Service and Repair Manual 5500 Watt Portable Generator Model

Transcription

1 Service and Repair Manual 5500 Watt Portable Generator Model This generator is rated in accordance with CSA (Canadian Standards Association) standard C22.2 No (motors and generators). BRIGGS & STRATTON POWER PRODUCTS GROUP, LLC Manual No GS Revision A

2 Briggs & Stratton Power Products Group, LLC P.O. Box 702 Milwaukee, WI Copyright All rights reserved. No part of this material may be reproduced or transmitted in any form without the express written permission of Briggs & Stratton Power Products Group, LLC. 2 BRIGGSandSTRATTON.COM

3 Table of Contents Important Safety Instructions Generator Components Alternator Components Generator Troubleshooting Alternator Disassembly Generator Specifications Generator Wiring Diagram Generator Schematic Engine Maintenance Engine Adjustments Fuel System and Carburetion Governor System Cylinder Head and Valves Starters Lubrication Systems Cylinders, Covers, and Sumps Crankshafts and Camshafts Piston, Rings, and Connecting Rod Engine Specifications Generator Illustrated Parts List Engine Illustrated Parts List

4 Equipment Description Save These Instructions Important Safety Instructions Read this manual carefully and become familiar with your generator. Know its applications, its limitations and any hazards involved. The generator is an engine-driven, revolving field, alternating current (AC) generator. It was designed to supply electrical power for operating compatible electrical lighting, appliances, tools and motor loads. The generator s revolving field is driven at about 3,600 rpm by a single-cylinder engine. NOTICE: Exceeding generator s wattage/amperage capacity could damage generator and/or electrical devices connected to it. DO NOT exceed the generator s wattage/amperage capacity. Every effort has been made to ensure that the information in this manual is both accurate and current. However, the manufacturer reserves the right to change, alter, or otherwise improve the generator and the documentation at any time without prior notice. The manufacturer cannot possibly anticipate every possible circumstance that might involve a hazard. The warnings in this manual, and the tags and decals affixed to the unit are, therefore, not all-inclusive. If you use a procedure, work method or operating technique that the manufacturer does not specifically recommend, you must satisfy yourself that it is safe for you and others. You must also make sure that the procedure, work method or operating technique that you choose does not render the generator system unsafe. Safety Symbols and Meanings Toxic Fumes Kickback Electrical Shock Fire Explosion Read Manual The Emission Control System for this generator is warranted for standards set by the Environmental Protection Agency and the California Air Resources Board. Moving Parts Flying Objects Hot Surface The safety alert symbol indicates a potential personal injury hazard. A signal word (DANGER, WARNING, or CAUTION) is used with the alert symbol to designate a degree or level of hazard seriousness. A safety symbol may be used to represent the type of hazard. The signal word NOTICE is used to address practices not related to personal injury. DANGER indicates a hazard which, if not avoided, will result in death or serious injury. WARNING indicates a hazard which, if not avoided, could result in death or serious injury. CAUTION indicates a hazard which, if not avoided, could result in minor or moderate injury. NOTICE addresses practices not related to personal injury. 4 BRIGGSandSTRATTON.COM

5 WARNING Starter cord kickback (rapid retraction) will pull hand and arm toward engine faster than you can let go, which could cause broken bones, fractures, bruises, or sprains resulting in serious injury. When starting engine, pull cord slowly until resistance is felt and then pull rapidly to avoid kickback. NEVER start or stop engine with electrical devices plugged in and turned on. WARNING Running engine gives off carbon monoxide, an odorless, colorless, poison gas. Breathing carbon monoxide can cause headache, fatigue, dizziness, vomiting, confusion, seizures, nausea, fainting or death. Operate generator ONLY outdoors. Install a battery operated carbon monoxide alarm near the bedrooms. Keep exhaust gas from entering a confined area through windows, doors, ventilation intakes, or other openings. DO NOT operate this product inside any building, carport, porch, mobile equipment, marine applications, or enclosure, even if windows and doors are open. WARNING The engine exhaust from this product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. WARNING Certain components in this product and related accessories contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands after handling. WARNING This generator does not meet U.S. Coast Guard Regulation 33CFR-183 and should not be used on marine applications. Failure to use the appropriate U.S. Coast Guard approved generator could result in death or serious injury and/or property damage. WARNING Fuel and its vapors are extremely flammable and explosive which could cause burns, fire or explosion resulting in death, serious injury and/or property damage. WHEN ADDING OR DRAINING FUEL Turn generator engine OFF and let it cool at least 2 minutes before removing fuel cap. Loosen cap slowly to relieve pressure in tank. Fill or drain fuel tank outdoors. DO NOT overfill tank. Allow space for fuel expansion. If fuel spills, wait until it evaporates before starting engine. Keep fuel away from sparks, open flames, pilot lights, heat, and other ignition sources. Check fuel lines, tank, cap and fittings frequently for cracks or leaks. Replace if necessary. DO NOT light a cigarette or smoke. WHEN STARTING EQUIPMENT Ensure spark plug, muffler, fuel cap, and air cleaner are in place. DO NOT crank engine with spark plug removed. WHEN OPERATING EQUIPMENT DO NOT operate this product inside any building, carport, porch, mobile equipment, marine applications, or enclosure. DO NOT tip engine or equipment at angle which causes fuel to spill. DO NOT stop engine by moving choke control to Choke position ( ). WHEN TRANSPORTING, MOVING OR REPAIRING EQUIPMENT Transport/move/repair with fuel tank EMPTY or with fuel shutoff valve OFF. DO NOT tip engine or equipment at angle which causes fuel to spill. Disconnect spark plug wire. WHEN STORING FUEL OR EQUIPMENT WITH FUEL IN TANK Store away from furnaces, stoves, water heaters, clothes dryers, or other appliances that have pilot light or other ignition source because they could ignite fuel vapors. 5

6 WARNING Generator voltage could cause electrical shock or burn resulting in death or serious injury. Use approved transfer equipment to prevent backfeed by isolating generator from electric utility workers. When using generator for backup power, notify utility company. Use a ground fault circuit interrupter (GFCI) in any damp or highly conductive area, such as metal decking or steel work. DO NOT touch bare wires or receptacles. DO NOT use generator with electrical cords which are worn, frayed, bare or otherwise damaged. DO NOT operate generator in the rain or wet weather. DO NOT handle generator or electrical cords while standing in water, while barefoot, or while hands and feet are wet. DO NOT allow unqualified persons or children to operate or service generator. WARNING Exhaust heat/gases could ignite combustibles, structures or damage fuel tank causing a fire, resulting in death, serious injury and/or property damage. Contact with muffler area could cause burns resulting in serious injury. DO NOT touch hot parts and AVOID hot exhaust gases. Allow equipment to cool before touching. Keep at least 5 feet (152 cm) of clearance on all sides of generator including overhead. It is a violation of California Public Resource Code, Section 4442, to use or operate the engine on any forestcovered, brush-covered, or grass-covered land unless the exhaust system is equipped with a spark arrester, as defined in Section 4442, maintained in effective working order. Other states or federal jurisdictions may have similar laws. Contact the original equipment manufacturer, retailer, or dealer to obtain a spark arrester designed for the exhaust system installed on this engine. Replacement parts must be the same and installed in the same position as the original parts. WARNING Unintentional sparking could cause fire or electric shock resulting in death or serious injury. WHEN ADJUSTING OR MAKING REPAIRS TO YOUR GENERATOR Disconnect the spark plug wire from the spark plug and place the wire where it cannot contact spark plug. WHEN TESTING FOR ENGINE SPARK Use approved spark plug tester. DO NOT check for spark with spark plug removed. WARNING Starter and other rotating parts could entangle hands, hair, clothing, or accessories resulting in serious injury. NEVER operate generator without protective housing or covers. DO NOT wear loose clothing, jewelry or anything that could be caught in the starter or other rotating parts. Tie up long hair and remove jewelry. WARNING Excessively high operating speeds could result in minor injury and/or generator damage. Excessively low speeds impose a heavy load. DO NOT tamper with governor spring, links, or other parts to increase engine speed. Generator supplies correct rated frequency and voltage when running at governed speed. DO NOT modify generator in any way. NOTICE Exceeding generators wattage/amperage capacity can damage generator and/or electrical devices connected to it. DO NOT exceed the generator s wattage/amperage capacity. Start generator and let engine stabilize before connecting electrical loads. Connect electrical loads in OFF position, then turn ON for operation. Turn electrical loads OFF and disconnect from generator before stopping generator. NOTICE Improper treatment of generator can damage it and shorten its life. Use generator only for intended uses. If you have questions about intended use, contact your authorized dealer. Operate generator only on level surfaces. DO NOT expose generator to excessive moisture, dust, dirt, or corrosive vapors. DO NOT insert any objects through cooling slots. If connected devices overheat, turn them off and disconnect them from generator. Shut off generator if: -electrical output is lost; -equipment sparks, smokes, or emits flames; -unit vibrates excessively. 6 BRIGGSandSTRATTON.COM

