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Honda GX690 Workshop Manual

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HONDA GX690
WORKSHOP MANUAL

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  • Page 1 HONDA GX690 WORKSHOP MANUAL...
  • Page 2: How To Use This Manual

    Honda, must determine the risks to their personal safety and the safe operation of this product. If you need to replace a part, use Honda Genuine parts with the correct part number or an equivalent part. We strongly recommend that you do not use replacement parts of inferior quality.
  • Page 3: Table Of Contents

    CONTENTS SPECIFICATIONS SERVICE INFORMATION MAINTENANCE TROUBLESHOOTING COVER FUEL SYSTEM GOVERNOR SYSTEM CHARGING SYSTEM IGNITION SYSTEM STARTING SYSTEM OTHER ELECTRICAL MUFFLER LUBRICATION SYSTEM CYLINDER CRANKCASE TECHNICAL FEATURES WIRING DIAGRAMS INDEX...
  • Page 4: Specifications

    ALL INFORMATION, ILLUSTRATIONS, DIRECTIONS AND SPECIFICATIONS INCLUDED IN THIS PUBLICATION ARE BASED ON THE LATEST PRODUCT INFORMATION AVAILABLE AT THE TIME OF APPROVAL FOR PRINTING. Honda Mo- tor Co., Ltd. RESERVES THE RIGHT TO MAKE CHANGES AT ANY TIME WITHOUT NOTICE AND WITHOUT INCURRING ANY OBLIGATION WHATSOEVER.
  • Page 5 How to use this manual SERVICE RULES • Use genuine Honda or Honda-recommended parts and lubricants or their equivalents. Parts that do not meet Honda’s design specifications may damage the unit. • Use the special tools designed for the product.
  • Page 6 How to use this manual ABBREVIATIONS Throughout this manual, the following abbreviations are used to identify the respective parts or systems Abbrev. term Full term Alternator American Petroleum institute Approx. Approximately Assy. Assembly ATDC After Top Dead Center Automatic Transmission Fluid Attachment Battery Bottom Dead Center...
  • Page 7: Specifications

    1. SPECIFICATIONS SERIAL NUMBER LOCATION ······················ 1-2 DIMENSIONAL DRAWINGS···························1-7 DIMENSIONS AND WEIGHTS PTO DIMENSIONAL DRAWINGS ··················1-9 SPECIFICATIONS ·········································· 1-2 ENGINE MOUNT DIMENSIONAL ENGINE SPECIFICATIONS ··························· 1-3 DRAWING ·····················································1-11 PERFORMANCE CURVES ···························· 1-4...
  • Page 8: Serial Number Location

    DIMENSIONS AND WEIGHTS SPECIFICATIONS Model GX630 GX630R GX660 GX660R GX690 GX690R Overall length Q type: 405 mm (15.9 in) V type: 426 mm (16.8 in) S type: 396 mm (15.6 in) T type: 429 mm (16.9 in) B type: 442 mm (17.4 in) DEN type: 371 mm (14.6 in)
  • Page 9: Engine Specifications

    SPECIFICATIONS ENGINE SPECIFICATIONS Model GX630 GX630R GX660 GX660R GX690 GX690R Description code GCBBK GCBEK GCBCK GCBFK GCBDK GCBGK Type 4 stroke, overhead valve, 90° V–twin cylinder Displacement 688.0 cm (41.97 cu–in) Bore x stroke 78.0 x 72.0 mm (3.07 x 2.83 in) Net power (SAE J1349)* 15.5 kW (21.1 PS) /...
  • Page 10: Performance Curves

    SPECIFICATIONS PERFORMANCE CURVES GX630/GX630R (N•m) (lbf•ft) (kgf•m) NET TORQUE (KW) (PS) NET POWER RECOMMENDED OPERATING SPEED RANGE (min 2000 3000 3600 ENGINE SPEED...
  • Page 11 SPECIFICATIONS GX660/GX660R (N·m) (lbf·ft) (kgf·m) NET TORQUE (KW) (PS) NET POWER RECOMMENDED OPERATING SPEED RANGE (min 2000 3000 3600 ENGINE SPEED...
  • Page 12 SPECIFICATIONS GX690/GX690R (N•m) (lbf•ft) (kgf•m) NET TORQUE (KW) (PS) NET POWER RECOMMENDED OPERATING SPEED RANGE (min 2000 3000 3600 ENGINE SPEED...
  • Page 13: Dimensional Drawings

    SPECIFICATIONS DIMENSIONAL DRAWINGS Unit: mm (in) 67 (2.6) 287.3 (11.31) (EXHAUST (EXHAUST PORT CENTER) M8x1.25 DEPTH 18 PORT END) (2 PLACES) M8x1.25 DEPTH 18 (2 PLACES) 135 (5.3) 198.5 (7.81) 207 (8.1) 405 (15.9) 245(9.6) 205(8.1) 205(8.1) 81 (3.2) (EXHAUST PORT END)
  • Page 14 SPECIFICATIONS HIGH MOUNT MUFFLER TYPE Unit: mm (in) 275.8(10.86) 380(15.0) 309.5 68(2.7) 130.5 102.5 SIDE MOUNT MUFFLER TYPE 166(6.5) 78(3.1) 238.5(9.39) 209(8.2) 280(11.0) 307(12.1)
  • Page 15: Pto Dimensional Drawings

    SPECIFICATIONS PTO DIMENSIONAL DRAWINGS MOUNT PART Unit: mm (in) 5/16-24UNF-2B TAP (4 PLACES) 3/8-16UNF-2B TAP (4 PLACES) 7/16-14UNF-2B TAP (4 PLACES) 18 (0.2) 4 (0.2) 18(0.7) Q TYPE 50 (2.0) 35 (1.4) 28 (1.1) 5 (0.2) +0.05 +0.002 (0.25 2 (0.1) 4.5 (0.18) 74 (2.9)
  • Page 16 SPECIFICATIONS T TYPE Unit: mm (in) 70 (2.8) 49 (1.9) 43.5 (1.71) 5 (0.2) +0.002 +0.05 0.25 4.5 (0.18) 6 (0.2) 90 (3.5) B TYPE 92 (3.6) 50 (2.0) 43.5 (1.71) 5 (0.2) +0.05 +0.002 9.53 (0.375 2 (0.1) 4.5 (0.18) 111.2 (4.38) V TYPE 2 •...
  • Page 17: Engine Mount Dimensional

    SPECIFICATIONS S TYPE Unit: mm (in) 41 (1.6) 35 (1.4) 28 (1.1) 5 (0.2) +0.05 +0.002 (0.3 4.5 (0.18) 3 (0.1) 50 (2.0) DEN TYPE 35 (1.4) 28 (1.1) 5 (0.2) TAPER 1/10 4.5 (0.18) 30.2 (1.19) 7.8 (0.31) ENGINE MOUNT DIMENSIONAL DRAWING 90.5 (3.56) 105 (4.1)
  • Page 18 MEMO...
  • Page 19: Service Information

    2. SERVICE INFORMATION MAINTENANCE STANDARDS ······················ 2-2 TOOLS·····························································2-6 TORQUE VALUES ········································· 2-4 HARNESS ROUTING······································2-8 LUBRICATION & SEAL POINT ····················· 2-5 TUBE ROUTING············································2-13...
  • Page 20: Maintenance Standards

