Yamaha MX800V Service Manual
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Yamaha MX800V Service Manual

Multi-purpose engines
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SERVICE MANUAL
MX800V
MX825V
LIT-19616-02-50
7UC-F8197-E0

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Summary of Contents for Yamaha MX800V

  • Page 1 SERVICE MANUAL MX800V MX825V LIT-19616-02-50 7UC-F8197-E0...
  • Page 3 MX800V, MX825V SERVICE MANUAL ©2017 by Yamaha Motor Corporation, U.S.A. 1st Edition, October 2017 All rights reserved. Any reprinting or unauthorized use without the written permission of Yamaha Motor Corporation, U.S.A. is expressly prohibited. LIT-19616-02-50...
  • Page 4 This manual was produced by the Yamaha Motor Powered Products Co., Ltd. primarily for use by Yamaha dealers and their qualified mechanics. It is not possible to include all the knowledge of a mechanic in one manual. Therefore, anyone who uses this book to perform maintenance and repairs on Yamaha machines should have a basic understanding of mechanics and the techniques to repair these types of machines.

  • Page 5: How To Use This Manual

    HOW TO USE THIS MANUAL This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check procedures are laid out with the individual steps in sequential order. •...
  • Page 6 SYMBOLS The following symbols are used in this manual for easier understanding. The following symbols are not relevant to every machine. SYMBOL DEFINITION SYMBOL DEFINITION Filling fluid Lubricant Special tool Tightening torque Wear limit, clearance Engine speed Electrical data Replace the part with a new one. Lithium-soap base grease Molybdenum disulfide grease Engine oil...

  • Page 7: General Information

    INDEX GENERAL INFORMATION PERIODIC CHECKS AND ADJUSTMENTS ENGINE FUEL ELECTRICAL TROUBLESHOOTING SPECIFICATIONS...

  • Page 8: Table Of Contents

    TABLE OF CONTENTS OIL COOLER ........2-9 GENERAL INFORMATION AIR FILTER ELEMENT ......2-9 ADJUSTING THE VALVE MACHINE IDENTIFICATION ......1-1 CLEARANCE ........2-9 SERIAL NUMBER .........1-1 CYLINDER HEADS STARTING SERIAL NUMBER....1-1 DECARBONIZATION ......2-13 ENGINE SPEED ......... 2-14 DIMENSIONS ..........1-2 ADJUSTING THE ENGINE SPEED..
  • Page 9 CYLINDER HEAD #2 ......3-21 REMOVING THE CAMSHAFT AND CHECKING THE ROCKER ARMS VALVE LIFTERS ......... 3-42 AND ROCKER ARM SHAFTS.....3-23 CHECKING THE CAMSHAFT .... 3-42 CHECKING THE PUSH RODS ...3-23 CHECKING THE VALVE LIFTERS ..3-43 REMOVING THE CYLINDER CHECKING THE REED VALVE ..3-44 HEADS ..........3-23 INSTALLING THE VALVE LIFTERS CHECKING THE CYLINDER...
  • Page 10 ELECTRICAL SPECIFICATIONS CIRCUIT DIAGRAM........5-1 GENERAL SPECIFICATIONS ....7-1 ELECTRICAL COMPONENTS....5-3 MAINTENANCE SPECIFICATIONS ..7-3 CHECKING THE SWITCH ENGINE ..........7-3 CONTINUITY.........5-5 ELECTRICAL ........7-7 CHECKING THE OIL PRESSURE TIGHTENING TORQUES ......7-8 SWITCH ..........5-5 GENERAL TORQUE CHECKING THE TCI UNIT SPECIFICATIONS........

  • Page 11: Machine Identification

    GENERAL INFORMATION MACHINE IDENTIFICATION SERIAL NUMBER The serial number is printed on the label “1” affixed to the position of the multi-purpose engine as shown in the illus- tration. • The first four digits identify the model, and the remaining digits indicates the production number.

  • Page 12: Dimensions

    DIMENSIONS DIMENSIONS mm (in) MOUNTING BASE mm (in) 3/8-16UNC *1: UNC: Unified coarse thread (Unit: in) *2: PCD: Pitch Circle Diameter...

  • Page 13: Rear

    DIMENSIONS REAR mm (in) 451.2(17.76) 235.1(9.26) REAR (For models equipped with a muffler) mm (in) 451.2(17.76) 235.1(9.26) 445.4(17.54)

  • Page 14: Right Side

    DIMENSIONS RIGHT SIDE mm (in) RIGHT SIDE (For models equipped with a muffler) mm (in) 116.7(4.59) 108.8(4.28)

  • Page 15: Important Information

    Be sure to use the correct special tool for the job to guard against damage. Oil, grease and seals Be sure to use genuine Yamaha oils, grease and sealers, or the equivalents. Expendable parts Always replace the gaskets, O-rings, cotter pins and cir-...

  • Page 16: All Replacement Parts

    • Make sure that the parts, move smoothly after each sec- tion of the machine is assembled. ALL REPLACEMENT PARTS We recommend the use of genuine Yamaha parts for all replacements. Use oil and/or grease, recommended by Yamaha, for assembly and adjustment.

  • Page 17: Bearings And Oil Seals

    BASIC SERVICE INFORMATION BEARINGS AND OIL SEALS Install the bearing(s) “1” and oil seal(s) “2” with their manu- facture’s marks or numbers facing outward. (In other words, the stamped letters must be on the side exposed to view.) When installing oil seal(s), apply a light coating of lightweight lithium base grease to the seal lip(s).
  • Page 18 BASIC SERVICE INFORMATION Checking the connections Check the leads, couplers, and connectors for stains, rust, moisture, etc. Disconnect: • Lead • Coupler • Connector NOTICE • When disconnecting a coupler, release the coupler lock, hold both sections of the coupler securely, and then disconnect the coupler.
  • Page 19 BASIC SERVICE INFORMATION Connect: • Lead • Coupler • Connector • When connecting a coupler or connector, push both sec- tions of the coupler or connector together until they are connected securely. • Make sure all connections are tight. Check: •...

