Yamaha YFM250XL(C) Service Manual
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Yamaha YFM250XL(C) Service Manual

Yamaha YFM250XL(C) Service Manual

Yfm250xl(c) yamaha
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YFM250XL(C)
SERVICE MANUAL
LIT-11616-12-01
4XE-F8197-10

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Summary of Contents for Yamaha YFM250XL(C)

  • Page 1 YFM250XL(C) SERVICE MANUAL LIT-11616-12-01 4XE-F8197-10...
  • Page 2 YFM250XL SERVICE MANUAL © 1998 by Yamaha Motor Corporation, U.S.A. First Edition, February1998 All rights reserved. Any reproduction or unauthorized use without the written permission of Yamaha Motor Corporation, U.S.A. is expressly prohibited. Printed in U.S.A. LIT-11616-12-01...

  • Page 3: Important Information

    EB001000 NOTICE This manual was produced by the Yamaha Motor Company 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, so it is assumed that anyone who uses this book to perform mainte- nance and repairs on Yamaha machine has a basic understanding of the mechanical ideas and the procedures of machine repair.
  • Page 4 EB002000 HOW TO USE THIS MANUAL MANUAL ORGANIZATION This manual is intended as a handy, easy-to-read reference book for the mechanic. It is divided into chapters, sections and sub-sections. Comprehensive explanations of all installa- tion, removal, disassembly, assembly, repair and inspection procedures are laid out with the individual steps in sequential order.
  • Page 5 EB003000 ILLUSTRATED SYMBOLS Illustrated symbols 1 to 9 are printed on the top right of each page and indicate the SPEC INFO subject of each chapter. 1 General information 2 Specifications INSP 3 Periodic inspections and adjustments 4 Engine 5 Carburetion 6 Drive train 7 Chassis 8 Electrical...
  • Page 6 CHAPTER TITLES GENERAL INFORMATION INFO SPECIFICATIONS SPEC PERIODIC INSPECTION AND INSP ADJUSTMENT ENGINE OVERHAUL CARBURETION CARB DRIVE TRAIN DRIVE CHASSIS CHAS – ELECTRICAL ELEC TROUBLESHOOTING TRBL SHTG...

  • Page 7: Table Of Contents

    CONTENTS CHAPTER 1. GENERAL INFORMATION MACHINE IDENTIFICATION ................ 1-1 VEHICLE IDENTIFICATION NUMBER ..........1-1 MODEL LABEL ..................1-1 IMPORTANT INFORMATION ..............1-2 PREPARATION FOR REMOVAL PROCEDURES ......... 1-2 REPLACEMENT PARTS ................ 1-2 GASKETS, OIL SEALS AND O-RINGS ..........1-2 LOCK WASHERS/PLATES AND COTTER PINS ........1-3 BEARINGS AND OIL SEALS ..............
  • Page 8 CHAPTER 3. PERIODIC INSPECTIONS AND ADJUSTMENTS INTRODUCTION ................... 3-1 PERIODIC MAINTENANCE/LUBRICATION ..........3-1 INFO FENDER AND FUEL TANK ................3-3 FRONT FENDER ..................3-3 SPEC REAR FENDER ..................3-5 FUEL TANK ................... 3-7 ENGINE ....................... 3-10 INSP VALVE CLEARANCE ADJUSTMENT ..........3-10 TIMING CHAIN TENSIONER ADJUSTMENT ........
  • Page 9 ELECTRICAL ....................3-38 BATTERY INSPECTION ..............3-38 FUSE INSPECTION ................3-41 HEADLIGHT BEAM ADJUSTMENT ........... 3-42 HEADLIGHT BULB REPLACEMENT ..........3-42 CHAPTER 4. ENGINE OVERHAUL ENGINE REMOVAL ..................4-1 PREPARATION FOR REMOVAL ............4-1 FRONT FENDER AND REAR FENDER ..........4-1 ENGINE OIL ..................
  • Page 10 TIMING CHAIN ................... 4-30 CAM SPROCKET AND CAM DRIVE SPROCKET ....... 4-31 TIMING CHAIN GUIDE ............... 4-31 TIMING CHAIN TENSIONER .............. 4-31 TAPPET COVER AND CAM SPROCKET COVER ....... 4-32 CYLINDER AND PISTON ..............4-32 PISTON RING AND PISTON PIN ............4-33 INFO CRANKSHAFT ..................

  • Page 11: Carburetion

    CHAPTER 5. CARBURETION CARBURETOR ....................5-1 REMOVAL ..................... 5-2 DISASSEMBLY ..................5-2 INSPECTION ..................5-4 ASSEMBLY ................... 5-6 INSTALLATION ..................5-8 FUEL LEVEL ADJUSTMENT ..............5-9 CHAPTER 6. DRIVE TRAIN MIDDLE GEAR SERVICE ................6-1 MIDDLE GEAR ..................6-1 MIDDLE GEAR SHIMS ................. 6-2 REMOVAL .....................
  • Page 12 CHAPTER 7. CHASSIS FRONT WHEELS AND FRONT BRAKE ............7-1 REMOVAL ..................... 7-2 INSPECTION ..................7-3 INFO INSTALLATION ..................7-6 REAR WHEELS/REAR BRAKE AND REAR AXLE ........7-9 REMOVAL ................... 7-11 SPEC INSPECTION ..................7-13 INSTALLATION ................... 7-16 STEERING SYSTEM ................... 7-20 INSP REMOVAL ...................
  • Page 13 IGNITION SYSTEM ..................8-7 CIRCUIT DIAGRAM ................8-7 TROUBLESHOOTING ................8-8 ELECTRIC STARTING SYSTEM ..............8-12 CIRCUIT DIAGRAM ................8-12 STARTING CIRCUIT OPERATION ............. 8-13 TROUBLESHOOTING ................. 8-14 STARTER MOTOR ................8-18 STARTER MOTOR INSPECTION ............8-19 STARTER MOTOR ASSEMBLY ............8-20 CHARGING SYSTEM .................
  • Page 14 FAULTY DRIVE TRAIN ................. 9-3 FAULTY GEAR SHIFTING ................9-4 HARD SHIFTING ................... 9-4 SHIFT PEDAL DOES NOT MOVE ............9-4 JUMPS OUT OF GEAR ................. 9-4 INFO CLUTCH SLIPPING ..................9-4 CLUTCH SLIPPING ................9-4 SPEC CLUTCH DRAGGING ..................9-4 CLUTCH DRAGGING ................

  • Page 15: Chapter 1. General Information

    MACHINE IDENTIFICATION INFO GENERAL INFORMATION MACHINE IDENTIFICATION VEHICLE IDENTIFICATION NUMBER The vehicle identification number 1 is stamped into the left side of the frame. MODEL LABEL The model label 1 is affixed to the frame. This information will be needed to order spare parts.

  • Page 16: Important Information

    5.Keep all parts away from any source of fire. EB101010 REPLACEMENT PARTS 1.Use only genuine Yamaha parts for all replacements. Use oil and grease recom- mended by Yamaha for all lubrication jobs. Other brands may be similar in func- tion and appearance, but inferior in qual- ity.

  • Page 17: Lock Washers/Plates And Cotter Pins

    IMPORTANT INFORMATION INFO EB101030 LOCK WASHERS/PLATES AND COTTER PINS 1.Replace all lock washers/plates 1 and cot- ter pins after removal. Bend lock tabs along the bolt or nut flats after the bolt or nut has been tightened to specification. EB101040 BEARINGS AND OIL SEALS 1.Install bearings and oil seals so that the manufacturer’s marks or numbers are vis-...

  • Page 18: Checking Of Connections

    CHECKING OF CONNECTIONS INFO EB801000 CHECKING OF CONNECTIONS Check the connectors for stains, rust, mois- ture, etc. 1.Disconnect: Connector 2.Check: Connector Moisture → Dry each terminal with an air blower. Stains/rust → Connect and disconnect the terminals several times. 3.Check: Connector leads Looseness →...

  • Page 19: Special Tools

    SPECIAL TOOLS INFO EB102001 SPECIAL TOOLS The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools; this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools may differ by shape and part number from country to country.
  • Page 20 SPECIAL TOOLS INFO Compression gauge Fuel level gauge P/N. 90890-03081 P/N. YM-01312-A Extension P/N. 90890-01312 P/N. 90890-04082 This gauge is used to measure the engine This gauge is used to measure the fuel level in compression. the float chamber. Rotor holder P/N.
  • Page 21 SPECIAL TOOLS INFO Slide hammer set Slide hammer bolt (M6) P/N. YU-01083-A P/N. 90890-01083 Weight P/N. 90890-01084 These tools are used when removing the These tools are used when removing the rocker arm shaft. rocker arm shaft. Valve spring compressor Valve guide remover and installer 6mm (0.24 in) Valve guide remover P/N.
  • Page 22 SPECIAL TOOLS INFO ® Sealant (Quick Gasket P/N. ACC-QUICK-GS-KT ® YAMAHA bond No. 1215 P/N. 90890-85505 This sealant (bond) is used for crankcase mat- ing surface, etc. Universal joint holder P/N. YM-04062 Attachment FOR DRIVE TRAIN SERVICE P/N. YM-33291 These tools are used to remove and install the universal joint.
  • Page 23 SPECIAL TOOLS INFO Yamaha brake grease P/N. 90793-40003 FOR CHASSIS SERVICE This Yamaha brake grease is used for rear brake dust seal. Dynamic spark tester P/N. YM-34487 FOR ELECTRICAL COMPONENTS This instrument is necessary for checking the ignition system components.
  • Page 24 INFO 1 - 10...

  • Page 25: Chapter 2. Specifications

    SPEC GENERAL SPECIFICATIONS SPECIFICATIONS GENERAL SPECIFICATIONS Item Standard Model code: 4XE1 (USA) 4XE2 (CAL) 4XE3 (CDN) Dimensions: Overall length 1,940 mm (76.4 in) Overall width 1,005 mm (39.6 in) Overall height 1,118 mm (44.0 in) Seat height 780 mm (30.7 in) Wheelbase 1,170 mm (46.1 in) Minimum ground clearance...
  • Page 26 SPEC GENERAL SPECIFICATIONS Item Standard Fuel: Type Unleaded fuel Fuel tank capacity 12 L (2.64 Imp gal, 3.17 US gal) Fuel reserve amount 1.6 L (0.35 Imp gal, 0.42 US gal) Carburetor: Type / quantity BST34/1 Manufacturer MIKUNI Spark plug: Type DR7EA Manufacturer...
  • Page 27 SPEC GENERAL SPECIFICATIONS Item Standard Tire pressure (cold tire): Recommended front 20 kPa (0.20 kg/cm , 2.9 psi) rear 25 kPa (0.25 kg/cm , 3.6psi) Minimum front 17 kPa (0.17 kg/cm , 2.5 psi) rear 22 kPa (0.22 kg/cm , 3.2 psi) Maximum front 23 kPa (0.23 kg/cm...

  • Page 28: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Cylinder head: Warp limit ---- 0.10 mm (0.004 in) Measuring point Lines indicate straight edge measurement. Cylinder: Bore size 70.97 ~ 71.02 mm (2.794 ~ 2.796 in) 71.10 mm (2.799 in) Measuring point 40 mm (1.6 in) ----...
  • Page 29 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit “C” 6.572 ~ 6.692 mm ---- (0.259 ~ 0.263 in) Camshaft runout limit ---- 0.03 mm (0.0012 in) Cam chain: Cam chain type / No. of links DID25SH/104 ---- Cam chain adjustment method Automatic ---- Rocker arm / rocker arm shaft: Rocker arm inside diameter...
  • Page 30 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Guide inside diameter 6.000~ 6.012mm ---- (0.236 ~ 0.237 in) 6.000~ 6.012mm ---- (0.236 ~ 0.237 in) Stem-to-guide clearance 0.010 ~ 0.037 mm 0.08 mm (0.0004 ~ 0.0015 in) (0.0031 in) 0.025 ~ 0.052 mm 0.10 mm (0.001 ~ 0.002 in) (0.0039 in)
  • Page 31 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Compressed pressure (installed) 162.8 ~ 200.1 N ---- (16.6 ~ 20.4 kg, 36.6 ~ 45.0 lb) 162.8 ~ 200.1 N ---- (16.6 ~ 20.4 kg, 36.6 ~ 45.0 lb) Tilt limit 2.5˚/1.6 mm (2.5˚/0.06 in) 2.5˚/1.6 mm (2.5˚/0.06 in) Direction of winding...
  • Page 32 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Side clearance (installed) 0.03 ~ 0.07 mm 0.12 mm (0.001 ~ 0.003 in) (0.005 in) 2nd ring: Type Taper ---- Dimensions (B × T) 1.2 × 2.8 mm (0.047 ~ 0.110 in) ---- End gap (installed) 0.15 ~ 0.30 mm 0.4 mm (0.006 ~ 0.012 in)
  • Page 33 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Clutch plate Thickness 1.45 ~ 1.75mm 0.2 mm (0.057 ~ 0.069 in) (0.008 in) Quantity 4 pcs. ---- Clutch spring Free length 35.1 mm (1.38 in) 32.9 mm (1.30 in) Quantity 4 pcs. ---- Clutch release method Outer push, cam push ----...
  • Page 34 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Lubrication system: Oil filter type Wire mesh ---- Oil pump type Trochoid type ---- Tip clearance “A” or “B” 0.15 mm (0.006 in) 0.20 mm (0.008 in) Side clearance 0.04 ~ 0.09 mm 0.09 mm (0.002 ~ 0.004 in) (0.004 in) Bypass valve setting pressure...
  • Page 35 SPEC MAINTENANCE SPECIFICATIONS Item Standard Lubrication chart: Crankcase tightening sequence: Crankcase (left) Crankcase (right) 2 - 11...
  • Page 36 SPEC MAINTENANCE SPECIFICATIONS Tightening torques Tightening torque Part Part to be tightened Thread size Q’ty Remarks name m·kg ft·lb Cylinder head (oil gallery plug) Bolt Cylinder head Flange bolt Apply oil to the washer Cylinder head and Cylinder Bolt Cam sprocket cover Screw Tappet cover Bolt...
  • Page 37 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Part Part to be tightened Thread size Q’ty Remarks name m·kg ft·lb Lock nut (clutch release adjuster) Starter clutch Bolt Stake Starter motor Screw Pinion gear (drive axle) Stake Bearing retainer (drive axle) Screw Bearing retainer (bearing housing) –...