    GX660: 3,850 ± 150 min (rpm) – GX660R: 3,850 ± 150 min (rpm) 3,200 ± 150 min (rpm) (VXE1 type only) GX690: 3,850 ± 150 min (rpm) GX690R: 3,850 ± 150 min (rpm) 3,200 ± 150 min (rpm) (VXE type only) Idle speed –...
  • Page 21 1 - 7/8 turns out (No.2 cylinder) GX660/660R: 1 - 3/4 turns out (No.1 cylinder) 1 - 7/8 turns out (No.2 cylinder) GX690/690R: 1 - 7/8 turns out (No.1 cylinder) 1 - 3/4 turns out (No.2 cylinder) Float height 15.5 (0.61) –...
  • Page 22: Torque Values

    SERVICE INFORMATION TORQUE VALUES ENGINE TORQUE VALUES Torque values Item Tread Dia. (mm) N·m kgf·m lbf·ft Cylinder nut M10 x 1.25 Oil drain plug bolt M20 x 1.5 Oil filter cartridge M20 x 1.5 Connecting rod bolt M7 x 1.0 Tappet adjusting nut M5 x 0.5 0.75...
  • Page 23: Lubrication & Seal Point

    SERVICE INFORMATION LUBRICATION & SEAL POINT Location Material Remarks Crankshaft pin, journal and gear Engine oil Crankcase bearing Crankcase cover bearing Piston outer surface and piston pin hole Piston pin outer surface Piston ring Cylinder inner surface Connecting rod big and small end bearing Connecting rod bolt threads and seating surface Camshaft cam profile, bearing, decompressor and gear...
  • Page 24 SERVICE INFORMATION TOOLS Float level gauge Oil pressure gauge attachment Oil pressure gauge set 07401-0010000 07406-0030000 07506-3000000 Tappet adjusting wrench 3 mm Pilot 17 mm Driver handle 15 x 135L 07708-0030400 07746-0040400 07749-0010000 Seat cutter 27.5 mm Seat cutter 33 mm Flat cutter 30 mm 07780-0010200 07780-0010800...
  • Page 25 SERVICE INFORMATION Oil seal driver attachment 60 mm Oil filter wrench 64 mm Clutch center holder 07GAD-PG40100 07HAA-PJ70100 07JMB-MN50301 Pilot screw wrench (D) 07KMA-MS60101...
  • Page 26: Harness Routing

    SERVICE INFORMATION HARNESS ROUTING FRONT VIEW FUEL CUT SOLENOID HIGH TENSION CORD ENGINE WIRE HARNESS No.1 IGNITION COIL No.2 IGNITION COIL IGNITION COIL 4P CONNECTOR HIGH TENSION FUEL CUT SOLENOID CORD CLIP ENGINE WIRE HARNESS No.1 IGNITION COIL HIGH TENSION CORD IGNITION COIL 4P CONNECTOR...
  • Page 27 SERVICE INFORMATION FRONT VIEW (AUTO THROTTLE TYPE) AUTO THROTTLE SOLENOID WIRE BAND UPPER SHROUD HARNESS AUTO THROTTLE Make sure there is no slack. No.1 IGNITION COIL SOLENOID HARNESS HIGH TENSION ENGINE WIRE CORD HARNESS Cut the band end so its length is 10 –...
  • Page 28 SERVICE INFORMATION TOP VIEW (AUTO THROTTLE TYPE) AUTO THROTTLE SOLENOID UPPER SHROUD AUTO THROTTLE SOLENOID HARNESS Make sure there is no slack. WIRE BAND ENGINE WIRE HARNESS No.1 IGNITION COIL 2-10...
  • Page 29 SERVICE INFORMATION SIDE VIEW (REMOTE CONTROL TYPE) CORD GROMMET CHARGE COIL CORD ENGINE WIRE HARNESS STARTER MOTOR CABLE STRAP OIL LEVEL SWITCH ENGINE WIRE HARNESS CORD GROMMET STARTER MOTOR Pass the engine wire harness over the charge coil cord. CHARGE COIL CORD CABLE STRAP OIL LEVEL SWITCH...
  • Page 30: Side View With Control Box Type

    SERVICE INFORMATION SIDE VIEW (WITH CONTROL BOX TYPE) WIRE BAND CHOKE CABLE THROTTLE CABLE ENGINE WIRE HARNESS CHARGE COIL REGULATOR/RECTIFIER CORD (2.7 A) STARTER MOTOR COMBINATION SWITCH 4P CONNECTOR WIRE GROUND TERMINAL HARNESS CLIP HOUR METER OIL LEVEL SWITCH 4P CONNECTOR CORD GROMMET ENGINE WIRE HARNESS REGULATOR/RECTIFIER...
  • Page 31: Tube Routing

    SERVICE INFORMATION TUBE ROUTING TOP VIEW TUBE CLAMP D10.0 BREATHER TUBE TUBE CLIP C11 TUBE CLAMP D10.0 FUEL FILTER FUEL TUBE A PURGE TUBE GROMMET Clamp the fuel tube A to the hock of FUEL TUBE B the fan cover. FUEL PUMP FRONT VIEW Clamp the fuel tube A to the hock of...
  • Page 32 SERVICE INFORMATION RIGHT SIDE VIEW FUEL FILTER FUEL TUBE A TUBE CLAMP D10.0 FUEL PUMP DRAIN TUBE 2-14...
  • Page 33: Maintenance

    3. MAINTENANCE MAINTENANCE SCHEDULE························· 3-2 SPARK PLUG REPLACEMENT ·····················3-7 ENGINE OIL LEVEL CHECK ························· 3-3 SPARK ARRESTER CLEANING····················3-7 ENGINE OIL CHANGE··································· 3-4 IDLE SPEED CHECK/ADJUSTMENT ············3-8 OIL FILTER REPLACEMENT ························ 3-4 VALVE CLEARANCE CHECK/ ADJUSTMENT ················································3-8 AIR CLEANER CHECK/CLEANING ·············· 3-5 COMBUSTION CHAMBER CLEANING ·······3-10 AIR CLEANER REPLACEMENT ···················...
  • Page 34: Maintenance Schedule

    MAINTENANCE MAINTENANCE SCHEDULE MAINTENANCE REGULAR SERVICE PERIOD (2) Each First Every Every Every Refer month year 2 years ITEM Perform at every indicated months page month or operating hour 20 hrs. 300 hrs. 500 hrs. interval, whichever comes 100 hrs. first.
  • Page 35: Engine Oil Level Check

    MAINTENANCE ENGINE OIL LEVEL CHECK Place the engine on a level surface. Start the engine and allow it to warm up for 1 to 2 minutes. Remove the oil level dipstick (1), and wipe it clean. Insert the oil level dipstick into the oil level pipe (2). Remove the oil level dipstick and check oil level shown on the tip of the level dipstick.
  • Page 36: Engine Oil Change

    MAINTENANCE ENGINE OIL CHANGE Drain the oil in the engine while the engine is warm. Warm oil drains quickly and completely. Place the engine on a level surface and place a suitable container under the drain plug bolt (1). Remove the oil filler cap (2) from the head cover (3) and the drain plug bolt to drain the oil into a suitable container.
  • Page 37: Air Cleaner Check/Cleaning

    MAINTENANCE AIR CLEANER CHECK/CLEANING A dirty air filter will restrict air flow to the carburetor, reducing engine performance. If the engine is operated in dusty areas, clean the air cleaner more often than specified in the MAINTENANCE SCHEDULE. Operating the engine without the air filters or with the filter installed loosely will allow dirt to enter the engine, causing rapid engine wear.
  • Page 38: Air Cleaner Replacement