  • Page 20: Special Tools And Testers

    SPECIAL TOOLS AND TESTERS SPECIAL TOOLS AND TESTERS The proper special tools are necessary for complete and accurate tune-up and assembly. Using the correct special tool will help prevent damage caused by the use of improper tools or improvised techniques. Valve spring compressor Ignition checker Digital tachometer...

  • Page 21: Periodic Checks And Adjustments

    Check leaks and anything operator notices  such as noises or abnormal operation. *1 For models equipped with a Yamaha muffler. *2 Items marked with an asterisk require special tools, data and technical skills, have a Yamaha dealer perform the service.

  • Page 22: Periodic Maintenance

    PERIODIC MAINTENANCE PERIODIC MAINTENANCE SPARK PLUGS WARNING Check and adjust the areas around the cylinder head after the engine has cooled down completely. Remove: • Spark plug caps “1” • Spark plugs NOTICE Before removing the spark plugs, use compressed air to clean the cylinder head covers to prevent dirt from falling into the engine.

  • Page 23: Muffler

    PERIODIC MAINTENANCE Install: • Spark plugs Spark plug: 20 N·m (2.0 kgf·m, 15 lb·ft) To prevent threads from being damaged, temporally tighten “a” the spark plug before tightening it to the speci- fied torque “b”. MUFFLER (For models equipped with a muffler) WARNING The engine and muffler will be very hot after the engine has been run.

  • Page 24: Engine Oil Leakage

    PERIODIC MAINTENANCE Remove: • Muffler (Refer to “MUFFLER (For models equipped with a muffler)” on page 3-4) Decarbonize: • Muffler Tap on the muffler in the area shown in the illustra- tion to loosen carbon buildup, and then shake it out from the end of the muffler.

  • Page 25: Engine Oil Level

    PERIODIC MAINTENANCE Check the areas outside of the engine for oil leakage. Oil leakage  Replace the gasket, oil seal, or O-ring. ENGINE OIL LEVEL Remove: • Oil filler cap “1” Check: • Check that engine oil is at the specified level. ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼...

  • Page 26: Replacing The Engine Oil

    PERIODIC MAINTENANCE Install: • Oil filler cap Check whether the oil warning light comes on by turning the main switch. Oil warning light comes on  Add oil. Oil warning light does not comes on  OK. REPLACING THE ENGINE OIL WARNING Avoid draining the engine oil immediately after stop- ping the engine.
  • Page 27 PERIODIC MAINTENANCE b. Lubricate the O-ring “3” of the new oil filter with a thin coat of engine oil. NOTICE Make sure the O-ring “3” is positioned correctly in the groove of the oil filter. c. Tighten the new oil filter to specification with an oil filter wrench.

  • Page 28: Fuel Leakage

    PERIODIC MAINTENANCE FUEL LEAKAGE Check: • Leakage Check at fuel pump, fuel hose, and carburetor assembly. NOTICE Replace fuel hose every four years. FUEL FILTER WARNING Do not smoke, and keep away from open flames, sparks, or any other source of fire when handling or in the vicinity of fuel.

  • Page 29: Oil Cooler

    PERIODIC MAINTENANCE OIL COOLER Check: • Oil cooler Damage  Replace. Dirt/clog  Clean. AIR FILTER ELEMENT NOTICE Be sure not to run the engine without air filter element. Otherwise this can result in excessive piston and/or cylinder wear. Remove: •...
  • Page 30 PERIODIC MAINTENANCE Remove: • Cylinder head cover “3” • Cylinder head cover gasket Remove: • Fan case cover “1” (Refer to “CASE AND FAN” on page 3-9) • Grass screen “2” (Refer to “CASE AND FAN” on page 3-9) Turn the crankshaft clockwise, and then set the piston at TDC (top-dead-center) on the compression stroke.
  • Page 31 PERIODIC MAINTENANCE Valve clearance (cold) Normal ENG operation range (between 1000 hr periodic maintenance): Intake: 0.02–0.2 mm (0.0008–0.01 in) Exhaust: 0.02–0.2 mm (0.0008–0.01 in) Original set value (adjust at 1000 hr peri- odic maintenance): Intake: 0.07–0.13 mm (0.003–0.005 in) Exhaust: 0.07–0.13 mm (0.003–0.005 in) Adjust: •...
  • Page 32 PERIODIC MAINTENANCE c. Check the thickness of the current adjusting pad. The thickness of each adjusting pad is indicated in 1/100 mm units “a” and inscribed on the side. Example: If the adjusting pad is marked “180”, the pad thick- ness is 1.80 mm (0.071 in).

  • Page 33: Cylinder Heads Decarbonization

    PERIODIC MAINTENANCE g. Install the rocker arm “5”. (Refer to “CYLINDER HEAD COVERS, CYLINDER HEADS” on page 3-19) Rocker arm shaft bolt: 4.0 N·m (0.40 kgf·m, 3.0 lb·ft) • Lubricate the rocker arm with engine oil. • Turn the crankshaft clockwise several full turns to seat the parts.

  • Page 34: Engine Speed

    PERIODIC MAINTENANCE ENGINE SPEED Warm up the engine for several minutes. Attach: • Digital tachometer “1” Digital tachometer: YU-39951-B, 90890-06760 Measure: • High engine speed (with no load) Out of specification  Adjust. High engine speed (with no load): 3550–3650 r/min ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼...

  • Page 35: Adjusting The Engine Speed

    PERIODIC MAINTENANCE b. Check the low engine speed. ▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲ ADJUSTING THE ENGINE SPEED Warm up the engine for several minutes. Attach: • Digital tachometer “1” Digital tachometer: YU-39951-B, 90890-06760 Adjust: • High engine speed ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. Move the throttle lever “1” to the high engine speed position “a”.

  • Page 36: Low Engine Speed (Replace The Carburetor Assembly)

    PERIODIC MAINTENANCE ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. Move the throttle lever “1” to the low engine speed position “a”. b. Turn the screw “2” in direction “b” or “c” until obtain adequet low engine speed. Direction “b” Low engine speed is decreased. Direction “c” Low engine speed is increased.

