10-21S-01 GT-225, SRM-225 1 1 INTRODUCTION We are constantly working on technical improvement of our products. For this reason, technical data, equipment and design are subject to change without notice. All specifications and directions in this SERVICE DATA are based on the latest products information available at the time of publication. ECHO SERVICE MANUAL Ord. 402-35 (Model : GT-225, SRM-225) contains lots of information for servicing this model. NOTE : Corrected tightening torque of muf er cover on page 4. CONTENTS page 1 SERVICE INFORMATION... 2 1-1 Speci cation... 2 1-2 Technical data... 3 1-3 Torque limits... 4 1-4 Special repairing materials... 4 1-5 Service limits... 5 1-6 Special tools... 6 2 CARBURETOR ADJUSTMENT PROCEDURE...7 2-1 General adjusting rules... 7 2-2 Presetting Idle adjust screw, Idle mixture needle and Hi speed mixture needle... 7 2-3 Adjusting carburetor... 8 Reference No. 10-21S-01 REVISED: 201304 ISSUED: 200810
2 SERVICE INFORMATION GT-225 SRM-225 1 SERVICE INFORMATION 1-1 Speci cations Model GT-225 SRM-225 Dimensions* Length mm (in) 1371 (54.0) 1793 (70.6) Width mm (in) 315 (12.4) 251 (9.9) Height mm (in) 539 (21.2) 328 (12.9) Dry weight* kg (lb) 4.6 (10.1) 5.5 (12.1) Engine Type KIORITZ, air-cooled, two-stroke, single cylinder Rotation Counterclockwise as viewed from the output end Displacement cm 3 (in 3 ) 21.2 (1.29) Bore mm (in) 32.2 (1.27) Stroke mm (in) 26.0 (1.02) Compression ratio 5.9 Carburetor Type Rotary type : Diaphragm, horizontal-draft, with purge bulb Model ZAMA RB-K93 Ignition Type CDI (Capacitor discharge ignition) system Variable Slope Timing (VST) : Slope advance ignition system combined with electronic speed governor Spark plug BPM8Y (CANADA : BPMR8Y) Exhaust Muf er type Spark arrester muf er with catalyst Starter Type i-30 Rope diameter x length mm (in) 3.0 x 830 (0.12 x 32.7) Fuel** Type Premixed two-stroke fuel Mixture ratio 50 : 1 (2%) Gasoline Minimum 89 octane Two-stroke engine oil ISO-L-EGD (ISO/CD13738), JASO M345-FC/FD Tank capacity L (U.S..oz.) 0.44 (14.9) Clutch Type Centrifugal, 2-shoe pivot Handle Type Front Loop handle Rear Integrated control grip Integrated control grip with throttle lock lever Drive shaft Type Flexible Diameter - Length mm 6.0-1219 6.15-1522 (in) (0.24-48.0) (0.24-59.9) Housing OD - ID mm 22.25-19.05 25.0-22.0 (in) (0.88-0.75) (0.98-0.87) Main pipe Length mm (in) 1130 (44.5) 1500 (59.1) Gear case Reduction ratio --- 1.4 Gear tooth --- Spiral bevel gear Lubrication Lithium based grease or ECHO LUBE TM Cutter Type Nylon line cutter, 8-tooth blade, 22-tooth blade, Others Pilot diameter for blade mm(in) Not available Option : 20.0 (0.79) Fastener type, size mm Not available Left-hand thread nut, M10 x 1.25 pitch Cutting rotation Clockwise as viewed from top Counterclockwise as viewed from top OD: Outer diameter. ID: Inner diameter. * Without shoulder harness and Nylon line head. ** Refer to Operators manual. Install blade conversion kit including metal shield when operating with metal blade.
GT-225 SRM-225 SERVICE INFORMATION 3 1-2 Technical data Model GT-225 SRM-225 Engine Idling speed rpm 2,900 +/- 400 Wide open throttle speed rpm* 6,900-8,100 7,600-8,700 Clutch engagement speed rpm 3,850-4,100 Compression pressure MPa (kgf/cm 2 ) (psi) 0.66 (6.7) (96) Ignition system Spark plug gap mm(in) 0.6-0.7 (0.024-0.028) Minimum secondary voltage at 1500 rpm kv 15 Primary coil resistance 320-420 Secondary coil resistance k 2.7-3.3 Pole shoe air gaps mm(in) 0.30-0.40 (0.012-0.016) Ignition timing at 1,000 rpm BTDC 17 at 3,000 rpm BTDC 27 at 8,000 rpm BTDC 42 PET-9000 Parameter #1 298 #2 03 Carburetor Venturi Size mm(in) 9.0 (0.354) Throttle Bore mm(in) 10.5 (0.413) Idle adjust screw initial setting turn in** 2 1/2 2 3/8 Idle mixture needle initial setting turn back*** 2 7/8 2 5/8 Hi speed mixture needle initial setting turn back*** 3/4 Test Pressure, minimum MPa (kgf/cm 2 ) (psi) 0.05 (0.5) (7.0) Metering lever height mm(in) 0.1-0.25 (0.004-0.01) lower than diaphragm seat BTDC: Before top dead center. *With Nylon line cutter and shield. ** Set idle speed screw to the point that its tip just contacts throttle plate before initial setting. ***Turn Idle/Hi speed mixture needles counterclockwise from point that needle is lightly seated.