    MAINTENANCE AIR CLEANER REPLACEMENT Remove the air cleaner cover (page 3-5). Remove the wing nut and air cleaner filters (page 3-5). Wipe dirt from the inside of the air cleaner case and the air cleaner cover, using a rag. Check the air cleaner case packing for deterioration or damage.
  • Page 39: Spark Plug Replacement

    MAINTENANCE SPARK PLUG REPLACEMENT If the engine has been running, the engine will be very hot. Allow it to cool before proceeding. Remove the spark plug cap, and then remove the spark plug using a spark plug wrench (page 3-6). Verify the new spark plug gap is correct (page 3-6).
  • Page 40: Idle Speed Check/Adjustment

    MAINTENANCE Clean the carbon deposits from the spark arrester screen (1) with a wire brush. Check the spark arrester screen for damage. If the screen is damaged, replace the spark arrester. Reinstall the spark arrester to the muffler. Install the muffler protector (side mount type only). IDLE SPEED CHECK/ADJUSTMENT Start the engine and allow it to warm up to normal operating temperature.
  • Page 41 MAINTENANCE Insert a thickness gauge between the valve rocker arm (1) and valve stem (2) to measure the valve clearance. VALVE CLEARANCE: IN: 0.08 ± 0.02 mm EX: 0.10 ± 0.02 mm Set the piston of the No.2 cylinder at the top dead center of the cylinder compression stroke (both valves fully closed) by rotating the flywheel (1) 270 degrees clockwise slowly.
  • Page 42: Combustion Chamber Cleaning

    MAINTENANCE COMBUSTION CHAMBER CLEANING Remove the cylinder (page 14-2). Prepare a cylinder of a thick paper or equivalent material (1), which diameter is as large as to fit against the inner wall of the cylinder, and insert the paper into the cylinder.
  • Page 43: Fuel Tube Check

    MAINTENANCE FUEL TUBE CHECK Gasoline is highly flammable and explosive. You can be burned or seriously injured when han- dling fuel. • Keep heat, sparks and flame away. • Handle fuel only outdoors. • Wipe up spills immediately. Remove the air cleaner case (page 6-3). Check the fuel tube (1) for deterioration, cracks or signs of leakage.
  • Page 44 MEMO...
  • Page 45: Troubleshooting

    4. TROUBLESHOOTING BEFORE TROUBLESHOOTING···················· 4-2 TROUBLESHOOTING ····································4-2...
  • Page 46: Before Troubleshooting

    TROUBLESHOOTING BEFORE TROUBLESHOOTING TROUBLESHOOTING • Use a known-good battery for troubleshooting. • Check that the connectors are connected securely. • Check the sufficient fresh fuel in the fuel tank. • Read the circuit tester's operation instructions carefully, and observe the instructions during inspection. •...
  • Page 47: Hard Starting

    TROUBLESHOOTING HARD STARTING Does not crank Turn the combination switch to the START Perform the STARTING SYSTEM position and check whether the engine TROUBLESHOOTING (page 10-2). cranks. Cranks Low oil Check the engine oil level (page 3-3). Add engine oil (page 3-3) and restart the engine.
  • Page 48 TROUBLESHOOTING ENGINE DOES NOT STOP WHEN COMBINATION SWITCH IS TURNED OFF No continuity Check the continuity of the wire harness Replace the engine wire harness. connecting the combination switch and ignition coils (Yellow). Continuity Continuity Replace the combination switch (page 7-10). Check the continuity between IGN terminal (Black) of the combination switch and the engine ground at ON position (page 11-4).
  • Page 49: Cover

    5. COVER FAN COVER REMOVAL/INSTALLATION····· 5-2 LOWER SHROUD REMOVAL/ INSTALLATION···············································5-5...
  • Page 50: Fan Cover Removal/Installation

    COVER FAN COVER REMOVAL/INSTALLATION COVER FAN COVER PROTECTOR TYPE FUEL TUBE A Clamp the fuel tube A to the hock of the fan cover. FUEL PUMP COVER TAPPING SCREW (5 x 20mm) (2) 4 N·m (0.4 kgf·m, 3.0 lbf·ft) SPECIAL SCREW (6 x 15 mm) (2) 4.4 N·m (0.45 kgf·m, 3.2 lbf·ft) FAN COVER...
  • Page 51 COVER SCREEN GRID/SCREEN GRID COVER TYPE FUEL TUBE A Clamp the fuel tube A to the hock of the fan cover. FUEL PUMP COVER SCREEN GRID HOLDER BOLT(8 x 18 mm) (3) TAPPING SCREW (5 x 20mm) (2) 4 N·m (0.4 kgf·m, 3.0 lbf·ft) SCREW(6 x 16 mm) (3) SPECIAL SCREW (6 x 15 mm) (2)
  • Page 52 COVER FRONT PTO/SCREEN GRID TYPE FUEL PUMP COVER FUEL TUBE A Clamp the fuel tube A to the hock of the fan cover. FAN COVER TAPPING SCREW (5 x 20mm) (2) 4 N·m (0.4 kgf·m, 3.0 lbf·ft) SPECIAL SCREW (6 x 15 mm) (2) 4.4 N·m (0.45 kgf·m, 3.2 lbf·ft) FRONT PTO...
  • Page 53 COVER LOWER SHROUD REMOVAL/ INSTALLATION Remove the fan cover (page 5-2). L. LOWER SHROUD HIGH TENSION CORD GROMMET INSTALLATION: Align the grommet (1) with the BOLT(6 x 20 mm) cutout in the L. lower shroud (2) as shown. L. LOWER SHROUD BOLT(6 x 16 mm) (2) R.
  • Page 54 MEMO...
  • Page 55: Fuel System

    6. FUEL SYSTEM SYSTEM DIAGRAM ······································· 6-2 CARBURETOR DISASSEMBLY/ ASSEMBLY ·····················································6-6 FUEL SYSTEM TROUBLESHOOTING ········· 6-2 PILOT SCREW REMOVAL/ INSTALLATION···············································6-7 AIR CLEANER REMOVAL/ INSTALLATION·············································· 6-3 CARBURETOR BODY CLEANING ················6-7 FUEL PUMP REMOVAL/INSTALLATION ····· 6-4 CARBURETOR INSPECTION ························6-8 CARBURETOR REMOVAL/ INSTALLATION·············································· 6-5...
  • Page 56: Fuel System Troubleshooting

    FUEL SYSTEM SYSTEM DIAGRAM FUEL SYSTEM BATTERY Bl/Y Bl/Y COMBINATION FUEL CUT SOLENOID SWITCH FUEL SYSTEM TROUBLESHOOTING FUEL DOES NOT REACH CARBURETOR No fuel Add fresh gasoline. Check the quantity and freshness of the fuel in the fuel tank. Sufficient fuel Operate Check the fuel cut solenoid operation by Check for clogged fuel filter, fuel tube and...
  • Page 57: Air Cleaner Removal

    FUEL SYSTEM AIR CLEANER REMOVAL/ INSTALLATION AIR CLEANER COVER OUTER FILTER (FOAM) WING NUT 0.8 N·m (0.08 kgf·m, 0.6 lbf·ft) NUT(6 mm) INNER FILTER (PAPER) BOLT(6 x 18 mm) (4) AIR CLEANER ELEMENT STAY AIR CLEANER CASE PACKING AIR CLEANER CASE...
  • Page 58: Fuel Pump Removal/Installation