7 Generator Components A R B C P D N E F M L G K H J A - Fuel Tank Capacity of seven (7) U.S. gallons (26.5 L) B - Fuel Valve Used to turn fuel supply on and off to engine. C - Choke Lever Used when starting a cold engine. D - Air Cleaner Protects engine by filtering dust and debris out of intake air. E - Recoil Starter Used to start the engine. F - Engine Rocker Switch Set this switch to ON before using recoil starter. Set switch to OFF to stop engine. G - Oil Fill Cap Check and fill engine with oil here. H - Oil Drain Plug Drain engine oil here J - Grounding Fastener Consult your local agency having jurisdiction for grounding requirements in your area. K - Identification Label Provides model, revision, and serial number of generator. Please have this readily available when calling for assistance. L - Rocker Switch Circuit Breaker The receptacles are provided with a rocker switch circuit breaker to protect the generator against electrical overload. M - 120/240 Volt AC, 30 Amp Locking Receptacle May be used to supply electrical power for the operation of 120 and/or 240 Volt AC, 30 Amp, single phase, 60 Hz electrical, lighting, appliance, tool, and motor loads. N - Spark Arrester Muffler Exhaust muffler lowers engine noise and is equipped with a spark arrester screen. P - Engine Data Tag Provides model, type, trim, and date code for the engine. R Volt AC, 20 Amp, Duplex Receptacles May be used to supply electrical power for the operation of 120 Volt AC, 20 Amp, single phase, 60 Hz electrical, lighting, appliance, tool, and motor loads. 7

8 Alternator Components E J A H B C D G F E A - Alternator Adapter B - Rotor Assembly C - Slip Rings D - Stator E - Roll Pin F - Rear Bearing Carrier G - Taptite H - Brush Holder / Bridge Rectifier Assembly J - Hex-Head Cap Screw 8 BRIGGSandSTRATTON.COM

9 Brush Holder / Bridge Rectifier Assembly This generator is equipped with a bridge rectifier (A, Figure 1) attached to the brush holder assembly (B). A How it Works Figure 3 is an operating diagram of a revolving field alternator with a bridge rectifier. C B A C D F B Figure 1 The brush holder is mounted to the rear bearing carrier. The positive (+) brush contacts the slip ring nearest the rotor bearing. E G B The bridge rectifier is made up of four diodes and a varistor, shown schematically in Figure 2. The diode (rectifier) permits current flow in one direction only. Stator excitation winding (AC) output leads connect to the two terminals labeled J1 and J2 (C, Figure 1) located on top of the bridge rectifier. Direct current (DC) is taken from the bridge rectifier and applied to the rotor via the brush and slip rings. The varistor is a variable resistor which protects the diodes against high voltage surges. Figure 2 NOTICE: The brushes are made of a carbon material and can easily break. Use care when removing and installing the brushes. Figure 3 A - Rotor D - Bridge Rectifier B - Magnetic Lines of Flux E - Power Winding C - Excitation Winding F - Receptacle G - Slip Ring The brush rectifi er acts to supply direct current (DC) fl ow to the rotor winding. The increase in current fl ow through the rotor results in a proportional increase in the rotor s magnetic fi eld strength, which induces alternating currect (AC) in the windings of the stator. 1. The rotor (A) may be considered a permanent magnet since some residual magnetism is always present in the steel laminations. 2. The rotor (A) is rotated at a pre-determined speed. 3. Residual or stored magnetism in the rotor winding creates magnetic lines of flux (B) which cut through stator excitation winding (C) and power winding (E), to induce Electro Motive Force (EMF) into both windings. 4. Winding (C) is the excitation winding. The EMF induced into this winding produces an alternating currect (AC) flow, which is applied to a bridge rectifier (D). 5. The bridge rectifier changes alternating current (AC) into direct current (DC). 6. Direct current (DC) from the bridge rectifier is applied to the rotor windings (A) via the slip rings (G) and brush assembly, to create a magnetic field that is stronger than that created by the residual magnetism of the rotor. 7. This stronger magnetic field induces a greater EMF (and resulting current flow) into both stator windings (C and E). 8. The cycle then repeats itself until a predetermined (AC) output is reached. Any load(s) connected to the receptacle (F) completes circuit. 9

10 Generator Troubleshooting Refer to Figure 4 for wire identification and locations when performing the troubleshooting procedures. LEGEND WIRE NUMBER WIRE COLOR 0 Green 2 Red 6 Blue 11 Blue 22 Red 33 Black 44 Gray Figure 4 10 BRIGGSandSTRATTON.COM

11 Figure 5 is a troubleshooting flowchart for Direct Excited (Brush Type) generators. Test 1: Check AC output voltage and frequency Low voltage less than 1 volt or zero? Low voltage and frequency Test 2: Flash the Field Check and Adjust Engine Governor NO Output OK? YES END Output OK? YES END NO Test 3: Isolate Control Panel Output OK at Harness? NO YES See: Check Alternator Inspect Control Panel Figure 5 11

12 TEST 1 - Check Voltage and Frequency Output 1. Disconnect any electrical loads. 2. Check all circuit breakers and verify they are ON. 3. Set meter to measure AC volts. 4. Connect the meter test leads into a 120 VAC generator receptacle. 5. Connect a frequency meter into a generator receptacle. 6. Start the generator engine, let it stabilize and warm up. 7. Read the no-load voltage and frequency, and analyze the results as follows: If zero volts or less than 1VAC is indicated proceed to Test 2 - Flash the Field. If low voltage is indicated, but readings is above 1VAC and AC frequency is normal proceed to Test 3 - Isolate the Control Panel. If low voltage is indicated, but reading is above 6VAC and AC frequency is low the engine governor may need adjustment. Refer to the appropriate engine manual for further governor troubleshooting. TEST 2 - Flash the Field In normal generator operation, upon startup there is some residual magnetism in the rotor to get the generating process started. Residual magnetism is what is left in the rotor after the unit has shut down. When residual magnetism is lost, the unit will have an output voltage that will remain at zero. This usually occurs if the unit is out of use for a long period of time. If residual magnetism is lost, it can usually be restored by fl ashing the fi eld with a simple process involving a (DC) battery. 1. Obtain a 12VDC battery and two jumper leads with alligator clip ends. 2. Remove the four screws and remove the rear bearing cover. 3. Locate the brush/bridge rectifier inside the rear bearing carrier. 4. Remove wires #2 and #6 (red and blue) from the rectifier terminals J1 and J2. NOTICE: Isolate wires #2 and #6. Do not let the terminals touch or contact ground. 5. Apply 12VDC across terminals J1 and J2, polarity is not important. Connect battery negative last (Figure 6). WARNING Battery posts, terminals and other components in this product and related accessories contain chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. Wash hands after handling. WARNING Starter and other rotating parts could entangle hands, hair, clothing, or accessories resulting in serious injury. NEVER operate generator without protective housing or covers. DO NOT wear loose clothing, jewelry or anything that could be caught in the starter or other rotating parts. Tie up long hair and remove jewelry. WARNING Generator voltage could cause electrical shock or burn resulting in death or serious injury. DO NOT touch bare wires or receptacles. DO NOT allow unqualified persons or children to operate or service generator. Figure 6 6. Start the engine and allow it to stabilize at running speed. 7. After about 5 seconds, shut the engine down. 8. Disconnect the battery wires from the brushes. (Disconnect negative (-) battery wire last). 9. Restart the unit and check once again for proper (AC) output voltage. If output voltage is within specifications, troubleshooting is complete. If output voltage is not within specifications, proceed to Test 3- Isolate Control Panel. 12 BRIGGSandSTRATTON.COM