  • Page 38: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Item Standard Limit Steering system: Steering bearing type Ball bearing ---- Front suspension: Shock absorber travel 117 mm (4.61 in) ---- Suspension spring free length 293 mm (11.54 in) ---- Spring rate (K1) 10 N/mm (1.0 kg/mm, 56 lb/in)/ ---- 0 ~ 117 mm (0 ~ 4.61 in) Optional spring...
  • Page 39 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Front drum brake: Type Leading and trailing ---- Drum inside diameter 160 mm (6.30 in) 161 mm (6.34 in) Lining thickness 4.0 mm (0.16 in) 2.0 mm (0.08 in) Shoe spring free length 71.0 mm (2.80 in) ---- Rear drum brake: Type...
  • Page 40 SPEC MAINTENANCE SPECIFICATIONS Tightening torques Tightening torque Parts Part to be tightened Thread size Q’ty Remarks name m·kg ft·lb M10 × 1.25 Front panel wheel and brake drum Front brake drum and steering M14 × 1.5 knuckle Front brake cam lever and cam M6 ×...
  • Page 41 SPEC MAINTENANCE SPECIFICATIONS Tightening torque Parts Part to be tightened Thread size Q’ty Remarks name m·kg ft·lb M22 × 1.5 Pivot shaft and nut (right) Swingarm and final drive gear M8 × 1.25 case Rear axle housing and final drive M10 ×...

  • Page 42: Electrical

    Source coil resistance / color ---- Brown – Black C.D.I. unit model / manufacturer F8T09273/MITSUBISHI ---- Ignition coil: Model / manufacturer 2JN/YAMAHA ---- Minimum spark gap 6 mm (0.24 in) ---- 0.18 ~ 0.28 Ω at 20˚C (68˚F) Primary winding resistance ---- Secondary winding resistance 6.3 ~ 9.5 kΩ...
  • Page 43 SPEC MAINTENANCE SPECIFICATIONS Item Standard Limit Withstand voltage 200 V ---- Battery: Specific Gravity 1.280 Electric starter system: Type Constant mesh type ---- Starter motor: Model / manufacturer SM-14/MITSUBA ---- Output 0.5 kW ---- 0.004 ~ 0.005 Ω at 20˚C (68˚F) Armature coil resistance ---- Brush overall length...

  • Page 44: How To Use The Conversion Table

    HOW TO USE THE CONVERSION TABLE/ SPEC GENERAL TORQUE SPECIFICATIONS EB201000 EB202001 HOW TO USE THE CONVERSION GENERAL TORQUE TABLE SPECIFICATIONS All specification data in this manual are This chart specifies torque for standard fas- listed in SI and METRIC UNITS. teners with standard I.S.O.

  • Page 45: Lubrication Points And Lubricant Types

    Shift shaft Shift ball holder and guide Shift shaft and shift pedal ® Sealant (Quick Gasket Crankcase mating surfaces Yamaha Bond No. 1215 ® Sealant (Quick Gasket Adaptor (crankcase cover 1) and grommet Yamaha Bond No. 1215 2 - 21...

  • Page 46: Chassis

    Yamaha brake grease ® Sealant (Quick Gasket Rear backing plate and brake cam bracket Yamaha Bond No. 1215 Front brake cable joint Front and rear brake lever pivot Front brake cable adjuster and pin Rear brake cable adjuster and pin...

  • Page 47: Lubrication Diagrams

    SPEC LUBRICATION DIAGRAMS LUBRICATION DIAGRAMS 1 Drain plug 0 Crank pin 2 O-ring A Crankshaft 3 Compression spring B Main axle 4 Oil strainer C Drive axle 5 Oil pump gasket D Oil filter 6 Oil pump assembly 7 Oil pump driven gear 8 Oil pump drive gear 9 Camshaft 2 - 23...
  • Page 48 SPEC LUBRICATION DIAGRAMS 1 Bypass valve 9 Crank pin 2 Oil filter 0 Crankshaft 3 Oil filter cover A Main axle 4 O-ring B Drive axle 5 Collar 6 Camshaft 7 Rocker arm 8 One way bearing (Automatic centrifugal clutch) 2 - 24...

  • Page 49: Cable Routing

    SPEC CABLE ROUTING CABLE ROUTING Å Do not route the handlebar 1 Rear brake lever switch lead the handlebar. Position the 2 Rear brake cable switch assembly lead through plastic band with its tab fac- 3 Cable guide the lower bracket cable guide. ing down.
  • Page 50 SPEC CABLE ROUTING 1 Cable guide B Throttle cable 2 Main switch C Rear brake cable 3 Fuel tank breather hose D Rear brake breather hose 4 Rectifier/regulator E Carburetor air vent hose 5 CDI unit F CDI magneto lead 6 Taillight Å...
  • Page 51 SPEC CABLE ROUTING Î Route the carburetor overflow hose between Ì Route the rear brake cable and rear brake the engine and upper rear engine mount and breather hose through the cable guide. Ó 10 mm (0.4 in) then between the engine and swingarm. È...
  • Page 52 SPEC CABLE ROUTING Å Make sure that the battery breather hose is not kinked or bent. 1 Battery breather hose ı Route the rear brake cable through the cable guide on the cyl- 2 Spark plug cap 3 Ignition coil inder.
  • Page 53 SPEC CABLE ROUTING Å 50 mm (2.0 in) 1 Wire harness ı Route the throttle cable and rear brake cable through the 2 Starter motor lead 3 Rear brake cable cable guide. Make sure that the throttle cable is routed to the 4 Throttle cable inside of the rear brake cable.
  • Page 54 SPEC 2 - 30...

  • Page 55: Chapter 3. Periodic Inspections And Adjustments

    INTRODUCTION/ INSP PERIODIC MAINTENANCE/LUBRICATION PERIODIC INSPECTIONS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended inspections and adjustments. These preventive maintenance procedures, if followed, will ensure more reli- able machine operation and a longer service life. In addition, the need for costly overhaul work will be greatly reduced.
  • Page 56 Battery* • Check breather pipe for proper operation. • Correct if necessary. It is recommended that these items be serviced by a Yamaha dealer. **: Lithium soap base grease. WARNING Indicates a potential hazard that could result in serious injury or death.

  • Page 57: Fender And Fuel Tank

    INSP FRONT FENDER FENDER AND FUEL TANK FRONT FENDER Removal 1.Place the machine on a level place. 2.Remove: Front carrier 1 3.Remove: Front bumper skid plate 1 4.Disconnect: Dual headlight leads 1 5.Remove: Front bumper 2 6.Remove: Front fender 1 3 - 3...
  • Page 58 INSP FRONT FENDER Installation: Reverse the “Removal” procedures. Note the following points. 1.Install: Front fender 1 Bolt 2 (front fender and frame): 7 Nm (0.7 m • kg, 5.1 ft • lb) Nut 3 (front fender and fender stay): 7 Nm (0.7 m • kg, 5.1 ft • lb) 2.Install: Front bumper 1 Bolt (front bumper and frame):...

  • Page 59: Rear Fender

    INSP REAR FENDER REAR FENDER Removal 1.Place the machine on a level place. 2.Remove: Rear carrier 1 2 with spacer 3.Remove: Seat 1 Pull up the seat lock lever 2 , then pull up the seat at the rear. 4.Disconnect: Battely leads (negative and positive) WARNING Disconnect the negative lead 1 first.
  • Page 60 INSP REAR FENDER Installation Reverse the “Removal” procedure. Note the following points. 1.Install: Rear fender 1 Bolt 2 (rear fender and frame): 7 Nm (0.7 m • kg, 5.1ft • lb) Bolt 3 (rear fender and rear foot- rest plate): 7 Nm (0.7 m •...
  • Page 61 INSP REAR FENDER/FUEL TANK 6.Install: Rear carrier 1 Bolt 2 (rear carrier and frame): 34 Nm (3.4 m • kg, 25 ft • lb) Bolt 3 (rear carrier and rear bumper): 9 Nm (0.9 m • kg, 6.5 ft • lb) NOTE: Do not forget to attach the spacer at the point where the carrier and bumper are...

  • Page 62: Fuel Tank

    INSP FUEL TANK 6.Turn the fuel cock lever to “OFF” position. 7.Disconnect: Fuel hose 1 NOTE: Place a rug on the engine to absorb a spilt fuel. WARNING Gasoline is highly flammable. Avoid spilling fuel on the hot engine. 8.Remove: Bolt 1 (with washer and collar) 9.Disconnect: Air duct 2 (with hoses)
  • Page 63 INSP FUEL TANK 4.Install: Fuel tank cover 1 Fuel tank cap 2 Rivet 3 Screw 4 Bolt 5 (with flange collar) Bolt (fuel tank cover and frame): 10 Nm (1.0 m • kg, 7.2 ft • lb) 5.Connect: Breather hose 1 6.Install: Seat Refer to the “REAR FENDER-Installation”...

  • Page 64: Engine

    INSP VALVE CLEARANCE ADJUSTMENT ENGINE VALVE CLEARANCE ADJUSTMENT NOTE: The valve clearance must be adjusted when the engine is cool to the touch. Adjust the valve clearance when the pis- ton is at the Top Dead Center (T.D.C.) on compression stroke. Removal 1.Place the machine on a level place.
  • Page 65 INSP VALVE CLEARANCE ADJUSTMENT Align the “T” mark 1 on the flywheel with the stationary pointer 2 on the crankcase cover. When the “T” mark is aligned with the stationary pointer, the piston is at Top Dead Center (TDC). NOTE: T.D.C.

  • Page 66: Timing Chain Tensioner Adjustment

    VALVE CLEARANCE ADJUSTMENT/ INSP TIMING CHAIN TENSIONER ADJUSTMENT Once again, measure the valve clearance. If the clearance is incorrect, repeat above steps until proper clearance obtained. ********************************** Installation Reverse the “Removal” procedure. Note the following points. 1.Install: Tappet cover 1 (exhaust) Tappet cover 2 (intake) NOTE: Install the tappet covers with its ridge fac-...

  • Page 67: Idle Speed Adjustment

    INSP IDLE SPEED ADJUSTMENT IDLE SPEED ADJUSTMENT 1.Place the machine on a level place. 2.Warm up engine for several minutes. 3.Adjust: Engine idle speed ********************************** Adjustment steps: Turn the pilot screw 1 clockwise until it is lightly seated. Loosen the pilot screw by turning it coun- terclockwise for the specified number of turns.

  • Page 68: Throttle Cable Free Play Adjustment

    INSP THROTTLE CABLE FREE PLAY ADJUSTMENT THROTTLE CABLE FREE PLAY ADJUSTMENT NOTE: Before adjusting the throttle cable free play, the engine idle speed should be adjusted. 1.Place the machine on a level place. 2.Check: Throttle cable free play a Out of specification → Adjust. Throttle cable free play: 3 ~ 5mm (0.12 ~ 0.20 in) 3.Adjust:...

  • Page 69: Speed Limiter Adjustment

    SPEED LIMITER ADJUSTMENT/ INSP SPARK PLUG INSPECTION WARNING After adjusting the free play, turn the han- dlebar to right and left, and make sure that the engine idling does not run faster. ********************************** SPEED LIMITER ADJUSTMENT The speed limiter keeps the carburetor throttle from becoming full-open even when the throttle lever is pushed to a maxi- mum.
  • Page 70 INSP SPARK PLUG INSPECTION 3.Inspect: Spark plug type Incorrect → Replace. Standard spark plug: DR7EA (NGK) 4.Inspect: Electrode 1 Wear/Damage → Replace. Insulator color 2 Normal condition is a medium to light tan color. Distinctly different color → Check the engine condition.

  • Page 71: Ignition Timing Check

    INSP IGNITION TIMING CHECK IGNITION TIMING CHECK NOTE: Engine idling speed and throttle cable free play should be adjusted properly before checking the ignition timing. 1.Place the machine on a level place. 2.Start the engine and let it warm up for several minutes, then stop the engine.

  • Page 72: Compression Pressure Measurement

    IGNITION TIMING CHECK/ INSP COMPRESSION PRESSURE MEASUREMENT 5.Install: Timing plug 6.Detach: Timing light Inductive tachometer COMPRESSION PRESSURE MEASUREMENT NOTE: Insufficient compression pressure will result in performance loss. Before measuring the compression pres- sure, the valve clearance should be adjusted. Refer to “VALVE CLEARANCE ADJUST- MENT”...

  • Page 73: Engine Oil Level Inspection

    COMPRESSION PRESSURE MEASUREMENT/ INSP ENGINE OIL LEVEL INSPECTION If pressure falls below the minimum level: 1) Squirt a few drops of oil into the affected cylinder. 2) Measure the compression again. Compression pressure (with oil introduced into cylinder) Reading Diagnosis Higher than with- Worn or damaged cyl- out oil...

  • Page 74: Engine Oil Replacement

    ENGINE OIL LEVEL INSPECTION/ INSP ENGINE OIL REPLACEMENT Screw the dipstick 1 completely out, and wipe the dipstick clean, then just rest the dipstick in the hole. Pull up the dipstick, and inspect the oil level whether or not it is between maxi- mum 2 and minimum level 3.
  • Page 75 INSP ENGINE OIL REPLACEMENT 6.Inspect: O-rings 1 Compression spring 2 Oil strainer 3 Oil filter 4 Damage → Replace. 7.Clean: Compression spring 2 Oil strainer 3 Oil filter 4 Drain plug 5 (crankcase) Oil filter cover 6 Wash them with a cleaning solvent. 8.Apply: Engine oil (light coating) (to the O-rings)
  • Page 76 INSP ENGINE OIL REPLACEMENT 11.Install: Dipstick 12.Warm up the engine for 5 minutes or more, and stop it. 13.Inspect: Oil leaks Oil level 14.Inspect: Oil flow ********************************** Inspection steps: Slightly loosen the oil gallery plug 1 in the cylinder head. Start the engine and keep it idling until oil begins to seep from the oil gallery plug.

  • Page 77: Clutch Adjustment

    INSP CLUTCH ADJUSTMENT/AIR FILTER CLEANING CLUTCH ADJUSTMENT Release lever free play adjustment 1.Adjust: DECREASE INCREASE Release lever free play Å ı ********************************** Adjustment steps: Loosen the locknut 1. Slowly turn the adjuster 2 counterclock- wise until resistance is felt, then turn back it 1/8 clockwise, hold the adjuster 2 in this position and tighten the locknut 1.