    FUEL SYSTEM FUEL PUMP REMOVAL/INSTALLATION Gasoline is highly flammable and explosive.You can be burned or seriously injured when handling fuel. • Keep heat, sparks and flame away. • Handle fuel only outdoors. • Wipe up spills immediately. SCREW(6 x 12 mm) (2) FUEL FILTER 3 N·m (0.3 kgf·m, 2.2 lbf·ft) FUEL TUBE A...
  • Page 59: Carburetor Removal

    FUEL SYSTEM CARBURETOR REMOVAL/ INSTALLATION Gasoline is highly flammable and explosive.You can be burned or seriously injured when handling fuel. • Keep heat, sparks and flame away. • Handle fuel only outdoors. • Wipe up spills immediately. Remove the air cleaner (page 6-3). Attach a commercially available tube clamp to the fuel tube.
  • Page 60: Carburetor Disassembly

    , 30 psi) or FUEL CUT SOLENOID less). 8.8 N·m (0.90 kgf·m, 6.5 lbf·ft) MAIN JET NUMBER: DRAIN GX630/GX630R: SCREW L side (No.1 CYLINDER) #102 R side (No.2 CYLINDER) #105 SCREW (4) GX660/GX660R: #112 GX690/GX690R: #118 TUBE CLIP B8 FROAT CHAMBER DRAIN TUBE...
  • Page 61: Pilot Screw Removal

    Check container instructions. If you are in doubt, do not use these products to clean a Honda carburetor. • High air pressure may damage the carburetor body. Use low air pressure (207 kPa (2.11 kgf/cm , 30 psi) or less) when cleaning passages and ports.
  • Page 62: Carburetor Inspection

    FUEL SYSTEM CARBURETOR INSPECTION FLOAT LEVEL HEIGHT Place the carburetor (1) in the position as shown and measure the distance between the float (2) top and carburetor body when the float just contacts the seat without compressing the valve spring. TOOL: Float level gauge (3) 07401-0010000...
  • Page 63: Governor System

    7. GOVERNOR SYSTEM GOVERNOR ARM/CONTROL REMOVAL/ AUTO THROTTLE SOLENOID/GOVERNOR INSTALLATION·············································· 7-2 ARM INSTALLATION ·····································7-6 MAXIMUM SPEED ADJUSTMENT················ 7-3 CONTROL BOX REMOVAL/ INSTALLATION···············································7-8 GOVERNOR ARM INSTALLATION (Without auto throttle type) ························· 7-3 THROTTLE CABLE INSTALLATION ·············7-9 GOVERNOR SPRING INSTALLATION ········· 7-4 CHOKE CABLE INSTALLATION ···················7-9 AUTO THROTTLE SOLENOID REMOVAL ···...
  • Page 64: Governor Arm/Control Removal

    GOVERNOR SYSTEM GOVERNOR ARM/CONTROL GOVERNOR SYSTEM REMOVAL/INSTALLATION Remove the air cleaner (page 6-3). RECESSED BOLT (3) PAN SCREW (MAXIMUM SPEED CABLE HOLDER ADJUSTING SCREW) PAN SCREW (IDLING SPEED ADJUSTING SCREW) CONTROL CONTROL ADJUST SPRING BOLT(6 x 14 mm) (2) RETURN SPRING CHOKE ROD REMOVAL: Turn the rod joint (1) to...
  • Page 65: Maximum Speed Adjustment

    GOVERNOR SYSTEM MAXIMUM SPEED ADJUSTMENT Start the engine and allow it to warm up to normal operating temperature. Turn the pan screw (1) of the control to obtain the specified maximum speed. MAXIMUM SPEED: 3,850 ± 150 min (rpm) 3,150 ± 150 min (rpm) (GX630R QYD, VEP4, GX660R VXF types only)
  • Page 66: Governor Spring Installation

    (page 1-2). Model Type Spring position GX630 All types GX630R Except QYD, VEP4, VXD8, VXE1, VXF QYD, VEP4, VXD8, VXE1, VXF GX660 All types GX660R Except VXE1 VXE1 GX690 All types GX690R Except VXE SPRING SPRING POSITION 1 POSITION 2...
  • Page 67: Auto Throttle Solenoid Removal

    GOVERNOR SYSTEM AUTO THROTTLE SOLENOID REMOVAL Remove the air cleaner case (page 6-3). Disconnect the choke rod from the control (page 7-2). Unhook the governor spring and start spring from the governor arm (page 7-2). SOLENOID PLATE BOLT(6 x 14 mm) (3) SOLENOID STAY SPECIAL CAP NUT (2) AUTO THROTTLE SOLENOID...
  • Page 68: Auto Throttle Solenoid/Governor

    GOVERNOR SYSTEM AUTO THROTTLE SOLENOID/ GOVERNOR ARM INSTALLATION Install the governor arm (1) on the governor arm shaft (2) by aligning the cutout. Tighten the governor arm nut (3). TORQUE: 11 N·m (1.1 kgf·m, 8 lbf·ft) Connect the governor rod (4) and throttle return spring (5) to the governor arm and carburetor.
  • Page 69 GOVERNOR SYSTEM Route the auto throttle solenoid harness on the upper shroud loosely (page 2-9). Install the control (1) on the cylinders and tighten the three bolts (2). Hook the governor spring and start spring to the governor arm (page 7-4). Rotate the governor arm (1) to fully open the throttle valve (2).
  • Page 70: Control Box Removal

    GOVERNOR SYSTEM CONTROL BOX REMOVAL/ INSTALLATION Disconnect the throttle cable and the choke cable from the control. Disconnect the combination switch terminals and con- nector from the starter motor and regulator/rectifier. CONTROL BOX THROTTLE CABLE CHOKE CABLE TERMINAL NUT 9 N·m (0.9 kgf·m, 6.6 lbf·ft) BOLT(6 x 20 mm) (2)
  • Page 71: Throttle Cable Installation

    GOVERNOR SYSTEM THROTTLE CABLE INSTALLATION Connect the throttle cable (1) to the throttle lever (2) of the control. Move the throttle lever (3) on the control box (4) to throttle off position. Pull the throttle cable and be sure not to slack it. Set the throttle cable to the cable holder (5) of the control as shown.
  • Page 72: Control Box Disassembly

    GOVERNOR SYSTEM CONTROL BOX DISASSEMBLY/ ASSEMBLY Remove the control box (page 7-8). CONTROL BOX BRACKET SOCKET BOLT THROTTLE LEVER (5 x 9 mm) (2) SPECIAL SCREW (5 x 10.5 mm) (2) CHOKE KNOB 4 N·m (0.4 kgf·m, 3.0 lbf·ft) CONTROL PANEL CHOKE CABLE FUSE COVER...
  • Page 73: Charging System