13 TEST 3 - Isolate Control Panel A No Output condition may or may not be related to the alternator windings. To help isolate where the issue is, follow these steps: 1. With the engine OFF, disconnect the power lead harness from the back of the control panel. 2. Set meter to measure AC volts. 3. Connect the test leads to the stator wires #11 and #22 located in the control panel connector. Polarity does not matter. 4. Start the engine and measure the voltage output. 5. Shut off the engine. A voltage output of 120VAC indicates the alternator is functioning, and the no output condition is likely in the control panel. Disassemble the control panel and inspect for any indication of what may cause no output. Refer to the unit wiring diagram to verify connections. A low voltage output indicates the alternator needs to be tested. Proceed to Check Alternator. Check Alternator Alternator Disassembly The alternator can be diagnosed without complete disassembly. To access the power winding, disconnect the connector from the back of the control panel. The Brush Rectifi er (D) is mounted inside the rear bearing carrier (E, Figure 7). To access the brush rectifi er, remove the four screws (A) and remove the plastic, rear bearing cover (B). Remove the two screws (C) and carefully pull out the brushes. Disconnect wires #2 and #6 (excitation winding). Once removed, the rotor slip rings can be accessed through the area where the brushes were mounted. C E NOTICE: The brushes are made of a carbon material and can easily break. Use care when removing and installing the brushes. D A Figure 7 B 13

14 Measure Winding Resistance Test Stator AC Power Winding Resistance 1. Set meter to measure Ohms. 2. Connect the test leads to stator wires #11 and #22 located in the harness going to the control panel connector (Figure 8). Figure 9 Figure 8 3. Measure the resistance and compare it the nominal resistance from the specifications listed in the back of this manual. 4. Connect the test leads to stator wires #33 and #44 located in the control panel connector (Figures 9). 5. Measure the resistance and compare it to the nominal resistance listed in the back of this manual. A reading within the specifications listed is acceptable. A reading of infinity or high resistance indicates an opening in the power winding. Replace the stator. A low reading indicates a shorted stator winding. Replace the stator. 6. Connect one meter test lead to a proper ground on alternator. Connect the other test lead to the stator power winding. A reading of infinity should be measured. If a reading of infinity is measured and the stator resistance is within specifications, the stator is functioning properly. A reading other than infinity indicates a stator winding shorted to ground. Replace the stator. 14 BRIGGSandSTRATTON.COM

15 Test Stator Excitation Winding Resistance The excitation wires may be colored (red and blue) or numbered (#2 and #6). Colored excitation wires must not be confused with the colored power wires. The excitation wires were disconnect earlier from the brush rectifi er earlier in Measuring Winding Resistance. 1. Set meter to measure Ohms. 2. Connect the test lead to the stator excitation wires #2 and #6 (Figure 10). These wires were previously disconnected from the brush rectifier. 5. Connect one test lead to an excitation wire. Connect the other test lead to a proper metal ground. A reading of infinity should be measured. A reading other than infinity indicates a winding shorted to ground. Replace the stator. Check Rotor Resistance 1. Set meter to measure Ohms. 2. Connect one test lead to each rotor slip ring (Figure 11). The slip rings can be accessed through the area where the brushes were removed. Polarity does not matter. Figure 11 Figure Measure the resistance and compare it to the nominal resistance listed in the back of this manual. A reading within the specifications listed is acceptable. A reading of infinity or high resistance indicates an opening in the power winding. Replace the stator. A low reading indicates a shorted winding. Replace the stator. 4. Connect one test lead to a stator power wire. Connect the other test lead to one of the stator excitation wires. A reading of infinity should be measured. If a reading of infinity is measured and the stator resistance is within specifications, the stator is functioning properly. A reading other than infinity indicates a power winding shorted to an excitation winding. Replace the stator. NOTICE: Do not connect the test lead terminals. Ensure that each test lead makes a connection to each slip ring. 3. Measure the rotor resistance. Compare it to the nominal resistance from the specifications listed in the back of this manual. A reading of infinity or a very high resistance indicates an open circuit or a partially open condition of the rotor windings. A very low resistance indicates a shorted rotor. Replace the rotor. If resistance is within specifications, proceed to Step Connect one test lead to a proper metal ground on the engine or alternator and the other test lead to either slip ring. A reading of infinity should be measured. If a reading of infinity is measured and the rotor resistance is within specifications, the rotor is functioning properly. A reading other than infinity indicates a rotor winding shorted to the rotor shaft. Replace the rotor. 15

16 Alternator Disassembly Refer to Figure 12 for part identification and to aid in the diasassembly of the alternator. K J E L A B C D E F G H Figure 12 A - Plastic End Cover B - Rotor Through Bolt C - Mounting Screws (2) for Brush Holder D - Rear Bearing Carrier E - Roll Pin F - Stator G - Steel Laminations H - Alternator Adapter J - Engine Adapter K - Mounting Screws (4) for Adapters L - Stator Bolts (4) 16 BRIGGSandSTRATTON.COM

17 Remove the Stator Ensure the engine/alternator assembly is set on a sturdy work surface. Do not set the engine/alternator assembly on the plastic end cover. 1. Remove the plastic end cover (A, Figure 12). 2. Remove the two mounting screws that secure the brush holder (C) to the rear bearing carrier. Disconnect the brush holder and set aside. 3. Remove the four stator bolts (L) that secure the rear bearing carrier to the alternator. 4. Remove the stator assembly. You may need to tap lightly on the stator assembly with a plastic, dead-blow hammer to loosen it from the alternator adapter (H). 5. Slide the stator out of the alternator adapter and off the rotor. NOTICE: Use care not to damage the windings. Set the stator on the laminations, not on the coils of the wire. Remove the Rotor 1. Remove the four screws (D) that secure the alternator adapter to the engine adapter (J). 2. Loosen, but do not remove, the rotor through-bolt (B). The rotor through-bolt will prevent the rotor from falling during disassembly. 3. While supporting and pulling the rotor with one hand, strike the rotor assembly, on the steel laminations with a plastic, dead blow hammer (Figure 13) until it separates from the engine shaft. Assemble the Alternator 1. Install the rotor and torque to values listed in Specifications. 2. With stator harness and lead wires facing away from the engine, place stator (A, Figure 14) over rotor and into adapter casting (B). Verify roll pin slot (C), in stator, lines up with the roll pin (D) in adapter. 3. Use a plastic, dead blow hammer to evenly seat stator into the adapter casting. B Figure 14 Figure Unscrew the through-bolt and carefully slide rotor off the engine crankshaft. Except for certain engine repairs, there is no need to remove the engine adapter from the engine. 17

18 4. Pull wires up through rear bearing carrier (A, Figure 15). Set rear bearing carrier on rotor bearing and stator. Verify second roll pin slot (B) in stator lines up with roll pin (C) in rear bearing carrier. 5. Using a plastic, dead blow hammer, tap rear bearing carrier evenly over rotor bearing and stator until it seats. NOTICE: Do not use stator bolts to draw assembly together. 6. Insert stator bolts into each hole around the rear bearing carrier. Tighten bolts in a criss-cross pattern until snug, then torque to values listed in Generator Specifications. 7. Rotate engine flywheel by hand slowly to ensure that the alternator is not binding. 8. Hold brush set with brushes down and tab (A, Figure 16) facing you. Attach red #6 wire to negative terminal (B) on the left. Attach blue #2 wire to positive terminal (C) on the right. C B Figure 16 A 9. Once wires are connect, rotate brush set three times to reduce the slack in the wires (A, Figure 17). A Figure 15 B Figure Set brushes down into slot on rear bearing carrier with tab facing down. Align holes in brush set and rear bearing carrier and insert screws (B). Torque screws to values listed in Generator Specifications. 11. Route wires away from all rotating parts, then install cover. 18 BRIGGSandSTRATTON.COM