  • Page 37: Fittings And Fasteners

    PERIODIC MAINTENANCE FITTINGS AND FASTENERS Check: • All fittings and fasteners Looseness  Tighten. Rough movement  Replace the defective part(s). Damage/pitting  Replace. 2-17...
  • Page 38 PERIODIC MAINTENANCE MEMO 2-18...

  • Page 39: Engine

    ENGINE ENGINE INSPECTION MEASURING THE COMPRESSION PRESSURE The following procedure applies to all of the cylinders. Measure the compression pressure after checking and adjusting the valve clearance. Warm up the engine for several minutes. Remove: • Spark plug cap • Spark plug NOTICE Before removing the spark plug, use compressed air to clean the cylinder head cover to prevent dirt from...
  • Page 40 ENGINE INSPECTION ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. If the compression pressure is below the minimum specification, pour a teaspoonful of engine oil into the spark plug hole and measure again. Refer to the following table. Reading Diagnosis Higher than • Worn cylinder, piston, and piston ring(s) without oil •...

  • Page 41: Air Filter

    AIR FILTER AIR FILTER 1.8 N ・ m (0.18 kgf ・ m, 1.3 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 7 N ・...

  • Page 42: Muffler (For Models Equipped With A Muffler)

    MUFFLER (For models equipped with a muffler) MUFFLER (For models equipped with a muffler) 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) 3.5 N ・ m (0.35 kgf ・ m, 2.6 lb ・ ft) Order Job/Parts to remove Q’ty...

  • Page 43: Oil Cooler

    OIL COOLER OIL COOLER 14 N ・ m (1.4 kgf ・ m, 10 lb ・ ft) 9 N ・ m (0.9 kgf ・ m, 6.6 lb ・ ft) 17 N ・ m (1.7 kgf ・ m, 13 lb ・ ft) 62 N ・...

  • Page 44: Removing The Oil Cooler

    OIL COOLER REMOVING THE OIL COOLER Remove: • Hose clamp (Clic-R) “1” • Remove the hose clamp using the hose clamp pliers “2”. • When removing the hose clamp, make sure that the thick tip “a” of the hose clamp pliers is directed as shown in the illustration.
  • Page 45 OIL COOLER • Make sure the oil seal is positioned properly. • Align the projection “a” on the adapter with the hole “b” in the crankcase cover 2. Install: • Oil filter • Oil hose 2 • Oil hose 1 •...

  • Page 46: Rectifier/Regulator

    RECTIFIER/REGULATOR RECTIFIER/REGULATOR 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the rectifier/regulator Remove the parts in the order listed. Earth terminal Engine hunger For maintenance.

  • Page 47: Case And Fan

    CASE AND FAN CASE AND FAN 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 7 N ・...

  • Page 48: Removing The Case And Fan

    CASE AND FAN REMOVING THE CASE AND FAN Remove: • Air filter case (Refer to “AIR FILTER” on page 3-3) Remove: • Rectifier/regulator (Refer to “RECTIFIER/REGULATOR” on page 3-8) Remove: • Fuel pump (Refer to “FUEL PUMP” on page 4-1) Remove: •...

  • Page 49: Checking The Case And Fan

    CASE AND FAN CHECKING THE CASE AND FAN Check: • Fan case cover “1” • Grass screen “2” • Fan case “3” • Fan “4” Damage  Replace. Dirt/clog  Clean. INSTALLING THE CASE AND FAN Install: • Fan “1” •...
  • Page 50 CASE AND FAN Insert the tab “a” of the fan case cover “4” into the hole “b” of the fan case “2” first and then install. Install: • Oil filler pipe • Oil filler pipe bolt Oil filler pipe bolt: 7 N·m (0.7 kgf·m, 5.2 lb·ft) •...

  • Page 51: Tci Units, Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY TCI UNITS 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 10 N ・...

  • Page 52: Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY FLYWHEEL AND STATOR COIL ASSEMBLY 180 N ・ m (18 kgf ・ m, 133 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the flywheel and stator coil...

  • Page 53: Removing The Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY REMOVING THE FLYWHEEL AND STATOR COIL ASSEMBLY Remove: • Air filter case (Refer to “AIR FILTER” on page 3-3) Remove: • Rectifier/regulator (Refer to “RECTIFIER/REGULATOR” on page 3-8) Remove: • Fuel pump (Refer to “FUEL PUMP” on page 4-1) Remove: •...

  • Page 54: Checking The Flywheel And Stator Coil Assembly

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY Remove: • Flywheel “1” • Woodruff key • Remove the flywheel “1” using the heavy duty puller “2”. • Fully tighten the tool holding bolts, making sure the tool body is parallel with the flywheel. If necessary, one bolt may be backed out slightly to level the tool body.
  • Page 55 TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY Install: • Washer “1” • Flywheel nut “2” Flywheel nut: 180 N·m (18 kgf·m, 133 lb·ft) Tighten the flywheel nut “2” using the primary clutch holder “3” to hold the flywheel. Primary clutch holder: YU-01235 Rotor holding tool: 90890-01235...

  • Page 56: Installing The Tci Units

    TCI UNITS, FLYWHEEL AND STATOR COIL ASSEMBLY INSTALLING THE TCI UNITS The following procedure applies to all of the TCI units. Install: • TCI unit • TCI unit bolts TCI unit bolt: 10 N·m (1.0 kgf·m, 7.4 lb·ft) Measure: • TCI unit air gap Out of specification ...

  • Page 57: Cylinder Head Covers, Cylinder Heads

    CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD #1 11 N ・ m (1.1 kgf ・ m, 8.1 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 12 N ・...
  • Page 58 CYLINDER HEAD COVERS, CYLINDER HEADS 11 N ・ m (1.1 kgf ・ m, 8.1 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 12 N ・...

  • Page 59: Cylinder Head #2

    CYLINDER HEAD COVERS, CYLINDER HEADS CYLINDER HEAD #2 11 N ・ m (1.1 kgf ・ m, 8.1 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 12 N ・...
  • Page 60 CYLINDER HEAD COVERS, CYLINDER HEADS 11 N ・ m (1.1 kgf ・ m, 8.1 lb ・ ft) 4.0 N ・ m (0.40 kgf ・ m, 3.0 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 12 N ・...