    8. CHARGING SYSTEM SYSTEM DIAGRAM ······································· 8-2 CHARGE COIL REMOVAL/ INSTALLATION···············································8-6 CHARGING SYSTEM TROUBLESHOOTING···································· 8-3 CHARGE COIL INSPECTION·························8-7 COOLING FAN/FLYWHEEL REMOVAL/ REGULATOR/RECTIFIER SYSTEM INSTALLATION·············································· 8-4 INSPECTION ···················································8-7 REGULATOR/RECTIFIER INSPECTION ·······8-8...
  • Page 74 CHARGING SYSTEM SYSTEM DIAGRAM CHARGING SYSTEM 2.7 A CHARGE COIL TYPE CHARGE COIL (2.7 A) REGULATOR/ RECTIFIER FUSE (30 A) BATTERY 17 A CHARGE COIL TYPE CHARGE COIL (17 A) Bl/Y Bl/Y Bl/Y Bl/Y COMBINATION SWITCH REGULATOR/ FUSE (30 A) BATTERY RECTIFIER 26 A CHARGE COIL TYPE...
  • Page 75 CHARGING SYSTEM CHARGING SYSTEM TROUBLESHOOTING BATTERY DAMAGED OR WEAK No continuity Check the continuity between LO terminal Replace the combination switch (page 7-10). (Black/yellow) and BAT terminal (White) of the combination switch in the ON position (page 11-4). Continuity No continuity Check the continuity of the sub harness Replace the sub harness.
  • Page 76 CHARGING SYSTEM COOLING FAN/FLYWHEEL REMOVAL/ INSTALLATION REMOVAL Remove the following parts. – Fan cover (page 5-2) – L./R. lower shroud (page 5-5) – Ignition coil (page 9-4) Hold the flywheel (1) with the special tool (2) and remove the special nut (3). TOOL: Clutch center holder (2) 07JMB-MN50301...
  • Page 77 CHARGING SYSTEM INSTALLATION Clean the tapered part of the crankshaft (1) and flywheel (2) of dirt, oil, grease and other foreign material before installation. Be sure there are no metal parts or other foreign material on the magnet part of the flywheel.
  • Page 78 CHARGING SYSTEM CHARGE COIL REMOVAL/ INSTALLATION Remove the flywheel (page 8-4). CHARGE COIL (17A) BOLT(6 x 32 mm) (4) BOLT(6 x 12 mm) CABLE STRAP CHARGE COIL (2.7A) HARNESS BRACKET INSTALLATION: Be sure not to pinch the charge coil wire (1) with BOLT(6 x 32 mm) (3) the harness bracket (2).
  • Page 79: Charge Coil Inspection

    CHARGING SYSTEM CHARGE COIL INSPECTION Disconnect the charge coil connector/s. 2.7 A / 17 A TYPES: Measure the resistance between the terminals of the charge coil. Resistance: 2.7 A: 1.95 - 2.93 17 A: 0.18 - 0.28 26 A: 0.17 - 0.25 Check for continuity between each terminal and engine ground.
  • Page 80: Regulator/Rectifier Inspection

    CHARGING SYSTEM REGULATOR/RECTIFIER INSPECTION Disconnect the regulator/rectifier connector/s. 2.7 A TYPE: Measure the resistance between the terminals and be CHG2 sure that measurements within specifications in the table below. • Use a following range of recommended analog multitester. SP-15D (SANWA): k range TH-5H (KOWA): R x 100 range 2.7 A:...
  • Page 81: Ignition System

    9. IGNITION SYSTEM SYSTEM DIAGRAM ······································· 9-2 IGNITION COIL REMOVAL/ INSTALLATION···············································9-4 IGNITION SYSTEM TROUBLESHOOTING···································· 9-2 SPARK TEST ··················································9-5...
  • Page 82: Ignition System Diagram

    IGNITION SYSTEM SYSTEM DIAGRAM IGNITION SYSTEM No. 2 No. 1 IGNITION IGNITION COIL COIL SPARK SPARK PLUG PLUG OIL LEVEL SWITCH COMBINATION SWITCH IGNITION SYSTEM TROUBLESHOOTING NO SPARK AT SPARK PLUG Indicator is on or low oil Check whether the oil indicator is on Add engine oil (page 3-3).
  • Page 83 IGNITION SYSTEM From page 9-2 No continuity Replace the engine wire harness. Check the continuity of the wire harness connecting the combination switch and ignition coils (Black). Continuity Replace the ignition coil with a new one, and recheck (page 9-4).
  • Page 84 IGNITION SYSTEM IGNITION COIL REMOVAL/ INSTALLATION REMOVAL Remove the following parts: – Fan cover (page 5-2). – L./R. lower shroud (page 5-5). HIGH TENSION CORD CLAMP BOLT(6 x 32 mm) (4) IGNITION COIL INSTALLATION Attach the ignition coil (1) and loosely tighten the two flange bolts (2).
  • Page 85: Spark Test

    IGNITION SYSTEM SPARK TEST Inspect the following before spark test. • Faulty spark plug • Loose spark plug cap • Water in the spark plug cap (Leaking the ignition coil secondary voltage) • Check the ignition coil connection Disconnect the spark plug cap (1) from the spark plug (2).
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  • Page 87: Starting System

    10. STARTING SYSTEM SYSTEM DIAGRAM ····································· 10-2 STARTER MOTOR DISASSEMBLY/ ASSEMBLY ···················································10-4 STARTING SYSTEM TROUBLESHOOTING·································· 10-2 STARTER MOTOR INSPECTION·················10-5 STARTER MOTOR REMOVAL/ BRUSH REPLACEMENT······························10-8 INSTALLATION············································ 10-3 10-1...
  • Page 88 STARTING SYSTEM SYSTEM DIAGRAM STARTING SYSTEM Bl/W Bl/W FUSE COMBINATION (30 A / 40 A) SWITCH BATTERY STARTER MOTOR STARTING SYSTEM TROUBLESHOOTING STARTER MOTOR DOES NOT OPERATE No good Check the battery condition. Replace with a known-good battery. If the battery runs out again, perform the CHARGING SYSTEM Good TROUBLESHOOTING (page 8-3).
  • Page 89 STARTING SYSTEM STARTER MOTOR REMOVAL/ INSTALLATION Disconnect the starter motor wires from the starter motor. STARTER MOTOR REGULATOR/ RECTIFIER BOLT(10 x 40 mm) (2) REGULATOR/RECTIFIER BRACKET BOLT(6 x 32 mm) 10-3...
  • Page 90: Starter Motor Disassembly

    STARTING SYSTEM STARTER MOTOR DISASSEMBLY/ ASSEMBLY DISASSEMBLY MAGNETIC SWITCH SNAP RING TERMINAL COVER DISASSEMBLY: ARMATURE PINION DRIVE Hold the armature (1) upright and ASSEMBLY: LEVER drive the clutch stop collar A (2). Visually inspect the commutator Then remove the snap ring (3). surface for dust or other damage.
  • Page 91: Starter Motor Inspection

    STARTING SYSTEM ASSEMBLY Attach the pinion drive lever (1) to the magnetic switch (2). Set the pinion drive lever to the overrunning clutch (3) of the armature. Install the magnetic switch and armature to the drive housing (4) and tighten the flange nuts to secure the magnetic switch.
  • Page 92: Overrunning Clutch

    STARTING SYSTEM MAGNETIC SWITCH Check the continuity between the terminals of the magnetic switch. There should be no continuity between the terminals. If there is continuity, replace the magnetic switch (page 10-4). BRUSH LENGTH Measure the brush length. STANDARD: 10 mm (0.4 in) SERVICE LIMIT: 6 mm (0.2 in) If brush length is less than the service limit, replace the brush (page 10-8).
  • Page 93 STARTING SYSTEM MICA DEPTH Clean the commutator, and then measure the mica depth. SERVICE LIMIT: 0.2 mm (0.01 in) If the measurement is less than the service limit, replace the armature (page 10-4). ARMATURE CONTINUITY CHECK - COMMUTATOR SEGMENTS Check for continuity between segments. If an open circuit (no continuity) exists between any two segments, replace the armature (page 10-4).
  • Page 94: Brush Replacement

