue Pith No. 2 M Liquifire tooth Two Silver 39 tooth AM53949 Blue Pith No. 2 M Liquifire tooth Two Blak 40 tooth AM54279 Blue Pith No. 2 M66384 *21 tooth gear - M tooth gear - M tooth gear - M tooth gear - M66323 **66 pith hain - M pith hain - M66321 Gear Ratios 1.67:1 - With 24/40 gears and 68 pith hain 1.86:1 - With 21/39 gears and 66 pith hain

166 50 Power Train 5-6 General Information Cluthing Reommendations - Cylone and Liquifire (Serial No. 55,001-70,000) ALTITUDE 6,000 TO 12,000 FEET Cluth Governed Spaers in Primary Snowmobile Engagement Speed *Gearing Primary Cluth Model (rpm) (rpm) Sprokets Cluth Spring 340 Cylone tooth One Silver 42 tooth 440 Cylone tooth One Silver 39 tooth 340 Liquifire tooth One Silver 35 tooth 440 Liquifire tooth None Blak 39 tooth Primary Cluth Arm Kit AM54287 AM54279 AM54287 AM54289 Spring and Position in Seondary Seondary Cluth Cluth Cam **Chain Blue Pith No. 2 M66384 Blue Pith No. 2 M66384 Blue Pith No. 2 M66348 Blue Pith No. 2 M66348 * 17 tooth Gear - M tooth Gear - M tooth Gear - M65B09 39 tooth Gear - M tooth Gear - M65B10 * *62 pith hain - M pith hain - M66122 Gear Ratios 1.86:1 - With 21/39 gears and 66 pith hain 2.06:1 - With 17/35 gears and 62 pith hain 2.47:1 - With 17/42 gears and 66 pith hain NOTE: The 440 Cylone and Liquifire (Serial No. 55,001 to 70,000) are equipped with a long spaer (M66346) between the 40-tooth gear (M66323) and shaft as standard equipment. When using the 39-tooth gear (M65693) a shorter spaer (M66133) must be used.

167 Power Train 50 General Information 5-7 r Cluthing Reommendations-340 Cylone Snowmobile (Serial No. 70,001- ) Cluth Governed Engagement Speed Altitude (rpm) (rpm) ' Gearing Sprokets Spring Spaers in Primary Primary Position in Primary Cluth Cluth Seondary Cluth Spring Arm Kit Cluth Seondary Cluth Cam " Chain Sea Level Tooth 39 Tooth One Silver AM54279 No M Pith Tooth 39 Tooth One Silver AM54279 No M Pith Tooth 35 Tooth One Silver AM53949 No M Pith Tooth 35 Tooth One Silver AM53949 No M Pith Tooth 42 Tooth One Silver AM54288 No M Pith * 17 tooth gear - M tooth gear - M tooth gear - M tooth gear - M tooth gear - M65810 ** 62 pith hain - M pith hain - M66122 Gear Ratios 1.86:1 With 21/39 gears and 66 pith hain 2.06:1 With 17/35 gears and 62 pith hain 2.47:1 With 17/42 gears and 66 pith hain Litho in U. S.A.

168 50 Power Train 5-8 General Information SM-2108 (Aug-77) Cluthing Reommendations Cylone Snowmobile (Serial No. 70,001- ) Cluth Governed Engagement Speed Altitude (rpm) (rpm) -Gearing Sprokets Spring Spaers in Primary Primary Position in Primary Cluth Cluth Seondary Cluth Spring Arm Kit Cluth Seondary Cluth Cam --Chain Sea Level Tooth 40 Tooth Two Silver AM54279 No M Pith Tooth 40 Tooth Two Silver AM54279 No M Pith Tooth 39 Tooth 21 Tooth 39 Tooth One One Silver AM54279 Silver AM54279 No. 2 No M M Pith 66 Pith ) Tooth 35 Tooth One Silver AM53949 No M Pith * 17 tooth gear - M tooth gear - M tooth gear - M tooth gear - M tooth gear - M tooth gear - M66323 ** 62 pith hain - M pith hain - M pith hain - M66321 Gear Ratios 1.67:1 With 24/40 gears and 68 pith hain 1.86:1 With 21/39 gears and 66 pith hain 2.06:1 With 17/35 gears and 62 pith hain

169 Power Train 50 General Information 5-9 r Cluthing Reommendations Liquifire Snowmobile (Serial No. 70,001- ) Cluth Governed Engagement Speed Altitude (rpm) (rpm) ' Gearing Sprokets Spring Spaers in Primary Primary Position in Primary Cluth Cluth Seondary Cluth Spring Arm Kit Cluth Seondary Cluth Cam -'Chain Sea Level Tooth 39 Tooth One Silver AM54279 No M Pith Tooth 39 Tooth One Silver AM54279 No M Pith Tooth 39 Tooth One Silver AM54279 No M Pith Tooth 39 Tooth One Silver AM53949 No M Pith Tooth 35 Tooth One Silver AM54288 No M Pith * 17 tooth gear - M tooth gear - M tooth gear - M65B09 39 tooth gear - M65693 Gear Ratios 1.86:1 With 21/39 gears and 66 pith hain 2.06:1 With 17/35 gears and 62 pith hain * * 62 pith hain - M pith hain - M66122 Litho in U.S.A

170 50 Power Train 5-10 Generallnformation SM-2108 (Aug-77) Cluth Governed Engagement Speed Altitude (rpm) (rpm) Cluthing Reommendations Liquifire Snowmobile (Serial No. 70,001- ) 'Gearing Sprokets Spring Spaers in Primary Primary Position in Primary Cluth Cluth Seondary Cluth Spring Arm Kit Cluth Seondary Cluth Cam "Chain J Sea Level Tooth 40 Tooth Two Blak AM54279 No M Pith Tooth 40 Tooth Two Blak AM54279 No M Pith Tooth 40 Tooth Two Silver AM54279 No M Pith Tooth 40 Tooth Two Silver AM53949 No M Pith Tooth 35 Tooth One Blak AM54288 No M Pith * 17 tooth gear - M tooth gear - M tooth gear - M tooth gear - M66323 Gear Ratios 1.67:1 With 24/40 gears and 68 pith hain 2.06:1 With 17/35 gears and 62 pith hain * * 62 pith hain - M pith hain - M66321 ).J

171 Power Train General Information r DIAGNOSING MALFUNCTIONS John Deere (Comet) 102C Drive Sheave Drive Belt Glazed Exessive slippage. Sheave Cluthing at Too Low rpm Spring weak or broken. Oil on sheave surfaes. r r r Inorret roller arm (weights) being used. Sheave Cluthing at Too High rpm Wrong spring. Drive sheave dirty internally. Worn spider buttons. Cluth Stiking Mold release from belt builds up on enter post and movable fae an not slide properly. Errati Shifting Oil or grease on drive or driven sheaves. Drive Belt Not Operating Smoothly in Drive Sheave Sheave faes rough, grooved, pitted or sored. Drive belt defetive. John Deere Driven Sheave Driven Sheave Not Opening Properly Nylon ramp buttons worn. Ramp on movable fae damaged. Moveable sheave half binding on fixed half. Inorret spring installed. Spring pretensioned improperly. Driven Sheave Opening Too Easily Spring weak or broken. Spring pretensioned improperly. Drive Belt Uneven Belt Wear Sheaves misaligned. Engine mounts loose. Belt Worn Narrow in One Setion Exessive slippage aused by stuk trak. Belt Too Tight at Idle Speed Engine idle set too fast. Inorret distane between sheaves. Inorret belt length. Belt Edge Cord Breakage Sheaves misaligned. Brake Brake Not Holding Properly Brake able out of adjustment. Brake puks worn. Brake puks oil-saturated. Key sheared on brake disk. Brake Not Releasing Properly Return spring weak or broken. Brake lever bent or damaged ausing binding. Chain Case Leaking Chain Case Assembly Gaskets on drive shaft bearing flangettes or seondary shaft bearing flangettes damaged. a-ring on drive shaft or seondary shaft bearings damaged. Chain ase raked or broken. Rapid Chain and Sproket Wear Insuffiient oil in hain ase. Sprokets out of alignment due to improper assembly. Chain tension blok spring broken.

172 50 Power Train 5-12 Generallnformation SM-21OB (Aug-77) J Litho in U.S.A

173 Power Train John Deere (Comet) Drive Sheave Group 10 JOHN DEERE (COMET) DRIVE SHEAVE GENERAL INFORMATION The drive sheave is "mathed" to the driven sheave and to the engine to provide smooth operation. It is important to use the proper omponents for repair. The drive sheave provides belt engagement as shown in the harts on pages through at altitudes from sea level to 12,000 feet ( m). r Fig. 1-John Deere (Comet) 102C Drive Sheave The entrifugally-operated drive sheave, Fig. 1, is both a luth and variator. See Group 5 of this setion for "Priniple of Operation". IMPORTANT: Never operate the engine with the drive belt removed. The engine ould overspeed and ause possible engine and drive sheave failure. A CAUTION: To hek drive sheave operation, use a dynamometer or blok up the snowmobile seurely, so the trak an be run at operating speeds without danger. Group 5 of this setion ontains "Diagnosing Malfuntions" to help orret problems assoiated with the drive sheave. ( (

174 Power Train John Deere (Comet) Drive Sheave SM-21GB (Aug-77) DISASSEMBLY AND REPAIR J M20986 A- Fixed Fae Sheave B- Bronze Bushing C- Washers (6 used) O-Roller Arm (3 used) E-Spring Pin (3 used) F -Pivot Pin (3 used) G-Movable Fae Sheave H-Spaing Washer I -Button (6 used) J -Spider K-Spring L -Retaining Cap Srew with Lok Washer M-Cap Srew (6 used) N-Pilot Washer O-Cover Plate with Bushing P- Washers (6 used) Q-Roller (3 used) R-Pin (3 used) Fig. 2-Exploded View of John Deere (Comet) 102C Drive Sheave Removing Drive Sheave Raise hood and drive belt guard. Remove drive belt and knok-out plug from side of pan. Use JDM-41-2 Compressor ring (8, Fig. 3) to ompress movable fae to expose ross hole (A) in hub. ) Fig. 4-JDM-41-4 Two-Piee Nut Installed on Hub A-Cross Hole B-JOM-41-2 Fig. 3-JDM-41-2 Compressor Ring Installed Install JDM-41-4 Two-Piee Nut, Fig. 4, around hub. Engage pins on nut in hub ross hole. Litho in U. S.A.

175 Power Train 50 John Deere (Comet) Drive Sheave 10-3 r Plae JDM-41-3 Spider Tool (A, Fig. 6) over hub with spring pins on tool engaging spider. Install JOM Hub Lok tool (8) over hub with pin of tool through ross hole in hub. A-JOM-41-4 Nut 8-JOM-12-2 Nut Wrenh Fig. 5-Removing Drive Sheave Hold nut JOM-41-4(A) with JOM-12-2 Nut Wrenh (8, Fig. 5) and remove retaining ap srew, lok washer and pilot washer. Turn JDM-41-1 Puller into hub, until drive sheave omes loose from the rankshaft. Disassembling Drive Sheave Remove JDM-41-1 Puller from hub. Remove every other srew seuring drive sheave over plate to movable fae. Remove the three remaining ap srews equally, a few turns at a time. This allows the over plate to ome off slowly and equally. Remove over plate and spring. A-JOM-41-5 Hub Lok 8-JOM-41-3 Spider Tool Fig. 7-Removing Spider From The Hub Clamp assembly very seurely into vise and install a 1/2-inh drive long handle into JOM-41-3 Spider Tool (8, Fig. 7) and turn ounterlokwise to loosen spider from the hub. Remove JOM-41-3 Spider Tool (8) and JOM-41-5 Hub Lok (A). Turn spider off the hub by hand. IMPORTANT: Remove spaer rings and movable fae. Take note of the number of spaers for installation later on. M1925SN A-JOM-41-3 Spider Tool B-JOM-41-5 Hub Lok Fig. 6-Spider Tool and Hub Lok Tool Installed

176 50 Power Train 10-4 John Deere (Comet) Drive Sheave INSPECTION Inspeting Bushings NOTE: Small dot (B) on guide buttons (A) must be positioned straight up or straight down, Fig. 9. This allows bearing surfae of guide button to math bearing surfae in movable fae. Inspeting Roller Arms J '!119255NY Fig. 8-Cover Plate and Bushing Inspet bushing and over plate, Fig. 8. If bushing is worn or damaged, replae over plate. Inspeting Guide Buttons and Rollers M192.?NY A- Spring Pin B-Pivot Pin Fig. 10-Removing Spring Pin From Pivot Pin Inspet roller arms for wear and replae as neessary. Use srewdriver to pry spring pin out as far as possible and then use side utters to remove spring pin (A, Fig. 10), from the end of the pivot pin (8). Remove pivot pin, roller and three steel washers. ) ) f ny A-Guide Button B-Dot C-Steel Washers D-Fiber Washer E-Roller Fig. 9-lnstalling Guide Buttons,]:il ~258JJy" A-Spring Pin B-Steel Washers C-Pivot Pin D-Roller Arm Inspet guide buttons (A, Fig. 9) and rollers (E) in spider. Replae if neessary. Use pliers to remove guide buttons (A). Then remove pin, roller and two washers. Plae roller in spider with a steel washer (C) on eah side of the roller. Install pin and guide buttons (A). Tap buttons gently until they are seated. Fig. 11-lnstalling Pivot Pin Install roller arm (D, Fig. 11) in movable fae with a steel washer (8) on eah side of the arm. Install pivot pin (C) from left to right. Install steel washer and NEW spring pin (A) through pivot pin (C). NOTE: 1977 Model 440 have a fiber washer (0, Fig. 9) on the thrust side of the spider.

177 SM-2108 (Aug-77) Power Train John Deere (Comet) Drive Sheave r Inspeting Fixed and Movable Faes Chek sheave faes for pitting or wear and replae as neessary. Inspet bushing of movable fae and hub of fixed fae for damage or exessive wear. Measure outside diameter of fixed fae hub and inside diameter of movable fae bushing. Maximum allowable learane is inh (0.762 mm). If learane is greater than inh (0.762 mm), replae movable fae bushing. M19261NY am m ~(~~ ~ ~~ ~..... A Disk Disk C Handle Fig. 14-Tool For Installing Movable Fae Bushing To omplete installation of bushing, use Owatonna Tool Company, Bushing, Bearing and Seal Driver Sets. Install Disk and Disk to Handle as shown in Fig. 14. This ombination will install movable fae bushing. M19259NY Fig. 12-Cuts in Movable Fae Bushing Use a haksaw blade and arefully ut through the movable fae bushing in several plaes, Fig. 12. IMPORTANT: DO NOT saw into the metal of the movable fae. This ould weaken and damage the movable fae. Remove bushing with a small old hisel and hammer. Fig. 15-lnstalling Movable Fae Bushing Use a press and ring ompressor (Fig. 15) to install bushing flush with movable fae. r M19260NY Fig. 13-Snap Ring Position of Movable Fae Bushing Install new bushing in movable fae with snap ring of bushing up as shown in Fig. 13. NOTE: Use JOM-50 Ring Compressor for trator engines to ompress snap ring when installing movable fae bushing.