19 Generator Specifications No Load Voltage No Load Frequency (RPM) Hertz ( RPM) Starting Wattage 8,250 watts Wattage* 5,500 watts AC Load Current at 120 Volts 45.8 Amps at 240 Volts 22.9 Amps Phase Single Phase Rated Frequency 60 Hertz Displacement ci (305 cc) Spark Plug Gap in. (0.76 mm) Fuel Capacity 7 U.S. gallons (26.5 L) Oil Capacity 28 Ounces (0.83 Liters) Resistance Values Winding Resistance Rotor (at the slip rings) Ohm Power (wires & 33-44) / Ohm Excitation (wires 2-6) Ohm Engine Adapter to Engine Alternator Adapter to Engine Adapter Rotor Bolt to Crankshaft Brushes to Rear Bearing Carrier Stator Bolt Fastener Torque Values 200 lb-in. (23 Nm) 200 lb-in. (23 Nm) 200 lb-in. (23 Nm) 50 lb-in. (7 Nm) 80 lb-in. (9 Nm) Power Ratings: The gross power rating for individual gas engine models is labeled in accordance with SAE (Society of Automotive Engineers) code J1940 (Small Engine Power & Torque Rating Procedure), and rating performance has been obtained and corrected in accordance with SAE J1995 (Revision ). Torque values are derived at 3060 RPM; horsepower values are derived at 3600 RPM. Actual gross engine power will be lower and is affected by, among other things, ambient operating conditions and engine-to-engine variability. Given both the wide array of products on which engines are placed and the variety of environmental issues applicable to operating the equipment, the gas engine will not develop the rated gross power when used in a given piece of power equipment (actual "on-site" or net power). This difference is due to a variety of factors including, but not limited to, accessories (air cleaner, exhaust, charging, cooling, carburetor, fuel pump, etc.), application limitations, ambient operating conditions (temperature, humidity, altitude), and engine-to-engine variability. Due to manufacturing and capacity limitations, Briggs & Stratton may substitute an engine of higher rated power for this Series engine. * This generator is rated in accordance with CSA (Canadian Standards Association) standard C22.2 No (motors and generators). 19

20 Generator Wiring Diagram 20 BRIGGSandSTRATTON.COM

21 Generator Schematic 21

22 Notes 22 BRIGGSandSTRATTON.COM

23 Engine Maintenance Fuel and Oil Recommendations Fuel must meet these requirements: Clean, fresh, unleaded gasoline. A minimum of 87 octane / 87 AKI (90 RON). Gasoline with up to 10% ethanol (gasahol) or up to 15% MTBE (methyl tertiary butyl ether) is acceptable. NOTICE: Do not use unapproved gasoline, such as E85. Do not mix oil in gasoline or modify the engine to run on alternate fuels. This will damage the engine components and void the engine warranty. To protect the fuel system from gum formation, mix a fuel stabilizer into the fuel. All fuel is not the same. If starting or performance problems occur, change fuel providers or change brands. This engine is certifi ed to operate on gasoline. The emissions control system for this engine is EM (Engine Modifi cations). High Altitude At altitudes over 5,000 feet (1524 meters), a minimum 85 octane / 85 AKI (89 RON) gasoline is acceptable. To remain emissions compliant, high altitude adjustment is required. Operation without this adjustment will cause decreased performance, increased fuel consumption, and increased emissions. Operation of the engine at altitudes below 2,500 feet (762 meters) with the high altitude kit is not recommended. Oil must meet these requirements: Briggs & Stratton warranty certified oils are highly recommended for best performance. Other high-quality detergent oils are acceptable if classified for service SF, SG, SH, SJ or higher. Do not use special additives. Outdoor temperatures determine the proper oil viscosity for the engine. Use the chart (Figure 15) to select the best viscosity for the outdoor temperature range expected. Maintenance Chart First 5 Hours Change oil Every 8 Hours or Daily Check engine oil level Clean area around muffler and controls Clean finger guard Every 25 Hours or Annually Clean air filter* Clean pre-cleaner* Every 50 Hours or Annually Change engine oil Check muffler and spark arrester Annually Replace air filter Replace pre-cleaner Replace spark plug Replace fuel filter Clean air cooling system* *In dusty conditions or when airborne debris is present, clean more often. Combustion Chamber Combustion Chamber Remove combustion chamber deposits every 500 hours or whenever the cylinder head is removed. With the piston at Top Dead Center (TDC), scrape deposits from top of piston and upper bore with a plastic scraper. Remove the loosened deposits from around the top ring land area using compressed air or a shop vacuum and a soft bristle brush. NOTICE: Use care to prevent debris from entering push rod or oil return cavities in cylinder. Do not damage bore, top of piston, cylinder head, or cylinder head gasket surfaces. It is not necessary to remove the discoloration marks on the piston, valves, and/or cylinder head. These marks are normal and will not affect engine operation. Figure 15 23

24 Air Filter Maintenance A correctly serviced air fi lter protects internal engine parts from airborne dirt and dust. Poor fi lter maintenance will allow dirt and dust to be drawn into the engine, causing wear to the intake system and contamination of the oil. Dirt in the oil forms an abrasive mixture which wears down moving parts. NOTE: Do not use pressurized air or solvents to clean the fi lter. Pressurized air can damage the fi lter and solvents will dissolve the fi lter. 1. Loosen screws (A, Figure 16) and remove air cleaner cover (B). 2. Carefully remove cartridge (C) from base (D). 3. Install clean (or new) air cleaner assembly inside cover. Dispose of old filter properly. 4. Assemble air cleaner cover onto base and tighten screws. Spark Plug Maintenance Spark plugs should be replaced every year. NOTICE: Spark plugs have different thread reach and heat ranges. When changing a spark plug, use only the specifi ed replacement, otherwise engine damage could occur. NOTE: In some areas, local law requires using resistor spark plugs to suppress radio frequency interference. 1. Disconnect spark plug wire. 2. Remove and inspect spark plug for wear and damage. Replace spark plug if electrodes are burned away, or the porcelain is cracked. 3. Do not blast clean spark plugs. Clean by scraping or wire brushing, and then washing in a commercial solvent. 4. Using a wire gage, check and set the gap (A, Figure 17). See Engine Specifications. 5. Re-install spark plug and torque to values listed in Specifications. 6. Connect spark plug wire. Figure 16 Figure BRIGGSandSTRATTON.COM

25 Cooling System Maintenance Dirt or debris can restrict air fl ow and cause the engine to overheat, resulting in poor performance and reduced engine life. Continued operation with a clogged cooling system can cause severe overheating and possible engine damage. Clean these areas (A, Figure 18) yearly or more often when dust or airborne debris is present. NOTICE: Do not use water to clean the engine. Water could contaminate the fuel system. Use a brush or dry cloth to clean the engine. A Inspect Exhaust System All exhaust system components must be inspected whenever the exhaust system is disassembled. Check muffl er mounting bracket and/or muffl er adapters for cracked welds or breakage. Check muffl er for split seams, loose internal parts, or cracked welds. Replace any damaged parts with new OEM parts. Never reinstall broken or damaged components. Clean and Inspect the Spark Arrester 1. To remove muffler heat shield (A, Figure 19) from muffler (B), remove four screws that connect guard to muffler bracket. 2. Remove four screws that attach spark arrestor screen (C). 2. Inspect screen and obtain a replacement if torn, perforated or otherwise damaged. DO NOT use a defective screen. If screen is not damaged, clean it with a commercial solvent. 3. Reattach screen and muffler guard. C Figure 18 Exhaust System Maintenance A WARNING Exhaust heat/gases could ignite combustibles, structures or damage fuel tank causing a fire, resulting in death, serious injury and/or property damage. Contact with muffler area could cause burns resulting in serious injury. DO NOT touch hot parts and AVOID hot exhaust gases. Allow equipment to cool before touching. Keep at least 5 feet (152 cm) of clearance on all sides of generator including overhead. It is a violation of California Public Resource Code, Section 4442, to use or operate the engine on any forestcovered, brush-covered, or grass-covered land unless the exhaust system is equipped with a spark arrester, as defined in Section 4442, maintained in effective working order. Other states or federal jurisdictions may have similar laws. Contact the original equipment manufacturer, retailer, or dealer to obtain a spark arrester designed for the exhaust system installed on this engine. Replacement parts must be the same and installed in the same position as the original parts. B Figure 19 25