    STARTING SYSTEM BRUSH REPLACEMENT Cut off the brush lead (1) at the point shown and Cut here remove the brush (2). Remove the remaining brush lead and deposited solder from the terminal. Hold a new brush (1) in the same direction of the Press here removed brush and put a new plate (2) over the new brush and terminal (3) and press it using a pair of pliers...
  • Page 95: Other Electrical

    11. OTHER ELECTRICAL COMPONENT LOCATION ··························· 11-2 AUTO THROTTLE SOLENOID INSPECTION ·················································11-3 OIL LEVEL SWITCH INSPECTION ············· 11-3 COMBINATION SWITCH INSPECTION ·······11-4 OIL PRESSURE SWITCH INSPECTION ····· 11-3 HOUR METER INSPECTION························11-5 11-1...
  • Page 96: Component Location

    OTHER ELECTRICAL COMPONENT LOCATION OTHER ELECTRICAL Control box type: COMBINATION SWITCH HOUR METER OIL LEVEL SWITCH AUTO THROTTLE SOLENOID OIL PRESSURE SWITCH 11-2...
  • Page 97: Auto Throttle Solenoid

    OTHER ELECTRICAL OIL LEVEL SWITCH INSPECTION Disconnect the engine wire harness from the oil level switch. Check continuity between the switch terminals. There should be no continuity when the engine is full of oil. Drain the engine oil completely (page 3-4). Check continuity between the switch terminals.
  • Page 98: Combination Switch Inspection

    OTHER ELECTRICAL COMBINATION SWITCH INSPECTION Remove the combination switch (page 7-10). Check continuity between the terminals at each switch position. If the correct continuity is not obtained, replace the combination switch (page 7-10). (Bl/Y) (Bl/Y) (Bl) IGN GND Disconnect the charge coil connectors and combination switch 4P connector (1).
  • Page 99: Hour Meter Inspection

    OTHER ELECTRICAL HOUR METER INSPECTION Remove and disconnect the hour meter 4P connector (1). Apply a 9 V battery voltage between the PULSE terminal (Yellow) and GND terminal (Green). The hour meter should start counting time. Apply a 4.5 V battery voltage between the LED terminal (Blue) and GND terminal (Green).
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  • Page 101: Muffler

    12. MUFFLER HIGH MOUNT MUFFLER REMOVAL/ EXHAUST PIPE STUD BOLT INSTALLATION············································ 12-2 REPLACEMENT············································12-5 SIDE MOUNT MUFFLER REMOVAL/ HIGH MOUNT MUFFLER MOUNTING STUD INSTALLATION············································ 12-3 BOLT REPLACEMENT·································12-5 12-1...
  • Page 102 MUFFLER HIGH MOUNT MUFFLER REMOVAL/ MUFFLER INSTALLATION The muffler becomes very hot during operation and remains hot for a while after stopping the engine. Be careful not to touch the muffler while it is hot. Al- low it to cool before proceeding. HOT MARK MUFFLER PROTECTOR BOLT(6 x 8 mm) (6)
  • Page 103 MUFFLER SIDE MOUNT MUFFLER REMOVAL/ INSTALLATION The muffler becomes very hot during operation and remains hot for a while after stopping the engine. Be careful not to touch the muffler while it is hot. Al- low it to cool before proceeding. REMOVAL EXHAUST PIPE EXHAUST PIPE...
  • Page 104 MUFFLER INSTALLATION Make marks on the exhaust pipe (1) in the positions as shown. MARK B MARK A 55 mm (2.2 in) 35 mm (1.4 in) Install the muffler band (1) to the muffler (2) and insert the exhaust pipe (3) into the muffler to mark A. Install the two exhaust muffler gaskets (4) and exhaust pipe to the cylinders, then slide the exhaust pipe to mark B.
  • Page 105 MUFFLER EXHAUST PIPE STUD BOLT REPLACEMENT Thread two nuts onto the stud bolt and tighten them together, then use a wrench to turn the stud bolt out. Install new stud bolts. SPECIFIED LENGTH: 22 mm (0.87 in) 22 mm (0.9 in) HIGH MOUNT MUFFLER MOUNTING STUD BOLT REPLACEMENT Thread two nuts onto the stud bolt and tighten them...
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  • Page 107: Lubrication System

    13. LUBRICATION SYSTEM LUBRICATION SYSTEM DIAGRAM ··········· 13-2 OIL PUMP INSPECTION·······························13-4 OIL PRESSURE TEST ································· 13-3 13-1...
  • Page 108: Lubrication System Diagram

    LUBRICATION SYSTEM LUBRICATION SYSTEM DIAGRAM LUBRICATION SYSTEM ROCKER ARM PISTON CRANKSHAFT OIL PRESSURE SWITCH OIL FILTER OIL PUMP OIL STRAINER 13-2...
  • Page 109: Oil Pressure Test

    LUBRICATION SYSTEM OIL PRESSURE TEST Check the engine oil level (page 3-3). FRONT MOUNT Remove the oil pressure switch (1) or sealing plug (2). TYPE: SIDE MOUNT TYPE: Install the special tools (1)(2). FRONT MOUNT TYPE: TOOLS: Oil pressure gauge attachment (1) 07406-0030000 Oil pressure gauge set (2) 07506-3000000 TORQUE: 9 N·m (0.9 kgf·m, 6.6 lbf·ft)
  • Page 110: Oil Pump Inspection

    LUBRICATION SYSTEM Clean the oil pressure switch or sealing bolt threads, apply liquid sealant (Threebond 1207B, 1141G,1215) to the threads as shown. Tighten the oil pressure switch or sealing bolt to the specified torque. TORQUE: 9 N·m (0.9 kgf·m, 6.6 lbf·ft) Do not apply liquid sealant to the tip of the threads.
  • Page 111: Cylinder

    14. CYLINDER CYLINDER/PISTON REMOVAL ·················· 14-2 PISTON DISASSEMBLY/ASSEMBLY··········14-6 PISTON INSTALLATION ····························· 14-3 CYLINDER/PISTON INSPECTION ···············14-6 CYLINDER INSTALLATION ························ 14-3 VALVE SEAT RECONDITIONING··············14-13 CYLINDER DISASSEMBLY/ASSEMBLY···· 14-5 CYLINDER STUD BOLT REPLACEMENT··········································14-14 14-1...
  • Page 112: Cylinder/Piston Removal

    CYLINDER CYLINDER/PISTON REMOVAL CYLINDER Set the piston at the top dead center of the cylinder compression stroke (page 3-8). Remove the following parts: – Air cleaner (page 6-3) – Carburetor (page 6-5) – Muffler (page 12-2), (page 12-3) – Control and governor arm (page 7-2) –...
  • Page 113: Piston Installation