  • Page 78: Air Filter Cleaning

    INSP AIR FILTER CLEANING 3.Remove: Air filter element 1 Foam cover 2 CAUTION: The engine should never be run without the air filter; excessive piston and/or cylin- der wear may result. 4.Inspect: Air filter element 1 Foam cover 2 Damage → Replace. 5.Clean: Air filter element Use compressed air to blow off dust from...
  • Page 79 INSP AIR FILTER CLEANING 7.Install: Foam cover (to air filter) 8.Install: Air filter assembly NOTE: Make sure its sealing surface matches the sealing surface of the case so there is no air leak. 9.Install: Cover (air filter case) Seat Refer to “REAR FENDER-Installation” sec- tion.

  • Page 80: Chassis

    FRONT AND REAR BRAKE LINING INSPECTION/ INSP FRONT BRAKE ADJUSTMENT CHASSIS FRONT AND REAR BRAKE LINING INSPECTION Front brake 1.Apply the front brake. 2.Inspect: Wear indicator 1 Indicator reaches the wear limit mark 2 → Replace brake shoes as a set. Refer to the “FRONT WHEEL AND FRONT BRAKE”...

  • Page 81: Rear Brake Lever And Pedal Adjustment

    FRONT BRAKE ADJUSTMENT/ INSP REAR BRAKE LEVER AND PEDAL ADJUSTMENT 2.Adjust: Front brake lever free play ********************************** Adjustment steps: Loosen the locknut 1 and turn the adjuster 2 clockwise to release the ten- sion in the front brake cable. Visually check the cable joint 3 in the equalizer 4 to verify it is horizontal.
  • Page 82 INSP REAR BRAKE LEVER AND PEDAL ADJUSTMENT 2.Adjust: Brake lever free play Brake pedal free play ********************************** Adjustment steps: NOTE: Before adjusting the free play, pump the brake pedal 2 to 3 times. Fully loosen the locknut 1 (handlebar) and fully turn in the brake lever adjuster Fully loosen brake lever cable adjuster 3 and brake pedal adjuster 4.

  • Page 83: Drive Select Lever Position Adjustment

    DRIVE SELECT LEVER POSITION ADJUSTMENT/ INSP FINAL DRIVE GEAR OIL LEVEL INSPECTION DRIVE SELECT LEVER POSITION ADJUSTMENT 1.Adjust: Drive select lever position ********************************** Adjustment steps: Place the machine on a level place. Shift the transmission in first gear, and move the select lever 1 to reverse posi- tion.

  • Page 84: Final Drive Gear Oil Replacement

    FINAL DRIVE GEAR OIL LEVEL INSPECTION/ INSP FINAL DRIVE GEAR OIL REPLACEMENT If the oil level is low, add the recom- mended oil up to the specified level. Refer to “FINAL DRIVE GEAR OIL REPLACE- MENT” section. Inspect the copper washer for damage. If damaged, replace it Install the copper washer and filler bolt.

  • Page 85: Drive Shaft Dust Boot Inspection

    FINAL DRIVE GEAR OIL REPLACEMENT/DRIVE SHAFT DUST INSP BOOT INSPECTION/STEERING SYSTEM INSPECTION Recommended oil: SAE 80 API “GL-4” hypoid gear If desired, and SAE 80W90 hypoid gear oil may be used for all condition. Periodic oil change: 0.25 L (0.21 Imp qt, 0.27 US qt) Total amount: 0.27 L (0.24 Imp qt, 0.29 US qt) 7.Install:...

  • Page 86: Steering System Inspection

    STEERING SYSTEM INSPECTION/ INSP TOE-IN ADJUSTMENT 4.Raise the front end of the machine so that there is no weight on the front wheels. 5.Check: Knuckles and/or wheel bearings Move the wheels laterally back and forth. Excessive free play → Replace the follow- ing parts.
  • Page 87 INSP TOE-IN ADJUSTMENT Toe-in: 0 ~ 5 mm (0 ~ 0.2 in) If the toe-in is incorrect, adjust the toe-in. ********************************** 3.Adjust: Toe-in ********************************** Adjustment steps: Place a confirmation marks 1 on the both tie-rods end. Loosen the rod end locknuts 2 of both tie- rods.

  • Page 88: Front And Rear Shock Absorbers Inspection

    TOE-IN ADJUSTMENT/FRONT AND REAR SHOCK ABSORBERS INSP INSPECTION/REAR SHOCK ABSORBER ADJUSTMENT FRONT AND REAR SHOCK ABSORBERS INSPECTION 1.Place the machine on a level place. 2.Check: Ball joint complete 1 (front) Cracks/Damage → Replace as a set. Damper rod 2 (rear) Scratch/Damage →...

  • Page 89: Tire Inspection

    TIRE CHARACTERISTICS 1) Tire characteristics influence the han- dling of ATV’s. The tires listed below have been approved by Yamaha Motor Co., Ltd. for this model. If other tire combinations are used, they can adversely affect your machine’s han- dling characteristics and are therefore not recommended.
  • Page 90 INSP TIRE INSPECTION 1.Measure: Tire pressure (cold tire pressure) Out of specification → Adjust. NOTE: Low-pressure tire gauge 1 included in the standard equipment. If dust or the like is stuck to this gauge, it does not provide correct readings. There- fore, make two measurements on the tire pressure and get the second reading.

  • Page 91: Wheel Inspection

    INSP WHEEL INSPECTION WHEEL INSPECTION 1.Inspect: Wheels 1 Cracks/Bends/Damage → Replace. NOTE: Always balance the wheel when a tire or wheel has been changed or replaced. WARNING Never attempt even small repairs to the wheel. 3 - 37...

  • Page 92: Electrical

    INSP BATTERY INSPECTION ELECTRICAL BATTERY INSPECTION WARNING Battery electrolyte is dangerous; it contains sulfuric acid and therefore is poisonous and highly caustic. Always follow these preventive measures: Avoid bodily contact with electrolyte as it can cause severe burns or permanent eye injury.
  • Page 93 INSP BATTERY INSPECTION 4.Inspect: Battery fluid level Battery fluid level low → Fill. Fluid level should be between upper level UPPER LEVEL 1 and lower level 2 marks. LOWER LEVEL CAUTION: Refill with distilled water only; tap water contains minerals harmful to a battery. 5.Inspect: Battery fluid specific gravity Out of specification →...
  • Page 94 INSP BATTERY INSPECTION 7.Inspect: Battery breather hose Obstruction → Remove. Damage → Replace. 8.Install: Battery 1 Battery breather hose 2 Refer to the “CABLE ROUTING” section in CHAPTER 2. CAUTION: When installing the battery, be sure the breather hose is routed correctly. If the breather hose touches the frame or exits in such a way as to cause battery electrolyte or gas to exit onto the frame, structual and...

  • Page 95: Fuse Inspection

    INSP FUSE INSPECTION FUSE INSPECTION CAUTION: Don’t forget to turn off the main switch when checking or replacing the fuse. Other- wise, it may cause accidental shortcircuit- ing. WARNING Do not use fuses of a higher amperage rat- ing than those recommended. Substitu- tion of a fuse of improper rating can cause extensive electrical system damage and possible fire.

  • Page 96: Headlight Beam Adjustment

    FUSE INSPECTION/HEADLIGHT BEAM ADJUSTMENT/ INSP HEADLIGHT BULB REPLACEMENT 4.Replace: Blown fuse ********************************** Blown fuse replacement steps: Turn off ignition and the circuit. Install a new fuse of proper amperage. Turn on the switches and see if the electri- cal device operates. Fuse interrupts the circuit again’...
  • Page 97 INSP HEADLIGHT BULB REPLACEMENT 5.Remove: Bulb 1 WARNING Keep flammable products or your hands away from the bulb while it is on, it will be hot. Do not touch the bulb until it cools down. 6.Install: Bulb 1 (new) NOTE: Make sure the projection 2 on the bulb is meshed with the slot 3 on the light case.
  • Page 98 INSP 3 - 44...

  • Page 99: Chapter 4. Engine Overhaul

    ENGINE REMOVAL ENGINE OVERHAUL ENGINE REMOVAL NOTE: It is not necessary to remove the engine in order to remove the following compo- nents: * Cylinder head * Cylinder * Piston * Primary and secondary clutches * Oil pump * Shift shaft * CDI Magneto It is necessary to remove the rear wheel drive assembly in order to remove the...

  • Page 100: Engine Oil

    ENGINE REMOVAL ENGINE OIL 1.Drain: Engine oil Refer to the “ENGINE OIL REPLACE- MENT” section in CHAPTER 3. EXHAUST PIPE AND MUFFLER 1.Remove: Exhaust pipe 1 Muffler 2 CARBURETOR 1.Drain: Fuel (float chamber) NOTE: Place a rag under the over flow hose to absorb a spilt fuel.

  • Page 101: Starter Motor

    ENGINE REMOVAL STARTER MOTOR 1.Disconnect: Starter motor lead 1 2.Remove: Starter motor bracket 2 Starter motor 3 REAR BRAKE CABLES AND FOOTREST 1.Remove: Adjusters 1 (brake lever and brake pedal) Pins 2 Springs 3 2.Disconnect: Brake cable 4 (from brake cable bracket 5 . 3.Remove: Footrest 1 (left) Shift pedal 2...

  • Page 102: Rear Wheel Drive Assembly And Swingarm

    ENGINE REMOVAL REAR WHEEL DRIVE ASSEMBLY AND SWINGARM 1.Disconnect: Breather hose 1 (final gear housing and rear brake drum) (from the cable guides 2 of main frame) 2.Block the front wheels, and elevate the rear wheels by placing the suitable stand under the frame.

  • Page 103: Engine Disassembly

    ENGINE DISASSEMBLY ENGINE DISASSEMBLY CYLINDER HEAD ASSEMBLY, CYLINDER AND PISTON NOTE: With the engine mounted cylinder head assembly, cylinder and piston can be main- tained by removing the following parts. Fuel tank Exhaust pipe Carburetor Engine stays (top) 1.Remove: Recoil starter assembly 1 2.Remove: Timing plug 1 Drive select lever assembly 2...
  • Page 104 ENGINE DISASSEMBLY 5.Align: “T” mark on the rotor With the stationary pointer on the crank- case cover. ********************************* TDC alignment steps: Turn the crankshaft counterclockwise with wrench. Align the “T” mark 1 on the rotor with the stationary pointer 2 on the crankcase cover.
  • Page 105 ENGINE DISASSEMBLY 8.Remove: Bolt 1 Cam sprocket 2 NOTE: Fasten a safety wire 3 to the timing chain to prevent if from falling into the crank- case. When removing the cam sprocket, it is not necessary to separate the timing chain. Hold the starter pulley 4 by the Rotor Holder to loosen the bolt on the cam sprocket.

  • Page 106: Starter Pulley Cdi Magneto

    ENGINE DISASSEMBLY 11.Remove: Bolts 1 (cylinder) Cylinder 2 Gasket 3 (cylinder) Dowel pins 4 O-ring 5 12.Remove: Piston pin clip 1 Piston pin 2 Piston 3 NOTE: Before removing the piston pin clip, cover the crankcase with a clean rag so you will not accidentally drop the clip into the crankcase.
  • Page 107 ENGINE DISASSEMBLY 1.Remove: Starter pulley 1 NOTE: Hold the starter pulley by the Rotor Holder to loosen the bolt on the starter pulley. Rotor holder: P/N. YU-01235, 90890-01235 2.Remove: Crankcase cover 1 3.Remove: Gasket 1 Dowel pins 2 Shaft 3 Washer 4 Idle gear 5 (starter) 4.Remove:...

  • Page 108: Middle Driven Pinion Gear

    ENGINE DISASSEMBLY 5.Remove: Woodruff key 1 Driven gear 2 (starter) Washer 3 6.Remove: Chain guide 1 (intake) Timing chain 2 MIDDLE DRIVEN PINION GEAR 1.Remove: Bolts 1 (bearing housing) 2.Remove: Bolts 1 (middle gear case cover) Middle gear case cover 2 3.Remove: Middle driven pinion gear assembly 1 Dowel pins 2...

  • Page 109: Primary And Secondary Clutches

    ENGINE DISASSEMBLY PRIMARY AND SECONDARY CLUTCHES NOTE: With the engine mounted, the primary and secondary clutches can be maintained by removing the following parts: Starter motor Crankcase cover (right) 1.Remove: Oil filter cover 1 Oil filter 2 O-ring 3 Clutch cover protector 4 Crankcase cover 5 (right) Dowel pins 6 Gasket 7...
  • Page 110 ENGINE DISASSEMBLY 5.Remove: Lock washer 1 Clutch carrier assembly 2 Washer 3 Clutch housing 4 (primary) Washer 5 NOTE: The secondary clutch housing has two grooves 1 machined into it to permit the primary drive gear behind the primary clutch to clear the secondary clutch. Align one of these grooves with the primary gear 2 before removing the primary clutch assembly.

  • Page 111: Oil Pump And Shifter

    ENGINE DISASSEMBLY 9.Straighten: Lock washer tab 1 (clutch boss) 10.Remove: Nut 2 (clutch boss) NOTE: Hold the clutch boss 3 by the Rotor Holder 4 to loosen the nut. Rotor holder: P/N. YU-01235, 90890-01235 11.Remove: Lock washer 1 Clutch boss 2 Friction plates 3 Clutch plates 4 Pressure plate 5...

  • Page 112: Balancer Driven Gear

    ENGINE DISASSEMBLY 3.Remove: Shift lever assembly 1 Washer 2 Return spring 3 Stopper lever 4 Washer 5 NOTE: Push the shift pawl and the stopper lever to the arrow direction and remove them from the segment. 4.Remove: Segment 1 (shift cam) ®...

  • Page 113: Crankcase (Left)

    ENGINE DISASSEMBLY 3.Remove: Lock washer 1 Balancer gear 2 (driven) Straight key 3 CRANKCASE (LEFT) 1.Remove: Screws (crankcase) NOTE: Working in a crisscross pattern, loosen all screws 1/4 turn each. Remove them after all are loosened. 2.Remove: Crankcase 1 (left) Dowel pins ********************************* Removal steps:...