  • Page 61: Checking The Rocker Arms And Rocker Arm Shafts

    CYLINDER HEAD COVERS, CYLINDER HEADS CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS The following procedure applies to all of the rocker arms and rocker arm shafts. Check: • Rocker arm “1” • Rocker arm shaft “2” Wear/damage/cracks  Replace. CHECKING THE PUSH RODS The following procedure applies to all of the push rods.

  • Page 62: Installing The Cylinder Head Assembly

    CYLINDER HEAD COVERS, CYLINDER HEADS Check: • Cylinder head combustion chamber Check the combustion chamber for carbon depos- its. Any carbon deposits  Eliminate. Be sure not to damage the sealing surface of the cylinder head. Check: • Cylinder head Cracks/damage around the hole of spark plug ...
  • Page 63 CYLINDER HEAD COVERS, CYLINDER HEADS Cylinder head bolt: 1st: 12 N·m (1.2 kgf·m, 8.9 lb·ft) 2nd: 50 N·m (5.0 kgf·m, 37 lb·ft) 3-25...

  • Page 64: Valves

    VALVES VALVES Order Job/Parts to remove Q’ty Remarks Remove the parts in the order listed. Removing the valves The following procedure applies to both cylin- ders. Refer to “CYLINDER HEAD COVERS, CYL- Cylinder head assembly INDER HEADS” on page 3-19. Valve cotter Valve spring retainer Intake valve spring...

  • Page 65: Removing The Valves And Valve Springs

    VALVES REMOVING THE VALVES AND VALVE SPRINGS The following procedure applies to all of the valves, valve springs and related components. Remove: • Valve cotter “1” • Valve spring retainer “2” • Valve spring “3” • Valve stem seal “4” •...
  • Page 66 VALVES Measure: • Valve stem diameter “a” Valve stem diameter (Intake): 5.948–5.963 mm (0.2342–0.2348 in) Valve stem diameter (Exhaust): 5.940–5.955 mm (0.2339–0.2344 in) Limit (Intake): 5.918 mm (0.2330 in) Limit (Exhaust): 5.910 mm (0.2327 in) Out of specifications  Replace. Measure: •...

  • Page 67: Checking The Valve Seats

    VALVES Installed compression spring force (Intake): 67.7 N (6.90 kgf, 15.2 lbf) Installed compression spring force (Exhaust): 118.1 N (12.0 kgf, 26.5 lbf) Installed length (Intake): 29.3 mm (1.1535 in) Installed length (Exhaust): 29.0 mm (1.1417 in) Measure: • Valve spring tilt “a” Tilt limit: 1.7 mm (0.0669 in) Out of specifications ...

  • Page 68: Valve Lapping

    VALVES Measure: • Valve face contact width “a” Make sure that the contact width along the entire valve face is within specifications. Valve face contact width (Intake): 0.9–1.1 mm (0.0354–0.0433 in) Valve face contact width (Exhaust): 0.9–1.1 mm (0.0354–0.0433 in) Limit (Intake): 1.6 mm (0.063 in) Limit (Exhaust):...

  • Page 69: Installing The Valves And Valve Springs

    VALVES Once the contacting surface of the valve face is pol- ished and becomes shiny, apply mechanic’s blue lay- out fluid to make sure that there are traces of even contact in the center of the valve face. NOTICE Do not let the lapping compound enter the gap between the valve stem and the valve guide.

  • Page 70: Oil Pump

    OIL PUMP OIL PUMP 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 30 N ・ m (3.0 kgf ・ m, 22 lb ・ ft) 12 N ・ m (1.2 kgf ・ m, 8.9 lb ・ ft) 30 N ・...

  • Page 71: Disassembling The Oil Pump

    OIL PUMP DISASSEMBLING THE OIL PUMP Remove: • Crankcase cover 2 Remove: • Relief valve “1” Remove: • Oil pump cover “1” Remove: • Oil strainer cover “1” • Oil strainer “2” • Inner rotor “3” • Outer rotor “4” CHECKING THE OIL PUMP Check: •...

  • Page 72: Checking The Relief Valve

    OIL PUMP Measure: • Inner-rotor-to-outer-rotor-tip clearance “a” and “b” Out of specification  Replace the defective part(s). Inner-rotor-to-outer-rotor-tip clearance “a”: 0.0 mm (0.0 in) Inner-rotor-to-outer-rotor-tip clearance “b”: 0.19–0.35 mm (0.008–0.013 in) Check: • Oil pump operation Rough movement  Replace the defective part(s). CHECKING THE RELIEF VALVE Check: •...

  • Page 73: Assembling The Oil Pump

    OIL PUMP Engage the two threads of the oil pressure switch screw with the crankcase cover 2, apply LOCTITE®, and tighten to the specified torque. ASSEMBLING THE OIL PUMP Lubricate: • Inner rotor • Outer rotor Recommended lubricant: Engine oil Install: •...

  • Page 74: Installing The Crankcase Cover 2

    OIL PUMP INSTALLING THE CRANKCASE COVER 2 Clean: • Mating surfaces of the crankcase and the crank- case cover 2 (with a cloth dampened with lacquer thinner) Apply: • Sealant (onto the crankcase cover 2 mating surfaces) Three bond No.1217G® Install: •...

  • Page 75: Pistons, Camshaft, Crankcase, And Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CRANKCASE 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 9 N ・...
  • Page 76 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 10 N ・ m (1.0 kgf ・ m, 7.4 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 9 N ・...

  • Page 77: Pistons, Camshaft, And Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT PISTONS, CAMSHAFT, AND CRANKSHAFT 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) 20 N ・ m (2.0 kgf ・ m, 15 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the pistons, camshaft, and Remove the parts in the order listed.

  • Page 78: Removing The Flyweight Shaft Assembly And Governor Fork

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT REMOVING THE FLYWEIGHT SHAFT ASSEMBLY AND GOVERNOR FORK Remove: • Crankcase cover 1 • Governor assembly Remove: • Clips “1” • Governor fork “2” • Washers “3” Remove: • Flyweight shaft assembly “1” • Washer “2” Remove the flyweight shaft assembly by tapping the weight shaft from outside of the crankcase cover 1.