4 SERVICE INFORMATION GT-225 SRM-225 1-3 Torque limits Descriptions Size kgfcm Nm inlbf Starter Starter pawl assembly M 8 80-100 8-10 70-90 system Starter case M 4* 30-45 3-4.5 25-40 Ignition Flywheel M 8 160-200 16-20 140-175 system Ignition coil M 4 35-50 3.5-5 30-44 Fan cover M 4 30-45 3-4.5 25-40 Spark plug M 14 130-170 13-17 112-150 Fuel Carburetor M 5 30-45 3-4.5 25-40 system Intake insulator M 5* 35-45 3.5-4.5 30-40 Fuel tank with stand M 5* 40-60 4-6 35-55 Cylinder cover Fan cover side M 5 25-45 2.5-4.5 22-40 Starter side M 5 30-40 3-4 25-35 Engine Crankcase M 5 70-110 7-11 60-95 Cylinder M 5 70-110 7-11 60-95 Muf er M 5* 90-110 9-11 80-95 Exhaust guide M 4 15-30 1.5-3 13-25 Muf er cover Fan cover side M 5* 25-45 2.5-4.5 22-40 Starter side M 5 30-40 3-4 25-35 Other Cutter fastener LM 10 280-320 28-32 245-280 Regular bolt, nut and screw M 3 6-10 0.6-1 5-9 LM: Left-hand thread. Tapping screw M 4 15-25 1.5-2.5 13-22 M 5 25-45 2.5-4.5 22-40 M 6 45-75 4.5-7.5 40-65 M 8 110-150 11-15 95-130 * Apply thread locking sealant. (See below) ** The torque differences among four bolts should not exceed 20 kgfcm (2Nm, 17inlbf) on one cylinder or crankcase 1-4 Special repairing materials Material Location Remarks Grease Drive shaft Gear case Rewind spring Lithium based grease or ECHO LUBE TM Starter center post Oil seal inner lips Thread locking Starter case sealant Muf er Muf er cover Loctite #242, ThreeBond #1324 or equivalent Fuel tank Intake insulator Loctite #675
GT-225 SRM-225 SERVICE INFORMATION 5 1-5 Service limits A B C D E F G H K L M Description mm (in) A Cylinder bore When plating is worn and aluminum can be seen B Piston outer diameter Min. 32. 10 (1.264) C Piston pin bore Max. 8. 030 (0.3161) D Piston ring groove Max. 1. 6 (0.063) E Piston ring side clearance Max. 0. 1 (0.004) F Piston pin outer diameter Min. 7. 97 (0.3138) G Piston ring width Min. 1. 45 (0.057) H Piston ring end gap Max. 0. 5 (0.02) K Con-rod small end bore Max. 12. 000 (0.4724) L Crankshaft runout Max. 0. 03 (0.001) M Clutch drum bore Max. 51. 5 (2.03)
6 SERVICE INFORMATION GT-225 SRM-225 1-6 Special tools 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 17 18 16 Key Part Number Description Used for: 1 990511-30017 Tachometer PET-1000 Measuring engine speed 2 363018-00310 Washer Installing crankcase oil seal 3 X605-000050 Torx L wrench Removing and installing bolt 4 897603-23030 PTO shaft puller Removing driven (PTO) shaft 5 897701-06030 Bearing wedge Removing ball bearings on crankshaft 6 897701-14732 Bearing tool Removing and installing crankcase ball bearings 7 897702-30131 Piston pin tool Removing and installing piston pin (Use 8 mm dia. adapter.) 8 91004 Module air gap gauge Adjusting pole shoe air gaps 9 897712-04630 2-pin wrench Removing and installing pawl carrier 10 91020 Limiter plug tool Removing and installing plug 11 897726-09130 Oil seal tool Installing crankcase oil seals 12 990511-30023 Spark tester Checking ignition system 13 897803-30133 Pressure tester Checking carburetor and crankcase leakages 14 91009 Retaining ring pliers Removing and installing retaining ring 15 900100-08008 Bolt Removing magneto rotor ( ywheel) 16 433019-12330 Flange nut Removing magneto rotor ( ywheel) 17 91037 Compression gauge Measuring cylinder compression 18 900300 Ignition Analyzer : PET-9000 Measuring Ignition timing, Primary/Secondary voltage