  • Page 114: Balancer Shaft, Transmission And Crankshaft

    ENGINE DISASSEMBLY NOTE: Fully tighten the tool holding bolts, but make sure the tool body is parallel with the case. If necessary, one screw may be backed out slightly to level tool body. As pressure is applied, alternately tap on the front engine mounting boss, transmis- sion shafts and balancer shaft.

  • Page 115: Cylinder Head

    ENGINE DISASSEMBLY 2.Remove: Transmission assembly 1 (main axle and drive axle) Washer 2 (drive axle) 3.Remove: Circlip 1 4.Remove: Balancer drive gear 2 Crankshaft 3 (from right crankcase) Woodruff key 4 NOTE: Use a hydraulic press to remove the bal- ancer drive gear 2 from the crankshaft.

  • Page 116: Valve

    ENGINE DISASSEMBLY 4.Remove: Rocker arm shafts 1 Rocker arms (intake/exhaust) NOTE: Attach the Slide Hammer Set 2 to the rocker arm shaft, and then slide out the them. Slide hammer set: P/N. YU-01083-A Slide hammer bolt: P/N. 90890-01083 Weight: P/N. 90890-01084 VALVE NOTE: Before removing the internal parts (valve,...

  • Page 117: Recoil Starter

    ENGINE DISASSEMBLY 2.Remove: Valve cotters 1 NOTE: Attach the Valve Spring Compressor 2 between the valve spring seat and cylinder head to remove the valve cotters. Valve spring compressor: P/N. YM-04019, 90890-04019 3.Remove: Valve spring seat 1 (upper) Valve spring 2 (outer) Valve spring 3 (inner) Valve 4 Valve stem seal 5...

  • Page 118: Inspection And Repair

    INSPECTION AND REPAIR INSPECTION AND REPAIR CYLINDER HEAD 1.Eliminate: Carbon deposit Use a rounded scraper 1. NOTE: Do not use a sharp instrument to avoid damaging or scratching: Spark plug threads Valve seat Cylinder head 2.Measure: Cylinder head warpage Out of specification → Resurface/Replace. Cylinder head warp: Less than 0.10 mm (0.004 in) INTAKE AND EXHAUST VALVE...

  • Page 119: Valve Guide

    INSPECTION AND REPAIR 3.Measure: Valve stem runout Out of specification → Replace. Stem runout: Less than: 0.03 mm (0.0012 in) 4.Measure: Valve stem clearance Valve stem clearance = Valve guide inside diameter Å – Valve stem diameter ı Out of specification → Replace either valve and/or guide.

  • Page 120: Valve Seat

    INSPECTION AND REPAIR 3.Install: Circlip 1 (new) Valve guide 2 (new) Use the Valve Guide Installer 3 with the Valve Guide Remover 4. Valve guide installer: P/N. YM-04065-A, 90890-04065 Valve guide remover (6.0 mm): P/N. YM-04064-A, 90890-04064 4.Bore valve guide 2 to obtain proper valve stem clearance.
  • Page 121 INSPECTION AND REPAIR Press the valve through the valve guide and onto the valve seat to make a clear pattern. Remove the valve from the cylinder head. Measure the valve seat width a. When the valve seat and valve face make contact, bluing will be applied to the valve face.
  • Page 122 INSPECTION AND REPAIR ı Valve seat is in the middle of the valve face ı but too narrow. Valve seat cutter set Desired result To achieve a uni- form valve seat 45˚ cutter width of 1.0 mm (0.04 in) Ç Valve seat is too narrow and right up near valve margin.

  • Page 123: Valve Spring

    INSPECTION AND REPAIR Apply a molybdenum disulfide oil to the valve stem. Install the valve into the cylinder head. Turn the valve until the valve face and valve seat are evenly polished, then clean off all compound. NOTE: To obtain the best lapping result, lightly tap the valve seat while rotating the valve back and forth between your hand.

  • Page 124: Valve Installation

    INSPECTION AND REPAIR 2.Measure: Valve spring installed force Out of specification → Replace inner and outer springs as a set. a Installed length Valve spring installed force Inner spring 8.4 ~ 10.2 kg (18.5 ~ 22.5 lb) (IN/EX) at 30.5 mm (1.2 in) Outer spring 16.6 ~ 20.4 kg (36.6 ~ 45.0 lb) (IN/EX)

  • Page 125: Cam Shaft

    INSPECTION AND REPAIR NOTE: All valve springs must be installed with the larger pitch a upward as shown. 1 Outer spring 2 Inner spring 4.Check: Valve sealing Leakage at valve seat → Reface, relap or replace valve, relap. Refer to “VALVE SEAT”. ********************************* Valve seat checking steps: Pour a clean solvent 1 into the intake and...

  • Page 126: Rocker Arm And Rocker Arm Shaft

    INSPECTION AND REPAIR 2.Inspect: Cam lobes Pitting/Scratches/Blue discoloration → Replace. 3.Measure: Cam lobes Use a Micrometer. Out of specification → Replace. Cam lobe Cam lobe Limit “A” Limit “B” 36.437 mm 30.031 mm Intake (1.435 in) (1.182 in) 36.482 mm 30.152 mm Exhaust (1.436 in)
  • Page 127 INSPECTION AND REPAIR Calculate the clearance by subtracting the rocker-arm-shaft outside diameter from the rocker-arm inside diameter. Arm-to-shaft clearance = Rocker arm inside diameter a – Rocker arm shaft outside diameter b Out of specification → Replace as a set. Arm-to-shaft clearance: 0.009 ~ 0.037 mm (0.0004 ~ 0.0013 in)

  • Page 128: Timing Chain

    INSPECTION AND REPAIR 5.Install: Camshaft bushing 1 NOTE: The cut-out portion 2 of the bushing must be flush with the cylinder head. CAUTION: Do not cock the bushing during installa- tion. The bushing must be perpendicular to the camshaft during installation. 6.Install: Retainer 1 (camshaft bushing) Lock washer (new)

  • Page 129: Cam Sprocket And Cam Drive Sprocket

    INSPECTION AND REPAIR CAM SPROCKET AND CAM DRIVE SPROCKET 1.Inspect: Cam sprocket Cam drive sprocket (crank shaft) Wear/Damage → Replace cam sprocket and timing chain as a set. 1 1/4 tooth 2 Correct 3 Roller 4 Sprocket TIMING CHAIN GUIDE 1.Inspect: Timing chain guide 1 (exhaust) Timing chain guide 2 (intake)

  • Page 130: Tappet Cover And Cam Sprocket Cover

    INSPECTION AND REPAIR TAPPET COVER AND CAM SPROCKET COVER 1.Inspect: Tappet covers (intake 1 and exhaust 2) Cam sprocket cover 3 O-rings 4 Cracks/Damage → Replace. CYLINDER AND PISTON 1.Eliminate: Carbon deposits (from the piston crown and ring grooves.) 2.Inspect: Cylinder and piston walls Vertical scratches →...

  • Page 131: Piston Ring And Piston Pin

    INSPECTION AND REPAIR 2nd steps Measure the piston skirt diameter “P” with a micrometer. b 4 mm (0.16 in) from the piston bottom edge Piston skirt Diameter “P” 70.92 ~ 70.97 mm Standard (2.792 ~ 2.794 in) Oversize 2 71.50 mm (2.815 in) Oversize 4 72.00 mm (2.846 in) If out of the specification, replace the pis-...
  • Page 132 INSPECTION AND REPAIR Side clearance Standard Limit 0.12 mm 0.03 ~ 0.07 mm ring (0.005 in) (0.001 ~ 0.003 in) 0.12 mm 0.02 ~ 0.06 mm ring (0.005 in) (0.0008 ~ 0.0024 in) 2.Position: Piston ring (into cylinder) NOTE: Insert the ring into the cylinder, and push it approximately 20 mm (0.8 in) into the cylin- der.
  • Page 133 INSPECTION AND REPAIR Oil control ring Expander spacer of bottom ring (oil con- trol ring) is color-coded to identify sizes. Size Color Oversize 2 Blue Oversize 4 Yellow Piston pin 1.Inspect: Piston pin Blue discoloration/Grooves → Replace then inspect lubrication system. 2.Measure: Outside diameter a (piston pin) Out of specification →...

  • Page 134: Crankshaft

    INSPECTION AND REPAIR CRANKSHAFT 1.Measure: Crank width A Out of specification → Replace or repair. Crank width: 55.95 ~ 56.00 mm (2.203 ~ 2.205 in) Runout c Out of specification → Replace or repair. <Runout limit>: : 0.03 mm (0.0012 in) : 0.06 mm (0.0024 in) Side clearance D Out of specification →...

  • Page 135: Balancer Drive Gear And Driven Gears

    INSPECTION AND REPAIR ********************************* Crankshaft reassembling point: The crankshaft 1 and the crank pin 2 oil passages must be properly interconnected with a tolerance of less than 1 mm (0.04 in). ********************************* BALANCER DRIVE GEAR AND DRIVEN GEARS 1.Inspect: Balancer drive gear teeth 1 Balancer driven gear teeth 2 Wear/Damage →...

  • Page 136: Secondary Clutch

    INSPECTION AND REPAIR 3.Inspect: Bolts 1 (starter clutch) Loose → Replace with a new one, and calk the end of the bolt. Bolts (starter clutch): 30 Nm (3.0 m • kg, 22 ft • lb) ® LOCTITE Calk the end of the bolt PRIMARY CLUTCH Clutch housing 1.Inspect:...
  • Page 137 INSPECTION AND REPAIR Clutch boss and pressure plate 1.Inspect: Clutch boss splines 1 Pressure plate splines 2 Scoring/Wear/Damage → Replace clutch boss assembly and/or pressure plate. Friction plates 1.Inspect: Friction plate 1 Damage/Wear → Replace friction plate as a set. 2.Measure: Friction plate thickness Measure at all four points.

  • Page 138: Oil Pump

    INSPECTION AND REPAIR Clutch spring 1.Inspect: Clutch spring Wear/Damage → Replace. 2.Measure: Clutch spring free length a Out of specification → Replace springs as a set. Clutch spring minimum length: 32.9 mm (1.30 in) Clutch release lever 1.Inspect: Release lever 1 Adjuster 2 O-ring 3 Cracks/Wear/Damage →...

  • Page 139: Transmission And Shifter

    INSPECTION AND REPAIR TRANSMISSION AND SHIFTER Shift fork and guide bar 1.Inspect: Shift forks On the gear and shift cam contact sur- faces. Wear/Chafing/Bends/Damage → Replace. 2.Inspect: Guide bars (Roll the guide bar on a flat surface. Bends → Replace. WARNING Do not attempt to straighten a bent guide bar.
  • Page 140 INSPECTION AND REPAIR 2.Inspect: Gears (transmission 1 and drive pinion 2) Mating dogs Cracks/Damage/Wear → Replace. NOTE: When the drive pinion gear is replaced, be sure to adjust the drive pinion gear shim(s), refer to the “DRIVE TRAIN-MIDDLE GEAR SERVICE” section in CHAPTER 6. 3.Check: Gear movement (transmission) Unsmooth operation →...

  • Page 141: Middle Gear

    INSPECTION AND REPAIR MIDDLE GEAR 1.Inspect: Middle driven pinion gear 1 Bearing 2 Middle driven shaft 3 Reverse gear 4 Bearing housing 5 Damage/Wear → Replace. 2.Check: Bearing movement Turns roughly → Replace. NOTE: When the driven pinion gear, reverse gear, middle driven shaft and/or bearing housing are replaced, be sure to adjust the middle gear shim(s).

  • Page 142: Recoil Starter

    INSPECTION AND REPAIR 3.Inspect: Crankcase Cracks/Damage → Replace. Oil delivery passages Clog → Blow out with compressed air. NOTE: When the crankcase is replaced, be sure to adjust the middle gear shim(s), refer to “DRIVE TRAIN-MIDDLE GEAR SERVICE” section in CHAPTER 6. RECOIL STARTER 1.Inspect: Drive plate 1...

  • Page 143: Engine Assembly And Adjustment

    ENGINE ASSEMBLY AND ADJUSTMENT ENGINE ASSEMBLY AND ADJUSTMENT RECOIL STARTER 1.Install: Starter spring 1 NOTE: Mesh the spring hook 2 wise the case slit, then carefully wind the spring counterclock- wise, and fit the spring into the case. 2.Install: Plate 1 Starter spring case 2 NOTE: Mesh the end 3 of the sheave spring with...
  • Page 144 ENGINE ASSEMBLY AND ADJUSTMENT 6.Install: Spring (drive pawl) 1 Drive pawl 2 Circlip 3 Spring 4 Drive plate 5 Bolt 6 NOTE: When installing the spring (drive pawl), align the spring end 7 with the groove a on the sheave drum. 7.Turn the sheave drum 3-turns clockwise to preload the starter spring.

  • Page 145: Crankshaft/Balancer

    ENGINE ASSEMBLY AND ADJUSTMENT CRANKSHAFT/BALANCER 1 Balancer driven gear 7 Woodruff key 2 Bearing 8 Crank (right) 3 Straight key 9 Connecting rod 4 Balancer 0 Small end bearing 5 Oil seal A Crank pin 6 Balancer drive gear B Crank (left) PISTON TO CYLINDER CLEARANCE: CRANKSHAFT: 0.04 ~ 0.06 mm (0.0016 ~ 0.0024 in)

  • Page 146: Transmission

    ENGINE ASSEMBLY AND ADJUSTMENT TRANSMISSION 1 Bearing 8 2nd wheel gear E 2nd pinion gear 2 1st wheel gear 9 Drive axle F Oil seal 3 5th wheel gear 0 Bearing retainer G Shim 4 Circlip A Main axle 5 Washer B 5th pinion gear 6 3rd wheel gear C 3rd pinion gear...

  • Page 147: Shifter

    ENGINE ASSEMBLY AND ADJUSTMENT SHIFTER 1 Guide bar #1 (long) 8 Guide bar #2 (short) 2 Shift fork #2 9 Shift fork #1 3 Shift fork #3 4 Shift cam segment 5 Pin 6 Bearing 7 Shift cam 4 - 49...

  • Page 148: Crankshaft, Transmission And Balancer Shaft

    ENGINE ASSEMBLY AND ADJUSTMENT CRANKSHAFT, TRANSMISSION AND BALANCER SHAFT 1.Install: Crankshaft 1 (to right crankcase) NOTE: Hold the connecting rod at top dead center with one hand while installing the crank- shaft. 2.Install: Transmission assembly 1 (main axle and drive axle) 3.Install: Balancer shaft 1 Shift fork #1 2...