178 50 Power Train 10-6 John Deere (Comet) Drive Sheave SM-21GB (Aug-77) ASSEMBLY Lubriating Drive Sheave Lubriate the drive sheave before assembly. Use Never-Seez Lubriant (PT569) or its equivalent on the following : ) 1. Roller arms and roller pins in the movable fae. 2. Guide buttons in the spider and on mating surfae of movable fae. NOTE: Use Lotite (grade A V, red) (A TL 4927) on the spider-to-hub threads. This will prevent spider from loosening while in use. Assembling Drive Sheave Fig. 17-ldentifiation Marks on Spider and Movable Fae Install spider on movable fae. Align identifiation marks on spider with identifiation marks on movable fae, Fig. 17. Proper alignment of these marks is neessary for proper balane of the drive sheave. ) ) Fig. 16-lnstalling Spaer Rings Install movable fae over fixed fae hub and plae required number of spaer rings, Fig. 16, on hub. M192 5J!Y A-Fixed Sheave B-Movable Sheave Fig. 18-lnstalling Spider and Movable Fae With one hand, grasp the spider assembly and movable sheave (8, Fig. 18). Hold the fixed sheave (A) and with the other hand turn the spider and movable sheave lokwise to start the threads of the spider onto the hub post. Continue to tighten the assembly as far as possible by hand. ) Litho in U. S.A.

179 Power Train John Deere (Comet) Drive Sheave r Installing Drive Sheave Clean rankshaft tapered surfae and plae drive sheave on rankshaft. ( ( A-JOM-41-5 Hub Lok Fig. 19-Tightening Spider to the Hub B-JOM-41-3 Spider Tool Plae JOM-41-3 Spider Tool (8, Fig. 19) over hub with spring pins on tool engaging spider. Install JOM Hub Lok (A) over hub. Clamp assembly very seurely into vise. Install a 1/2-inh drive long handle in JOM-41-3 Spider Tool and turn lokwise to tighten spider to hub. Remove JOM-41-3 Spider Tool (8) and JOM-41-5 Hub Lok (A). Install spring and over plate. Tighten the six srews evenly and seurely. A-JOM-41-4 Two-Piee Nut 8-JOM-41-2 Compressor Ring Fig. 20-lnstalling Drive Sheave C-JOM-12-2 Nut Wrenh Use JOM-41-2 Compressor Ring (8, Fig. 20) and ompress movable fae to expose ross hole in hub. Install JOM Two-Piee Nut (A) and hold with JOM-12-2 Nut Wrenh (C). Install lok washer and pilot washer onto retaining ap srew. Install and tighten retaining ap srew to 50 ft-ibs (67.79 Nm) torque, Fig. 20. IMPORTANT: Do not torque the retaining ap srew more than 50 ft-ibs (67.79 Nm) beause it will "swell" the hub end ausing the drive sheave to "stik." Install drive belt, belt guard and seure hood.

180 50 Power Train 10-8 John Deere (Comet) Drive Sheave ) ) Litho in U. SA

181 SM-21GB (Aug-77) Power Train John Deere Driven Sheave r GENERAL INFORMATION Group 15 JOHN DEERE DRIVEN SHEAVE DISASSEMBL V AND REPAIR r ' Fig. 1-John Deere Driven Sheave The John Deere Driven Sheave, Fig. 1, is used on the 340 and 440 Cylone and Liquifire. The driven sheave ats as a take-up for the ation of the drive sheave. The driven sheave is also "torque-sensitive". See "Priniple of Operation" in Group 5 of this setion. Group 5 also ontains "Diagnosing Malfuntions" to help orret problems assoiated with the driven sheave. M19269N A-Bushing B-Cam Braket C-Spring D-Button E-Sheave and Post F-Shims G-Bushing H-Movable Sheave Fig. 2-Exp/oded View of Driven Sheave Removing Driven Sheave Raise the hood and drive belt guard. Remove drive belt. Fig. 3-Removing Driven Sheave Remove ap srew and washer and slide driven sheave with key off the shaft, Fig. 3. -

182 50 Power Train 15-2 John Deere Driven Sheave Disassembling Driven Sheave Inspet movable fae bushing (A, Fig. 5) and fixed fae hub (B) for wear. Replae parts as neessary. Exessive looseness ould ause binding. Replae movable fae bushing as follows:.j A-Cap Srews 8-Cam C-Fixed Fae D-Spring E-Spaers F-Movable Fae Fig. 4-Disassembling Driven Sheave Remove three ap srews (A, Fig. 4) seuring am (B) to movable fae (F). Remove am (B), spring (D) and fixed fae (C) with insert buttons from movable fae (F). Do not lose spaers (E) between movable fae (F) and fixed fae (C). INSPECTION AND REPAIR Thoroughly lean all omponents in solvent. M1927"3NY A Disk Disk C Handle Fig. 6-Tool For Removing Movable Fae Bushing 1. To remove and install bushing use Owatonna Tool Company, Bushing, Bearing and Seal Driver Sets. Install Disk (B) and Disk (A) to Handle (C) as shown in Fig. 6. This ombination will remove and install movable fae bushing. ) ) Fig. 7-Removing Movable Fae Bushing 2. Use a press and remove old bushing, Fig. 7. J.J192?2NY A-Movable Fae Bushing B-Fixed Fae Hub Fig. 5-Movable Fae Bushing and Fixed Fae Hub J

183 r Power Train John Deere Driven Sheave Replae bushing in am as follows: Fig. 8-lnstalling Movable Fae Bushing Use a press and install new bushing flush with the hub of movable fae, Fig. 8. Inspet spring for raks or pits. Replae as neessary. Fig. 10-Removing Cam Bushing 1. Plae am on two wooden bloks and use a old hisel to remove bushing, Fig. 10. ( Chek sheave faes with a straight-edge. Replae if badly worn, grooved, sored or pitted. M19276NY A-Cam B-Bushing C-Fixed Fae Hub Fig. 9-Cam Bushing and Fixed Fae Hub Inspet bushing (B, Fig. 9) in am (H) and fixed fae hub (C) for wear. Replae parts as neessary. Fig. 11-lnstalling Cam Bushing 2. Install new bushing by pushing in plae with your thumbs, Fig. 11. Be sure bushing is aligned properly when installing.

184 Power Train John Deere Driven Sheave INSPECTION AND REPAIR-Continued ASSEMBLY Pretensioning Driven Sheave NOTE: The spring in the driven sheave must be pre tensioned differently as altitude and temperature hanges our. As temperature or altitude inreases, engine horsepower dereases. The drive system now upshifts too rapidly for an engine with less horsepower. In order to ounterat this, the drive system must be modified to obtain proper governed speed. Low governed speed results in poor performane. M19279NY Engine governed speed should be as follows : 1976 SNOWMOBILES (Serial No. 50,001-70,000) ) Fig. 12-lnspeting Insert BuNons Snowmobile Governed Speed Inspet insert buttons for wear, Fig. 12. Buttons and mating surfaes on am must be smooth. Replae insert buttons as a set if worn. If not replaed as a set, binding and improper sheave operation ould result. Replae insert buttons as follows: 1. Use pliers and break off insert button ramp. 340 Cylone 440 Cylone 340 Liquifire 440 Liquifire Snowmobile 19n SNOWMOBILES (Serial No. 70,001- and up) rpm rpm rpm rpm Governed Speed 340 and 440 Cylone rpm 340 and 440 Liquifire rpm See harts on pages , through for luth engagement speeds. I IMPORTANT: Do not adjust the driven sheave to provide engine speeds in exess of the governed speeds listed. NOTE: The arburetor must be hanged for inreases in altitude as well as spring tension on the driven sheave. See Setion 30, page for proper arburetor hanges. ) Fig. 13-Drilling Out Insert BuNon Shank 2. Use a 15/64-inh drill and very CAREFULLY drill out the shank of the insert button, Fig. 13. DO NOT enlarge the hole or the new insert button will not fit snug. 3. Use two part epoxy glue on the shank of the new insert button and tap it in plae very LIGHTLY with a plasti hammer. Be areful not to break the insert button. Additional driven sheave pretension inreases engine speed; less pretension dereases speed. The John Deere driven sheave an be pretensioned as shown in the hart on page

185 SM-2108 (Aug-77) Power Train John Deere Driven Sheave PRETENSIONING CHART FOR DRIVEN SHEAVE SPRING Plae am and spring over fixed fae hub with tang on spring in hole of fixed Insert spring tang in fae. Rotate am lokwise Pounds of spring tension when am hole number. past the ramp indiated. Degrees of pretension. measured at sheave rim. 1 1 ramp 50 5 Ibs. 2* 1 ramp 80 6 Ibs. 3 1 ramp Ibs. 4 2 ramps Ibs. *This is the fatory setting for 340 and 440 Cylone and Liquifire. Assembling Driven Sheave M19282NY ( U19281NY Fig. 14-lnstalling Spaer 1. Lay movable sheave flat with posts up. Plae spaers on hub of movable sheave, Fig Install fixed sheave hub through movable sheave. Fig. 1S-Spring Installed in Cam 3. Install spring in proper hole in am, Fig. 15, as indiated in the hart above. The proper hole for most appliations is No.2. NOTE: Refer to pages through for the orret am to be used. Use the 38 degree am in all the snowmobiles for high altitude appliations.

186 50 Power Train 15-6 John Deere Driven Sheave Installing Driven Sheave 1. Lubriate shaft and inside of driven sheave hub with Never-Seez Lubriant (PT569). J 2. Be sure spaers are on shaft. Fig. 16-lnstalling Cam With Spring on Fixed Fae Post 4. Install am with spring over post of fixed fae with tang of spring in hole in fixed fae, Fig Rotate am past the proper ramp as indiated in the hart on page Push down on am making sure posts of movable fae fit in reesses in am. 6. Install and tighten ap srews seurely. Fig. 17-lnstalling Driven Sheave on Shaft 3. Plae key in driven sheave. Plae sheave inline with shaft and bak key out of sheave slightly, Fig. 17. This will help line-up sheave with keyway in shaft. 4. Slide sheave in plae and push key in to lok sheave to shaft. 5. Install washer and retaining ap srew. Tighten ap srew to 20 ft-ibs (27 Nm) torque. NOTE: To be sure sheave is installed orretly, rehek alignment. See page ) )

187 SM-2108 (Aug-77) Power Train 50 Drive Belt 20-1 Group 20 DRIVE BELT GENERAL INFORMATION REMOVING AND INSTALLING DRIVE BELT IMPORTANT: Mark the diretion of rotation before removing the drive belt so it an be reinstalled in the same diretion. 1. Raise the hood. 2. Pull spring lok and tip belt guard forward to provide aess to drive belt. M10775N r r Fig. 1-Cutaway View of Drive Belt The funtion of the drive belt is to transmit power from the drive sheave to the driven sheave. The snowmobile drive belt ontains layers of ords, Fig. 1, lose to the outer surfae. The drive belts are not interhangeable between snowmobiles even though the width may be the same. The drive belt should be replaed when its width is redued by 1/8 inh (3.175 mm) or more beause snowmobile performane will be affeted. Fig. 2-Removing Drive Belt 3. Push in on enter of driven sheave as shown in Fig. 2 and lift belt up and over sheave half to remove. 4. Remove belt from drive sheave last. IMPORTANT: Never pry belt over sheaves. If driven sheave is opened properly, no prying is neessary. A CAUTION: Keep fingers out of area between enter of driven sheave halves when sheave is opened. If driven sheave stiks losed, use are in opening it to prevent fingers from being pinhed. 5. Install belt in opposite sequene from whih it was removed making sure it operates in the same diretion as it did before being removed. This provides longer belt life by not disturbing the wear pattern. 6. Tip belt guard bak into position and seure with spring lok. Seure hood.

188 J Power Train Drive Belt ALIGNING DRIVE BELT / , ( \ I I I I I I I I I I I I \ ' _./.J " A-JDM-81 Cluth Aligning Tool B-Engine Mounting Bolts C-Shims (0.018 or lnh) Fig. 3-Aligning Drive Belt ) Proper belt alignment is important beause it affets belt life. A misaligned belt an be ruined in a few hours of operation. Chek drive belt alignment whenever the engine is installed or whenever rapid belt failure ours. The distane between the sheave shaft enters is adjustable by loosening the engine mounting bolts and moving the engine forward or rearward. Side-toside adjustment is obtained by adding or deduting shims between the driven sheave and bearing. Adjust as follows: 1. Remove drive belt. 2. Remove driven sheave and shims from between the driven sheave and seondary shaft bearing. 3. Install JDM-81 Cluth Aligning Tool on seondary shaft and drive shaft, Fig For side-to-side adjustment, remove JDM-81 Cluth Aligning Tool and add shims (C) between the tool and seondary shaft bearing to give proper dimension, Fig. 3. Shims are available in or inh thiknesses. 5. For forward or rearward adjustment, loosen engine mounting bolts and move engine as required to properly align with JDM-81 Cluth Aligning Tool, Fig. 3, )»

189 Power Train 50 Drive Belt 20-3 Refer to "Diagnosing Malfuntions" in Group 5 of this setion for additional information. ANALYSIS r Fig. 6-Drive Belt Disintegration Fig. 4-Drive Belt With Frayed Edge If drive belt wears rapidly exposing frayed edge ord, Fig. 4, belt is misaligned. Engine mounting bolts ould also be loose allowing engine to twist and misalign belt. Drive belt disintegration, Fig. 6, ould be aused by a misaligned belt, using an inorret drive belt, or oil on sheave surfaes. If badly misaligned, drive belt will roll over at high speed ausing belt disintegration. Never use grease or oil on sheave omponents exept for storage. When snowmobile is removed from storage, sheaves should be thoroughly leaned to remove lubriants. Fig. 5-Be/t Worn Narrow In One Setion If drive belt is worn narrow in one setion, Fig. 5, exessive slippage is indiated due to a stuk or frozen trak. Too high an engine idle speed ould also be indiated if several narrow setions are evident. Fig. 7-Drive Belt With Sheared Cogs A drive belt having sheared ogs, Fig. 7, ould indiate violent engagement of drive sheave aused by binding or improperly installed drive sheave omponents. Litho in U. S.A.