    CYLINDER PISTON INSTALLATION Position the connecting rod of the cylinder near top dead center by rotating the crankshaft slowly. Install the piston (1) on the connecting rod (2) with triangle mark (3) of the piston pointing toward the flywheel side as shown. Apply oil to the piston pin (4) outer surface, connecting rod small end and piston pin bore.
  • Page 114 CYLINDER Apply grease to the oil passage packing (1). Install the dowel pins (2) and oil passage packing on the crankcase. Apply oil to the cylinder inner surface, piston outer surface and piston rings. Install the cylinder (3) over the piston (4) while compressing the piston rings with your fingers.
  • Page 115: Cylinder Disassembly/Assembly

    CYLINDER CYLINDER DISASSEMBLY/ASSEMBLY Remove the cylinder (page 14-2). ENGINE HANGER BOLT (8 x 16 mm) VALVE SPRING RETAINER DISASSEMBLY: VALVE SPRING Push down and slide the valve spring retainer (1) to the side so that the valve stem (2) slips through the hole at side of the valve spring retainer.
  • Page 116: Piston Disassembly/Assembly

    CYLINDER PISTON DISASSEMBLY/ASSEMBLY Remove the piston (page 14-2). MARK TOP RING PISTON RING SET ASSEMBLY: SECOND RING 120° The top ring (1) and second ring (2) are not interchangeable. 120° Install the top ring and second ring on the piston 120°...
  • Page 117: Valve Seat Width

    CYLINDER CYLINDER SLEEVE I.D. Measure and record the cylinder I.D. at three levels in both the "X" axis (perpendicular to crankshaft) and the "Y" axis (parallel to crankshaft). Take the maximum reading to determine cylinder wear and taper. STANDARD: 78.000 – 78.015 mm BOTTOM (3.0709 –...
  • Page 118: Valve Spring Free Length

    CYLINDER Measure and record each valve guide I.D. STANDARD: 5.500 – 5.512 mm (0.2165 – 0.2170 in) SERVICE LIMIT: 5.560 mm (0.2189 in) If the measured valve guide I.D. is more than the service limit, replace the cylinder (page 14-5). VALVE STEM O.D.
  • Page 119 CYLINDER VALVE SPRING PERPENDICULARITY Measure the valve spring perpendicularity. STANDARD: 2° max. If the measured perpendicularity is more than the specification, replace the valve spring (page 14-5). PUSH ROD RUNOUT Check both ends of the push rod for wear. Check the push rod for straightness. If necessary, replace the push rod (page 14-2).
  • Page 120 CYLINDER ROCKER ARM SHAFT BEARING I.D. Measure the rocker arm shaft bearing I.D. STANDARD: 6.000 – 6.018 mm (0.050 – 0.077 in) SERVICE LIMIT: 6.043 mm (0.2379 in) If the measurement is more than the service limit, replace the cylinder (page 14-5). PISTON SKIRT O.D.
  • Page 121 CYLINDER PISTON PIN BORE I.D. Measure and record the piston pin bore I.D. of the piston. STANDARD: 18.002 – 18.008 mm (0.7087 – 0.7090 in) SERVICE LIMIT: 18.042 mm (0.7103 in) If the measurement is more than the service limit, replace the piston (page 14-6).
  • Page 122: Piston Ring End Gap

    CYLINDER PISTON RING WIDTH Measure each piston ring width. STANDARD: Top: 1.140 – 1.155 mm (0.0449 – 0.0455 in) Second: 1.140 – 1.155 mm (0.0449 – 0.0455 in) SERVICE LIMIT: Top: 1.120 mm (0.0441 in) Second: 1.120 mm (0.0441 in) If any of the measurements is less than the service limit, replace the piston rings (top, second, oil) as a set (page 14-6).
  • Page 123: Valve Seat Reconditioning

    CYLINDER VALVE SEAT RECONDITIONING Valve seat cutters/grinders or equivalent valve seat refacing equipment are recommended to correct worn valve seats. Using a 45° cutter remove enough material to produce a smooth and concentric seat. TOOLS: Cutter holder 5.5 mm (1) 07981-VA20101 Seat cutter 33 mm (45°...
  • Page 124: Cylinder Stud Bolt

    CYLINDER Lap the valves into their seats, using a commercially available valve lapper (1) and lapping compound. After lapping, wash all residual compound off the cylinder and valve. To avoid severe engine damage, be sure to remove all lapping compound from the engine before reassembly. Adjust the valve clearance after reassembly (page 3-8).
  • Page 125: Crankcase

    15. CRANKCASE CRANKCASE COVER REMOVAL/ VALVE LIFTER DISASSEMBLY/ INSTALLATION············································ 15-2 ASSEMBLY ···················································15-8 CRANKSHAFT/CONNECTING ROD/ CRANKCASE COVER/CRANKCASE/ CAMSHAFT/VALVE LIFTER REMOVAL/ CRANKSHAFT/CONNECTING ROD/ INSTALLATION············································ 15-4 CAMSHAFT/VALVE LIFTER INSPECTION ·················································15-8 CAMSHAFT INSTALLATION······················· 15-5 CRANKSHAFT OIL SEAL REPLACEMENT (CRANKCASE COVER SIDE) ····················15-13 BREATHER DISASSEMBLY/ ASSEMBLY ··················································...
  • Page 126 CRANKCASE CRANKCASE COVER REMOVAL/ CRANKCASE INSTALLATION REMOVAL Drain the engine oil (page 3-4). OIL LEVEL PIPE DOWEL PIN(8 x 14 mm) (2) O-RING O-RING CRANKCASE COVER REMOVAL: Insert a screwdriver into the recess (1) as shown and remove the crankcase cover from the crankcase.
  • Page 127 CRANKCASE INSTALLATION Clean the mating surfaces of the crankcase cover and crankcase of old liquid gasket, oil and other foreign material. Apply a bead ( 1.0 – 1.5 mm ( 0.04 – 0.06 in) of liquid gasket (Threebond TB1207B) to the mating surface of the crankcase cover as shown.
  • Page 128 CRANKCASE CRANKSHAFT/CONNECTING ROD/ CAMSHAFT/VALVE LIFTER REMOVAL/ INSTALLATION Remove the following: – Flywheel (page 8-4) – Cylinder (page 14-2) – Crankcase cover (page 15-2) CONNECTING ROD UPPER CONNECTING ROD BEARING INSTALLATION: LOCK PIN Install the connecting rod bearing(1) on the connecting rod upper (2) and lower (3) in the direction as shown.
  • Page 129: Camshaft Installation

    CRANKCASE CAMSHAFT INSTALLATION Open the valve lifters in the crankcase. Install the camshaft (1) to the crankcase (2) by aligning the punch marks (3) on the camshaft and the crankshaft (4) (marked on the timing gear). BREATHER DISASSEMBLY/ ASSEMBLY Remove the charge coil (page 8-6). OIL OUTLET VALVE STOPPER PLATE SCREW(3 x 8 mm)
  • Page 130: Breather Cover Installation