  • Page 149: Crankcase (Left)

    Sealant 1 (to matching surfaces of both case halves) ® Sealant (Quick Gasket ACC-QUICK-GS-KT Yamaha bond No. 1215: 90890-85505 2.Install: Dowel pins 2 3.Fit the left crankcase onto the right case. Tap lightly on the case with a soft ham- mer.
  • Page 150 ENGINE ASSEMBLY AND ADJUSTMENT Crankshaft installer set 1: P/N. YU-90050 Buffer boss installer set 2: P/N. 90890-04088 Adapter #11 3: P/N. YM-33279 Spacer 4 (crankshaft): P/N. YM-90070-A, 90890-04060 2.Install: Balancer gear 1 (driven) Straight key 2 NOTE: Align the drive gear mark 3 with the driven gear mark 4.

  • Page 151: Shift Shaft/Oil Pump

    ENGINE ASSEMBLY AND ADJUSTMENT SHIFT SHAFT/OIL PUMP 1 Adjuster 8 Stopper lever 2 Spring 9 Return spring 3 Release lever 0 Oil seal 4 Shift guides A Shift pedal 5 Ball holder B Oil pump assembly 6 Shift shaft C Gasket 7 Torsion spring 4 - 53...

  • Page 152: Shifter And Oil Pump

    ENGINE ASSEMBLY AND ADJUSTMENT SHIFTER AND OIL PUMP 1.Install: Segment 1 Pin 2 (long) Pin 3 (short) NOTE: Install the pin 2 (long) to the match mark 4 position. 2.Install: Segment (shift cam) NOTE: Align the hole 1 of the shift cam with the pin 2 (long) of the segment.
  • Page 153 ENGINE ASSEMBLY AND ADJUSTMENT 6.Apply: 4-stroke engine oil (to the oil pump inner parts) 7.Install: Rotor housing 1 Outer rotor 2 Inner rotor 3 Dowel pins 4 Oil pump driven gear 5 Dowel pin 6 Oil pump cover 7 Screw 8 Screw: 7 Nm (0.7 m •...

  • Page 154: Clutch

    ENGINE ASSEMBLY AND ADJUSTMENT CLUTCH 1 Push rod 8 Washer 2 Bearing 9 Clutch housing (secondary) 3 Bearing holder 0 Clutch carrier assembly 4 Clutch boss A Washer 5 Clutch plate B Inner collar 6 Friction plate C One way bearing 7 Pressure plate D Clutch housing (primary) CLUTCH SPRING MINIMUM LENGTH:...

  • Page 155: Primary And Secondary Clutches

    ENGINE ASSEMBLY AND ADJUSTMENT PRIMARY AND SECONDARY CLUTCHES 1.Install: Clutch housing 1 (secondary) Washer 2 2.Install: Friction plates 1 Clutch plates 2 (to clutch boss 3) NOTE: Install the clutch plates and friction plates alternately on the clutch boss, starting with a friction plate and ending with a friction plate.
  • Page 156 ENGINE ASSEMBLY AND ADJUSTMENT NOTE: Hold the clutch boss 2 by the Rotor Holder 3 to tighten the nut. Rotor holder: P/N. YU-01235, 90890-01235 6.Bend the lock washer tab 4. 7.Install: Clutch springs 1 Bearing holder 2 Bearing 3 Push rod 4 Bolts (clutch spring): 6 Nm (0.6 m •...
  • Page 157 ENGINE ASSEMBLY AND ADJUSTMENT 11.Install: Washer 1 Clutch housing 2 (primary) Washer 3 Clutch carrier assembly 4 NOTE: The secondary clutch housing has two grooves 1 machined into it permit the primary drive gear behind the primary clutch to clear the secondary clutch. Align one of these grooves with the pri- mary gear 2 before installing the primary clutch housing.
  • Page 158 ENGINE ASSEMBLY AND ADJUSTMENT 15.Install: Shift guide #2 1 Ball holder 2 Shift guide #1 3 Spring 4 (clutch release lever) NOTE: The slot 5 in the shift guide #2 must engage the shift shaft projection 6. The slot 7 in the shift guide #1 must engage the stopper shaft 8.

  • Page 159: Middle Driven Pinion Gear

    (to matching surface of middle shaft case cover) ® Sealant (Quick Gasket P/N. ACC-QUICK-GS-KT Yamaha Bond No. 1215: P/N. 90890-85505 3.Install: Case cover 1 (middle driven shaft) Bolt (middle shaft case cover): 10 Nm (1.0 m • kg, 7.2 ft • lb)

  • Page 160: Starter Pulley (Except For Usa)/Cdi Magneto

    ENGINE ASSEMBLY AND ADJUSTMENT STARTER PULLEY (EXCEPT FOR USA)/CDI MAGNETO 1 Timing chain 0 CDI magneto 2 Timing chain guide (intake) A Starter idle gear 3 Woodruff key B Shaft 4 Washer C Washer 5 Starter driven gear D Circlip 6 Starter clutch E Stator assembly 7 Dowel pin...

  • Page 161: Starter Pulley (Except For Usa) And Cdi Magneto

    ENGINE ASSEMBLY AND ADJUSTMENT STARTER PULLEY (EXCEPT FOR USA) AND CDI MAGNETO 1.Inspect: Timing chain 1 Chain guide 2 (intake) Chain guide (intake): 8 Nm (0.8 m • kg, 5.8 ft • lb) NOTE: Fasten a safety wire 3 to the timing chain to prevent it from falling into the crankcase.
  • Page 162 ENGINE ASSEMBLY AND ADJUSTMENT 5.Install: Starter pulley 1 Bolt (starter pulley): 50 Nm (5.0 m • kg, 36 ft • lb) NOTE: Hold the starter pulley by the Rotor Holder to tighten the bolt. Rotor holder: P/N. YU-01235, 90890-01235 Before installing the starter pulley, apply the grease to the oil seal rip 2 and O-ring 4 - 64...

  • Page 163: Cylinder And Cylinder Head Assembly

    ENGINE ASSEMBLY AND ADJUSTMENT CYLINDER AND CYLINDER HEAD ASSEMBLY 1 Spark plug 8 Cam sprocket cover 2 Tappet cover (intake) 9 Oil seal 3 O-ring 0 Cylinder 4 Tappet cover (exhaust) 5 Cylinder head 6 Bearing retainer 7 Lock washer CYLINDER HEAD WARP LIMIT: 0.10 mm (0.004 in)

  • Page 164: Piston, Camshaft And Timing Chain

    ENGINE ASSEMBLY AND ADJUSTMENT PISTON, CAMSHAFT AND TIMING CHAIN 8 Timing chain 1 Gasket 9 Timing chain guide (exhaust) 2 Timing chain tensioner 0 Piston ring 3 Gasket A Piston pin clip 4 Timing chain guide (intake) B Piston 5 Camshaft C Piston pin 6 Camshaft bushing 7 Cam sprocket...

  • Page 165: Cylinder Head Assembly, Cylinder And Piston

    ENGINE ASSEMBLY AND ADJUSTMENT CYLINDER HEAD ASSEMBLY, CYLINDER AND PISTON 1.Install: Piston 1 Piston pin 2 Piston pin clips 3 NOTE: The arrow 4 on the piston must point to the front of the engine. Before installing the piston pin clip, cover the crankcase with a clean towel or rag so you will not accidentally drop the pin clip and material into the crankcase.
  • Page 166 ENGINE ASSEMBLY AND ADJUSTMENT 5.Install: Cylinder 1 Bolts (cylinder)-temporary tighten NOTE: Install the cylinder with one hand while compressing the piston rings with the other hand. Pass the timing chain through the chain cavity. 6.Install: Chain guide 1 (exhaust) Oil seal 2 Dowel pins 3 Gasket 4 (cylinder head) WARNING...
  • Page 167 ENGINE ASSEMBLY AND ADJUSTMENT Turn the crankshaft counterclockwise until the TDC mark 3 is aligned with the station- ary pointer 4 on the crankcase cover. Place the timing chain onto the cam sprocket. Install the cam sprocket onto the cam- shaft, and finger tighten the sprocket bolt.
  • Page 168 ENGINE ASSEMBLY AND ADJUSTMENT Insert a small screwdriver 3 into the ten- sioner body slit. While pressing the ten- sioner rod, rotate screwdriver clockwise until it stops turning. While holding the screwdriver in this posi- tion, and install the tensioner assembly 2 (with the gasket) onto the cylinder, then temporary tighten the tensioner assembly holding bolts 4.
  • Page 169 ENGINE ASSEMBLY AND ADJUSTMENT 13.Install: Tappet cover 1 (intake) Tappet cover 2 (exhaust) Spark plug 3 Bolt (tappet cover): 10 Nm (1.0 m • kg, 7.2 ft • lb) Spark plug: 17.5 Nm (17.5 m • kg, 12.5 ft • lb) 14.Install: Cam sprocket cover 1 Carburetor joint 2...

  • Page 170: Remounting Engine

    ENGINE ASSEMBLY AND ADJUSTMENT REMOUNTING ENGINE Reverse the “ENGINE REMOVAL” proce- dure. Note the following points. WARNING Securely support the machine so there is no danger of it falling over. 1.Install: Engine assembly (from right side) 2.Install: Bolt 1 (engine mounting - rear lower) Bolt 2 (engine mounting - rear upper) Bolt 3 (engine mounting - front) Bolts 4 (engine mounting - top)
  • Page 171 ENGINE ASSEMBLY AND ADJUSTMENT 3.Install: Rear wheel drive assembly and swing- arm. NOTE: Before installing the swingarm. Lubricate the following parts. Swingarm pivot side: 1) Bearings 1 2) Oil seals 2 3) Collars 3 4) Pivot shafts 4 Drive shaft side: 1) Drive shaft splines 5 2) Coupling gear splines 6 Lithium-soap Base Grease...
  • Page 172 ENGINE ASSEMBLY AND ADJUSTMENT 7.Tighten: Bolt 1 (engine mounting - rear lower) Bolt 2 (engine mounting - rear upper) Bolt 3 (engine mounting - front) Bolts 4 (engine mounting - top) Pivot shafts 5 (swingarm) Locknut (pivot shaft - right) Bolt 6 (rear shock absorber - top) Bolt (engine mounting - rear lower):...
  • Page 173 ENGINE ASSEMBLY AND ADJUSTMENT 11.Install: Spring 1 Footrest 2 (right) Bolt (footrest): 65 Nm (6.5 m • kg, 47 ft • lb) 12.Install: Front fender stay 1 Sift pedal 2 Footrest 3 (left) Bolt (shift pedal): 10 Nm (1.0 m • kg, 7.2 ft • lb) Bolt (footrest): 65 Nm (6.5 m •...
  • Page 174 ENGINE ASSEMBLY AND ADJUSTMENT 17.Install: Carburetor 1 Refer to “CARBURETOR” section in the CHAPTER 5. Hose clamp: 2 Nm (0.2 m • kg, 1.4 ft • lb) 18.Install: Exhaust pipe 1 Muffler 2 Bolt (muffler): 34 Nm (3.4 m • kg, 25 ft • lb) Bolt (muffler and exhaust pipe): 20 Nm (2.0 m •...
  • Page 175 ENGINE ASSEMBLY AND ADJUSTMENT 22.Install: Rear fender Rear carrier Front fender Front bumper Front carrier Fuel tank Seat Refer to the “FENDERS AND FUEL TANK- Installation” section in CHAPTER 3. 23.Inspect: Oil leakage 24.Check: “NEUTRAL” indicator light operation “REVERSE” indicator light operation Poor operation →...
  • Page 176 4 - 78...

  • Page 177: Chapter 5. Carburetion

    CARB CARBURETOR CARBURETION CARBURETOR 1 Vacuum chamber cover A Main jet SPECIFICATIONS 2 Spring B Needle valve set ID MARK 4XE1 00 3 Jet needle set C Throttle stop screw MAIN JET (M.J.) 4 Piston valve D Float pin PILOT JET (P.J.) #42.5 5 Pilot air jet E Float...

  • Page 178: Removal

    CARB CARBURETOR REMOVAL 1.Turn the fuel cock lever to “OFF”. 2.Remove: Air vent hose 1 Overflow hose 2 Fuel hose 3 3.Loosen: Clamp screws 4 4.Remove: Carburetor assembly 5.Remove: Throttle valve cover 1 6.Remove: Throttle cable end 1 7.Loosen: Throttle cable adjusting nut 1 8.Remove: Throttle cable 2 DISASSEMBLY...
  • Page 179 CARB CARBURETOR 2.Remove: Pilot air jet 1 3.Remove: Float chamber 1 O-ring 2 4.Remove: Float pin 1 Float 2 Needle valve 3 NOTE: Remove the float pin in the direction of the arrow. 5.Remove: Throttle stop screw 1 Valve seat 2 Main jet 3 Pilot jet 4 Pilot screw set 5...

  • Page 180: Inspection

    CARB CARBURETOR 7.Remove: Cover (coasting enricher) 1 Spring 2 Diaphragm 3 8.Remove: Starter plunger 1 INSPECTION 1.Inspect: Carburetor body Starter jet 1 Float chamber Cracks/damage → Replace. Fuel passage Contamination → Clean as indicated. Fuel chamber body Contamination → Clean. ********************************* Cleaning steps: Wash the carburetor in a petroleum based...
  • Page 181 CARB CARBURETOR 3.Inspect: Float 1 Float tang 2 Damage → Replace. 4.Inspect: Main jet 1 Needle jet 2 Pilot jet 3 Pilot air jet 4 Wear/damage → Replace. Contamination → Blow out the jets with compressed air. 5.Inspect: Spring 1 Spring seat 2 Jet needle set 3 Piston valve 4...
  • Page 182 CARB CARBURETOR 8.Inspect: Throttle stop screw 1 Pilot screw 2 Contamination/wear → Replace. O-ring 3 Damage → Replace. 9.Check: Free movement (piston valve) Sticks → Replace. Insert the piston valve into the carburetor body, and check for free movement. 10.Check: Free movement (throttle valve) Sticks →...
  • Page 183 CARB CARBURETOR 3.Install: O-ring Washer Spring Pilot screw Pilot screw: 2 turns out 4.Install: Needle valve 1 Float 2 Float pin 3 NOTE: Install the float pin in the direction of the arrow. 5.Measure: Float height a Out of specification → Adjust. Float height (F.H.): 12 ~ 14 mm (0.47 ~ 0.55 in) *********************************...