190 J 50 Power Train 20-4 Drive Belt

191 SM-2108 (Aug-77) Power Train 50 Chain Case, Seondary Shaft and Drive Shaft 25-1 r Group 25 CHAIN CASE, SECONDARY SHAFT AND DRIVE SHAFT GENERAL INFORMATION M19287N A-Speedometer Drive C-Idler Wheel ( -80,000) B-Drive Wheels D-Seondary Shaft E-Brake Disk F-Brake Puk G-Upper Sproket H-Chain Case Cover I-Chain Tensioner J-Lower Sproket Fig. 1-Cutaway View of Chain Case (1976 ) - The hain ase, Fig. 1, is a sealed unit ontaining an upper sproket (G), lower sproket (J), endless silent hain and self-adjusting hain tensioner (I). NOTE: A single hain tensioner is used on Serial No. 70,001 and up. The endless hain annot be servied. If worn or broken, it must be replaed. Polyurethane drive wheels on the drive shaft en- gage with the lugs on the inside surfae of the trak to drive the trak. NOTE: The idler wheel (C) is used on snowmobiles (Serial No.. -80,000). The brake disk (E) is mounted on the seondary shaft (0). Two brake puks (F), one on eah side of the brake disk, provide the braking ation. See Group 30 of this setion for brake maintenane and adjustments. Sealed ball bearings support both the seondary shaft and the drive shaft.

192 Power Train Chain Case, Seondary Shaft and Drive Shaft SM-2108 (Aug-77) FINAL DRIVE RATIOS The following hart lists the final drive ratios possible for most snowmobiling onditions. Upper Sproket Snowmobile (No. of Teeth) 340 Cylone and Liquifire Cylone and Liquifire 24 All Mahines 17 All Mahines 17 Lower Sproket Chain Length (No. of Teeth) (No. of Pithes) Ratio :1 * :1 ** : :1 *The 340 Cylone and Liquifire Snowmobile final drive standard ratio is 1.86:1 with the 2.06:1 as the first optional ratio. The other ratios may be used as required. *The 440 Cylone and Liquifire Snowmobile final drive standard ratio is 1.67:1 with the 1.86:1 as the first optional ratio. The other ratios may be used as required. The long spaer (C, Fig. 2), is required with the 40-tooth sproket on Cylone and Liquifire (Serial No. 50,001-70,000) beause this sproket is minus the shoulder present on the other sprokets. ) NOTE: Cylone and Liquifire (Serial No. 70,001 and up), use the short spaer (A, Fig. 2), beause the 40-tooth sproket has a shoulder ast as an integral part of the gear. IMPORTANT: 440 Cylone (Serial No. 70,001 to 71,001) use the long spaer and 40 tooth sproket without the shoulder. A-M66133 Short Spaer 8-35, 39 and 42-Tooth Sproket C-M66346 Long Spaer 0-40-Tooth Sproket Fig. 2-Lower Sprokets and Spaers I J

193 Power Train 50 Chain Case, Seondary Shaft and Drive Shaft 25-3 DISASSEMBL V A B ~O ~ o ~ o q~ ri '- ~ C L t~ /$' o ~ ~Q) (j fa f.' M20993N A-Shims B-Bearing Flangette C-Bearing D-I;learing Mount E-Bearing Spaer F-Key ~Seondary Shaft H-Woodruff Key I -Brake Disk J -Chain Case K-Gasket L-O-Ring M-Upper Sproket N-Washer O-Cap Srew P-Chain Case Cover Q-Plug R-Pin S -Chain Tensioner T-Spring U -Silent Chain V -Cotter Pin W-Rubber Gasket X-Spaer V -Drive Shaft Fig, 3-Exp/oded View of Chain Case, Seondary Shaft and Drive Shaft Z -Drive Wheel AA-Lok Nut BB-Set Srew* CC-Loking Collar* DO-Idler Wheel* EE-Spaer FF -Speedometer Bushing G~Speedometer Core HH-Speedometer Drive II -Lower Sproket JJ -Single Chain Tensioner** * Used on snowmobiles (Serial No, -80,000), **Used on snowmobiles (Serial No. 70,001- ).

194 50 Power Train 25-4 Chain Case, Seondary Shaft and Drive Shaft Removing Drive Chain and Sprokets 1976 (Serial No. 55,001-70,000) Loosen hain ase over srews and allow the oil to drain out. Remove hain ase over. Remove ap srews seuring upper and lower sprokets. M20994Y A-Upper Sproket B-Drive Chain C-Lower Sproket ) Fig. 5-Drive Chain and Sprokets Remove sprokets and drive hain as an assembly, Fig. 5. M19290NY A-Upper Sproket B-Drive Chain C-Chain Tensioners D-Lower Sproket Fig. 4-Sprokets, Drive Chain and Chain Tensioners Remove sprokets, drive hain and hain tensioners as an assembly, Fig. 4. IMPORTANT: Reord the number of shims between sprokets and shafts. This will help determine the orret shims for reassembly. IMPORTANT: Reord the number of shims between sprokets and shafts. This will help determine the orret shims for reassembly. Removing Seondary Shaft and Brake Disk Remove drive belt and driven sheave. Reord the number of shims behind the driven sheave for reassembly. These shims orretly align driven sheave and drive sheave. Remove sprokets and drive hain from hain ase (Serial No. 70,001 and up) Loosen hain ase over srews and allow the oil to drain out. Remove hain ase over. Remove ap srews seuring upper and lower sprokets. Remove hain tensioner.

195 Power Train 50 Chain Case, Seondary Shaft and Drive Shaft 25-5 r - Fig. 6-Bearing and Bearing Flangettes Remove flangettes and bearing from left side of tunnel, Fig. 6. Slide seondary shaft out of hain ase bearing and out of brake disk. Remove hain ase bearing flangettes, bearing and O-ring if replaement is neessary. Remove brake puk body, brake puk, and baking plate. Remove brake disk. Remove brake puk from hain ase. Removing Drive Shaft Siphon all fuel from the fuel tank and drain oil from the hain ase by loosening hain ase over srews. Close fuel shut-off valve. Remove battery if snowmobile is so equipped. NOTE: If the JDST-24 Lift and Repair Stand is not available, turn the snowmobile on its side to remove the suspension. Remove drive belt and seondary sheave. Disonnet speedometer able from speedometer drive. Remove hain ase over. Remove upper and lower sprokets, hain and hain tensioners. Turn snowmobile upside-down with the JDST-24 Lift and Repair Stand. Remove slide suspension. See page Fig. 7-Drive Wheels Positioned in the Center Remove bolts seuring drive wheels to drive shaft and slide drive wheels toward the enter, Fig. 7. This allows aess to bearing flangette ap srews. Fig. 8-Removing Drive Shaft Remove ap srews seuring drive shaft flangettes to tunnel, Fig. 8. Slide drive shaft toward the hain ase side. Lift the opposite end with spaer up far enough to lear tunnel and remove drive shaft. Removing Chain Case Relieve tension on the trak. Loosen hain ase over srews and allow the oil to drain out. Remove hain ase over. Remove ap srews seuring upper and lower sprokets.

196 Power Train Chain Case, Seondary Shaft and Drive Shaft Remove sprokets, hain and hain tensioners as an assembly. Remove seondary shaft and brake disk. Remove upper and lower bearing flangette nuts. Fig. 11-Seondary Shaft Bearings and O-Ring Inspet seondary shaft bearings, Fig. 11, and replae them if they are binding, worn, or noisy. Install a new O-ring on bearing in hain ase. Fig. 9-Removing Chain Case Inspeting Drive Chain, Sprokets and Chain Tensioners Remove two nuts seuring hain ase to tunnel and remove hain ase, Fig. 9. INSPECTION Thoroughly lean all omponents prior to inspetion. Inspeting Seondary Shaft Fig. 12-Drive Chain, Sprokets and Tensioners Inspet drive hain, Fig. 12, for exessive wear. Replae it if it is badly worn or broken. The drive hain is an endless hain and annot be repaired. M19293NY Fig. 10-Seondary Shaft Inspet sproket teeth, Fig. 12, for wear. If a new drive hain is installed, replae sprokets also, beause a new hain will not properly math worn sprokets. NOTE: To remove seondary shaft, remove exhaust silener and slide shaft past the hain ase and out the right-hand side. Inspet seondary shaft bearing surfaes, Fig. 10, for evidene of bearings turning on shaft. Also inspet ondition of splined-end threads. Replae shaft if it is defetive. Rapid hain and sproket wear ould be aused by sproket misalignment from improper assembly or from lak of lubriation. Replae hain tensioners, Fig. 12, if ontat surfaes are worn deeply. Replae tension spring if it is raked, broken, or pitted.

197 Inspeting Drive Shaft Assembly Power Train 50 Chain Case, Seondary Shaft and Drive Shaft 25-7 Inspeting Chain Case.. A-Drive Shaft B-Bearings C-O-Ring D-Drive Wheels Fig. 14-Chain Case Inspet hain ase, Fig. 14, for raks or other damage that ould ause hain and sproket misalignment or oil leakage. r Fig. 13-Drive Shaft Assembly Inspet drive shaft bearing surfaes, Fig. 13, for evidene of bearings turning on shaft. Also inspet speedometer drive ore and bushing for tightness. Inspet drive shaft bearings, Fig. 13, and replae them if they are binding, worn, or noisy. Use a new O-ring on lower hain ase bearing. Inspet drive wheels and replae them if lugs are worn down to metal enter. Rapid wear of this type on the leading edge of the drive lugs indiates snowmobile was run without snow lubriation. Wear on the trailing edge of the drive lugs is normal after many hours of regular operation. Install new rubber gasket when installing hain ase over. ASSEMBLY Installing Chain Case Install upper bearing and flangettes to hain ase. Do not tighten nuts at this time. Fig. 15-lnstalling Chain Case Install hain ase and seure with two nuts, Fig. 15.

198 50 Power Train 25-8 Chain Case, Seondary Shaft and Drive Shaft SM-2108 (Aug-77) Installing Drive Shaft IMPORTANT: Be ertain O-ring on bearing between flangettes on hain ase side is in orret position, or oil leakage will result. Seure hain ase bearing flangettes to hain ase with three ap srews, Fig. 17. Do not tighten until opposite bearing flangette is 'seured to tunnel. Insert speedometer ore into left-hand end of drive shaft. Attah bearing flangettes, spaer and speedometer drive to tunnel with three ap srews. Tighten all ap srews seurely. Move drive wheels into position and seure with bolt, washers and lok nut. J M Y A-Bearing Flangettes B-Bearings C-Spaer D-Loking Flanges Fig. 16-Drive Shaft Assembled Assemble bearing flangettes (A), bearings (8) and spaer (C) on drive shaft as shown in Fig. 16. Lubriate and install O-ring on hain ase bearing. IMPORTANT: Loking flanges (D) on bearings must fae splined end of drive shaft as shown in Fig. 16. Install new gasket on flangette side faing the hain ase. Gasket stiks to flangette and is between flangette and hain ase. Install slide suspension. See page Turn the snowmobile right-side-up. Install sprokets, hain and hain tensioner in hain ase. NOTE: Upper and lower sproket must be aligned within inh (0.254 mm). Align sprokets as instruted on pages and Install speedometer able to speedometer drive. Install seondary sheave and drive belt. Fill hain ase with SAE 90 oil. Install battery if snowmobile is so equipped. Fill fuel tank and open fuel shut-off valve. Adjust trak tension. See page Aligning Drive Chain and Sprokets Install four inh (0.254 mm) shims and spaer on lower shaft and install lower sproket. Install two inh (0.457 mm) shims and upper sproket. Install washers and ap srews and tighten seurely. Fig. 17-lnstalling Drive Shaft Position drive shaft assembly in tunnel by plaing splined end of drive shaft into position, Fig

199 SM-210B. (Aug-77) Power Train 50 Chain Case, Seondary Shaft and Drive Shaft 25-9 ( Fig. l8-cheking Sproket Alignment Plae straight-edge on flat surfae of lowe'r sproket, Fig. 18, and slide up toward upper sproket to hek alignment. If sprokets do not align, add or dedut shims as neessary. IMPORTANT: Use a maximum of three inh (0.457 mm) shims behind the upper sproket and ten inh (0.254 mm) shims behind the lower sproket. Shims on lower sproket should be between spaer and bearing. When sprokets are shimmed orretly the shafts should be reessed into the sprokets. DO NOT allow the shafts to protrude beyond the sprokets. Remove the sprokets and leave spaer and shims in plae (Serial No. 50,001-70,000) Plae drive hain f1round both sprokets and install hain tensioners on hain between sprokets. Head of hain tensioner bolt should be to the outside. Install the spring in the,grooves of the hain tensioners. Position JDM-82 Chain Tensioner Tool over the hain tensioners, Fig. 19. Install the spr.okets, hain and hain tensioners in the hain ase as an assembly. Remove JDM-82 Chain Tensioner Tool. Apply Lotite (grade AV, red) (ATL 4927) to the ap srew threads and seure sprokets with washers and ap srews. Fig. 19-Positioning JDM-82 Chain Tensioner Tool 1977 (Serial No. 70,001 and up) Fig. 20-lnstalling Drive Chain Tensioner Plae drive hain around both sprokets and install sprokets and hain in the hain ase as an assembly. Install hain tensioner on pin in the hain ase, Fig. 20. Be sure the hyfax of the hain tensioner is aligned properly with the hain. Apply Lotite (grade AV, red) (ATL 4927) to the ap srew threads and se e sprokets with washers and ap srews. -

200 Power Train Chain Case, Seondary Shaft and Drive Shaft Install hain ase over. Remove upper and lower plugs. Install a good grade of SAE 90 oil in the upper hole until it starts to run out the lower hole. Replae plugs. Installing Seondary Shaft and Brake Disk Install brake puk in hain ase. Position brake disk and slide seondary shaft through disk and hain ase bearing. Fig. 21-Chain Case Gasket Installed Install rubber gasket on hain ase with gap in ~asket at the eleven o'lok position, Fig. 21. The gap In the gasket should be 1/16 to 3/16 inh (1.588 to mm). This serves as the vent for the hain ase and prevents pressure build-up in the ase. NOTE: On 1977 (Serial No. 70,001 and up) the gasket is one piee and the seam in the gasket must be at the eleven o'lok position. IMPORTANT: If the one piee gasket is used on 1976 (Serial No. 50,001-70,000) a inh hole must be drilled lengthwise through the upper plug. IMPORTANT: Use Never-Seez on the seondary shaft in the area of the brake disk. This will keep the disk from binding or stiking. DO NOT allow Never-Seez to get on the fae of the brake disk. Install flangettes and bearing over shaft and seure to the left side of the tunnel. Install sprokets and drive hain in hain ase. Plae seondary shims over shaft (these were removed during disassembly) and install driven sheave. Rehek sheave alignment. Install drive belt. Install brake puk body with baking plate and brake puk. See Group 30 of this setion for brake adjustment. ) Litho in U.S.A

201 '", r r GENERAL INFORMATION The mehanial brake disk is keyed to and rotates with the seondary shaft. Squeezing the brake lever auses a am to push two pins against the baking plate and puk in the brake puk body. The puk in the body ontats the brake disk. Further pressure on the brake lever auses the puk in the brake puk body to slide the brake disk on the seondary shaft. The disk ontats the puk in the hain ase and the ation of the puks against the disk slows or stops the snowmobile. The brake an be adjusted easily, but the seondary shaft and brake puk body must be removed to replae the disk or puks. DISASSEMBLY AND REPAIR Removing Brake Disk Remove air silener. Remove drive belt and driven sheave. Reord the number of the shims between driven sheave and bearing for reassembly. Remove hain ase over, sprokets, drive hain and hain tensioner. Reord the number of shims between the upper sproket and bearing for reassembly. Do not remove spaer and shims from the lower drive shaft. Remove the bearing flangettes and bearing from the seondary shaft on the left side of the tunnel. Slide seondary shaft out to free shaft from the brake disk. Power Train 50 Mehanial Disk Brake 30-1 Group 30 MECHANICAL DISK BRAKE A-Cotter Pin B-Adjusting Nut Fig. 1-Removing Cotter Pin and Adjusting Nut Remove otter pin (A, Fig. 1) and adjusting nut (8) from stud of brake puk body. Loosen jam nuts seuring brake able to braket. Remove am and spring with brake able and braket from the stud of brake puk body. A--Brake Puk Body B-Brake Puk C--Baking Plate D--Pins Fig. 2-Removing Brake Puk Body Remove brake puk body (A, Fig. 2), brake puk (8), baking plate (C) and pins (D). NOTE: When removing puks on 1977 it may be neessary to heat the puk with a hand torh before removing it. The puks are installed with Lotite and heat (400 degrees) is required to loosen the puk.