26 Oil and Oil Filter Maintenance Change oil after the fi rst 5 hours of operation. After that, change oil after every 50 hours of operation. Change oil more often if engine is operated in dirty or dusty conditions, under heavy loads, or in high ambient temperatures. 1. Remove oil drain plug from side or bottom of engine and drain oil while the engine is still warm. 2. Install drain plug. 3. Remove oil fi lter, if equipped. 4. Apply light coat of clean engine oil to new filter gasket. Screw new fi lter on by hand until gasket contacts fi lter mounting adapter. Then tighten an additional 1/2 to 3/4 turn. 5. Fill crankcase with the correct amount of new oil. 6. Start engine and run at idle for a minute or so. Shut engine off and wait for oil to settle back into the cylinder. 7. Check dipstick. If necessary, add more oil slowly to bring level to FULL mark on dipstick. NOTICE: Do not overfi ll. Overfi lling can cause seals to fail, smoke from the exhaust, or overheating due to oil foaming. 8. Replace oil fill cap and dipstick. 9. Start and run engine. Check for oil leaks. 26 BRIGGSandSTRATTON.COM

27 Engine Adjustments Governor Adjustments A complete governor system adjustment includes a static adjustment, engine warm-up, idle and/or governed idle adjustment, and top no-load adjustment. Be sure to complete all steps. Static Adjustment 1. Loosen screw holding governor lever to governor crank (A, Figure 20). 2. Rotate throttle linkage from idle position to wide open throttle. Note direction of rotation of the governor arm attached to the throttle linkage. 3. While holding linkage at wide open throttle, use the appropriate tool to rotate the governor shaft until it stops in the direction noted in Step Tighten screw holding governor lever to governor crank per Engine Specifications. 5. Before starting engine, manually actuate throttle linkage to check for binding. Idle and Top No Load Adjustment 1. Start engine and run until it reaches operating temperature. 2. Place throttle in SLOW position. 3. Hold throttle lever against idle speed screw, and, using Tachometer #19200 or #19389, adjust screw to obtain 1300 RPM. Release throttle lever. 4. Using Tang Bender #19229 or #19352, bend governed idle spring tang to obtain 1750 RPM (Figure 21). Figure Place throttle in FAST position. 6. Adjust screw to obtain correct Top No Load RPM (Figure 22). Figure 20 Figure 22 NOTE: Correct Top No Load RPM for each model-type-trim can be found in the engine replacement data on Briggs & Stratton websites. 27

28 Adjust Valve Clearance NOTE: Check valve clearance while the engine is cold. 1. Turn crankshaft counterclockwise until piston is at top dead center on the compression stroke. This prevents the compression release from holding the valves open. 2. Insert a narrow screwdriver or rod into the spark plug hole as a gauge, then slowly turn crankshaft counterclockwise until the piston has moved down the bore by 1/4 (6mm). 3. Using a feeler gauge (A, Figure 23), adjust rocker nut to obtain the clearance as listed in Specifications. 4. Hold rocker nut and tighten the rocker ball setscrew (B) to the torque valve shown in Specifications. 5. Check clearance again and re-adjust, if necessary. 6. Repeat for other valve. NOTE: On some models, the nut and setscrew are positioned above the push rod ends. Figure BRIGGSandSTRATTON.COM

29 Fuel Systems and Carburetion WARNING Fuel and its vapors are extremely flammable and explosive which could cause burns, fire or explosion resulting in death, serious injury and/or property damage. WHEN ADDING OR DRAINING FUEL Turn generator engine OFF and let it cool at least 2 minutes before removing fuel cap. Loosen cap slowly to relieve pressure in tank. Fill or drain fuel tank outdoors. DO NOT overfill tank. Allow space for fuel expansion. If fuel spills, wait until it evaporates before starting engine. Keep fuel away from sparks, open flames, pilot lights, heat, and other ignition sources. Check fuel lines, tank, cap and fittings frequently for cracks or leaks. Replace if necessary. DO NOT light a cigarette or smoke. WHEN STARTING EQUIPMENT Ensure spark plug, muffler, fuel cap, and air cleaner are in place. DO NOT crank engine with spark plug removed. WHEN OPERATING EQUIPMENT DO NOT operate this product inside any building, carport, porch, mobile equipment, marine applications, or enclosure. DO NOT tip engine or equipment at angle which causes fuel to spill. DO NOT stop engine by moving choke control to Choke position ( ). WHEN TRANSPORTING, MOVING OR REPAIRING EQUIPMENT Transport/move/repair with fuel tank EMPTY or with fuel shutoff valve OFF. DO NOT tip engine or equipment at angle which causes fuel to spill. Disconnect spark plug wire. WHEN STORING FUEL OR EQUIPMENT WITH FUEL IN TANK Store away from furnaces, stoves, water heaters, clothes dryers, or other appliances that have pilot light or other ignition source because they could ignite fuel vapors. Fuel Tanks and Shut-off Valves Removal 1. Close shut-off valve, if equipped. 2. Remove air cleaner assembly. 3. Remove screws (A, Figure 24) and the control panel/ trim plate. 4. Release hose clamp and disconnect fuel hose from carburetor fitting. 5. Place hose in appropriate container, open shut-off valve, and allow fuel to completely drain from tank. 6. Remove the mounting screws from tank support. Carefully slip fuel hose under governor link and allow spark plug wire to slip through hole in support as tank is removed. 7. Remove tank support from tank, if equipped. Figure 24 NOTE: Replace air cleaner gaskets and mounting gaskets whenever carburetor is removed for service. NOTE: Do not insert a screw in the end of the fuel hose to stop fuel fl ow. Screw threads will loosen rubber particles which will get into the carburetor. NOTE: Before servicing the carburetor, turn the fuel shutoff valve to the OFF position. 29

30 Inspection 1. Clean gummy or dirty fuel tanks with Briggs & Stratton Carburetor Cleaner # or #100042, or equivalent. 2. Inspect fuel tank for: Corrosion Leaks Broken mounting brackets 3. Check fuel cap and filler neck for: Proper seals Vents Functional quantity gauge (if equipped) 4. Check fuel filter for blockage of any kind. 5. Check fuel shut off valve for proper operation. Clean or replace parts as required. Fuel filter replacement is recommended annually or any time the fuel system is serviced. Installation 1. Install tank support to tank. Slip fuel hose under governor link and spark plug wire through hole in support as tank is installed. Torque screws to values listed in Engine Specifications. 2. Assemble shut-off valve and fuel filter, if equipped, to fuel hose. 3. Install hose assembly to tank fitting and carburetor fitting with new clamps. 4. Install control panel/trim plate. Torque screws to values listed in Engine Specifications. 5. Add small amount of fuel to tank, open shut off valve, and check for leaks. Repair as necessary. 6. Install air cleaner assembly. 7. Start engine and check for leaks. Repair as necessary. Carburetor Service LMT Carburetor Two versions of this carburetor have been used (Figures 25 and 26). These carburetors have a fi xed high speed main jet with a screw for idle mixture and idle speed adjustment. The letters LMT are cast into the body of the carburetor while the identifi cation numbers are stamped into the carburetor mounting fl ange next to the idle mixture screw or above the fuel inlet. Figure 25 Figure 26 WARNING Before servicing the carburetor or other fuel system components, drain all fuel from the tank and turn OFF the fuel valve (if equipped). DO NOT attempt to stop the fuel flow by plugging the fuel hose. 30 BRIGGSandSTRATTON.COM