  • Page 79: Assembling The Flyweight Shaft Assembly

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Weight • Flyweight shaft • Collar • Washer • Weight shaft Wear/damage  Replace. ASSEMBLING THE FLYWEIGHT SHAFT ASSEMBLY Install: • Weight shaft “1” • Circlip “2” • Washer “3” • Collar “4” •...

  • Page 80: Removing The Camshaft And Valve Lifters

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Adjust: • Governor (Refer to “INSTALLING THE CARBURETOR ASSEMBLY” on page 4-5) REMOVING THE CAMSHAFT AND VALVE LIFTERS The following procedure applies to all of the camshaft and valve lifters. Remove: • Camshaft “1” Remove the camshaft when the camshaft gear mark “a” and the crankshaft gear mark “b”...

  • Page 81: Checking The Valve Lifters

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Camshaft lobe dimensions “a” and “b” Camshaft lobe dimensions Lobe height “a” (Intake): 32.885 mm (1.2947 in) Limit: 32.785 mm (1.2907 in) Lobe height “a” (Exhaust): 33.957 mm (1.3369 in) Limit: 33.857 mm (1.3330 in) Base circle diameter “b”...

  • Page 82: Checking The Reed Valve

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Check: • Valve lifter Damage  Replace. CHECKING THE REED VALVE Check: • Reed valve Damage  Replace. INSTALLING THE VALVE LIFTERS AND CAMSHAFT The following procedure applies to all of the camshaft and valve lifters. Install: •...

  • Page 83: Installing The Cover 2

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Apply: • Sealant (onto the crankcase mating surfaces) Three bond No.1217G® Install: • Cover 1 • Cover 1 bolts “1” to “5” Tighten the bolts to the specified torque in order from “1” to “5”. Cover 1 bolt: 9 N·m (0.9 kgf·m, 6.6 lb·ft) INSTALLING THE COVER 2...

  • Page 84: Installing The Crankcase Cover 1

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT INSTALLING THE CRANKCASE COVER 1 Install: • Crankcase cover 1 • Crankcase cover 1 bolts “1” to “8” Tighten the bolts to the specified torque in two steps and in order from “1” to “8”. Crankcase cover 1 bolt: 1st: 12 N·m (1.2 kgf·m, 8.9 lb·ft) 2nd: 30 N·m (3.0 kgf·m, 22 lb·ft)
  • Page 85 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Measure cylinder bore “C” by taking side-to-side and front- to-back measurements of the cylinder. Bore: 80.000–80.020 mm (3.1496–3.1504 in) Warpage limit: 80.025 mm (3.1506 in) “C” = maximum of D b. If out of specification, replace the crankcase assembly, and replace the piston and piston rings as a set.

  • Page 86: Checking The Crankcase

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CHECKING THE CRANKCASE Check: • Crankcase Damage  Replace. • Bearing Noise/wear/rotational failure  Replace. CHECKING THE PISTON PINS The following procedure applies to all of the piston pins. Check: • Piston pin Blue discoloration/grooves  Replace the piston pin and then check the lubrication system.
  • Page 87 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Measure: • Piston ring side clearance Out of specification  Replace the piston and pis- ton rings as a set. Before measuring the piston ring side clearance, eliminate any carbon deposits from the piston ring grooves and pis- ton rings.

  • Page 88: Checking The Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Top ring End gap (installed): 0.20–0.35 mm (0.0079–0.0138 in) Limit: 0.60 mm (0.0236 in) 2nd ring End gap (installed): 0.20–0.35 mm (0.0079–0.0138 in) Limit: 0.60 mm (0.0236 in) Oil ring End gap (installed): 0.20–0.70 mm (0.0079–0.0276 in) CHECKING THE CRANKSHAFT Check: •...

  • Page 89: Checking The Connecting Rods Oil Clearance

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT CHECKING THE CONNECTING RODS OIL CLEARANCE The following procedure applies to all of the connecting rods. Measure the oil clearance if replacing the crankshaft or connecting rod. Place a piece of Plastigauge® “1” on the crank pin horizontally.

  • Page 90: Installing The Pistons And Piston Rings

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT INSTALLING THE PISTONS AND PISTON RINGS The following procedure applies to all of the pistons, piston rings and related components. Install: • Top ring “1” • 2nd ring “2” • Oil ring “3” • Be sure to install the top ring so that the “R” mark “a” faces toward the piston head.

  • Page 91: Installing The Crankshaft

    PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT INSTALLING THE CRANKSHAFT Make sure that the end gap of each piston ring is 90˚ positioned correctly, as shown in the illustration. 45˚ a. Top ring, oil ring expander b. Lower oil ring rail 90˚ c.
  • Page 92 • Piston #2 with the connecting rod #2 “1” position. • Make sure that the “ ” mark “a” on the piston #2 head faces toward the flywheel. • Make sure that the “YAMAHA” mark “b” on the connect- ing rod #2 faces toward the crankcase cover 1. Install: •...
  • Page 93 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT Install: • Connecting rod cap #2 “1” • Connecting rod cap #2 bolts “2” Connecting rod cap bolt: 20 N·m (2.0 kgf·m, 15 lb·ft) • Make sure that the “ ” mark “a” on the connecting rod #2 is aligned with the “...
  • Page 94 PISTONS, CAMSHAFT, CRANKCASE, AND CRANKSHAFT MEMO 3-56...

  • Page 95: Fuel

    FUEL FUEL PUMP 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the fuel pump Remove the parts in the order listed. Fuel filter Fuel hose Fuel pump Fuel pump bracket Pulsar hose Fuel delivery hose...

  • Page 96: Checking The Fuel Pump

    FUEL PUMP CHECKING THE FUEL PUMP Check: • Fuel hose “1” • Fuel delivery hose “2” • Pulsar hose “3” • Fuel pump “4” Cracks/damage  Replace. Check: • Fuel pump operation ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. Connect the manual vacuum pump (Pressure/vac- uum tester) “1”...