202 Power Train Mehanial Disk Brake NOTE: If the brake disk is warped or puks are raking, install heavy-duty brake kit. ~ \ :. Ml9.JIUllY A-Brake Disk B-Brake Puk Fig. 3-Brake Disk Removed Remove brake disk (A, Fig. 3). Remove brake puk (8) from hain ase. INSPECTION Replae brake puks if they are oil ontaminated. or if no more adjustment is left to tension brake properly. Inspet brake disk, am, pins and brake able. Replae worn or damaged parts, beause brake adjustment and safe operation ould be affeted. ASSEMBLY M19306Nl A-Brake Puk Body B-Baking Plate C-Brake Puk Fig. 5-lnstalling Baking Plate and Brake Puk in Brake Puk Body Install baking plate (8) and brake puk (C) in brake puk body (A, Fig. 5). Install body and brake able braket to hain ase. Install key in keyway of seondary shaft and install shaft through brake disk and bearing in hain ase. Install bearing flangettes and bearing on seondary shaft on the left side of tunnel. IMPORTANT: Use Never-Seez on seondary shaft in the area of the brake disk. This prevents disk from seizing or stiking on shaft. Fig. 4-lnstalling Brake Puk and Brake Disk Plae brake puk and brake disk in hain ase Fig. 4. NOTE: Before installing puk, spray it with Lokwik Primer, Grade T, then wipe off. Apply Lotite 306 to the puk and install puk on hainase side only. Fig. 6-lnstalling Shims on Seondary Shaft Plae shims on seondary shaft, Fig. 6, and install driven sheave and drive belt. Litho in U.S.A

203 SM-21GB (Aug-77) Power Train 50 Mehanial Disk Brake 30-3 ( Install drive hain, sprokets and hain tensioners in hain ase. Chek sproket alignment as explained on page Install hain ase over and add oil. ( Fig. 9-Adjusting Brake Tighten the adjusting nut on the brake body post until 1 to inhes (25 to 38 mm) learane exists between the brake lever and handgrip, Fig. 9. Install otter pin through adjusting nut. Fig. 7-lnstalling Cam Install pins in brakepuk body. Install spring and am on stud of brakepuk body, Fig. 7. Install washer and adjusting nut. Do not tighten nut at this time. ADJUSTMENT After adjusting brake, hek operation of stoplight swith. Chek for a "frozen " swith if stoplight does not work. Fig. 8-Adjusting Cam Loosen or tighten jam nuts on brake able until the am is parallel with the ground (level) and pointing straight ahead, Fig. 8.

204 50 Power Train 30-4 Mehanial Disk Brake SM-2108 (Aug-77) ) Litho in U. S.A

205 Power Train 50 Speifiations 35-1 Group 35 SPECIFICATIONS SPECIFICATIONS Drive Belt Total Width: All /4 in. (31.75 mm) Drive Belt Effetive Length: All ± 0.25 in. ( ± 6.35 mm) Drive Sheave Alignment All See Page TORQUE FOR HARDWARE Loation Drive Sheave Retaining Cap Srew Driven Sheave Retaining Cap Srew Torque 50 ft-ibs (68 Nm) 20 ft-ibs (27 Nm) - Litho in U. S.A.

206 Power Train Speifiations

207 Suspension 60 General Information 5-1 CONTENTS Setion 60 SUSPENSION Group 5 GENERAL INFORMATION - -. Page GROUP 5 - GENERAL INFORMATION Desription Diagnosing Malfuntions GROUP 10 - SLIDE SUSPENSION (Serial No. -80,000) General Information Disassembly and Repair Removing Slide Suspension Replaing Tunnel Wear Bars Replaing Slide Suspension Wear Bars Replaing Wear Bloks Replaing Idler Wheels Installing Slide Suspension Adjusting Trak Tension Adjusting Suspension Springs Adjusting Steering Response (Ski Lift) GROUP 12 - SLIDE SUSPENSION (Serial No. 80,001- General Information Repair Removing Slide Suspension Replaing Tunnel Wear Bars Replaing Slide Suspension Wear Bars Replaing Idler Wheel Axle Replaing Slide Suspension Components Installing Slide Suspension Adjustments Adjusting Trak Tension Adjusting Slide Suspension Springs Litho in U. S.A. Page GROUP 15 - JOHN DEERE AND GOODYEAR TRACKS General Information Grouser Bar Trak Analysis Failures Covered Under Warranty Ply Separation Trak Streth Poor Bond Tensile Cord Misloated Variation in Trak Thikness Non-Warranty Failures Obstrution Damage Worn Grouser Bars Lug Damage Ratheting Damage Over-Tension Damage Loose Trak Damage Impat Damage Edge Damage Broken Grouser Bar Disassembly and Repair Replaing Grouser Bars Removing Trak and Drive Shaft Installing Trak and Drive Shaft GROUP 20 - SKIS AND STEERING General Information Analysis Repair Replaing Ski Wear Rods Replaing Wear Plates Replaing Ski Springs Replaing Ski Bumpers and Saddles Replaing Ski Spindles and Bushings Replaing Steering Arms Replaing Tie Rod and Drag Link Replaing Steering Post Assembly Replaing Steering Post Bushings Adjustment Aligning Skis Eliminating Loose Steering GROUP 25 - SPECIFICATIONS Torque for Hardware

208 Suspension General Information DESCRIPTION A- Skis 8-Shok Absorbers C-Ski Spring D-Steering Arm E-Ski Spindle F-SJide Suspension G- Rear Idler Assembly H-Steering Column Fig. 1-Slide Suspension Components The slide suspension system, Fig. 1, onsists of the skis and steering mehanism, the trak and slide suspension and the rear idler assembly. The system also inorporates a weight transfer adjustment, replaeable wear bars, adjustable suspension springs and hydrauli shok absorber. The ombination of these features and adjustments will give exellent ride and performane. The rear idler shaft turns in double lip, sealed ball bearings. The idler assembly is easily adjusted to properly tension the trak. The rubber trak has lugs on the inside surfae of the trak whih engage with the drive wheels on the drive shaft for maximum effiieny. The skis have replaeable wear rods. Ski springs are replaeable only as a omplete set. Ski spindles and tie rods are designed to bend rather than break when subjeted to severe shok loads, providing additional operator safety. Litho in U.S.A

209 SM-21GB (Aug-77) Suspension 60 General Information 5-3 DIAGNOSING MALFUNCTIONS Trak Assembly Trak Edge Frayed Trak out of alignment. Trak Grooved On Inner Surfae Trak run exessively tight. Rear idler shaft bearings frozen. Trak Drive Ratheting Trak too loose. Rear Idlers Turning on Shaft Rear idler shaft bearings frozen. Skis and Steering Loose Steering Tie rod ends loose. Spindle bushings worn. Spindle splines stripped. Skis Not Turning Equally In Both Diretions Tie rod adjusted improperly. Steering arms installed improperly. Rapid Ski Wear Skis out of alignment. Wear rods worn out. Spring wear plate worn out. r - -

210 60 Suspension 5-4 General Information

211 SM-2108 (Aug-77) Suspension 60 Slide Suspension ( -80,000) 10-1 GENERAL INFORMATION Group 10 SLIDE SUSPENSION (Serial No. -80,000) A-Replaeable Wear Bars B-Suspension Springs C-Shok Absorber D-Grouser Bar Trak Fig. 1-S/ide Suspension System The slide suspension system onsists of replaeable wear bars (A, Fig. 1), shok absorber (C), adjustable suspension springs (B), and a grouser bar trak (0). Replaeable polyethylene wear bars provide low frition between grouser bars and slide rail. The shok absorber dampens the suspension and the adjustable springs permit varying the degree of ride from soft to firm. The molded rubber bars and lugs in the trak give good tration on ie and during ornering. The molded-in-steel or riveted grouser bars provide good tration for aeleration. The steel grouser bars are also replaeable. - --

212 60 Suspension 10-2 Slide Suspension ( -80,000) SM-2108 (Aug-77) DISASSEMBLY AND REPAIR 5~ ~_11 ~78 5 I ~Q~~ ~ ~J / 1 ~,~ 7 I ~ f\~ ~165 ~ ~ J~ / i t ~~~ ~!O 9 \ '0f!!!!/@ J 2 18 ~ M22J05N \ ~ 1-Tunnel Wear Strip 2-Pop Rivet 3-Semi-Tubulor Rivet 4-Rear Idler Axle 5-Rear Wheel 6-Spaer 7-Washer 8-Spaer 9-Cap Srew 10-Washer 11-Spaer 12-Lok Nut 13-Wear Bar Stop 14-Cup Srew 15-Trak 16-Lok Washer 17-Nut 18-Cap Srew 19-5lide Rail 20-Slide Wear Bar 21-Grouser Bar 22-Steel Pop Rivet 23-Cap Srew 24-Washer 25-Washer 26-Lok Nut 27-Rubber Bumper 28-No. 10 Mahine Srew, Lok Washer and Nut Fig. 2-Exploded View of Rear Idler, Trak and Slide Rails Litho in U.S.A

213 SM-2108 (Aug-77) Slide Suspension ( Suspension -80,000) ~2 \ M20642F 1-Front Pivot 2-Loking Bolt 3-Bearing 4-Lok Nut 5-Washer 6-Shok Absorber 7-Rear Pivot 8-Pivot Shaft 9-Washer 10-Rear Slip Bearing 11-Washer 12-Cap Srew 13-Pivot Spring 14-Bearing 15-Cap Srew 16-Shok Absorber Shaft 17-Spaer 18-Washer 19-Washer 20-Adjusting Arm Clip Fig. 3-Exploded View of Slide Rail Pivots and Springs 21-Round Head Bolt 22-Adjusting Plate 23-Lok Nut 24-Washer 25-Cap Srew 26-Loking Bolt 27-Washer 28-Front Reinforement Braket 29-Adjusting Arm 30-Pivot Shaft 31-Pivot Spring Removing Slide Suspension IMPORTANT: Siphon all fuel from the fuel tank and use a syringe to remove all oil from the hain ase. - Use onveniene tool JDST -24, Snowmobile Lift and Repair Stand. Raise and rotate the mahine to provide easy aess to the slide suspension. Fig. 4-Trak Adjusting Srews Bak out adjusting srews, Fig. 4, to relieve trak tension.

214 60 Suspension 10-4 Slide Suspension ( -80,000) SM-2108 (Aug-77) A-Tunnel Wear Bars B-Seat Srews Fig. 7-Tunnel Wear Bars Fig. 5-Removing Spring Adjusting Srews Use a large 1-1/ 4-inh wrenh to relieve spring tension, Fig. 5, and remove four adjustment srews, (two on eah side). Chisel off the old rivets from the top or seat side. Install new wear bars using semi-tubular rivets. NOTE: Install all rivets from the wear bar side. Install suspension and seat. Replaing Slide Suspension Wear Bars Turn the snowmobile on its side. Remove retaining nut and bolt seuring front of wear bar to suspension. Remove wear bar stop from rear of suspension on 1977 (Serial No. 70,001- ). Fig. 6-Cap Srews Seuring Suspension to Tunnel Release trak tension. Remove four ap srews seuring suspension to tunnel, Fig. 6, and remove suspension. Replaing Tunnel Wear Bars The polyethylene tunnel wear bars prevent the steel grouser bars from damaging the tunnel. Remove the suspension. Lay the trak over the front of the mahine to expose the tunnel wear bars (A, Fig. 7). Remove two ap srews (8) seuring seat and remove seat. Fig. 8-Removing Slide Rail Wear Bar Use a hisel and hammer, as shown in Fig. 8, drive the wear bar to the rear to remove it. NOTE: Suspension was removed for photographi purposes.