31 Remove Carburetor 1. Remove air cleaner assembly. Discard the gasket. 2. Move clamp and disconnect hose from carburetor. 3. Remove two carburetor screws or nuts while holding carburetor. 4. Carefully rotate carburetor to disconnect throttle (A, Figure 27) and spring (B) and the choke link during removal. 3. Remove float hinge pin, float, and inlet needle. Discard the hinge pin and inlet needle. 4. Screw a 1/4-20 tap into fuel inlet seat 3-4 turns and remove. 5. Place a hex nut (A, Figure 29) and washer (B) on a 1/4-20 screw. Place 1/4 drive 3/8 socket (C) over fuel inlet seat. 6. Thread screw into tapped inlet seat until screw bottoms. Thread nut down to washer and continue turning nut until inlet seat is free from carburetor body. Figure 27 Disassemble Carburetor 1. Remove solenoid and solenoid washer. Discard washer. Remove float bowl and float bowl gasket from carburetor. Discard gasket. 2. Using Carburetor Nozzle Screwdriver #19280, remove the main carburetor emulsion tube (A, Figure 28). Figure Remove idle mixture limiter cap, when used, then remove idle mixture screw with spring and idle speed screw with spring. 8. Rotate throttle shaft to closed position and remove throttle valve screws and throttle valve. 9. Remove throttle shaft, foam seal, and throttle shaft seal from carburetor body. Discard seals. 10. If carburetor is equipped with a plastic choke shaft, rotate choke shaft to wide open position, then pull choke valve out of choke shaft. Remove choke shaft, return spring (when used), and foam seal. Discard seal. Figure 28 31

32 - OR - If carburetor is equipped with a metal choke shaft, rotate choke shaft to closed position. Remove two choke valve screws and choke valve. Remove choke shaft, return spring and foam seal. Discard seal. 11. With a modified pin punch (A, Figure 30) remove welch plug (B) from carburetor body. NOTE: Do not attempt to remove the pilot jets, which are pressed in and not serviceable. Assemble Carburetor Consult the Illustrated Parts List to obtain the appropriate carburetor overhaul kit before reassembling the carburetor. 1. Install new welch plug (A, Figure 31) with pin punch (B) of slightly smaller diameter than the plug. Press against the plug until it is flat in the carburetor opening. Do not cave in plug. Seal the edge of the plug with nonhardening sealant. 2. If carburetor is equipped with a metal choke shaft, Figure 31 Figure 30 Inspect and Clean Carburetor 1. Inspect openings in the carburetor body for evidence of wear or damage. If found, replace the entire carburetor assembly. 2. Inspect the choke shaft, choke valve, throttle shaft, and throttle valve for evidence of wear or damage. Replace parts as necessary. 3. Using Carb/Choke Cleaner # or #100042, thoroughly clean the following components, then follow with compressed air to dry: Passages in the fixed main jet (bowl nut) or emulsion tube Inside and outside of the fuel bowl Float Choke shaft and choke valve Throttle shaft and throttle valve All passages, openings, and the inside and outside of the carburetor body NOTE: Do not soak non-metallic components, such as fl oats, o-rings, seals, or diaphragms, in carb/choke cleaner or they will be damaged. 4. If any passages remain plugged after cleaning, replace the component or the entire carburetor assembly. Install new foam seal and return spring (C, Figure 32) on choke shaft, hooking small hook (A) in notch on choke lever (D). Insert choke shaft assembly into carburetor body and engage large end of return spring (E) on boss. If carburetor has detent spring, guide spring into slot in choke shaft lever (B). Place choke valve (F) on shaft and install screws, then actuate the choke shaft to check for proper movement. Figure BRIGGSandSTRATTON.COM

33 - OR - 3. If carburetor is equipped with a plastic choke shaft, Install new foam seal and return spring on choke shaft (C, Figure 33) with straight end of spring against choke shaft lever (B). Insert choke shaft assembly into carburetor body and engage large end of return spring on anchor pin or boss (A). Lift choke slightly and turn counterclockwise until stop on lever clears anchor pin or boss, then push shaft down. 5. Install idle speed screw and spring, then install idle mixture screw with spring and turn until head of screw touches spring. 6. Using Knockout Pin #19135, press new fuel inlet seat (A, Figure 35) until flush with fuel inlet boss (B). Figure 33 Insert choke valve (D) into choke shaft with dimples (E) toward fuel inlet side of carburetor. Actuate the choke shaft to check for proper movement. 4. Install new throttle shaft seal (C, Figure 34) with sealing lip down in carburetor body until top of seal is flush with top of carburetor (D). Install new foam seal (B) on throttle shaft, then slide shaft into carburetor body. Rotate shaft until flat is facing out. Position throttle valve (E) on flat with numbers facing out, then install screws. Actuate the throttle shaft to check for proper movement. Figure Insert new inlet needle in slot on float, then position float in carburetor body. Secure with new hinge pin and center the pin between the float bosses. 8. Install emulsion tube using Carburetor Screwdriver #19280 until tube seats (A, Figure 36). 9. Place new bowl gasket on carburetor body and install fuel bowl. Place new washer on solenoid and install. 10. After installing emulsion tube, use compressed air to blow out any chips or debris that may have been loosened while installing tube. Figure 36 Figure 34 33

34 Install Carburetor NOTE: Always replace air cleaner gaskets and carburetor mounting gaskets any time the carburetor has been removed for service. 1. Position new gasket on studs with long edge of gasket opposite fuel inlet of carburetor. 2. Hook governor spring (B, Figure 37) in throttle lever hole without grommet. Hook governor link (A) in throttle lever hole with grommet. Figure Hook choke link into outer hole of choke shaft from underneath. Slide other end of choke link into slot in governor control bracket. 4. Position carburetor on engine. Install screws or nuts and torque to values listed in Engine Specifications. 5. Connect fuel hose to carburetor and secure with hose clamp. 6. Using new gasket, install air cleaner assembly to carburetor. 7. After final carburetor adjustment (last step below), use Knockout Pin #19135 (A, Figure 38) to install new limiter cap (B) with flat side facing up. Figure BRIGGSandSTRATTON.COM

35 Governor Systems Linkage and Spring Orientation NOTE: Be sure to note hole position of linkage before removing. Governor Service The mechanical governor is part of the crankcase cover. The governor gear (A, Figure 40) is driven by the crankshaft timing gear (B) through an idler gear (C). The governor crank (D) is mounted in the cylinder assembly. NOTE: Stamped side of idler gear faces out. Figure 39 Governed RPM Limits To comply with specifi ed top governed speed limits, Briggs & Stratton supplies engines with an adjustable top speed limit, which the equipment manufacturers set to their own specifi - cations. Top governed speed should be checked with a tachometer when the engine is operating on a completely assembled unit. The equipment should be operated under no load when making these checks. If a governor spring must be replaced, consult the appropriate Illustrated Parts List for the correct part number. After a new governor spring is installed, check the engine top governed speed with an accurate tachometer, as noted above, and adjust as required. Figure 40 Disassemble 1. Drain oil from engine. Remove burrs and clean crankshaft, then remove crankcase cover. Set aside. 2. Loosen governor lever nut (A, Figure 41). 3. Slide lever off governor crank (B) and disconnect from governor link (C). 4. Remove push nut and washer (D) from governor crank. Remove any burrs from governor crank, and then remove crank from inside cylinder. Figure 41 35

36 Inspect Governor 1. Check governor gear assembly for worn weight pins, worn or damaged governor cup, and chipped or damaged teeth. 2. If wear or damage is found, remove the governor gear by carefully prying it off the spindle with two flat-bladed screw drivers (A, Figure 42). Discard the washer at the base of the spindle. Assemble 1. Install governor crank from inside cylinder. Slide washer (when used) on crank and install new push nut. 2. Slide the governor lever on crank and finger-tighten bolt and nut until crank turns with a slight resistance. 3. Rotate crank until paddle is aligned with cup on governor gear assembly. 4. Install new crankcase cover gasket(s) of same thickness as originally removed from cylinder. 5. Place seal protector in oil seal and slide cover over crankshaft until it seats. NOTE: It may be necessary to rotate crankshaft to engage idler gear with timing gear. 6. Install cover or sump screws in order shown in Figure 43. Torque to values listed in Engine Specifications. 7. Adjust governor system. 4 6 Figure Install new washer on spindle, then carefully press new governor gear assembly on spindle until fully seated. 4. Check idler gear for wear or damage. If found, remove retainer clip and gear, then install new gear. 5. Check governor crank for wear or damage. Replace if necessary Figure BRIGGSandSTRATTON.COM