  • Page 97: Carburetor Assembly

    CARBURETOR ASSEMBLY CARBURETOR ASSEMBLY REMOVING THE CARBURETOR 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) 8 N ・ m (0.8 kgf ・ m, 5.9 lb ・ ft) 1.1 N ・...

  • Page 98: Disassembling The Carburetor

    CARBURETOR ASSEMBLY DISASSEMBLING THE CARBURETOR 1.8 N ・ m (0.18 kgf ・ m, 1.3 lb ・ ft) 1.6 N ・ m (0.16 kgf ・ m, 1.2 lb ・ ft) 1.6 N ・ m (0.16 kgf ・ m, 1.2 lb ・ ft) 1.0 N ・...

  • Page 99: Removing The Carburetor Assembly

    CARBURETOR ASSEMBLY REMOVING THE CARBURETOR ASSEMBLY Remove: • Governor spring • Governor assembly • Throttle lever comp • Link rod/spring Remove: • Breather hose “1” • Joint 1 “2” • Carburetor assembly “3” • Gaskets “4” CHECKING THE CARBURETOR ASSEMBLY Check: •...
  • Page 100 CARBURETOR ASSEMBLY Install: • Link rod/spring • Throttle lever comp • Governor assembly • Governor spring “1” • Install the bending portion (short) “a” of the governor spring “1” into the hole “c” of the throttle lever comp while installing the bending portion (long) “b” of the governor spring “1”...

  • Page 101: Intake Manifold

    INTAKE MANIFOLD INTAKE MANIFOLD 3.0 N ・ m (0.30 kgf ・ m, 2.2 lb ・ ft) 7 N ・ m (0.7 kgf ・ m, 5.2 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the intake manifold Remove the parts in the order listed. Air filter case Refer to “AIR FILTER”...

  • Page 102: Removing The Intake Manifold

    INTAKE MANIFOLD REMOVING THE INTAKE MANIFOLD Remove: • Intake manifold “1” • Intake manifold joints “2” • Gaskets “3” CHECKING THE INTAKE MANIFOLD Check: • Intake manifold • Intake manifold joints Cracks/damage  Replace. INSTALLING THE INTAKE MANIFOLD Install: • Gaskets “1” •...
  • Page 103 INTAKE MANIFOLD MEMO...

  • Page 104: Circuit Diagram

    ELECTRICAL CIRCUIT DIAGRAM Br/G...
  • Page 105 CIRCUIT DIAGRAM 1. Spark plug 8. Mil light 2. TCI unit 9. Oil warning light 3. TCI magneto 10.Battery 4. Rectifier/regulator 11.Rollover switch 5. Starter relay 12.Fuel cut solenoid 6. Starter motor 13.Oil pressure switch 7. Main switch Color code Black Black/White Green...

  • Page 106: Electrical Components

    ELECTRICAL COMPONENTS ELECTRICAL COMPONENTS...
  • Page 107 ELECTRICAL COMPONENTS 1. Oil pressure switch 2. TCI unit 3. Stator coil assembly 4. Rectifier/regulator 5. Starter motor...

  • Page 108: Checking The Switch Continuity

    ELECTRICAL COMPONENTS CHECKING THE SWITCH CONTINUITY Check each switch for continuity with the tester. If the con- tinuity reading is incorrect, check the wiring connections O.L” and if necessary, replace the switch. NOTICE Never insert the tester probes into the coupler termi- Ω”...

  • Page 109: Checking The Ignition Spark Gap

    ELECTRICAL COMPONENTS Coil resistance: 8.8–11.9 k ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. Remove the TCI unit. b. Connect the digital circuit tester () to the terminal. Model 88 Multimeter with tachometer: YU-A1927 • Positive tester probe  High tension cord “1” • Negative tester probe  Body ground “2”...

  • Page 110: Checking The Spark Plug Caps

    ELECTRICAL COMPONENTS CHECKING THE SPARK PLUG CAPS The following procedure applies to all of the spark plug caps. Remove: • Spark plug cap Check: • Spark plug cap resistance Out of specification  Replace the spark plug cap. Spark plug cap resistance: 3.75–6.25 k...

  • Page 111: Checking The Rectifier/Regulator

    ELECTRICAL COMPONENTS • Positive tester probe  White • Negative tester probe  White b. Measure the stator coil resistance. ▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲ CHECKING THE RECTIFIER/REGULATOR Check: • Rectifier/regulator output voltage Out of specification  Replace the rectifier/regula- tor. Regulated voltage: 14–15 V ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼...
  • Page 112 ELECTRICAL COMPONENTS ▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼ a. Connect the jumper lead “1” to the starter relay ter- minals on the battery side and the starter motor side. WARNING • A wire that is used as a jumper lead must have at least the same capacity of the battery lead, other- wise the jumper lead may burn.

  • Page 113: Electric Starting System

    ELECTRIC STARTING SYSTEM ELECTRIC STARTING SYSTEM REMOVING THE STARTER MOTOR 9 N ・ m (0.9 kgf ・ m, 6.6 lb ・ ft) 23 N ・ m (2.3 kgf ・ m, 17 lb ・ ft) Order Job/Parts to remove Q’ty Remarks Removing the starter motor Remove the parts in the order listed.

  • Page 114: Disassembling The Starter Motor

    ELECTRIC STARTING SYSTEM DISASSEMBLING THE STARTER MOTOR 6 N ・ m (0.6 kgf ・ m, 4.4 lb ・ ft) 9 N ・ m (0.9 kgf ・ m, 6.6 lb ・ ft) 11 N ・ m (1.1 kgf ・ m, 8.1 lb ・ ft) Order Job/Parts to remove Q’ty...

  • Page 115: Checking The Armature Coil

    ELECTRIC STARTING SYSTEM CHECKING THE ARMATURE COIL Check: • Commutator (outer surface) Dirty  Clean it with #600 grit sandpaper. Measure: • Mica (insulation depth between the commutator segments) Out of specification  Scrape the mica to the proper measurement using a hacksaw blade which has been grounded to fit the commutator.