215 SM-21G8 (Aug-77) Slide Suspension ( Suspension -80,000) NOTE: In some ases the wear bars are diffiult to remove beause the opening in the rail is too narrow. Use the following method: 1. Drill a 3/8-inh diameter hole in the enter of the wear bar, 18 inhes (45.7 m) from the rear of the bar. NOTE: Drill arefully so that drill bit does not ontat the metal rail. A-Wear Blok B-Cap Srew C-Washer Fig. 10-Replaing Rear Wear Bloks Remove ap srew (8, Fig. 10), washer (C) and wear blok (A) from eah end of lower pivot shaft. Install new wear blok. Install ap srew and washer. Tighten ap srew seurely. Replaing Idler Wheels 1976 (Serial No. -70,000) A-3/S x 3/4-lnh Cap Srew B-Wear Bar Fig. 9-Removing Slide Rail Wear Bar 2. Install a 3/8 x 3/4-inh ap srew (A, Fig. 9) and use a hisel or steel bar to drive wear bar (8) out the rear Chek the width of the opening in the rail. It should be 0.44 to 0.50-inh (11.1 to 12.7 mm) in width. If the measurement is less, arefully pry open the rail to the orret measurement before installing a new wear bar. A-Cap Srew B-Washer C-Wheel Spaer D-Idler Wheel E-Wheel Spaer F-Idler Axle Lubriate rail with grease. Install new wear bar from the rear, and use a soft mallet to drive it into plae. Do not use a hisel for installation. Install front retaining bolt and nut. Install rear wear bar stop on 1977 (Serial No. 70,001- ). Replaing Wear Bloks NOTE: The suspension need not be removed to replae wear bloks. Fig. 11-Removing Rear Idler Axle, Wheels and Spaers Remove suspension. Remove ap srew (A) and washer (8) from one side of idler axle (F, Fig. 11). Drive axle (F) out the other side and remove idler wheels (D) and wheel spaers (C and E). To reassemble; install axle through one rear idler wheel and one spaer, enter idler wheel, spaer and third idler wheel. Use washer and tighten ap srew to seure axle. Use Lotite on ap srew. Litho in U.S.A

216 Suspension Slide Suspension ( -80,000) SM-2108 (Aug-77) Replaing Idler Wheels-Continued Installing Slide Suspension 1977 (Serial No. 70,001- Remove suspension. A- Arm B-Spring C-Tape Fig. 13-Arms and Springs Installed on Slide Suspension Assemble springs (8) and arms (A) to the slide suspension as shown in Fig. 13. Use tape (C) to hold springs in plae and to hold arms to springs. A-Cap Srew and Washer B-Outer Spaer C-Idler Wheel D-Washer E-Inner Spaer F-Idler Axle Fig. 12-Removing Rear Idler Axle, Wheels and Spaers Remove ap srew and washer (A) from one side of idler axle (F, Fig. 12). Drive axle (F) out the other side and remove idler wheels (C), inner spaers (E), washers (D) and outer spaers (8). To reassemble: Plae ap srew with washer in one end of the axle and install idler wheel and outer spaer. Plae this assembly through the suspension, and install washer, inner spaer, idler wheel, inner spaer and washer. Push the shaft ompletely through suspension and install outer spaer, idler wheel, washer and ap srew. Use Lotite on ap srews. Install suspension with arms and springs inside trak into plae in tunnel. Install front two ap srews and then rear two ap srews, Fig. 6. Tighten all four ap srews seurely. NOTE: It is important to keep these four srews tight. Advise ustomer to hek them periodially and tighten if neessary. Use a large 1-1/ 4-inh wrenh over the end of the spring arm, Fig. 5. Press down on wrenh to pivot spring arm to allow installation of spring adjustment srew and speial nut. Turn adjustment srew through nut until srew is through nut by two threads. Repeat proedure on remaining three adjustment srews. NOTE: Adjust these four srews to give a firm or soft ride after the trak has been adjusted, page Turn both trak adjusting srews (see Fig. 4) in until the trak is fairly tight. Do not tighten the jam nuts on the adjusting srews. Remove snowmobile from onveniene tool JDST- 24, Snowmobile Lift and Repair Stand. Install SAE-90 oil in hain ase and refill fuel tank with proper fuel-oil mixture.

217 SM-21GB (Aug-77) Slide Suspension ( Suspension -BO,OOO) A trak that is too loose or too tight requires additional power to operate. A loose trak auses exessive slap whih an damage the trak, tunnel or slide assembly. 1. Suspend and support the rear of the snowmobile until trak is lear of the ground. ADJUSTING TRACK TENSION A A M21140 A-Lower Shok Absorber Mount B-BoHom of Slide Wear Bar C-O.OO to 0.25 Inh (0.00 to mm) D-Inside of Trak Band M21139 A-Lower Shok Absorber Mount B-BoHom of Slide Wear Bar C-O.OO to 0.38 Inh (0.00 to mm) D-Top of Drive Lug Fig. 14-Adjusting Molded Grouser Bar Trak 2. To adjust the molded grouser bar trak, Fig. 14, tension the trak until the dimension between the bottom of the slide wear bar and the top of the drive lug is 0.00 to 0.38 inh (0.00 to mm). Measure the dimension below the lower shok absorber mount. Fig. 1S-Adjusting Riveted Grouser Bar Trak 3. To adjust the riveted grouser bar trak, tension the trak until the dimension between the bottom of the slide wear bar and the top of the trak is 0.00 to 0.25-inh (0.00 to mm). Measure the dimension below the lower shok absorber mount. Both sides must be equal. 4. Tighten the jam nuts. 5. Start the engine and idle the trak slowly so that it rotates several times. Shut off the engine and allow the trak to oast to a stop. DO NOT apply the brake. 6. Chek alignment by observing where the rear idler wheels run with respet to the drive lugs. The rear idler wheels should run in the enter of the drive lugs. 7. Look under the trak to determine if the slide rail wear bar is diretly in the middle of both slide rail openings on the trak. 8. If Step 6 or 7 indiates a need for adjustment, repeat the tension proedure. NOTE: A trak will always run to the loose side. For proper tensioning, the adjusting srew on the loose side should be tightened. For example, if the trak is too far to the left side, tighten that side to move the trak over. t;

218 Suspension Slide Suspension ( -80,000) SM-2108 (Aug-77) ADJUSTING SUSPENSION SPRINGS Turning adjusting srews in (lokwise) gives a firm ride; turning adjusting srews out (ounterlokwise) gives a soft ride. Adjust srews equally, side-to-side. Ski Lift (Cylone and Liquifire ) Fig. 16-Suspension Spring Adjusting Srews IMPORTANT: Never turn adjusting srews, Fig. 16, all the way out. At least two threads on eah srew must protrude through its respetive adjusting nut. NOTE: For the smoothest ride, leave the front adjusting srews loose with two threads protruding through the nuts. Tighten rear srews suffiiently to prevent suspension from "bottoming" on al/ but the severest bumps. A firm setting should be used if a passenger is riding with the operator. ADJUSTING STEERING RESPONSE The Cylone and Liquifire are adjusted for maximum steering response and minimum lift on the skis at the fatory. The steering response an be dereased for trail or mountain riding in deep snow onditions by adjusting the steering response srews or repositioning the front pivot arm or both. The front pivot arm an only be repositioned on the 1976 Liquifire (Serial No. -70,000). By adjusting the steering response srews or repositioning the front pivot arm, weight transfer to the trak is inreased. This weight transfer allows the front end weight of the snowmobile to shift to the rear of the snowmobile. Fig. 17-Steering Response Adjusting Srews Adjust as follows: 1. Turning the srews, Fig. 17, out dereases steering response and gives lift to the skis. 2. Turning the srews in inreases steering response and dereases lift on the skis. 3. Adjust srews equally. IMPORTANT: On 340 and 440 Cylone, never bak the adjusting srews out any further than "flush" with the weld nut. On and 440 Liquifire (Serial No. 70,000), never bak adjusting srews out more than 0.37 inh (9.39 mm) when front pivot arm is in the upper hole. Dimension is from the underside of adjusting srew to the top of the loking nut.

219 SM-2108 (Aug-77) Slide Suspension ( Suspension -80,000) ( r Additional Ski Lift (1976 Liquifire Only) (Serial No. 50,001-70,000) This adjustment is to be used for extremely deep snow onditions when additional ski lift is needed beyond that whih an be aomplished with the steering response srews. 1. Lift and support the rear of the snowmobile so trak is lear of the ground. Bak out the trak adjusting srews to relieve trak tension. Fig. f8-maximum Ski Lift Adjustments 2. Bak out the front and rear suspension spring adjusting srews, Fig. 18, to relieve tension on the springs. 3. Bak out steering response adjusting srews. 4. Remove ap srew seuring front pivot arm shaft to right-hand slide rail. 5. Pull front pivot arm shaft with ap srew out the left-hand side of the snowmobile. 6. Move front pivot arm to the lower holes. Install shaft from left-hand side. Seure shaft to the righthand slide rail with ap srew. 7. Turn in steering response adjusting srews. When front pivot arm is in the lower hole, turn srews in so that end of srew is flush with bottom of bushing. Continuing to turn the srews in will derease ski lift. /). CAUTION: When front pivot arm is in the.. lower holes and steering response srews are baked out the maximum allowable distane, sudden starts will lift the skis ompletely off the snow. Avoid this type of start beause of lak of steering and the possibility of injury to the operator, passenger or both. 8. Install suspension spring adjusting srews. Adjust srews equally for desired ride. 9. Readjust trak tension. IMPORTANT: When front pivot arm is in the lower holes, trak should be adjusted to 1-1/2 to 2 inhes (38 to 50 mm) learane between grouser bars and slide rail. DO NOT adjust trak for less than this learane. 10. Remove support from rear of snowmobile. Ski Steering Control For optimum steering ontrol on ross ountry high speed running, skis should be installed to spindles by the front holes of the ski saddles. With skis in the front holes "astor" inreases and ski "darting" is held to a minimum. For slow trail riding move skis to rear holes to redue steering effort. NOTE: For optimum ride and steering ontrol (ross ountry high speed running) plae the slide suspension front pivot arm in the upper holes. Install skis to spindles by front holes of ski saddles. For slow trail riding, plae front pivot arm in upper holes and install skis to spindles by rear holes in ski saddles.

220 J 60 Suspension Slide Suspension ( -80,000) SM-2108 (Aug-77) ) J ).. )

221 SM-2108 (Aug-77) Suspension Slide Suspension (80,001- ) r Group SLIDE SUSPENSION (Serial No. 80,001- GENERAL INFORMATION 12 ) A-Replaeable Wear Bars B-Suspension Springs C-Shok Absorber D-Grouser Bar Trak Fig. 1-S/ide Suspension System The slide suspension system onsists of replaeable wear bars (A, Fig. 1), shok absorber (C), adjustable suspension springs (8) and a grouser bar trak (D). Replaeable polyethylene wear bars provide low frition between grouser bars and slide rail. The shok absorber dampens the suspension and the adjustable springs permit varying the degree of ride from soft to firm. The molded rubber bars and lugs in the trak give good tration on ie and during ornering. The molded-in-steel or riveted grouser bars provide good tration for aeleration. The steel grouser bars are also replaeable. -

222 60 Suspension 12-2 Slide Suspension (80,001- ) SM-2108 (Aug-77) REPAIR M2240BN l-flat Washer 2-Wear Strip 3-Pop Rivet 4--Trak Guide 5-Slide Rail 6-Shok Absorber Shaft 7-Lok Nut 8--Flat Washer 9-Slide Rail Cap 10-Cap Srew ll-cap Srew l2-self-tapping Bolt l3-wear Bar l4--spaer 15-Flat Washer 16-Cap Srew 17-Cap Srew l8--flat Washer 19-5paer 20-Cap Srew 21-Nut 22-Flat Washer 23-Cap Srew 24--Wear Bar Stop 25-Flat Washer 26-Rear Idler Wheel 27-Lok Nut 28--Cap Srew 29-Push Nut 30-Bumper 31-Rivet Fig. 2-Exploded View of Rear Idler and Slide Rails

223 SM-2108 (Aug-77) Suspension Slide Suspension (80,001 - ) ( M2240 '1N 1-Pivot Shaft 2-Pivot Spring 3-Cap Srew 4-Lok Nut 5-Flat Washer 6-Bolt 7-Pivot Shaft 8-Front Swing Arm 9-Spring 10--Hinge 11-Eye Bolt 12- Flat Washer 13-Lok Nut 14-Pivot Tube 15-Hinge Bolt 16-Shok Absorber 17-Cap Srew 18-Flat Washer 19-Axle 20--Shaft 21-Swing Arm Fig. 3-Exp/oded View of Pivots and Springs Removing Slide Suspension Remove suspension bolts, Fig. 4. Lift up rear of snowmobile to remove suspension. ~_2242NY Fig. 4-Removing Suspension

224 60 Suspension 12-4 Slide Suspension (80,001- ) Replaing Tunnel Wear Bars Replaing Idler Wheel Axle SM-2108 (Aug-77) Fig. 5-Replaing Tunnel Wear Bars Remove seat and suspension. Chisel off rivets holding tunnel wear bars, Fig. 5, from seat side and remove wear bars. A-Flat Surfae Fig. 7-Replaing Axle B-Adjusting Bolt Install new wear bars by installing rivets from wear bar side. Replaing Slide Suspension Wear Bars Whenever the idle wheel axle is being replaed, make sure the flat surfae, (A, Fig. 7) faes the adjusting bolt (8). ) ) Fig. 6-Removing Wear Bar NOTE: It is not neessary to remove the slide suspension to replae wear bars. 1. Remove rear stops. 2. Drive wear bar off slide rail with a hammer and hisel. 3. Drive wear bar onto slide rail with a soft mallet until it is flush with slide rail ap. 4. Install rear stops. Litho in U. SA

225 SM-2108 (Aug-77) Suspension Slide Suspension (80,001- ) Replaing Slide Suspension Components Any omponents that must be replaed on the suspension should be reinstalled as shown in Fig. 8. Replae hardware indiated by the arrows and apply Lotite. Installing Slide Suspension Support snowmobile on it's side. Plae suspension inside trak. Fig. 8-Replaing Slide Suspension Components Install front suspension bolts (A), Fig. 9. Disonnet the long end of rear pivot springs (8) from their anhor bolts to relieve tension. Install rear suspension bolts (A), Fig. 10. M22246NY A-Front Suspension Bolts B-Rear Pivot Springs Fig. 9-lnstalling Slide Suspension - Retension rear pivot springs (8). If neessary, tension trak as instruted on page A-Rear Suspension Bolts B-Rear Pivot Springs Fig. 10-lnstalling Slide Suspension (

226 Suspension Slide Suspension (80,001- ) SM-2108 (Aug-77) ADJUSTMENTS Adjusting Trak Tension Support rear of snowmobile so that trak is lear of ground. Adjusting Slide Suspension Springs Condition Spring Tension Heavy or Two Riders Rear Inrease Light Rider or Normal Riding Redue Deep Snow (for More Lift) Front Inrease Light Snow (for More Redue Steering Control) Fig. 11-Adjusting Trak Tension Tension the trak to have 0.00 to 0.25 inh (0.00 to 6.35 mm) between the inside of trak and bottom of,the wear bar, Fig. 11. Measure below the shok absorber mount and make sure both sides are equal. Tighten jam nuts. Start engine and idle trak slowly until it rotates several times. Shut off engine and allow trak to oast until stopped. DO NOT apply brake. Fig. 12-Tensioning Front Spring Turn adjusting nuts ounterlokwise to redue tension or lokwise to inrease tension, Fig. 12. Chek alignment as follows: 1. Rear idler wheels should run in enter of drive lugs. 2. Slide rail wear bar should run in enter of slide rail opening on eah side of trak. If not, retension trak. NOTE: Traks run to the loose side. For example, if the trak is too far to the left side, tighten the left side to move trak over. fi ny Fig. 13-Tensioning Rear Spring Plae long end of spring over bottom bolt to redue tension or top bolt to inrease tension, Fig. 13. Run trak again to rehek.