    CRANKCASE BREATHER COVER INSTALLATION Clean the mating surfaces of the breather cover and crankcase of old liquid gasket, oil and other foreign material. Apply a bead ( 1.0 – 1.5 mm ( 0.04 – 0.06 in) of liquid gasket (Threebond TB1207B) to the mating surface of the crankcase as shown.
  • Page 131 CRANKCASE GOVERNOR/OIL PUMP/OIL FILTER DISASSEMBLY/ASSEMBLY Remove the crankcase cover (page 15-2). BOLT OIL PUMP GEAR (6 x 35 mm) BOLT (6 x 28 mm) OIL PUMP COVER BOLT(6 x 90 mm) (2) BOLT(6 x 20 mm) (3) OIL FILTER DOWEL PIN(8 x 10 mm) (2) FILTER (O-ring) BASE...
  • Page 132 CRANKCASE VALVE LIFTER DISASSEMBLY/ ASSEMBLY Remove the valve lifter (page 15-4). CLIP VALVE LIFTER SPRING VALVE LIFTER COLLAR VALVE LIFTER SHAFT VALVE LIFTER CRANKCASE COVER/CRANKCASE/ CRANKSHAFT/CONNECTING ROD/ CAMSHAFT/VALVE LIFTER INSPECTION CRANKSHAFT AXIAL CLEARANCE Remove the connecting rods (page 15-4). Reinstall the crankcase cover. Measure the crankshaft axial clearance.
  • Page 133 CRANKCASE MAIN JOURNAL I.D.: CRANKCASE COVER SIDE Measure the main journal I.D. of the crankcase cover. STANDARD: 40.025 – 40.041 mm (1.5758 – 1.5764 in) SERVICE LIMIT: 40.06 mm (1.577 in) If the measurement is more than the service limit, replace the crankcase cover (page 15-7).
  • Page 134 CRANKCASE CRANK PIN O.D. Measure the crank pin O.D. of the crankshaft. STANDARD: 44.973 – 44.983 mm (1.7706 – 1.7710 in) SERVICE LIMIT: 44.920 mm (1.7685 in) If the measurement is less than the service limit, replace the crankshaft (page 15-4). CRANKSHAFT MAIN JOURNAL O.D.
  • Page 135 CRANKCASE CONNECTING ROD BIG END I.D. Set the connecting rod lower and connecting rod bearings to the connecting rod upper and tighten the connecting rod bolts to the specified torque. TORQUE: 22 N·m (2.2 kgf·m, 16 lbf·ft) Measure the connecting rod big end I.D. STANDARD: 44.988 –...
  • Page 136 CRANKCASE CAMSHAFT O.D. Measure the camshaft O.D. of the camshaft. STANDARD: 16.982 – 17.000 mm (0.6686 – 0.6693 in) SERVICE LIMIT: 17.100 mm (0.6732 in) If the measurement is less than the service limit, replace the camshaft (page 15-5). DECOMPRESSOR WEIGHT Check for worn and weakened weight return spring (1).
  • Page 137: Crankshaft Oil Seal

    CRANKCASE CRANKSHAFT OIL SEAL REPLACEMENT (CRANKCASE COVER SIDE) LOCATION CRANKSHAFT OIL SEAL (38 x 58 x 9 mm) CRANKSHAFT OIL SEAL (38 x 58 x 9 Remove the crankcase cover (page 15-2). Remove the oil seal (1) from the crankcase cover (2). Apply oil to the outer surface of a new oil seal.
  • Page 138: Crankcase Side

    CRANKCASE CRANKSHAFT/GOVERNOR ARM SHAFT OIL SEAL REPLACEMENT (CRANKCASE SIDE) LOCATION CRANKSHAFT OIL SEAL (38 x 58 x 9 mm) GOVERNOR ARM SHAFT OIL SEAL (10 x 16 x 5 mm) CRANKSHAFT OIL SEAL (38 x 58 x 9 Remove the crankshaft (page 15-4). Remove the oil seal (1) from the crankcase (2).
  • Page 139 CRANKCASE GOVERNOR ARM SHAFT OIL SEAL (10 x 16 x 5 mm) Remove the governor arm shaft (page 15-4). Remove the oil seal (1) from the crankcase (2). Apply oil to the outer surface of a new oil seal. Drive the new oil seal until it is fully seated on the end using the special tools.
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  • Page 141: Technical Features

    16. TECHNICAL FEATURES HIGH-COMPRESSION ENGINE ·················· 16-2 16-1...
  • Page 142: High-Compression Engine

    HIGH-COMPRESSION ENGINE TECHNICAL FEATURES OUTLINE The GX630/GX630R/GX660/GX660R/GX690/GX690R engines have more combustion efficiency and cylinder cooling capability than previous models. This results in increased the compression (increased to 9.3 from 8.3) and higher engine output. FEATURE Combustion efficiency and intake/exhaust efficiency improvement Combustion efficiency improvement: The S/V ratio (Surface Volume ratio of the combustion chamber) and resulting thermal efficiency have been increased by making the combustion chamber hemispherical.
  • Page 143 Knocking tends to occur when the compression ratio is increased, and the engine can be damaged by gas vibration and high temperature in the combustion chamber. The GX630/GX630R/GX660/GX660R/GX690/GX690R engines are equipped with the C.D.I ignition coil that sets the optimum ignition timing in accordance with the engine speed to prevent knocking.
  • Page 144 MEMO...
  • Page 145: Wiring Diagrams

    17. WIRING DIAGRAMS 2.7A CHARGE COIL / REMOTE CONTROL 17A CHARGE COIL / CONTROL BOX TYPE····························································· 17-2 TYPE······························································17-3 2.7A CHARGE COIL / CONTROL BOX 26A CHARGE COIL / REMOTE CONTROL TYPE····························································· 17-2 TYPE······························································17-4 17A CHARGE COIL / REMOTE CONTROL TYPE····························································· 17-3 17-1...
  • Page 146 WIRING DIAGRAMS 2.7A CHARGE COIL / REMOTE CONTROL TYPE WIRING DIAGRAMS Black Brown Yellow Orange Blue Light blue CHARGE Green Light green COIL Pink (2.7 A) White Gray COMBINATION SWITCH IGN GND REGULATOR/ RECTIFIER (Gr) (Gr) (Bl) (Bl) FUSE (30 A) (Bl) (Bl) (Bl/Y)
  • Page 147 WIRING DIAGRAMS 17A CHARGE COIL / REMOTE CONTROL TYPE Black Brown Yellow Orange Blue Light blue CHARGE Green Light green COIL Pink W/Bu W/Bu (17 A) White Gray Bl/Y Bl/Y COMBINATION SWITCH IGN GND REGULATOR/ (Gr) (Gr) RECTIFIER (Gr) (Gr) (Bl/Y) (Bl/Y) FUSE (30 A)
  • Page 148 WIRING DIAGRAMS 26A CHARGE COIL / REMOTE CONTROL TYPE Black Brown Yellow Orange Blue Light blue CHARGE Green Light green COIL Pink (26 A) White Gray COMBINATION SWITCH W/Bu IGN GND (Gr) (Gr) REGULATOR/ (Gr) (Gr) RECTIFIER (Gr) (Gr) FUSE (40 A) (Bl) (Bl) (Bl/Y)
  • Page 149: Index

    INDEX INDEX AIR CLEANER CHECK/CLEANING································· 3-5 HIGH-COMPRESSION ENGINE ···································· 16-2 AIR CLEANER REMOVAL/INSTALLATION····················· 6-3 HOUR METER INSPECTION········································· 11-5 AIR CLEANER REPLACEMENT······································ 3-6 AUTO THROTTLE SOLENOID INSPECTION ··············· 11-3 IDLE SPEED CHECK/ADJUSTMENT ······························ 3-8 AUTO THROTTLE SOLENOID REMOVAL······················ 7-5 IGNITION COIL REMOVAL/INSTALLATION ··················· 9-4 AUTO THROTTLE SOLENOID/GOVERNOR ARM INSTALLATION ································································...

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