  • Page 184: Installation

    CARB CARBURETOR 6.Install: Piston valve 1 NOTE: Match the tab on the rubber diaphragm to the matching recess in the carburetor body. INSTALLATION Reverse the “REMOVAL” procedure. Note the following points. 1.Install: Carburetor assembly Clamp screw: 2 Nm (0.2 m • kg, 1.4 ft • lb) 2.Adjust: Idle speed Refer to “IDLE SPEED ADJUSTMENT”...

  • Page 185: Fuel Level Adjustment

    CARB CARBURETOR FUEL LEVEL ADJUSTMENT 1.Measure: Fuel level a Out of specification → Adjust. Fuel level: 1.0 ~ 2.0 mm (0.04 ~ 0.08 in) Above the float chamber mat- ing surface ********************************* Fuel level measurement and adjustment steps: Place the machine on a level surface. Connect the fuel level gauge 1 to the drain pipe 2.
  • Page 186 CARB 5 - 10...

  • Page 187: Chapter 6. Drive Train

    DRIV MIDDLE GEAR SERVICE DRIVE TRAIN MIDDLE GEAR SERVICE MIDDLE GEAR 1 Universal joint A Reverse gear K O-ring 2 Bearing retainer 1 B Dog clutch L Lever 3 Bearing C Middle driven shaft M Shift lever shaft 4 Shims D Driven pinion gear N Circlip 5 Bearing housing...

  • Page 188: Middle Gear Shims

    DRIV MIDDLE GEAR SERVICE MIDDLE GEAR SHIMS When the crankcase assembly and/or the middle gear comp., etc. are replaced, be sure to adjust the middle gear shim(s). Refer to the “MIDDLE GEAR SHIM SELECTION” and “MIDDLE GEAR LASH ADJUSTMENT” section. 1 Drive pinion gear 2 Driven pinion gear (forward gear) 3 Reverse gear...

  • Page 189: Removal

    DRIV MIDDLE GEAR SERVICE REMOVAL NOTE: It is necessary to remove the rear wheel drive assembly and/or engine assembly in order to service the middle gear, refer to the “ENGINE OVERHAUL” section in CHAPTER 1.Drain: Engine oil Refer to the “ENGINE OIL REPLACE- MENT”...
  • Page 190 DRIV MIDDLE GEAR SERVICE 2.Remove: Bolts 1 (middle gear case cover) Middle gear case cover 2 Dowel pins 3.Remove: Middle driven shaft assembly 1 Bearing 2 Shim 3 Driven pinion gear 4 Middle drive axle 1.Remove: Nut 1 (middle drive pinion gear) Middle drive pinion gear 2 NOTE: Flatten the punched portion of the middle...

  • Page 191: Disassembly

    DRIV MIDDLE GEAR SERVICE 3.Remove: Bearing retainers 1 Use a #40 Torx Driver. 4.Remove: Bearing 1 Shim 2 DISASSEMBLY Middle driven shaft 1.Remove: Universal joint ********************************* Removal steps: Remove the circlips 1. Place the U-joint in a press. With a suitable diameter pipe beneath the yoke, press the bearing into the pipe as shown.
  • Page 192 DRIV MIDDLE GEAR SERVICE Universal joint holder: P/N. YM-04062, 90890-04062 Attachment: P/N. YM33291, 90890-04096 3.Remove: Middle driven shaft 1 Dog clutch 2 4.Remove: Bearing retainer 1 NOTE: Use a Bearing retainer wrench 2. Bearing retainer wrench 32 mm (1.26 in): P/N.

  • Page 193: Inspection

    DRIV MIDDLE GEAR SERVICE 6.Remove: Bearing retainer 1 NOTE: Use a Ring nut wrench 2. Ring nut wrench: P/N. YM-1391, 90890-01391 Bearing 3 Shift lever 1.Remove: Shift fork guide bar 1 Shift fork 2 Ball 3 Spring 4 NOTE: When removing the shift fork guide bar, the ball will fall off.
  • Page 194 DRIV MIDDLE GEAR SERVICE 3.Check: Universal joints 1 Yoke 2 Bearings 3 Wear/Cracks/Damage → Replace. 4.Inspect: Shift fork 4 1 On the dog clutch and shift lever contact surfaces. Wear/Chafing/Bends/Damage → Replace. Spring 2 Wear/Damage → Replace. Ball (stopper) 3 Wear/Damage/Scratches →...

  • Page 195: Middle Gear Shim Selection

    DRIV MIDDLE GEAR SERVICE 8.Inspect: Bearing housing 1 Cracks/Damage → Replace bearing hous- ing assembly. O-ring 2 Wear/Damage → Replace. NOTE: When the bearing housing assembly is replaced, be sure to adjust the middle gear shim(s), refer to the “MIDDLE GEAR SHIM SELECTION”...
  • Page 196 DRIV MIDDLE GEAR SERVICE Shim location Å = Drive pinion gear shim ı = Driven pinion gear shim Ç = Reverse gear shim Î = Middle driven shaft shim 1 Drive pinion gear 2 Driven pinion gear 3 Reverse gear 4 Middle driven shaft Replaced parts Adjust shim...
  • Page 197 DRIV MIDDLE GEAR SERVICE ********************************* Middle gear shims selection steps: Shim selection Å When the crankcase and/or the drive pin- ion gear are replaced, be sure to adjust the drive pinion gear shim Å. To find drive pinion gear shim thickness “A”...
  • Page 198 DRIV MIDDLE GEAR SERVICE In the example above, the calculated shim thickness is 0.57 mm. The chart instructs you, however, to round off the 7 to 5, then shim thickness is 0.55 mm. Shim selection ı When the crankcase and/or the driven pin- ion gear are replaced, be sure to adjust the driven pinion gear shim ı.
  • Page 199 DRIV MIDDLE GEAR SERVICE Hundredths Round value 0, 1 2, 3 4, 5, 6 7, 8 In the example above, the calculated shim thickness is 0.95 mm. The chart instructs you, however, to round off the 5 to 5, then shim thickness is 0.95 mm.
  • Page 200 DRIV MIDDLE GEAR SERVICE Reverse gear shim 0.15 0.40 Thickness (mm) 0.20 0.50 0.30 Because shims can only be selected in 0.05 mm increments, round off hundredths digit and select appropriate shim(s). Hundredths Round value 0, 1 2, 3 4, 5, 6 7, 8 In the example above, the calculated shim thickness is 0.51 mm.
  • Page 201 DRIV MIDDLE GEAR SERVICE Example: 1) If the bearing hauging is stamped “–03”..j = 1 – 0.03 = 0.97 2) If the crankcase is stamped “45” ..c = 110 + 0.45 = 110.45 3) If the pinion gear is stamped “–02” ..

  • Page 202: Assembly

    DRIV MIDDLE GEAR SERVICE ASSEMBLY Reverse the “DISASSEMBLY” procedures. Note the following points. Middle driven shaft 1.Apply: Lithium base grease To the oil seal and O-ring. 2.Install: Shift lever shaft 1 Shift lever 2 Stopper shaft 3 Circlip 4 3.Install: Spring 1 (to shift fork 4) Ball 2 NOTE:...
  • Page 203 DRIV MIDDLE GEAR SERVICE 6.Install: Bearing 1 (to bearing housing) Bearing retainer 2 NOTE: Use a Ring nut wrench 3. Ring nut wrench: P/N. YM-1391, 90890-01391 7.Tighten: Bearing retainer Bearing retainer: 60 Nm (6.0 m • kg, 43 ft • lb) 8.Install: Shim(s) 1 Reverse gear 2...
  • Page 204 DRIV MIDDLE GEAR SERVICE 11.Tighten: Bearing retainer Bearing retainer: 60 Nm (6.0 m • kg, 43 ft • lb) ® Use LOCTITE 12.Install: Middle driven shaft 1 Dog clutch 2 13.Install: U-joint 1 Washer 2 Nut 3 (U-joint) NOTE: Hold the U-joint 1 by the Universal Joint Holder 4 and Attachment 5, and tighten the U-joint securing nut to specification.
  • Page 205 DRIV MIDDLE GEAR SERVICE 14.Install Universal joint ********************************* Installation steps: Install the opposite yoke into the U-joint. Apply the “Wheel bearing grease” to the bearings. Install the bearing 1 onto the yoke. CAUTION: Check each bearing. The needles can easily fall out of their races.
  • Page 206 DRIV MIDDLE GEAR SERVICE 3.Install: Middle drive axle assembly 1 Refer to the “ENGINE ASSEMBLY AND ADJUSTMENT-CRANK SHAFT, TRANS- MISSION AND BALANCER SHAFT” sec- tion in CHAPTER 4. 4.Install: Middle drive pinion gear 1 Nut 2 Nut (middle drive pinion gear): 60 Nm (6.0 m •...

  • Page 207: Middle Gear Lash Adjustment

    MIDDLE GEAR SERVICE 2.Apply: Sealant 1 To the mating surface of both case halves. ® Sealant (Quick Gasket) P/N. ACC-QUICK-GS-KT Yamaha bond No. 1215 P/N. 90890-85505 3.Install: Dowel pins Middle gear case cover 2 NOTE: Before installing the middle gear case cover onto the crankcase, shift the gear into “FORWARD”.

  • Page 208: Installation

    DRIV MIDDLE GEAR SERVICE 2.Shift: Drive select lever For forward drive. 3.Measure: Gear lash Gently rotate the middle drive axle from engagement to engagement. Over specified limit → Repair. Middle driven gear lash: (using measurement tool): 0.1 ~ 0.2 mm (0.004 ~ 0.008 in) NOTE: Measure the gear lash at 4 positions.
  • Page 209 DRIV MIDDLE GEAR SERVICE 2.Install: Rear wheel drive assembly and swingarm Refer to “REMOUNTING ENGINE” section in the CHAPTER 4. 3.Adjust: Rear brake Refer to “REAR BRAKE LEVER AND PEDAL ADJUSTMENT” section in the CHAPTER 3. 4.Install: Rear fender Rear carrier Front fender Front bumper Front carrier...

  • Page 210: Final Drive Gear And Drive Shaft

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT FINAL DRIVE GEAR AND DRIVE SHAFT 1 Bearing housing 8 Bearing E O-ring 2 O-ring 9 Oil seal F Oil seal 3 Oil seal 0 Bearing G Collar 4 Bearing A Drive pinion gear H Drive shaft 5 Ring gear shim B Final drive gear shim...

  • Page 211: Troubleshooting

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT TROUBLESHOOTING The following conditions may indicate damage drive train components: Symptoms Possible causes 1.A pronounced hesitation or “jerky” move- ment during acceleration, deceleration, or A. Bearing damage. sustained speed. (this must not be con- fused with engine surging or transmission B.
  • Page 212 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT Inspection notes 1.Investigate any unusual noises ********************************* The following “Noises” may indicate a machanical problem: A “rolling rumble” noise during coasting, acceleration, or deceleration. The noise increases with rear wheel speed, but it does not increase with higher engine or transmission speeds.
  • Page 213 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 3.Inspect: Oil leakage By the following inspection steps. ********************************* Oil leakage inspection steps: Clean the entire machine thoroughly, then dry it. Apply a leak-localizing compound or dry powder spray to the shaft drive. Road test the machine long enough to locate the leak.

  • Page 214: Removal

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT REMOVAL WARNING Securely support the machine so there is no danger of it falling over. 1.Drain: Final gear oil Refer to the “FINAL GEAR OIL REPLACE- MENT” section in CHAPTER 3. 2.Remove: Seat Rear carrier Rear fender Refer to the “FENDERS AND FUEL TANK-...

  • Page 215: Disassembly

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT NOTE: When the final gear case until is removed from the swingarm, the drive shaft 3 may fall off. Be careful not to lose these parts. DISASSEMBLY 1.Remove: Bolts 1 (8 mm) Bolts 2 (10 mm) NOTE: Working in a crisscross pattern, loosen bolt 1/4 turn each.
  • Page 216 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 3.Remove: Bearing retainer (drive shaft - final) NOTE: Final-drive-shaft-bearing-retainer has left- hand threads. Turn retainer clockwise to loosen it. NOTE: When remounting the bearing retainer, use the Bearing Retainer Wrench 1. Bearing retainer wrench: P/N.

  • Page 217: Inspection

    2.Inspect: Bearings 4 Damage → Replace. NOTE: Reuse of roller bearing OK, but Yamaha recommends installation of new bearing. Do not reuse the oil seal. When the final drive pinion gear and/or ring gear are replaced, be sure to adjust the shim of the final drive pinion gear and/ or ring gear, refer to the “FINAL DRIVE...

  • Page 218: Final Drive Pinion Gear And Ring Gear Shim Selection

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 4.Inspect: Final gear case 1 Bearing housing 2 (ring gear) Cracks/Damage → Replace. NOTE: When the final gear case and/or ring gear bearing housing are replaced, be sure to adjust the shim of the final drive pinion gear and/or ring gear, refer to the “FINAL DRIVE GEAR AND RING GEAR SHIM SELECTION”...
  • Page 219 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT Example: 1) If the “+01” is stamped on the final drive pinion gear, a = 79 + 0.01 = 79.01 2) If the “50” is stamped on the final gear case, b = 78 + 0.50 = 78.50 3) Therefore, “A”...
  • Page 220 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT ********************************* Shim selection steps: To find ring gear shim thickness “B”, use the following formula. Ring gear shim thickness: “B” = c + d – (e + f) c= The stamped number on the final gear case is either added to or subtracted from “42”.

  • Page 221: Assembly

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT ASSEMBLY Reverse the “DISASSEMBLY” procedures. Note the following points. 1.Install: Roller bearing (drive pinion gear) ********************************* Installation steps: Heat the main housing only to 150˚C (302˚F) Install the roller bearing outer race using the proper adapted.
  • Page 222 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT Thrust washer selection 1.Measure/Select: Ring gear thrust clearance “C” ********************************* Thrust clearance measurement steps: ® Place four pieces of Plastigauge between originally fitted thrust washer and ring gear. Install the ring gear assembly and tighten the bolts to specification.