227 Suspension John Deere and Goodyear Traks Group 15 JOHN DEERE AND -GOODYEAR TRACKS GENERAL INFORMATION.. M21141 Fig. 1-John Deere and Goodyear Grouser Bar Traks - The Goodyear grouser bar trak, Fig. 1, is a molded rubber trak with nylon fabri and fiberglass ord. The steel grouser bars are molded into the rubber and are replaeable. The John Deere grouser bar trak, Fig. 1, is of a similar material but the grouser bars are riveted in plae rather than molded into the rubber. These bars are also replaeable. The traks are equipped with lugs on the inside of the trak whih engage with lugs on the drive wheels to provide smooth, effiient transfer of power. Eah grouser bar trak is date oded as shown in Fig. 1. The date ode is loated in two plaes on the trak, 180 degrees apart. The ode indiates the month and year of manufature and should be inluded on any warranty laim.

228 60 Suspension 15-2 John Deere and Goodyear Traks NOTE: The grouser bar traks are rugged and long-lasting, providing proper tension and alignment are maintained. The majority of trak failures are aused by operator abuse. GROUSER BAR TRACK ANALYSIS NOTE: A pith is the distane (enter-to-enter) from one drive lug to the other. Poor Bond (Goodyear Traks Only) J Failures Covered Under Warranty Ply Separation Fig. 4-Poor Bond of Rubber to Grouser Bar Fig. 2-Ply Separation Ply separation an be identified by obvious parting of the rubber from the tensile ords, Fig. 2, on any of the three belts. Trak Streth WARRANTY If a grouser bar dislodges due to poor bond of the rubber to the metal bar, it an be identified by lean, straight, untorn lines of rubber, usually aross the fae of all three belts, Fig. 4. Suh a failure will our EARLY in the use periqd. The metal grouser bar if found, will not have muh, if any, rubber adhering to it. Tensile Cord Misloated M16029NY -ONE PITCH Fig. 3-Measuring Trak for Streth Trak streth ours only on a used trak. The first indiation of trak streth is running out of adjustment on the trak-adjusting srews, making it impossible to adjust the trak. Remove the used trak and lay it flat. Measure ten pithes on the trak. This distane should not exeed 25.7 inhes (65.2 m), Fig. 3. TENSILE CORDS SHOULD EXTEND TO EDGE OF TRACK OR UP TO 1/2 INCH (12.70 mm) INSIDE EDGE M160J1Nl Fig. 5-Tensile Cord The heavy tensile ords, Fig. 5, whih are wound radially, should extend to the edge of the trak or not more than 1/2 inh (12.70 mm) inside the edge.

229 SM-21GB (Aug-77) Suspension John Deere and Goodyear Traks ( Variation in Trak Thikness Fig. 7-Grouser Bar Torn from the Trak - - Fig. 6-Variation in Trak Thikness A great variation in thikness, Fig. 6, ould ause the trak to vibrate and thump. A O.060-inh (1.52 mm) variane in trak thikness is the maximum allowed. Use a aliper and inside mirometer for measurements. Measurements should be taken on eah belt of the trak in four or five different plaes around the trak. Non-Warranty Failures Obstrution Damage Apparent uts, slashes or gouges in the surfae of the trak are aused by obstrutions suh as broken glass, sharp roks or buried steel. The trak is highly resistant to obstrutions but, invariably, damage will our during rapid aeleration or side-skidding over foreign objets. If the grouser bar is bent, broken, raked or torn from the trak due to buried objets, obstrutions or road hazards, neither repair nor replaement will be onsidered for warranty. When the grouser bar is torn from the trak, rubber will be torn away from the bonding area, Fig. 7. The metal grouser bar will be bent, broken or damaged and will have rubber adhering to the bar. Worn Grouser Bars Fig. 8-Worn Grouser Bars Exessively worn grouser bars, Fig. 8, are related to operating on rough and dry terrain suh as nonsnow overed fields, railroad and highway roadsides, gravel roads and other non-approved snowmobile field onditions. The polyethylene suspension wear bar beomes hot and sand, dirt and grit imbed in the wear bar ausing wear on the grouser bars. The suspension wear bars must be replaed.

230 60 Suspension 15-4 John Deere and Goodyear Traks Lug Damage Over-Tension Damage Fig. 9-Lug Damage Lug damage, Fig. 9, to the sides or rear edges of the lug is usually aused by lak of snow lubriation. Exessive trak tension, dirt or soil, (summer operating onditions) entering the drive mehanism is also a frequent ause. Raheting Damage Fig. 11-0ver-Tension Damge Tightening the trak too muh auses exessive frition between the polyethylene wear bars and the grouser bars. The wear bars will melt and adhere to the grouser bars, Fig. 11. The first indiation of this ondition is that the trak may "stik" or have a tendeny to "lok-up", ausing loss of engine horsepower. Loose Trak Damage Fig. 10-Raheting Damage Raheting damage, Fig. 10, to the top of the lugs is aused by insuffiient trak tension, pulling too great a load, or frequent prolonged periods of rapid aeleration. Constant "jak-rabbit" starts are not neessary with a snowmobile. Fig. 12-Loose Trak Damage Operating a trak loose auses the outer edge to flex too muh, resulting in damage as shown in Fig. 12. Some wear on the driving lugs may also be visible. Riding double (exessive weight) an also ause the trak to flex and break the edge. Litho in U. SA

231 Suspension John Deere and Goodyear Traks Impat Damage M16039NY Fig. 13-lmpat Damage Impat damage, Fig. 13, will ause the rubber on the tread side to open up allowing the ords to beome visible. This will happen in more than one plae. Edge Damage Broken Grouser Bar Grouser bar breakage is normal and expeted in the enter belt area of the trak. Grouser bars are nothed and installed in a staggered pattern. This predetermines the fatigue area for grouser bar breakage, preventing breaks in unwanted areas. If the grouser bar breaks but still remains seurely bonded to the enter of the trak, it is not neessary to replae the grouser bar. DISASSEMBLY AND REPAIR Replaing Grouser Bars Goodyear Traks NOTE: Bent or broken grouser bars an be replaed individually. If the grouser bar is broken in the enter but still seurely attahed to the belts it need not be replaed. NOTE: If the JDST-24 Lift and Repair Stand is not available, turn the snowmobile on its side. r Fig. 14-Edge Damage Edge damage of the type illustrated in Fig. 14, or similar damage, is the fault of the operator. The most frequent ause is tipping the snowmobile on its side to lear the trak, allowing the trak to ome in ontat with an abrasive surfae. A Fig. 15-Removing Grouser Bar (Trak Removed for Illustration Purposes) CAUTION: Be sure fuel tank has been drained and apped. Keep propane torh away from fuel tank area. Use a propane torh and apply heat to the grouser bar, Fig. 15. Clamp a "Vise-Grip" pliers to the grouser bar and twist the bar loose from the belt. NOTE: Use minimum heat required and break grouser bar loose from one belt at a time.

232 60 Suspension 15-6 John Deere and Goodyear Traks. Position new grouser bar in plae. Drill eight 3/16- inh (4.762 mm) holes in belts using the new grouser bar as a template. John Deere Traks NOTE: Bent or broken grouser bars an be replaed individually. If the JDST-24 Lift and Repair Stand is not available, turn the snowmobile on its side. A CAUTION: Be sure fuel tank has been drained and apped. Use a hammer and old hisel to remove rivets seuring grouser bar to trak. J ) Fig. l6-lnstalling Grouser Bar Use eight bolts and nuts (AM53418), Fig. 16, to seure grouser bar to trak. Install bolt from the inside or drive lug side of the trak, with nut to the outside. Tighten nut seurely and then peen the bolt tight against the nut using two hammers; one for baking and the other for peening. Fig. l7-grouser Bars Installed in a Staggered Pattern NOTE: When installing new grouser bars, nothes in bars should be installed in a staggered pattern as shown in Fig. 17. This predetermines the fatigue area for grouser bar breakage, preventing breaks in unwanted areas. I I I I ~ 00 ~ M21142 A-Small Head Stud Bolt B-Baking Plate C-Large Head Stud Bolt D-Hex. Nuts Fig. l8-lnstalling Grouser Bar Install new grouser bar with four small head stud bolts (A), four baking plates (8), five large head stud bolts (C) and nine hex. nuts (D) as shown in Fig. 18. NOTE: Be sure to assemble a baking plate (B) under the head of eah small head stud bolt (A). Small head stud bolts and baking plates must be installed as indiated in Fig. 1B, so they do not interfere with the idler wheels. IMPORTANT: Use a hammer and hisel to peen the end of eah stud bolt after tightening hex. nuts. J )' J

233 Suspension John Deere and Goodyear Traks Removing Trak and Drive Shaft Siphon all fuel from the fuel tank and use a syringe to remove oil from the hain ase. Close fuel shut-off valve. Remove battery, if snowmobile is so equipped. NOTE: If the JDST-24 Lift and Repair Stand is not available, turn the snowmobile on its side and remove the suspension. Remove drive belt and seondary sheave. Disonnet speedometer able from speedometer drive. Remove hain ase over. Remove upper and lower sprokets, hain and hain tensioner. Fig. 20-Removing Drive Shaft- Snowmobile (Serial No. -80,000) /IIustrated Remove ap srews seuring drive shaft flangettes to tunnel, Fig. 20. Slide drive shaft toward the hain ase side. Lift opposite end (with spaer) up far enough to lear tunnel and remove drive shaft. Remove trak from snowmobile. Installing Trak and Drive Shaft Install new trak in snowmobile tunnel. Fig. 19-Drive Wheels Positioned In The Center Snowmobile (Serial No. -80,000) /IIustrated - Remove bolts seuring drive wheels to drive shaft and slide drive wheels toward the enter, Fig. 19. This allows aess to bearing flangette ap srews. M14458NY Fig. 21-Assembling Drive Shaft- Snowmobile (Serial No. -80,000) /IIustrated Assemble bearing flangettes, bearings, and spaer on drive shaft as shown in Fig. 21. Lubriate and install O-ring on hain ase bearing. IMPORTANT: Loking flanges on bearings must fae splined end of drive shaft as shown in Fig. 21. Install new gasket on side of flangette faing the hain ase. Gasket stiks to flangette and is between flangette and hain ase.

234 60 Suspension 15-8 John Deere and Goodyear Traks SM-2108 (Aug-77) Insert speedometer ore into left-hand end of drive shaft. Attah bearing flangettes, spaer and speedometer drive to tunnel with three ap srews. Tighten all ap srews seurely. Move drive wheels into position and seure with bolt and lok nut. Install slide suspension. See page Turn the snowmobile right side up. Install sprokets, hain and hain tensioner in hain ase. NOTE: Upper and lower sproket must be aligned within inh (0.254 mm). Refer to page for orret method of aligning sprokets. Fig. 22-lnstalling Drive Shaft - Snowmobile (Serial No. -80,000) I/Iustrated Position drive shaft assembly in tunnel, splined end first, Fig. 22. IMPORTANT: Be ertain O-ring on bearing between flangettes on hain ase side is in orret position, or oil leakage will result. Seure hain ase bearing flangettes to hain ase with three ap srews, Fig. 22. Do not tighten ap srews until opposite bearing flangette is seured to tunnel. Install speedometer able to speedometer drive. Install seondary sheave and drive belt. Fill hain ase with SAE 90 oil. Install battery if snowmobile is so equipped. Fill fuel tank and open fuel shut-off valve. Adjusting Trak Tension Refer to page

235 SM-21GB (Aug-77) Suspension 60 Skis and Steering 20-1 GENERAL INFORMATION Group 20 SKIS AND STEERING A-Spindle Housing 8-Ski Spring C-Skis D-Steering Arm E-Tie Rod F-Steering Post Fig. 1-Skis and Steering The skis, Fig. 1, have replaeable wear rods, wear plates, mono-leaf springs, 3 or 4-leaf springs and shok absorbers. The 3 and 4-leaf springs are replaeable as a omplete unit only. Beause spring leaves wear out simultaneously, replaing only the broken leaf would result in early failure of another leaf. The ski spindles are mounted in replaeable bearings and the bearings are pressed into the spindle housings. The tie rod and drag link ends are olor-oded for onveniene; silver olor indiates right-hand threads, gold olor indiates left-hand threads. The tie rod, drag link and spindles are designed to bend rather than break when subjeted to severe shok loads. The one-piee handlebar steering olumn is mounted in rubber at the top and a replaeable nylon bushing at the bottom.

236 Suspension Skis and Steering SM-21GB (Aug-77) h CAUTION: Worn, bent, or damaged ski.. and steering omponents are unsafe. Remember, a snowmobile travels at near-highway speeds. ANALYSIS M19076NY Fig. 4-Steering Arms Spindle and Bushings N190?4NY A- Wear Plate B-Worn Wear Rod Fig. 2-Wear Plate and Wear Rod Replae the wear rods (8) on the skis if worn as shown in Fig. 2. Rapid wear of this type indiates operation without snow lubriation. Worn wear rods are unsafe beause they ause a loss of snowmobile maneuverability. Replae the ski wear plates (A, Fig. 2) if badly worn or damaged. If a worn out wear plate is not replaed, the ski spring will wear through the ski, making ski replaement neessary. Stripped spindle and steering arm splines, Fig. 4, indiate operation without steering arm attahing ap srews tight or improper installation of steering arm. Never fore steering arms into plae. A bent spindle, Fig. 4, indiates ski was subjeted to severe fores suh as hitting an obstrution at high speed or landing on one ski after jumping. Whenever damage of this type is found, losely examine the rest of the ski and steering mehanism for bends, damage or raks. Replae ski spindle bushings, Fig. 4, if worn, raked or damaged. M190?5NY A-Bent Ski Saddle B-Broken Ski Spring C-Pin Wear Fig. 3-Ski Spring, Saddle and Pin Replae ski springs (8) if found broken, Fig. 3, or damaged. Inspet ski saddles (A, Fig. 3) and replae if bent or damaged. A bent saddle indiates ski was subjeted to severe fores, suh as hitting an obstrution at high speed, or landing on one ski after jumping. Replae ski attahing pins (C, Fig. 3) if worn. M190?7NY Fig. 5-Tie Rod and Drag Link A bent tie rod or drag link, Fig. 5, indiates ski was subjeted to severe fores. Replae the tie rod or drag link and losely inspet the rest of the steering mehanism for damage. Replae tie rod and drag link ends, Fig. 6, if exessively loose. A loose end an ause sloppy steering and ould be a safety hazard. Litho in U. S.A.