37 Before the cylinder head can be removed, other external parts must be removed, such as the air cleaner, fuel tank, oil fi ll tube, blower housing, muffl er, carburetor, control bracket assembly, and intake manifold. Cylinder Head and Valves Remove Cylinder Head 1. Remove four screws from rocker cover, then remove cover and gasket (A, Figure 44). Figure Remove the rocker arm studs. 3. Using thumbs, press down on each valve spring retainer and disengage retainer (A, Figure 46) from valve stem (B). Remove retainers, springs, valves, and intake valve stem seal/washer, if equipped. Figure Remove cylinder head screws, then remove head and gasket from cylinder. 3. Remove push rods one at a time, marking the location and orientation of each for proper installation later. NOTE: On model the intake push rod (lower, aluminum) is hollow and the exhaust push rod (upper, steel) has a red band of paint for identifi cation. 4. Using a plastic scraping tool, carefully clean all traces of head gasket from the head and cylinder mating surfaces. Disassemble Cylinder Head 1. Loosen rocker arm screws and/or lock nuts, and remove from rocker arm studs. Remove rocker arms and rocker balls from studs (A, Figure 45). Figure Remove push rod cylinder head plate and plate gasket. Remove and discard the plastic push rod guides from the head plate. Inspection 1. Visually inspect head for cracks, excessive heat discoloration, warping of the cylinder or rocker cover mating surfaces, and burned or damaged valve seats. Replace head, if any of these problems are found. 2. If head passes visual inspection, use Plug Gauge #19122 to check valve guides for wear. If gauge enters the guide 1/4 (6.4 mm) or more, replace the entire head. If plug gauge is not available, see Engine Specifications for the valve guide reject dimension. 37

38 3. If guides are replaced, or the original guides still meet specifications, use Finish Reamer #19066 and Reamer Guide #19191 to ensure proper sizing and to clean out the guides. Thoroughly clean all reaming debris from cylinder head. 4. Inspect valves for wear or damage. Replace if necessary. NOTE: Valve faces can be resurfaced on a commercially available valve grinder. However, Briggs & Stratton does not recommend this practice because the quality of the resurfacing may be insuffi cient. Instead, valve replacement is recommended. 5. Oil the intake valve guide and intake valve stem, then insert valve into head. 6. Using Valve Lapping Tool #19258 and Lapping Compound #94150, lap valve and seat together to assure a good sealing surface. Remove valve, the repeat procedure for the exhaust valve. 7. Thoroughly clean both valves and cylinder head of all lapping compound residue. Assemble Cylinder Head 1. Install new plastic push rod guides (A, Figure 47) into the cylinder head plate. 4. Oil inside diameter of new stem seal/washer and install on intake valve stem. Slide seal down against head plate or cylinder head. 5. Support valve side of cylinder head on clean shop rags. Place valve springs and valve spring retainers over valve stems. Using thumbs, press against each retainer until it securely locks into groove in valve stem (A, Figure 48). Figure 48 Install Cylinder Head 1. Coat threads of all cylinder head screws with Valve Guide Lubricant # Using a new head gasket, install cylinder head on cylinder and start screws by hand. Step-torque screws in sequence shown in Figures 49, until final torque value is achieved. Torque screws to value listed in Engine Specifications Figure Using new plate gasket, install the cylinder head plate. Torque screws to values listed in Engine Specifications. 3. Lightly coat valve stems with Valve Guide Lubricant # Then insert valves into cylinder head. Do not get lubricant on valve face, valve seat, or exposed end of valve stem. Figure BRIGGSandSTRATTON.COM

39 NOTE: Do not torque each screw in one step as it may result in a warped cylinder head. Step-torque all screws to approximately 1/3 of fi nal torque value, then to 2/3 fi nal torque value, then fi nish at fi nal torque values. 3. Install rocker arm studs. Torque to values listed in Engine Specifications. 4. Install push rods through guides and into same positions as removed. Ensure rods are seated in valve tappets. Place valve stem caps (if used) on valve stems (Figure 50). Figure Place rocker arms and rocker balls on rocker arm studs. Install rocker arm screws and/or lock nuts on studs and tighten until there is zero clearance between the valve stem caps and the rocker arms. 6. Rotate crankshaft at least twice to ensure proper movement of the push rods and rocker arms. 7. Adjust valve clearance, then install a new rocker cover gasket and the rocker cover. Torque screws to values listed in Engine Specifications. 39

40 Starters On some engines, the rewind starters are attached to the blower housing with screws and can be quickly removed. Other starters are riveted or spot welded to the blower housing and must be drilled to remove, following the procedures below. For installation, screws and nuts are available separately from the Illustrated Parts List and are included with complete replacement starters. Remove Blower Housing / Rewind Starter 1. Drain fuel tank or close fuel shut-off valve. Disconnect spark plug wire. 2. Remove the entire air cleaner assembly. 3. Remove the screws (A, Figure 51) and the control panel trim. Figure Remove the screws (B, Figure 52) and blower housing. 5. Carefully drill through all rivet heads and remove rewind starter. Do not allow drill bit to cut into the holes in the starter housing. NOTE: Do not attempt to drill out the rivets while the blower is still on the engine. The rivets are made of steel and the shavings will collect on the fl ywheel magnets. Rewind Starter Service WARNING The starter spring remains under tension even if the rope has been removed and the pulley has unwound. Wear safety glasses to prevent eye injury when removing or installing the pulley/spring assembly. Disassemble Rewind Starter 1. Pull out rope from rewind starter as far as it will go. Then allow rope to retract slightly until the hole in the pulley and the eyelet in the housing are lined up. Securely clamp the pulley and housing together to prevent the pulley from spinning. 2. Pull the rope knot out of the pulley. Untie the knot and then slip rope out of rewind starter. Remove insert from rope handle. Untie knot and slip insert and handle from rope. 3. Carefully release the clamp on the starter and allow the pulley to SLOWLY unwind until it stops. 4. Remove shoulder screw and retainer plate from pulley. Lift out the pawls and pawl springs (if used). 5. Rotate pulley until rewind spring is disengaged from anchor tab in the starter housing. Carefully lift out pulley with spring. DO NOT remove the spring from the pulley. Figure BRIGGSandSTRATTON.COM

41 Inspect Rewind Starter Parts NOTE: Do not remove the spring from the pulley. Both parts are serviced only as an assembly. 1. Inspect the pulley for wear, cracks, rough edges, or burrs in the rope groove and look for wear in the center hole. If wear or damage is found, replace the pulley and spring assembly. 2. Inspect the spring for broken ends, kinks, or burrs. If damage is found, replace the pulley and spring assembly. 3. Inspect the starter housing for wear or burrs at the rope eyelet, the center pivot post, and the anchor tab. If damage is found, replace the housing. 4. Inspect the drive pawls for wear at the tips or pivot points. Replace pawls if worn. 5. Inspect the rope for broken or frayed areas. Replace rope if necessary. Assemble Rewind Starter 1. Install pulley and spring assembly into starter housing. Rotate pulley clockwise until slight resistance is felt, which indicates that the spring has engaged in the anchor tab. 2. Install pawl springs (if used) and pawls. Position retainer plate on pulley. Ensure that the slots in the retainer fit over the tabs in the pulley, then install shoulder screw. Torque screw to value shown in Engine Specifications. 3. While holding retainer, rotate the pulley to extend and retract the pawls. If they do not move properly, remove and reinstall the retainer plate. 4. Turn pulley clockwise until the spring is wound tight. Then allow pulley to unwind slightly until the hole in the pulley and the eyelet in the housing are lined up. Securely clamp the pulley and housing together to prevent the pulley from spinning. 8. Carefully release the clamp on the starter and allow the pulley to SLOWLY unwind until the rope is retracted. Smoothly pull the rope handle several times to ensure proper operation of the starter assembly. Install Blower Housing / Rewind Starter Some starters are riveted or spot welded to the blower housing and must be drilled to remove. For installation, screws and nuts are available separately from the Illustrated Parts List and are included with complete replacement starters. 1. Install the blower housing and torque the screws to values listed in Engine Specifications. 2. Install the screws (A, Figure 53) and the control panel trim torquing the screws to values listed in Engine Specifications. 3. Install the air cleaner assembly. 4. Fill fuel tank or open fuel shut-off valve. Connect the spark plug wire. Figure 53 NOTE: Before proceeding, consult the Illustrated Parts List or Specifi cations to ensure correct diameter and length of rope is being installed. 5. Insert one end of starter rope through eyelet and then through hole in pulley. Tie an overhand knot in end of rope, then pull rope until knot is seated in pulley. Trim excess rope if necessary. 6. Slip other end of rope through handle and insert. Tie a knot in end of rope, then pull rope until knot is seated in the insert. Trim excess rope if necessary. 7. Quickly burn each end of the rope with an open flame to prevent swelling and fraying of the weave. Then press the handle insert into the rope handle. 41