  • Page 223: Final Gear Gear Lash Measurement And Adjustment

    DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 2.Install: Thrust washer 1 Ring gear 2 Shim(s) 3 (proper size as calculated) Bearing housing 4 NOTE: Before installing the ring gear, apply the grease to the oil seal rips. Before installing the bearing housing, apply the grease to the O-ring.
  • Page 224 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 4.Attach: Gear lash measurement tool 1 Dial gauge 2 Gear lash measurement tool: P/N. YM-01231, 90890-01231 Dial gauge: P/N. YU-03097, 90890-03097 a Measuring point 5.Measure: Gear lash Gently rotate the gear coupling from engagement to engagement.
  • Page 225 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 3.Adjust: Gear lash ********************************* Gear lash adjustment steps: Select the suitable shims and thrust washer by the following chart. Too-little gear lash → Reduce shim thickness. Too-large gear lash → Increase shim thickness. To add or reduce ring gear shim thickness Increase by more...

  • Page 226: Installation

    Lightweight lithium - soap base grease 2.Apply: Sealant 2 (to matching surfaces of swingarm 3 and final gear case 4) ® Sealant (Quick Gasket P/N. ACC-QUICK-GS-KT ® Yamaha Bond No. 1215 P/N. 90890-85505 3.Install: Drive shaft 1 (to universal joint) 6 - 40...
  • Page 227 DRIV FINAL DRIVE GEAR AND DRIVE SHAFT 4.Install: Final gear case unit 1 NOTE: Before installing the final gear case unit, apply the grease to the O-ring Bolt (final gear case – axle hous- ing) 3: 55 Nm (5.5 m • kg, 40 ft • lb) Nut (final gear case –...
  • Page 228 DRIV 6 - 42...

  • Page 229: Chapter 7. Chassis

    CHAS FRONT WHEELS AND FRONT BRAKE CHASSIS FRONT WHEELS AND FRONT BRAKE TIRE AIR PRESSURE 1 Brake camshaft lever 0 Bearing spacer 2 Wear indicator plate A Front brake drum Cold Tire Pressure Front Rear 3 Brake shoe plate B Oil seal 20 kPa 25 kPa 4 Brake shoe plate seal...

  • Page 230: Removal

    CHAS FRONT WHEELS AND FRONT BRAKE REMOVAL Front wheels 1.Place the machine on a level place. 2.Loosen: Nuts (front wheel) Apply the parking brake 1 . 3.Elevate the front wheels by placing the suitable stand under the frame. WARNING Securely support the machine there is no danger of falling over.

  • Page 231: Inspection

    CHAS FRONT WHEELS AND FRONT BRAKE 9.Remove: Brake camshaft lever 1 Wear indicator plate 2 Brake camshaft 3 Brake camshaft holder 4 Pivot pin 5 Brake shoe plate 6 INSPECTION 1.Inspect: Wheel Refer to the “WHEEL INSPECTION” sec- tion in CHAPTER 3. 2.Measure: Wheel runout Over specified limit →...
  • Page 232 CHAS FRONT WHEELS AND FRONT BRAKE 4.Inspect: Brake linings Glazed parts → Sand with coarse sandpa- per. 5.Measure: Brake lining thickness a Out of specification → Replace. Brake lining thickness: 4.0 mm (0.16 in) <Wear limit>: 2.0 mm (0.08 in) NOTE: Replace the brake shoes as a set (with shoe springs) if either is found to be worn to the...
  • Page 233 CHAS FRONT WHEELS AND FRONT BRAKE 9.Inspect: Bearings 1 (brake drum) Bearings allow play in the brake drum or the wheel tuns roughly → Replace. Oil seal 2 Wear/Damage → Replace. ********************************* Wheel bearing and oil seal replacement steps: Clean the outside of the brake drum. Remove the oil seal 1 use a flat-head screw driver.

  • Page 234: Installation

    CHAS FRONT WHEELS AND FRONT BRAKE INSTALLATION Reverse the “REMOVAL” procedure. Note the following points. 1.Lubricate: Oil seal lips 1 Bearings 2 Camshaft 3 Pivot pin 4 O-ring 5 Lithium-soap base grease CAUTION: Install the camshaft and the pivot pin lightly greased.
  • Page 235 CHAS FRONT WHEELS AND FRONT BRAKE 4.Install: Brake shoes WARNING Do not apply grease to the brake shoe lin- ings. 5.Connect: Front brake breather hose Brake cable (to brake shoe plate) 6.Install: Circlip 1 Spring 2 Washer (C-type) 3 Spring 4 Pin 5 Adjuster 6 7.Install:...
  • Page 236 CHAS FRONT WHEELS AND FRONT BRAKE 9.Install: Front wheel Nut (front wheel): 55 Nm (5.5 m • kg, 40 ft • lb) NOTE: Arrow mark 1 on the tire must point toward the rotating direction Å of the wheel. 10.Adjust: Front brake cable free play Refer to the “FRONT BRAKE ADJUST- MENT”...

  • Page 237: Rear Wheels/Rear Brake And Rear Axle

    CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE REAR WHEELS/REAR BRAKE AND REAR AXLE 1 Rear axle 2 Bearing 3 Oil seal 4 Wheel hub 5 Axle nut × A TIRE SIZE: AT22 10-10 × RIM SIZE: 8 WHEEL RUNOUT LIMIT: VERTICAL: 2.0 mm (0.08 in) TIRE WEAR LIMIT: 2.0 mm (0.08 in)
  • Page 238 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 1 Brake drum * Yamaha brake grease 2 Brake shoe 3 Bearing retainer 4 Brake shoe plate seal 5 Rear brake breather hose 6 Brake shoe plate 7 Brake camshaft 8 Wear indicator plate...

  • Page 239: Removal

    CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE REMOVAL 1.Place the machine on a level place. 2.Loosen: Nuts (rear wheel) Apply the parking brake 1. 3.Block the front wheels, and elevate the rear wheels by placing the suitable stand under the frame. WARNING Securely support the machine there is no danger of falling over.
  • Page 240 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 8.Remove: Adjusters 1 (brake lever and brake pedal) Pins Springs 9.Disconnect: Brake cable 2 Brake rod 3 Rear brake breather hose 4 10.Remove: Bearing retainer 1 Brake shoe plate assembly 2 11.Remove: Spring 1 Brake camshaft lever 2 Wear indicator plate 3 Brake camshaft 4...

  • Page 241: Inspection

    CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE INSPECTION 1.Inspect: Wheel Refer to the “WHEEL INSPECTION” sec- tion in CHAPTER 3. 2.Measure: Wheel runout Tire surfaces Refer to the “FRONT WHEEL AND FRONT BRAKE-INSPECTION” section. 3.Inspect: Wheel hub 1 Cracks/Damage → Replace. Splines 2 (wheel hub) Wear/Damage →...
  • Page 242 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 8.Inspect: Brake drum inner surface 1 Oil/Scratches → Remove. Use a rag soaked in lacquer thinner or a solvent. Use a emery cloth (lightly Scratches and evenly polishing). Spline 2 Wear/Damage → Replace. 9.Inspect: Brake shoe plate 1 Cracks/Bends/Damage →...
  • Page 243 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 13.Measure: Rear axle runout a Out of specification → Replace. Rear axle runout limit: 1.5 mm (0.06 in) WARNING Do not attempt to straighten a bent axle. 14.Inspect: Bearing 1 (rear axle) Bearing allow play in the axle hub or the bearing turns roughly →...

  • Page 244: Installation

    CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE INSTALLATION Reverse the “REMOVAL” procedures. Note the following points. 1.Lubricate: Oil seal lip 1 (rear axle) Bearings 2 (rear axle) Axle spline (rear axle) Lithium-soap base grease 2.Install: Rear axle 1 NOTE: Before installing the rear axle, loosen all the bolts on the final gear case 2.
  • Page 245 6.Apply: Sealant (to matching surface of brake shoe plate and swingarm) ® Sealant (Quick Gasket P/N. ACC-QUICK-GS-KT Yamaha bond No. 1215 P/N. 90890-85505 7.Install: Brake shoe plate assembly 1 Bearing retainer 2 NOTE: The brake shoe plate should be installed with the drain bolt 3 downward.
  • Page 246 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 8.Install: Brake shoes 9.Lubricate: Dust seal 1 (backing plate) Yamaha brake grease P/N. 90793-40003 CAUTION: Do not apply grease to the brake shoe lin- ings. Brake drum spline Lithium-soap base grease CAUTION: Do not apply grease on the axle shaft spline, or the extra grease may contami- nate the brake shoes during running.
  • Page 247 CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE 16.Install: Cotter pin 1 NOTE: Do not loosen the axle nut after torque tightening. If the axle nut groove is not aligned with the cotter pin hole, align groove with the hole by tightening up on the axle nut.

  • Page 248: Steering System

    CHAS STEERING SYSTEM STEERING SYSTEM 1 Handlebar holder (upper) 0 Tie-rod 2 Handlebar holder (lower) 3 Steering shaft 4 Steering bearing 5 Oil seal 6 Collar 7 Cable guide 8 Lock washer 9 Rod end TOE-IN: 0 ~ 5 mm (0 ~ 0.39 in) 7 - 20...

  • Page 249: Removal

    CHAS STEERING SYSTEM REMOVAL Handlebar 1.Remove: Front carrier Front bumper Front fender Refer to “FENDERS AND FUEL TANK- FRONT FENDER-Removal” section CHAPTER 3. 2.Disconnect: Main switch lead “NEUTRAL” indicator light leads “REVERSE” indicator light leads Handlebar switch (left) leads Brake switch leads 3.Remove: Handle protector 1 4.Disconnect:...
  • Page 250 CHAS STEERING SYSTEM Steering shaft 1.Straighten: Lock washer tabs 1 2.Remove: Bolts 2 Lock washer 3 Cable guide 4 3.Remove: Clip (steering shaft) Washer 4.Remove: Cotter pins Nuts Tie-rods 1 NOTE: When removing the rod ends from the steering shaft and knuckle arm, use a Gen- eral Bearing Puller.

  • Page 251: Inspection

    CHAS STEERING SYSTEM INSPECTION 1.Inspect: Handlebar Cracks/Bends/Damage → Replace. 2.Inspect: Steering shaft Bends/Damage → Replace. WARNING Do not attempt to straighten a bent shaft; this may dangerously weaken the shaft. 3.Inspect: Steering bearings 1 Oil seals 2 Wear/Damage → Replace. 4.Inspect: Tie-rod 1 Bend/Damage →...

  • Page 252: Installation

    CHAS STEERING SYSTEM 6.Adjust: Tie-rod assembly length ********************************* Tie-rod assembly length adjustment steps: Loosen the locknuts. Adjust the tie-rod assembly length a by turning both tie-rod ends. Tie-rod assembly length a: 296 mm (11.7 in) Å Right-hand-threads ı Left-hand-threads Ç To steering shaft Î...
  • Page 253 CHAS STEERING SYSTEM 2.Lubricate: Steering bearings 1 Oil seals 2 Lithium-soap base grease 3.Install: Oil seals 1 (to steering shaft) Collars 2 Steering bearings 3 NOTE: Be careful not to damage the oil seals dur- ing installation. 4.Install: Steering shaft 1 (with steering bearings) WARNING Make sure the brake cables and leads are properly routed, and are not damaged or...
  • Page 254 CHAS STEERING SYSTEM 7.Install: Cotter pin 1 NOTE: Do not loosen the axle nut after torque tightening. If the axle nut groove is not aligned with the cotter pin hole, align groove with the hole by tightening up on the axle nut. WARNING Always use a new cotter pin.
  • Page 255 CHAS STEERING SYSTEM Handlebar 1.Install: Handlebar holder (lower) 1 Handlebar 2 Handlebar holders (upper) 3 NOTE: The upper handlebar holder should be installed with the punched mark a forward CAUTION: Tighten the handlebar bolts so that clear- ances b are spaced evenly. Handlebar holder (upper): 20 Nm (2.0 m •...

  • Page 256: Front Shock Absorber And Front Arm

    CHAS FRONT SHOCK ABSORBER AND FRONT ARM FRONT SHOCK ABSORBER AND FRONT ARM 1 Front shock absorber 2 Steering knuckle 3 Lower arm 4 Bushing 7 - 28...

  • Page 257: Removal

    CHAS FRONT SHOCK ABSORBER AND FRONT ARM REMOVAL 1.Remove: Front carrier Front bumper Front fender Refer to the “FENDERS AND FUEL TANK- FRONT FENDER - Removal” section in CHAPTER 3. Front wheel Brake drum Brake shoe plate Refer to “FRONT WHEELS AND FRONT BRAKE - Removal”...
  • Page 258 CHAS FRONT SHOCK ABSORBER AND FRONT ARM 7.Inspect: Lower arms free play ********************************* Inspection steps: Inspect the lower arm brackets 1 of the frame. If bent, cracked or damaged, repair or replace the frame. Check the tightening torque of the lower arm securing nuts 2.

  • Page 259: Inspection

    CHAS FRONT SHOCK ABSORBER AND FRONT ARM INSPECTION 1.Inspect: Shock absorber Oil leaks → Replace the shock absorber assembly. Ball joint Cracks/Damage → Replace the shock absorber assembly. Spring Fatigue/Damage → Replace the shock absorber assembly. Move the spring up and down. 2.Inspect: Steering knuckle Cracks/Pitting/Damage →...

  • Page 260: Installation

    CHAS FRONT SHOCK ABSORBER AND FRONT ARM INSTALLATION Reverse the “REMOVAL” procedures. Note the following points. 1.Lubricate: Bushings 1 (inner surface) Lithium-soap base grease 2.Tighten: Nut 2 (lower arm) Nut (lower arm): 45 Nm (4.5 m • kg, 32 ft • lb) NOTE: Be sure to position the front arm securing bolts (front 1 and rear 2) so that the bolt...
  • Page 261 CHAS FRONT SHOCK ABSORBER AND FRONT ARM 5.Install: Cotter pin 3 NOTE: Do not loosen the axle nut after torque tightening. If the axle nut groove is not aligned with the cotter pin hole, align groove with the hole by tightening up on the axle nut.
  • Page 262 CHAS FRONT SHOCK ABSORBER AND FRONT ARM NOTE: Do not loosen the axle nut after torque tightening. If the axle nut groove is not aligned with the cotter pin hole, align groove with the hole by tightening up on the axle nut. WARNING Always use a new cotter pin.

  • Page 263: Rear Shock Absorber And Swingarm

    CHAS REAR SHOCK ABSORBER AND SWINGARM REAR SHOCK ABSORBER AND SWINGARM 1 Rear shock absorber 8 Swingarm 2 Thrust cover 9 Rubber boot 3 Locknut 0 Final gear case protector 4 Pivot shaft 5 Collar 6 Oil seal 7 Taper roller bearing SWINGARM FREE PLAY LIMIT: SIDE”...