237 Suspension Skis and Steering REPAIR p ( L M21143N r A-Lok Nut B-Wear Rod C-Ski D-Ski Bumper E-Mono-Ieaf Ski Spring F-Wear Plate Replaing Ski Wear Rods G-Cotter Pin H-Bumper Retainer (Liquifire) I - Ski Bumper J -3-leaf Ski Spring K- Drilled Pin L- Ski Spring Stop M- Ski Saddle N- Spaer O- Washer P-Cap Srew Q-Spindle R-Bushing S -Tie Rod End T -Jam Nut U -Steering Arm (Left-Hand Side) V -Steering Post W-Steering Post Bushing X-Drag Link V-Tie Rod Z-Steering Arm (Right-Hand Side) AA-Drag Link End BB-Adjusting Srew CC-4-Leaf Spring Fig. 6-Exp/oded View of Skis and Steering Mehanism Remove the lok nuts (8, Fig. 7) seuring the wear rod (A) to the ski. Pry wear rod down to get studs out of holes; then slide rod forward to remove bak of rod from rear hole (0) in ski, and remove. Plae forward end of new wear rod in position and slide it rearward, positioning bak end of rod and studs into holes in ski. Install lok nuts and tighten seurely. /1190?9NY A-Wear Rod B-Lok Nuts C-Front Hole D- Rear Hole Fig. 7-Rep/aing Wear Rod Replaing Wear Plates NOTE: Ski spring does not have to be removed to replae wear plate. Remove pin seuring forward end of ski spring. Lift spring up slightly and slide out old wear plate. Slide new wear plate into position, drop forward end of spring and seure with pin and otter pin.

238 60 Suspension 20-4 Skis and Steering Replaing Ski Springs The three- and four-leaf ski spring is available only as an assembly inluding the saddle, bumper retainer and bumper. The mono-leaf spring, saddle and bumper are also replaed as an assembly. The bumpers are replaeable individually on both springs. The saddle is replaeable on the three- and four-leaf springs. Replaing Ski Bumpers and Saddles Three- and Four-Leaf Springs ".---~, h " _" _,,_ ~ v ~_ ~ N _~_..., M1 9081NY A-lok Nuts B-Saddle C-Bumper Retainer O-Bumper..! l!Y A-Cap Srew B-Ski Spindle C-Cotter Pin O-Orilled Pin E-Wear Plate F-Ski Spring Stop Fig. B-Rep/aing Ski Springs Remove ap srew (A, Fig. 8) seuring the ski to the ski spindle (8). Remove ski spring stop (F) from spindle (8). Remove otter pins (C) and drilled pins (0, Fig. 8) seuring the spring assembly to the ski. Install new wear plate (E) if neessary. Install new spring assembly to ski with drilled pins and otter pins. Install spaer in ski spindle and plae ski spring stop over spindle. Attah ski assembly to spindle with ap srew, washer, and lok nut. Torque nut to 39 ft Ibs (53 Nm). Fig. 9-Three-Leaf Spring Remove the two lok nuts (A) seuring the saddle (8) and bumper retainer to the ski springs, Fig. 9. Remove the bumper retainer (C). Install a new bumper (D) and seure with bumper retainer and lok nuts. Tighten nuts to ft-ibs (47 to 58 Nm). IMPORTANT: Chek ondition of two ap srews seuring saddle and bumper retainer to ski springs. Replae ap srews if worn. Replae saddle if neessary. Mono-Leaf Spring The mono-leaf spring and saddle (A, Fig. 10) must be replaed as an assembly. The bumper (8) srews into the bottom of the saddle, and is replaeable. M NY A-Saddle B-Bumper Fig. to-mono-leaf Spring

239 Suspension 60 Skis and Steering 20-5 ( Replaing Ski Spindles and Bushings Remove ski and spring assembly and ski spring stop from the spindle. Remove spaer from the spindle. Remove the ap srew, washers and lok nut seuring the steering arm to the spindle and drive the spindle down and out of the front frame. Replae bushings if worn, damaged, or raked. Replae bushings as follows: Replaing Steering Arms Position handlebars and skis to point straight ahead. Remove exhaust silener. Disonnet tie rod from left- and right-hand steering arms. Disonnet drag link from right-hand steering arm. Remove steering arm retaining ap srews and lift arms off steering spindles. - - Fig. 11-Removing Steering Spindle Bushings 1. Use a drift punh to remove bushings as shown in Fig. 11. Drive lower bushing out from the top. Reverse proedure to remove the upper bushing. 2. Install new bushing until bushing bottoms on front frame. Use are not to rak or distort bushing during installation. Slide ski spindle up into plae from the bottom. Install spaer in spindle. Plae ski spring stop over the spindle and install ski and spring assembly. Seure with ap srew, washer, and lok nut. Tighten nut to 39 ft-ibs (53 Nm) torque. Fig. 12-Replaing Steering Arms With skis and handlebars pointing straight ahead, plae steering arm over spindle. To be sure steering arm is orretly installed, measure from the enter of the tie rod hole in the arm to the snowmobile frame. The approximate distane should be 5.9 inhes (14.9 m) as shown in Fig. 12. This distane may vary by 1/8-inh (3.175 mm) due to spline alignment of arm and spindle. When steering arm is positioned orretly on spindle, seure steering arm with ap srew, washers and lok nut. IMPORTANT: The approximate 5.9 inh (14.9 m) distane from steering arm to snowmobile frame is very important. This plaes the steering arms at the proper angle to prevent any interferene in steering effort. Connet tie rod and drag link to steering arms and align skis. See page Install exhaust silener.

240 Suspension Skis and Steering SM-21OB (Aug-77) Replaing Tie Rod and Drag Link Remove ap srews seuring tie rod and drag link. Remove tie rod through knok-out hole on left-hand side of pan. Replaing Steering Post Bushings Upper Bushing Install new tie rod. Attah gold-olored end to lefthand steering arm and silver-olored end to righthand steering arm. Silver olor indiates right-hand threads. Gold olor indiates left-hand threads. Install new drag link to steering post and righthand steering arm. Adjusting srew end of drag link must be attahed to steering arm. Align skis. Adjust drag link and tie rod. See page Replaing Steering Post Assembly Remove seat and air intak.. ~ silener. Close fuel shut-off valve and disonnet fuel line from in-line fuel filter. Remove fuel tank. Disonnet drag link from steering post. Remove otter pin and washer from bottom of steering post. Remove upper rubber bushing from bushing braket. Remove braket from dash. A-Lok Nuts Fig. 13-Replaing Upper Bushing B-Bushing Remove two lok nuts (A, Fig. 13) and lamp seuring bushing (8). Open bushing and remove from steering post. Install in opposite order. Lower Bushing Remove brake and throttle grips from handlebar. Pull up and twist and turn steering post to remove it. Reinstall in the opposite sequene. A-Washer B- Cotter Pin C-Bushing D-Washers E-Drag Link Fig. 14-Replaing Lower Bushing Disonnet drag link (E, Fig. 14) from steering post. Remove otter pin (8) and washer (A) from end of steering post. Slide steering post up suffiiently to remove two washers (D) and bushing (C). Install new bushing, plae two washers over steering post and slide it bak in plae. Seure with washer and otter pin. Litho in U. S.A.

241 Suspension 60 Skis and Steering 20-7 [ Aligning Skis ADJUSTMENT ( 5.9" " TUNNEL M /16" - MAX. Fig. 1S-Aligning Skis - Fig. 15 shows the proper positioning of the skis in relationship to the steering arms, tie rods and steering olumn. To align skis: 1. Raise the front of the snowmobile slightly to remove weight from the skis. 2. Position the handlebars straight ahead. 3. Measure the distane over the front and rear wear rod nuts. The two dimensions should be the same. 4. If the adjustment is neessary, remove the exhaust silener for aess to the tie rods. 5. Loosen the jam nuts on eah end of the lower tie rod. Rotate the tie rod until the skis are parallel and tighten the jam nuts. NOTE: Turn the tie rod toward the front of the snowmobile to spread the skis apart. Turn tie rod toward the rear of the snowmobile to bring the skis together. 6. To realign the handlebars, loosen jam nuts on both sides of the adjusting srew on the upper tie rod. Rotate the adjusting srew until the handlebars are aligned. Tighten the jam nuts. IMPORTANT: DO NOT exeed 1-5/16 inhes (33.34 mm) between tie rod and enter of tie rod end when adjusting the tie rod. DO NOT exeed two inhes (50.58 mm) between the drag link and drag link end when adjusting drag link. 7. After aligning the skis, make sure all the jam nuts are tight. Install the exhaust silener.

242 Suspension Skis and Steering SM-2108 (Aug-77) Eliminating Loose Steering M17620Y Fig. 16-Correting Loose Steering The two major auses of loose steering are as follows: 1. Exessively worn tie rod ends, Fig Exessively worn spindle bushings, Fig. 16. Tighten and replae parts as neessary. h CAUTION: Make it a habit to frequently.. hek steering omponents and hardware for ondition and tightness. )

243 SM-2108 (Aug-77) Suspension 60 Speifiations 25-1 "Group 25 SPECIFICATIONS TORQUE FOR HARDWARE Loation Torque Lower Chain Case Sproket Retaining Cap Srew ". " " " " " " " ". " " " ". " " " ". " ".. " " " " ". " " " " ". " " ". 30 to 38 ft-ibs (40 to 52 Nm) Driven Sheave Retaining Cap Srew " " " " " ". " " ". " " " " " " " " " ". " " " ". ".. " " ". "... ".. " "... " " ". 20 ft-ibs (27 Nm) Ski Mounting Cap Srew " ".. " " " ". " " ".. " " ".. " " " ". " " " " " " " " " " " " " ".. ". " ". " " ". " " ". " " ".. " " " ". " " " ".. " 39 ft-ibs (52 Nm) Ski Saddle to Ski Spring " ". " " " ". " " " " " " " " " ". " " ".. " " " ". " " " ". " " ".. " ". " " " ".. " " " ". " " ".. " " " ".. 35 to 43 ft-ibs (47 to 58 Nm) -

244 ) Suspension Speifiations SM-2108 (Aug-77)

245 .. - CONTENTS Page GROUP 5 - ESSENTIAL SERVICE TOOLS Engine Tools Cluth Tools Eletrial Tools Hand Tools GROUP 10 - CONVENIENCE SERVICE TOOLS Snowmobile Support Tools Engine Tools GROUP 15 - DYNAMOMETER TEST PRO- CEDURE General Information Set-Up Instrutions Operation Maintenane Dynamometer Test Worksheet The essential tools listed in this group will servie all John Deere. These essential tools are required for all snowmobile dealers. They an be ordered from: Servie Tool Division Owatonna Tool Co. P.O. Box 314 Owatonna, Minn ENGINE TOOLS Fig. 1-Cylinder Nut Wrenh M119J6NY JOM-SA Cylinder Nut Wrenh, Fig. 1, provides a means of removing and retorquing the ylinder-torankase nuts. Servie Tools 70 Essential Servie Tools 5-1 Setion 70 SERVICE TOOLS Group 5 ESSENTIAL SERVICE TOOLS NY Fig. 2-Starter Spring Winding Tool JOM-6 Starter Spring Winding Tool, Fig. 2, enables reoil starter springs to be rewound in a fast, safe and easy operation. Fig. 3-Piston Pin Servie Tools JOM-7 Piston Pin Servie Set, Fig. 3, is used to remove and install piston pins without damage to piston or rod bearings.

246 Servie Tools Esst:Jntial Servie Tools ENGINE TOOLS-Continued M12474NY Fig. 6-0ial Indiator Mounting Braket JDM-10 Dial Indiator Mounting Braket, Fig. 6, is used with JDM-15 or an equivalent dial indiator to measure the rankshaft runout. V Y Fig. 4-Crankshaft Bearing Servie Set and Bearing Tool Adapter Kit JDM-B Crankshaft Bearing Servie Set and JDM- 33 Bearing Tool Adapter Kit, Fig. 4, are used to remove and install the rankshaft bearings.. JOM NY Fig. 7-Spanner Wrenh M12~?3NY METRIC ~ CAP ~ ti l SCREI{S ~ Fig. 5-Flywheel Puller Assembly JDM-30 Spanner Wrenh, Fig. 7, is used to hold the axial ooling fan during assembly and disassembly proedures. JDM-9 Flywheel Puller Assembly, Fig. 5 is a versatile puller that inludes metri ap srews and washers to remove the flywheel. N18229NY Fig. 8-Flywheel Holding Tool JDM-64-1 Flywheel Holding Tool, Fig. 8, prevents the flywheel from rotating while removing and installing the retaining nut.

247 SM-2108 (Aug-77) Servie Tools 70 Essential Servie Tools 5-3 r.jdm-64-2 JOM-41-5 M182.JONY Fig. 9-Air Flow Meter JDM-64-2 Air Flow Meter is used to fine tune the Mikuni arburetors. CLUTCH TOOLS J OM- 82 M16045NY Fig. l2-john Deere (Comet) Drive Sheave Set JDM-41-A John Deere (Comet) Drive Sheave Set, Fig. 12, is used to remove, disassemble and assemble the drive sheave. The set onsists of JDM-41-1 Puller, JDM-41-2 Srew Assembly with Swivel and Ring, JDM-41-3 Spider Tool and JDM-41-4 Two Piee Nut and JDM-41-5 Hub Lok. M2108J Fig. 10-Chain Tensioner Tool JDM-82 Chain Tensioner Tool holds the hain tensioner "OPEN" during the installation of the drive hain and sprokets on 1976 Cylone and Liquifire. M21084 Fig. l3-engine and Cluth Aligning Tool JDM-81 Aligning Tool is used to aurately align the engine and seondary luth. This tool heks both enter distane and offset simultaneously on and 1978 Cylone and Liquifire. Fig. ll-ramp Plate Nut Wrenh JDM-12-2 Ramp Plate Nut Wrenh, Fig. 11, is used in onjuntion with JDM-41-4 to hold the Comet Cluth when removing retaining ap srew.