42 Lubrication Systems Extended Oil Fill and Dipstick These models use a plastic extended oil fi ll tube and a quarter-turn dipstick. The oil fi ll tube screws into the crankcase cover. Breathers Briggs & Stratton engines utilize a breather valve to control and maintain crankcase vacuum. The breather valve is a fi ber disc or reed which closes on the piston up stroke and opens on the piston down stroke. The breather is located on the cylinder or inside the rocker cover, depending on engine model. Remove Breather 1. Disconnect breather hose (B, Figure 54) from air cleaner. 2. Remove rocker cover with breather hose (A) and gasket. Discard gasket. Check Breather 1. Gently blow air into the breather tube. There should be no air flow out the valve. 2. Apply vacuum to the breather tube. Air should flow freely into the valve. 3. If air flow is restricted under vacuum at the tube, or has no resistance when blowing on the tube, replace the valve cover. Install Breather 1. Securely insert breather hose into hole in air cleaner base. 2. Place new gasket and valve cover on cylinder head. 3. Install four screws and torque to values listed in Engine Specifications. NOTE: Install three long screws on the sides and bottom edges of valve cover. Install short screw on top of valve cover. Securely insert other end of breather hose into hole in rocker cover. Oil Dipper Lubrication Figure 54 Two types of dippers are used on horizontal shaft engines. One is integral to the rod cap, the other is a separate part (A, Figure 55) attached to the rod cap with a connecting rod screw. Inspect the dipper for evidence of bending, cracking, or looseness. Replace if necessary following instructions listed under Pistons, Rings, and Connecting Rods. Figure BRIGGSandSTRATTON.COM

43 Cylinders, Covers and Sumps Inspect Cylinder 1. Visually check cylinder for cracks, stripped threads, and bore damage. If cracks are found, replace the cylinder. Stripped threads can sometimes be repaired using a helicoil, but if multiple holes have thread damage, replace the cylinder. Bore damage, if not severe, may be corrected by reconditioning or resizing (see below). Check cylinder head mounting surface for distortion with a straight edge (Figure 56). If mounting surfaces are distorted more than in. (0.1 mm), the cylinder must be replaced. Compare measurements to the standard cylinder bore sizes provided in Engine Specifi cations. If the cylinder bore is more than in. (0.08 mm) oversize, or in. (0.04 mm) out of round, it must be resized. Reconditioning Bore If cylinder bore is within specifi cations and shows no signs of scoring or other damage, it can be reconditioned using a rigid hone with fi nishing stones to restore the proper crosshatch angle. The correct crosshatch of approximately 45 (Figure 58) ensures proper lubrication and piston ring break-in. 45 Figure 58 Figure Check cylinder bore for war using Telescoping Gauge #19485 and Dial Caliper # Measure twice (90 apart) at the top, center, and bottom of the piston ring travel (Figure 57). NOTICE: IT IS MOST IMPORTANT THAT THE ENTIRE CYLINDER BE THOROUGHLY CLEANED AFTER HONING. Resizing Bore Always resize to exactly in. (0.51 mm) larger than standard bore size. Done accurately, the service oversize rings and pistons will fi t perfectly with proper clearances. Cylinder can be quickly resized with Hone #19205 or # Use the stones and lubrication recommended by the hone manufacturer to reproduce the sizing and fi nish. Figure 57 43

44 Cleaning Cylinder Covers and Sumps 1. Wash the cylinder thoroughly in a solvent such as kerosene or other commercial solvent. 2. Wash cylinder again using a stiff brush with soap and hot water. 3. Rinse cylinder thoroughly with hot running water. 4. Repeat washing and rinsing until all traces of honing grit are gone. NOTE: Honing grit is highly abrasive and will cause rapid wear to all of the internal components of the engine. When cylinder and crankcase have been thoroughly cleaned, use a clean white rage to wipe the cylinder bore. If honing grit is present, it will appear as a grey residue on the rag. Re-wash and rinse entire cylinder then check again. When there is no trace of honing grit on the rag, the cylinder is properly cleaned. Oil the cylinder bore to prevent rusting. Main Bearings Installation 1. Place seal protector on oil seal. 2. Make sure mechanical governor fear and oil pump (when used) is engaged with cam gear. Do not for force cover or sump. 3. Install screws and tighten in sequence shown (Figure 60). 4. Torque screws to values listed in Engine Specifications Check Bearings Main bearings should be replaced if scored or if a plug gauge (A, Figure 59) will enter bearing. Try gauge at several locations in bearing. 5 3 Figure 60 Figure BRIGGSandSTRATTON.COM

45 Crankshafts and Camshafts Remove Crankshaft and Camshaft 1. Drain oil from engine and all fuel from fuel tank. 2. Remove blower housing/rewind assembly and flywheel/ fan assembly. 3. Remove burrs and clean crankshaft, then remove crankcase cover or sump. Set aside. NOTE: If crankcase cover or sump sticks, tap lightly with a soft hammer on alternate sides near dowel pins (A, Figure 61). It is not necessary to remove dowel pins. Check Crankshaft 1. Inspect crankshaft for scoring on mag journal (A, Figure 63), crankpin journal (B), and PTO journal (C). Replace crankshaft if scoring is found or if crankshaft is bent. DO NOT attempt to straighten bent crankshafts. Figure 63 Figure Carefully tip engine with PTO-end facing up. 5. Rotate crankshaft until timing marks (A, Figure 62) are aligned. With camshaft in this position, the valve tappets will remain clear of cam lobes. Lift out camshaft (B). 2. Using a dial caliper, measure the journal diameters. Compare results to values listed in Engine Specifications. If wear exceeds the reject dimensions, replace the crankshaft. Check Camshaft 1. Check gear (A, Figure 64) for worn or damaged teeth. Check lobes (D) and journals (B, C) for scratching or scoring. Check compression release mechanism (A, Figure 65) for wear, burrs, or sticking. Replace camshaft if any of these conditions are found. Figure Rotate crankshaft to place piston at Top Dead Center. 7. Remove connecting rod cap, then slide out crankshaft. Figure 64 45

46 Install Crankcase Cover or Sump 1. Using a new gasket, install crankcase cover or sump using seal protectors. Do not force cover or sump on cylinder. NOTE: It may be necessary to rotate idler gear to mesh with timing gear when installing cover. 2. Install screws in sequence shown (Figure 67). NOTE: The screw in position 4 was coated with sealant. If sealant is missing, coat with a non-hardening sealant such as Permatex 2 or equivalent. Figure Using a dial caliper, measure the journal diameters and cam lobes. Compare results to values listed in Specifications. If wear exceeds the reject dimensions, replace the camshaft Install Crankshaft and Camshaft 1. Lubricate the cylinder bearing/oil seal with engine oil. 2. Install intake and exhaust valve tappets. 3. Support both ends of the crankshaft, and carefully install into the cylinder. 4. Assemble connecting rod assembly to crankshaft. 5. Install the timing gear to the crankshaft with timing mark out. 6. Install camshaft, making sure tappets clear cam lobes. Timing marks (A, Figure 66) must align. 7. Make sure the paddle on the governor shaft (B) is rotated in line with the governor cup inside the crankcase cover. 5 Figure 67 Check and Adjust Crankshaft End Play When the crankcase cover or sump is installed with a standard gasket, end play should match values listed in Engine Specifications. If end play is less than specified, remove cover or sump and install an additional gasket. Do not use more than two gaskets. If end play is more than specified, remove cover or sump and install a shim per the Illustrated Parts List, or replace the cover or sump. NOTE: If using shims, install shim on PTO-end of crankshaft (A, Figure 68). 3 Figure 66 Figure BRIGGSandSTRATTON.COM