  • Page 116: Checking The Brush

    ELECTRIC STARTING SYSTEM CHECKING THE BRUSH Measure: • Brush length (of each brush) “1” Out of specification  Replace. Brush wear limit length: 6.0 mm (0.2362 in) Check: • Brush spring “2” Fatigue/damage  Replace. CHECKING THE STARTER RELAY Measure: •...
  • Page 117 ELECTRIC STARTING SYSTEM Install: • Armature and starter drive lever “1” Install: • Starter relay “1” Starter relay nut: 11 N·m (1.1 kgf·m, 8.1 lb·ft) 5-14...
  • Page 118 ELECTRIC STARTING SYSTEM MEMO 5-15...

  • Page 119: Troubleshooting

    TROUBLESHOOTING ENGINE DOES NOT START IGNITION SYSTEM The ignition system fails to operate (no spark or intermittent spark). Checking steps Possible remedy • Clean the battery terminals. Check the battery. • Recharge or replace the battery. Check the spark plugs. Re-gap or replace the spark plugs.

  • Page 120: Electric Starting System

    ENGINE DOES NOT START ELECTRIC STARTING SYSTEM The starter motor fails to turn. Checking steps Possible remedy • Clean the battery terminals. Check the battery. • Recharge or replace the battery. Check the starter motor operation. If the starter motor operates normally, (Refer to “CHECKING THE STARTER MOTOR OPERA- the starter motor is OK.

  • Page 121: Other Troubles

    OTHER TROUBLES OTHER TROUBLES ENGINE STARTS BUT STALLS Checking steps Possible remedy Check the fuel level. Add the fuel if it is insufficient. Check if the fuel filter is clogged. Clean or replace. Check if the fuel hoses is clogged. Clean.

  • Page 122: Engine Speed Does Not Increase

    OTHER TROUBLES ENGINE SPEED DOES NOT INCREASE Checking steps Possible remedy Check the spark plugs for dirt and check the spark plug Clean, adjust, or replace the spark gap. plugs. Check the air filter element for dirt. Replace the air filter element. Clean or replace spark arrester, muffler Check spark arrester, muffler and air filter.

  • Page 123: Engine Speed Is Uneven

    OTHER TROUBLES ENGINE SPEED IS UNEVEN Checking steps Possible remedy Check the fuel level. Add the fuel if it is insufficient. Check if fuel has deteriorated. Replace the fuel. Check the spark plugs for dirt and check the spark plug Clean, adjust, or replace the spark gap.

  • Page 124: The Battery Is Not Charged

    OTHER TROUBLES THE BATTERY IS NOT CHARGED Checking steps Possible remedy • Clean the battery terminals. Check the battery. • Recharge or replace the battery. Check the stator coil. (Refer to “CHECKING THE STATOR COIL ASSEMBLY” on Replace the stator coil assembly. page 5-7) Check the rectifier/regulator.

  • Page 125: Governor Operation

    OTHER TROUBLES GOVERNOR OPERATION Checking steps Possible remedy Check that the governor link operate smoothly. Adjust or replace. Check that the governor spring is stretched. Replace. Check the governor adjustment. (Refer to “INSTALLING THE CARBURETOR ASSEMBLY” Adjust. on page 4-5) Check the governor weight and governor bushing function.

  • Page 126: Oil Pressure System

    OIL PRESSURE SYSTEM OIL PRESSURE SYSTEM If the oil pressure switch fails to operate. Checking steps Possible remedy • Clean the battery terminals. Check the battery. • Recharge or replace the battery. Check the main switch. Replace the main switch. Check the engine oil level.

  • Page 127: Specifications

    BPR6ES (NGK) Spark plug gap 0.7–0.8 mm (0.028–0.031 in) * Yamaha engine has been designed to use regular unleaded gasoline with a pump octane number ***** ((R+M)/2) of 86 or higher, or research octane number of 91 or higher. Gasohol containing ethanol can be used if the ethanol content does not exceed 10 % (E10).
  • Page 128 GENERAL SPECIFICATIONS NOTICE Use only unleaded gasoline. The use of leaded gasoline will cause severe damage to internal engine parts.

  • Page 129: Maintenance Specifications

    MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Piston: Piston-to-cylinder clearance 0.033–0.047 mm (0.0013–0.0019 in) Limit 0.15 mm (0.0059 in) Piston diameter 79.959–79.980 mm (3.1480–3.1488 in) Limit 79.900 mm (3.1457 in) Measuring point (from piston 5.1 mm (0.2007 in) skirt bottom) Oversize 1st 80.25 mm (3.1594 in) 80.50 mm (3.1693 in) Piston pin hole inside diameter...
  • Page 130 MAINTENANCE SPECIFICATIONS Crankshaft: Big end side clearance 0.20–0.65 mm (0.0079–0.0256 in) Runout limit 0.03 mm (0.0012 in) Crank pin outside diameter 40.950–41.050 mm (1.6122–1.6161 in) Connecting rod: Small end diameter 19.006–19.020 mm (0.7483–0.7488 in) Oil clearance 0.006–0.025 mm (0.0002–0.0010 in) Big end diameter 40.005–40.020 mm (1.5750–1.5756 in) Oil clearance...
  • Page 131 MAINTENANCE SPECIFICATIONS Limit (Intake) 1.6 mm (0.063 in) Limit (Exhaust) 1.6 mm (0.063 in) Valve stem runout limit 0.01 mm (0.0004 in) Valve guide Guide inside diameter (Intake) 6.000–6.012 mm (0.2362–0.2367 in) Guide inside diameter (Exhaust) 6.000–6.012 mm (0.2362–0.2367 in) Stem to guide clearance (Intake) 0.08 mm (0.0031 in) Stem to guide clearance...
  • Page 132 Oil pump: Inner-rotor-to-outer-rotor-tip 0.19–0.35 mm (0.008–0.013 in) clearance Relief valve operating pressure 342–538 kPa (3.42–5.38 kgf/cm², 49.59–78.01 psi) Carburetor: Type 7UC-10 (MX800V) 7UC-00 (MX825V) I.D. mark 7UC-E4101-10 (MX800V) 7UC-E4101-00 (MX825V) Bore size ø28 Main jet 1.19 mm (0.046 in) (Left)/1.15 mm (0.045 in) (Right) Main air jet 1.2 mm (0.047 in)