248 70 Servie Tools 5-4 Essential Servie Tools ELECTRICAL TOOLS M21085 Fig. 16-Speia/ Wiring Harness M12486NY Fig. 14-Continuity Tester JDM-14 Continuity Tester, Fig. 14, is used in onjuntion with JDM-15 Timing Indiator to quikly and aurately establish engine timing. It may also be used to loate open or losed eletrial iruits. JDM-74A-2 Speial Wiring Harness is used with the JDM-74 CD Tester to hek trigger output of the CDI system on and 440 Liquifire, 440 Cylone and 340 Cylone (Serial No. 70,401 and up). Fig. 17-Speia/ Wiring Harness JDM-74A-3 Speial Wiring Harness is used with JDM-74 CD Tester to hek stator output of the CDI system on and 440 Liquifire, 440 Cylone and 340 Cylone (Serial No. 70,401-up). M18233NY A-Tester B-Test Simulator C-Test Adapter D-Load Coil Fig. 15-Capaitor Disharge Ignition (COl) Tester JDM-74 Capaitor Disharge Ignition (COl) Tester, Fig. 15, onsists of the tester (A), test simulator (8), test adapter (C) and load oil (D). The tester measures peak energy output of CDI units, magneto harge and trigger oils. The ignition energy output is referened against a sale on the tester. The tester has two input ranges seleted by a toggle swith. The "LOW" range senses AC or DC voltage from 0.5 to 27 volts. The " HIGH" range senses AC or DC voltage from approximately 75 to 500 volts. M Fig. 18-Speia/ Wiring Harness JDM-74A -4 Speial Wiring Harness is used with JDM-74 CD Tester to hek trigger and stator output on 1975 JDX8 and 800 with CD ignition, , 340 and 440 Cylone and 340 and 440 Liquifire and Cylone (Serial No. 70,001-70,400). Litho in U.S.A

249 SM-2108 (Aug-77) Servie Tools 70 Essential Servie Tools 5-5 r HAND TOOLS M21088 Fig. 19-1gnition Test Plug JOM-74A-5 Ignition Test Plug is used to hek snowmobile ignition oil output. Allows servieman to hek ignition oils without removing oils from the engine. ADAPTERS Fig. 21-Pop Rivet Tool JOM-18 POp Rivet Tool, Fig. 21, is a heavy-duty hand-operated tool whih an be used with up to 3/16-inh diameter steel ore rivets. This tool an be used to replae the rivets of the grouser bars on the leated traks and for general appliation of pop rivets on the snowmobile hassis. Ml_2_48? N ~.~ Fig. 20-Snowmobi/e Timing Indiator JOM-15 Snowmobile Timing Indiator, Fig. 20, is a dial indiator graduated in inh inrements with a 1-inh range and ollar for fastening into the 14 mm and 18 mm spark plug hole. The adapters are also -- inluded. Use the indiator with the JOM-14 Continuity Tester to establish engine timing. The dial indiator an also be used with the JOM-10 Mounting Braket to measure rankshaft runout. In addition, this tool is required to hek rankshaft twist. -

250 70 Servie Tools 5-6 Essential Servie Tools

251 Servie Tools Conveniene Servie Tools r These tools are stritly for the onveniene of the mehani. They are not required but they will make any job quiker and easier. Group 10 CONVENIENCE SERVICE TOOLS SNOWMOBILE SUPPORT TOOLS - -!.f12489ny Fig. 1-Snowmobile Dolly JDM-17A Snowmobile Dolly, Fig. 1, is exellent for moving snowmobiles in or out of the servie shop or display area. Large 400 x 8 pneumati tires make for easy operation. One model fits all snowmobiles. Fig. 2-Rear Stand JDM-27 Rear Stand, Fig. 2, is designed to hold the snowmobile trak off the floor when the mahine is being servied or stored. JDST-24 Snowmobile Lift and Repair Stand, (Not Illustrated), is designed for most makes and models of snowmobiles. Raises and rotates mahines for preventive maintenane work. Allows servieman to position the unit at a onvenient working height to servie or repair diffiult-to-reah omponents. Can also be used in the sales showroom to show ustomers all the snowmobile features, inluding the underarriage. JDM-26 Fold-A-Ramp Loading Platform, (Not Illustrated), is a 41-inh wide, 1000 pound apaity ramp that attahes to a pikup tail gate. Folded the ramp is 36 inhes high. When ramp is lowered it extends 7 feet to the ground, making it easy to load or unload snowmobiles Tool Storage Panel (Not Illustrated) is a standard 24 x 28-1/2-inh pegboard panel for storage of tools not assigned to a speifi tool board. Uses standard pegboard hangers on 1 inh enters. Organizes and stores tools for ready aessibility. Complete with large "SERVICE TOOLS FOR JOHN DEERE" deals.

252 70 Servie Tools 10-2 Conveniene Servie Tools ENGINE TOOLS M12488NY M12492NY Fig. 3-Benh Mounted Servie Fixture JOM-16 Benh Mounted Servie Fixture, Fig. 3, will beome an indispensable item in your shop. The universal design enables you to mount all onsumer produt engines, as well as hydrostati units, seletive ontrol valves, hydrauli pumps and many more omponents. When mounted, any omponent weighing 350 pounds or less may safely be rotated 360 degrees with positive stops at 90 degree inrements. Fig. 4-Ring Compressor JOM-35 Ring Compressor, Fig. 4 is a band-type ring ompressor with two adapters, apable of use with piston diameters of 2-1/8 inh to 2-5/8 inh. Holds rings in ompressed position when installing piston in all John Deere snowmobile engines. U12493!lY Fig. 5-Piston Lok Ring Plier JOM-36 Piston Lok Ring Plier, Fig. 5 provides an easy way to install all sizes of piston pin lok rings safely and easily without destroying the rings. J

253 Servie Tools 70 Conveniene Servie Tools 10-3 JDM-75 o { M18234NY Fig. 8-Carburetor Choke Gauge JOM-75 Carburetor Choke Gauge, Fig. 8, is used to orretly set the hoke plunger on Mikuni Carburetors. M134?3NY Fig. 6-Pressure Testing Tool JOM-44 Pressure Testing Tool, Fig. 6, onsists of a ontrol valve, pressure gauge, rubber sheet, hoses and lamps. These items are used to seal the intake and exhaust system to pressure test the engine rankase. M182J5NY Fig. 9-Non-Magneti Feeler Gauge Set JOM-76 Non-Magneti Feeler Gauge Set, Fig. 9, is used to set the points on snowmobile engines. - M18232NY JDM Fig. 7-Cooling System Tester JOM-73 Cooling System Tester, Fig. 7, is used to test the system pressure and pressure ap of Liquid Cooled. It is used in onjuntion with JDM-44 Pressure Gauge. IMPORTANT: JOM-73-3 Adapter is required when pressure testing aps on snowmobiles (Serial No. 70,001- ). Litho in U. S.A.

254 Servie Tools Conveniene Servie Tools Litho in U.S.A

255 SM-2108 (Aug-77) Servie Tools 70 Dynamometer Test Proedure 15-1 r The JDM-45 Dynamometer is designed to do the following: 1. Chek total engine performane. 2. Chek operation of drive and driven sheaves. 3. Chek out overall snowmobile performane. 4. Chek trak alignment and suspension operation. 5. Perform pre-delivery heks on new snowmobiles. 6. Evaluate ondition of snowmobiles for trade-in value. Group 15 DYNAMOMETER TEST PROCEDURE GENERAL INFORMATION To order the JDM-45 Dynamometer ontat: Servie Tool Division Owatonna Tool Company P.O. Box 314 Owatonna, Minnesota SET-UP INSTRUCTIONS e..'~--- - l n... A-Drive-On Ramp and Defletor Shield 8-Control Console C-Pressure Gauge D-Speedometer E-System Load Valve F-Front Safety Ties G-Reservoir and Support Platform H-Slide Rail Lubriators I -Drive Trak Fig. 1-JDM-4S Dynamometer

256 Servie Tools Dynamometer Test Proedure SM-2108 (Aug-77) Perform the following steps when preparing the unit for use. 1. Remove four ap srews and left-hand front side panel from unit. 2. Attah the instrument pakage and onsole post with four ap srews, washers, and grommets. Remove hydrauli hoses and wiring harness from inside tunnel and install. 3. Plug the wiring harness into the onnetion in the side tunnel. Attah short hydrauli hose to relief valve and long hose to reservoir. Make ertain all onnetions are tight. Replae left-hand front side panel with four srews. 4. Remove the reservoir filler ap and add approximately 30 gallons of Hy-Gard Transmission and Hydrauli Oil or Dexron automati transmission fluid or Type A, Suffix A automati transmission fluid. 5. Set-up the trak lubriation system in the following sequene. a. Remove spray bar ap and spray bar assem bly through the openings in the side over from either end of the mahine. Seure the assembly to the Dynamometer frame with one thumb srew. Thread it through the mounting braket and into the side over bolt hole diretly above the water-valve. On the opposite side of the Dynamometer, plae the aluminum a - ring spray bar ap over the turned-down portion of the spray bar and push in until the roll pins hook behind the side panel. Rotate fitting 90 degrees so the outlet onnetion points down. b. Loate the water spraying assemblies, one on eah side of the Dynamometer, with four spring braket assemblies. Attah the four spring mounted spray heads by slipping the springs through them two to eah side.. Attah a garden hose between the valve and a onvenient water fauet. By opening the watervalve, water will now be direted to the inside of the dynamometer trak. This provides oolant for the drive sprokets and should always be used when operating the mahine at temperatues above freezing. Below 32 F (O C) snow or liquid detergent should be applied to the inside of the trak. Sine the spray bar and spray heads annot be drained, they should be removed and stored inside when freezing temperatures are expeted. d. By attahing the quik ouplers on the water spray assembly to the spray bar assembly, water will be direted to the heads both at the front and enter of the mahine on either side. The front spray jets should be direted at a point where the dynamometer and snowmobile traks ome together. On slide rail mahines, eah jet is to be direted at the openings in the trak where the slide rails ride. This will provide the oolant for the front half of the slide rails. Side jets should be direted at a point on the slide rail frame midway along the trak and just above the rails. In this manner, water will run down and along the rails providing oolant for the bak half of the slide rails. Below freezing, snow should be used to ool the slide rails. IMPORTANT: The slide rails will seize without some means of ooling. 6. Fasten safety hain to right side rail tube with ap srew, washer, and nut. Slide tubing over hain. Thread strap assembly through bukles on eah side of reservoir. 7. Plae hith post assembly in its position at rear of Dynamometer. Position bak ramp over hooks provided on the rear of the Dynamometer. The ramp is equipped with a safety shield.

257 Servie Tools 70 Dynamometer Test Proedure 15-3 r Perform the following steps in testing a snowmobile on the Dynamometer. Be ertain to observe all CAUTIONS and IMPORTANTS during testing. Prior to operation, and before starting the vehile, read through the instrutions to obtain a knowledge of the equipment and its funtion. Proeed as follows: 1. Drive the snowmobile onto the Dynamometer. Position the snowmobile so that the rear idler is over the last idler shaft on the Dynamometer. NOTE: Adjust snowmobile arburetor to speifiation or to a slightly rih ondition prior to running initial test. 2. Open the trap door on the rear ramp and insert the hith post into the hith soket. Seure the snowmobile and Dynamometer hithes together using levis pin on hith post. If the snowmobile is not equipped with a hith, hain the unit to the hith post. /). CAUTION: Do not allow anyone to stand.. in the area behind the snowmobile while it is running. There is danger of flying debris from the trak. OPERATION /). CAUTION: Do not operate snowmobile in.. a onfined and poorly ventilated working area. Attah neessary exhaust hose and or blowers. Carbon monoxide is a deadly gas. IMPORTANT: The operator should be ertain to wear a hearing protetor that omplies with OSHA standards as the noise level of a snowmobile on a dynamometer in an enlosed area is extremely high. 5. When starting a test sequene, the dynamometer pump should be set for zero pressure. This is done by turning the pressure ontrol valve fully ounterlokwise. 6. Hook up the remote engine tahometer to the snowmobile engine. 7. Turn on the water for ooling during the test. 8. Start the snowmobile and run at part throttle no load, until snowmobile and dynamometer have reahed normal operating temperatures. Now operate snowmobile at full throttle, no load, and reord the zero pressure engine and trak speed on the reording pads loated in the ontrol onsole. IMPORTANT: The hith post is so designed and loated to hold the ramp safety shield open. This forms a safety guard behind the snowmobile that stops and deflets downward debris that ould be projeted bak by the traks. Do not attempt to defeat this purpose. 3. Position the safety hain around the front of the snowmobile ski pivot spindles and hook to the stud welded on Dynamometer reservoir. 4. Hook safety straps to inside edges of skis. Best results will be obtained if the rear hith takes the strain of the snowmobile pulling forward, and the front safety hain and entering straps are somewhat slak. Best tration, with no slipping between the snowmobile trak and the Dynamometer trak results when the onnetion bar to the snowmobile rear hith angles up a bit, therefore pulling the rear of the snowmobile down as the mahine strains forward. NOTE: Too muh down pull will inrease trak wear. 9. Inrease the trak load from zero to 500 psi by turning the pressure ontrol valve lokwise while still maintaining full throttle. Reord the engine and trak speed. 10. Continue to inrease the trak load and reord the trak and engine speeds in inrements of 250 psi until the driven sheave is fully bak shifted. /). CAUTION: Do not ontinue to inrease.. the load after the driven sheave is fully bak shifted or damage to the snowmobile may our. IMPORTANT: The snowmobile should be run on the dynamometer only long enough to get the neessary information and/or heks. The snowmobile running on the dynamometer is not moving and engine ooling, in warm weather, is limited. Judgement is required to avoid overheating engines. A fan blowing air aross the ylinder ooling fins will help. Litho in U. S.A.

258 70 Servie Tools 15-4 Dynamometer Test Proedure OPERATION- 11. Adjustments to the snowmobile may now be made. A seond run should be made from zero pressure at full throttle through a full luth shift and the engine and trak speeds, reorded for omparison to those prior to the tune-up. Continued 12. Approximate trak horsepower may be obtained from the graph on page Join the point on the pressure urve diretly above the appropriate trak speed with the trak horsepower, read diretly to the left of this point. MAINTENANCE IMPORTANT: When running the dynamometer for long periods at high loads, the reservoir oil wi" beome hot. If you annot hold your knukle against the side of the reservoir without disomfort, allow oil to ool. Perform the following maintenane on the Snowmobile Dynamometer if it is neessary. Under normal usage and with proper are, the unit needs only periodi tightening and inspetion. Replaing Trak In the event the Dynamometer trak should require replaement, proeed as follows: 1. Disonnet the spray head quik ouplers from the spray bar. 2. Remove spray bar ap. 3. Remove the spray bar. 4. Remove side panels from both sides. 5. Loosen the trak adjustment srews and swing them out of the way (one on eah side). 6. Loosen the two rear idler frame mounting bolts at the rear of eah tunnel and slide the frame fully forward. 7. Disonnet wires from speedometer sender unit. 8. Remove all nuts and bolts from inside the righthand tunnel. 9. Remove the right-hand tunnel. 10. Replae the trak. 11. Replae the right-hand tunnel and all attahing nuts and bolts. 12. Slide the rear idler frame bak untir the trak adjustment srews an be swung into plae. 13. Tighten the trak by drawing up the adjusting srews alternately until there is approximately 8-3/4 to 9 inhes measured inside between the top and bottom of the trak. This adjustment is important sine it insures the proper engagement between the trak pithline and the sprokets. 14. Tighten rear idler frame ap srews. 15. Reonnet speedometer sending unit wires. 16. Replae side panels and hardware. 17. Replae spray bar, spray bar ap and make quik onnetions. Changing Oil Under normal ond itions the only time an oil hange is neessary is: 1. If water gets in the oil. 2. Unit has been allowed to run too hot and oil appears and smells burned.,.