  • Page 133: Electrical

    MAINTENANCE SPECIFICATIONS ELECTRICAL Ignition system: Coil resistance (TCI unit) 8.8–11.9 k Spark plug cap resistance 3.75–6.25 k TCI unit air gap 0.4–0.6 mm (0.0157–0.0236 in) Minimum ignition spark gap 6.0 mm (0.236 in) Charging system: Standard output at 3600 r/min 25 A: More than 25 A 25 A: 0.096–0.144 ...
  • Page 134 TIGHTENING TORQUES TIGHTENING TORQUES Item Thread size Tightening torque M14S  1.25 Spark plug 20 N·m (2.0 kgf·m, 15 lb·ft) Spark arrester screw — 3.5 N·m (0.35 kgf·m, 2.6 lb·ft) Oil filter — 14 N·m (1.4 kgf·m, 10 lb·ft) M12  1.5 Oil drain bolt 27 N·m (2.7 kgf·m, 20 lb·ft) M6 ...
  • Page 135 TIGHTENING TORQUES Item Thread size Tightening torque M6  1.0 Governor assembly bolt 8 N·m (0.8 kgf·m, 5.9 lb·ft) 1st: 3.0 N·m (0.30 kgf·m, 2.2 lb·ft) M6  1.0 Intake manifold nut and bolt 2nd: 7 N·m (0.7 kgf·m, 5.2 lb·ft) M8 ...

  • Page 136: Tightening Torques

    GENERAL TORQUE SPECIFICATIONS GENERAL TORQUE SPECIFICATIONS This chart specifies torque for standard fasteners with standard I.S.O. pitch threads. Torque specifi- cations for special components or assemblies are included in the applicable sections of this book. To avoid warpage, tighten multi fastener assemblies in a crisscross fashion, in progressive stages, until full torque is reached.

  • Page 137: Lubrication Points And Type Of Lubricants

    LUBRICATION POINTS AND TYPE OF LUBRICANTS LUBRICATION POINTS AND TYPE OF LUBRICANTS Part name Type of lubricant Oil seal lip Oil hose 1, 2 Governor fork oil seal lip Bearing Connecting rod big end Crank pin Crankshaft journal Connecting rod cap bolt Piston pin Piston Valve stem...

  • Page 138: Wire Routing Diagram

    WIRE ROUTING DIAGRAM WIRE ROUTING DIAGRAM UPPER SIDE VIEW 7-12...
  • Page 139 WIRE ROUTING DIAGRAM 1. Fuel delivery hose 4. Hose clamp 2. Intake manifold 5. Stay 3. Carburetor assembly A. Install yellow painted portion in the direction shown in the illustration. 7-13...
  • Page 140 WIRE ROUTING DIAGRAM 7-14...
  • Page 141 WIRE ROUTING DIAGRAM 1. TCI unit #1 lead 5. TCI unit #2 2. TCI unit #1 6. TCI unit #2 lead 3. Plastic locking tie 7. Wire harness 4. Intake manifold A. Direction of upper surface of the engine. B. Allowance 2.0 mm (0.08 in) or less C.

  • Page 142: Left Side View

    WIRE ROUTING DIAGRAM LEFT SIDE VIEW 7-16...
  • Page 143 WIRE ROUTING DIAGRAM 1. Rectifier/regulator 6. Starter motor 2. Earth terminal 7. Rectifier/regulator lead (white) 3. Spark plug cap 8. Rectifier/regulator lead (red) 4. Starter motor lead 9. Rectifier/regulator lead (black) 5. Starter relay lead A. Tighten the earth terminal together with the mounting bolt in the direction shown in the illustration. B.

  • Page 144: Right Side View

    WIRE ROUTING DIAGRAM RIGHT SIDE VIEW 7-18...
  • Page 145 WIRE ROUTING DIAGRAM 1. Hose clamp 5. Pulsar hose 2. Fuel pump 6. Plastic locking tie 3. Fuel hose 7. Oil pressure switch lead 4. Fuel filer A. • Install the air filter case cover as shown in the illustration. •...
  • Page 146 WIRE ROUTING DIAGRAM 7-20...
  • Page 147 WIRE ROUTING DIAGRAM 1. Oil hose 1 4. Oil hose 2 2. Oil cooler 5. Oil filter 3. Hose clamp A. Insert the oil hose all the way into the oil cooler. B. Face the projection inward. C. Install the white painted portion in the direction shown in the illustration. D.
  • Page 148 WIRE ROUTING DIAGRAM 7-22...
  • Page 149 WIRE ROUTING DIAGRAM 1. Oil pressure switch lead 4. Oil pressure switch 2. Pulsar hose 5. Spark plug cap 3. Fuel hose A. Oil pressure switch lead routing direction. B. Direction of upper surface of the engine 7-23...

  • Page 150: Rear Side View

    WIRE ROUTING DIAGRAM REAR SIDE VIEW 7-24...
  • Page 151 WIRE ROUTING DIAGRAM 1. Air filter case cover 1 4. Joint 2 2. Air filter case stay 5. Air filter case 3. Breather hose A. Install the air filter case stay into the groove in the air filter case. B. Insert the hose until it reaches the end as shown in the illustration. C.
  • Page 152 WIRE ROUTING DIAGRAM 7-26...
  • Page 153 WIRE ROUTING DIAGRAM 1. Fuel cut solenoid lead 4. Carburetor assembly lead (red) 2. Clamp 5. Carburetor assembly lead (green) 3. Fuel cut solenoid lead (red/blue) 6. Fuel cut solenoid lead (black) A. Main switch coupler B. Secure with a clamp so as not to get caught when assembling the fan case. 7-27...
  • Page 154 APPENDIX CIRCUIT DIAGRAM...
  • Page 155 1. Spark plug 8. Mil light 2. TCI unit 9. Oil warning light 3. TCI magneto 10.Battery 4. Rectifier/regulator 11.Rollover switch 5. Starter relay 12.Fuel cut solenoid 6. Starter motor 13.Oil pressure switch 7. Main switch Color code Black Black/White Green Br/G Brown/Green...
  • Page 156 MEMO...
  • Page 158 2017.10×1 !

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