  • Page 264: Removal

    CHAS REAR SHOCK ABSORBER AND SWINGARM REMOVAL 1.Remove: Rear wheel (left) Wheel hub Rear wheel (right) Brake drum Brake shoe plate Rear axle Refer to the “REAR WHEEL/REAR BRAKE AND REAR AXLE - REMOVAL” section. 2.Remove: Final gear case protector 1 3.Remove: Final gear case unit 1 Refer to the “FINAL DRIVE GEAR AN...
  • Page 265 CHAS REAR SHOCK ABSORBER AND SWINGARM 5.Remove: Nut 1 (shock absorber - upper) Bolt 2 Shock absorber 3 6.Remove: Spring (rear brake pedal) 1 7.Remove: Caps (pivot shaft) 8.Inspect: Swingarm free play ********************************* Free play inspection steps: Check the tightening torque of the pivot shafts 1 and locknut 2 (right side of pivot shaft).

  • Page 266: Inspection

    CHAS REAR SHOCK ABSORBER AND SWINGARM 9.Remove: Rear axle housing 1 10.Remove: Clamp 1 (rubber boot) Locknut (right side of pivot shaft) Pivot shaft (swingarm) 11.Remove: Swingarm 1 INSPECTION 1.Inspect: Shock absorber Oil leaks → Replace the shock absorber assembly. Shock absorber rod Bends/Damage →...
  • Page 267 CHAS REAR SHOCK ABSORBER AND SWINGARM 2.Inspect: Swingarm Cracks/Bends/Damage → Replace. Axle housing Cracks/Bends/Damage → Replace. 3.Inspect: Final gear case under cover Cracks/Bends/Damage → Replace. 4.Inspect: Pivot shaft 1 (right side) Pivot shaft 2 (left side) Spacer collar 3 Wear/Damage → Replace. 5.Inspect: Bearings 1 (swingarm) Bearings allow play in the swingarm or to...

  • Page 268: Installation

    CHAS REAR SHOCK ABSORBER AND SWINGARM Remove the bearings 3 using a general bearing puller. Install the new bearings and oil seal by reversing the previous steps. NOTE: Use a socket 4 that matches the outside diameter of the race of the bearing and oil seal.
  • Page 269 CHAS REAR SHOCK ABSORBER AND SWINGARM 3.Tighten: Pivot shafts (swingarm) Locknut (pivot shaft) ********************************* Pivot shaft tightening steps: Tighten the pivot shaft 1 (left) to specifi- cation. Pivot shaft (left): 130 Nm (13.0 m • kg, 94 ft • lb) Tighten the pivot shaft 2 (right) until it contacts the collar 3.
  • Page 270 CHAS REAR SHOCK ABSORBER AND SWINGARM 7.Install: Clip 8.Install: Final gear assembly 1 Refer to the “FINAL DRIVE GEAR AND DRIVE SHAFT - ASSEMBLY - INSTALLA- TION” section in CHAPTER 6. 9.Install: Rear axle Brake shoe plate Brake drum Rear wheel (right) Wheel hub (left) Rear wheel (left) Refer to the “REAR WHEEL/REAR BRAKE...

  • Page 271: Electrical

    – ELEC ELECTRICAL COMPONENTS EB800000 ELECTRICAL ELECTRICAL COMPONENTS 8 Reverse switch 1 Wire harness 9 Neutral switch 2 Fuses 0 Spark plug cap 3 Starter relay A Ignition coil 4 Starting circuit cut-off relay B Main switch 5 Battery C Neutral indicator light 6 CDI unit D Reverse indicator light 7 Rectifier/regulator...

  • Page 272: Switch Inspection

    – ELEC SWITCH INSPECTION SWITCH INSPECTION SWITCH INSPECTION Use a pocket tester to check the terminals for continuity. If the continuity is faulty at any point, replace the switch. Pocket tester: P/N. YU-03112, 90890-03112 NOTE: Set the pocket tester to “0” before starting the test.

  • Page 273: Switch Continuity Inspection

    – ELEC SWITCH INSPECTION 8 - 3...
  • Page 274 – ELEC SWITCH INSPECTION SWITCH CONTINUITY INSPECTION Refer to “SWITCH INSPECTION” and check for continuity between lead terminals. Poor connection, no continuity → Correct or replace. The coupler locations are circled. 8 - 4...
  • Page 275 – ELEC SWITCH INSPECTION 1 Lights switch 2 Lights switch (for New Hampshire and Maine) 3 Engine stop switch 4 Starter switch 5 Main switch 6 Rear brake lever switch 7 Rear brake lever switch (for New Hampshire and Maine) 8 Front brake lever switch (for New Hampshire and Maine) 9 Rear brake pedal switch (for New Hampshire and Maine) 0 Reverse switch...

  • Page 276: Checking Of Bulbs (For Headlight)

    – ELEC CHECKING OF BULBS CHECKING OF BULBS (FOR HEADLIGHT) CHECKING BULBS CONDITION 1.Remove the bulb. CAUTION: ACHTUNG: Be sure to hold the socket firmly when removing the bulb. Never pull the lead. Otherwise, the lead may be pulled off the terminal in the coupler.

  • Page 277: Ignition System

    – ELEC IGNITION SYSTEM EB802000 IGNITION SYSTEM CIRCUIT DIAGRAM 8 - 7...

  • Page 278: Troubleshooting

    – ELEC IGNITION SYSTEM EB802010 TROUBLESHOOTING IF THE IGNITION SYSTEM FAILS TO OPERATE (NO SPARK OR INTERMITTENT SPARK): Procedure Check: 6.Main switch 1.Spark plugs 7.Pickup coil resistance 2.Ignition spark gap 8.Source coil resistance 3.Spark plug cap resistance 9.Wiring connection 4.Ignition coil resistance (the entire ignition system) 5.Engine stop switch NOTE:...
  • Page 279 – ELEC IGNITION SYSTEM for EUR/AUS 2.Ignition spark gap Disconnect the spark plug cap from the spark plug. Connect the ignition checker 1 as shown. 2 Spark plug cap Turn the main switch to “ON”. Check the ignition spark gap a. Crank the engine by pushing the starter switch and increase the spark gap until a misfire occurs.
  • Page 280 – ELEC IGNITION SYSTEM C0NTINUITY Tester (+) lead → Orange lead terminal 4.Ignition coil resistance Tester (–) lead → Ignition coil base Disconnect the ignition coil connector from the wire harness. Connect the pocket tester (Ω × 1) to the ignition coil.
  • Page 281 – ELEC IGNITION SYSTEM C0NTINUITY 7.Pickup coil resistance Disconnect the CDI magneto coupler from the wire harness. Connect the pocket tester (Ω × 100) to the pickup coil terminal. Br W/G Tester (+) lead → White/Green terminal 1 Tester (–) lead → White/Red terminal 2 Check the pickup coil for the specified OUT OF SPECIFICATION resistance.

  • Page 282: Electric Starting System

    – ELEC ELECTRIC STARTING SYSTEM EB803000 ELECTRIC STARTING SYSTEM CIRCUIT DIAGRAM 8 - 12...

  • Page 283: Starting Circuit Operation

    – ELEC ELECTRIC STARTING SYSTEM STARTING CIRCUIT OPERATION The starting circuit on this model consists of the starter motor, starter relay, starting circuit cut-off relay, rear brake lever switch, and neutral switch. If the main switch is on position, the starter motor can be operated only if: The transmission is in neutral (the neu- tral switch is closed).

  • Page 284: Troubleshooting

    – ELEC ELECTRIC STARTING SYSTEM EB803020 TROUBLESHOOTING IF THE STARTER MOTOR FAILS TO OPERATE: Procedure Check: 7.Neutral switch 1.Fuse (main) 8.Rear brake lever switch 2.Battery 9.Start switch 3.Starter motor 10.Wiring connection 4.Starting circuit cut-off relay (the entire starting system) 5.Starter relay 6.Main switch NOTE: Pocket tester:...
  • Page 285 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY WARNING 3.Starter motor A wire that is used as a jumper lead must Connect the battery positive terminal 1 have the equivalent capacity or more as and starter motor cable 2 using a that of the battery lead, otherwise the jumper lead 3 jumper lead may burn.
  • Page 286 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY 5.Starter relay Remove the starter relay from the wire harness. Connect the pocket tester (Ω × 1) and the battery (12 V) to the starter relay termi- nals. Battery (+) terminal → Blue/White terminal 1 NO CONTINUITY Battery (–) terminal →...
  • Page 287 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY 8.Rear brake lever switch INCORRECT Refer to “SWITCH INSPECTION”. CORRECT Replace the rear brake lever switch. INCORRECT 9.Start switch Refer to “SWITCH INSPECTION”. CORRECT Replace the handlebar switch (left). EB803028 POOR CONNECTION 10.Wiring connection Check the connections of the entire start- ing system.

  • Page 288: Starter Motor Inspection

    – ELEC ELECTRIC STARTING SYSTEM STARTER MOTOR Order Job name/Part name Q’ty Remarks Starter motor removal Remove the parts in the order below. Starter motor lead Starter motor bracket Starter motor / O-ring Starter motor disassembly Disassemble the parts in the order below.

  • Page 289: Starter Motor Assembly

    – ELEC ELECTRIC STARTING SYSTEM STARTER MOTOR INSPECTION 1.Inspect: Commutator Dirty → Clean it with #600 grit sandpaper. 2.Measure: Commutator diameter a Out of specification → Replace the starter motor. Outside diameter: 28 mm (1.10 in) <Wear limit:> 27 mm (1.06 in) 3.Measure: Mica undercut b Out of specification →...
  • Page 290 – ELEC ELECTRIC STARTING SYSTEM 5.Measure: Brush length a (each) Out of specification → Replace the brush. Brush length: 10 mm (0.39 in) <Wear limit:> 3.5 mm (0.14 in) 6.Measure: Brush spring force Fatigue/out of specification → Replace as a set. Brush spring force: 730 ~ 970 g (7.16 ~ 9.52 N) 7.Inspect:...

  • Page 291: Charging System

    – ELEC CHARGING SYSTEM EB804000 CHARGING SYSTEM CIRCUIT DIAGRAM (GLAY) (BLA Å Br/W Br/W 2 Battery 3 Main fuse 6 Rectifier/regulator 7 CDI magneto 8 - 21...

  • Page 292: Troubleshooting

    – ELEC CHARGING SYSTEM EB804010 TROUBLESHOOTING IF THE BATTERY IS NOT CHARGED: Procedure Check: 1.Fuse (main) 4.Stator coil resistance 2.Battery 5.Wiring connections 3.Charging voltage (the entire charging system) NOTE: Inductive tachometer: Remove the following part(s) before trou- P/N. YU-8036-A bleshooting: Engine tachometer: 1)Seat P/N.
  • Page 293 – ELEC CHARGING SYSTEM Start the engine and accelerate to about 2,000 r/min. MEETS SPECIFICATION Charging voltage: 14 to 15 V at 2,000 r/min NOTE: Use a fully charged battery. The charging circuit is not faulty. OUT OF SPECIFICATION EB804012 4.Stator coil resistance Disconnect the AC magneto coupler from the wire harness.

  • Page 294: Lighting System

    – ELEC LIGHTING SYSTEM EB805000 LIGHTING SYSTEM CIRCUIT DIAGRAM 8 - 24...

  • Page 295: Troubleshooting

    – ELEC LIGHTING SYSTEM EB805010 TROUBLESHOOTING IF THE HEADLIGHT AND/OR TAILLIGHT FAIL TO COME ON: Procedure Check: 4.Lights switch 1.Fuse (main) 5.Wiring connections 2.Battery (the entire lighting system) 3.Main switch NOTE: Pocket tester: Remove the following part(s) before trou- P/N. YU-03112, 90890-03112 bleshooting: 1)Seat 2)Front carrier...
  • Page 296 – ELEC LIGHTING SYSTEM C0NTINUITY INCORRECT 3.Main switch Refer to “SWITCH INSPECTION”. CORRECT Replace the main switch. 4.Lights switch Refer to “SWITCH INSPECTION”. CORRECT Lights switch is faulty, replace the handle- bar switch (left). EB805013 5.Wiring connection POOR CONNECTION Check the connections of the entire light- ing system.
  • Page 297 – ELEC LIGHTING SYSTEM EB805020 LIGHTING SYSTEM CHECK 1.If the headlights fail to come on: NO CONTINUITY 1.Bulb and bulb socket Check the bulb and bulb socket for conti- nuity. Replace the bulb and/or bulb socket. CONTINUITY 2.Voltage Connect the pocket tester (DC 20 V) to the headlight couplers.
  • Page 298 – ELEC LIGHTING SYSTEM 2.If the taillight fails to come on: 1.Bulb and bulb socket NO CONTINUITY Check the bulb and bulb socket for conti- nuity. Replace the bulb and/or bulb socket. CONTINUITY 2.Voltage Connect the pocket tester (DC 20 V) to the taillight leads.

  • Page 299: Signal System

    – ELEC SIGNAL SYSTEM EB806000 SIGNAL SYSTEM CIRCUIT DIAGRAM 8 - 29...

  • Page 300: Troubleshooting

    – ELEC SIGNAL SYSTEM EB806010 TROUBLESHOOTING IF THE INDICATOR LIGHT AND/OR BRAKE LIGHT FAILS TO COME ON: Procedure Check: 1.Fuse (main) 2.Battery 3.Main switch 4.Wiring connections (the entire signal system) NOTE: Pocket tester: Remove the following part(s) before trou- P/N. YU-03112, 90890-03112 bleshooting: 1)Seat 2)Front carrier...
  • Page 301 – ELEC SIGNAL SYSTEM C0NTINUITY INCORRECT 3.Main switch Refer to “SWITCH INSPECTION”. CORRECT Replace the main switch. EB806011 POOR CONNECTION 4.Wiring connections Check the connections of the entire sig- nal system. Refer to “CIRCUIT DIAGRAM”. Properly connect the signal system. CORRECT Check the condition of each of the signal system’s circuits.
  • Page 302 – ELEC SIGNAL SYSTEM SIGNAL SYSTEM CHECK EB806024 1.If the neutral indicator light fails to come NO CONTINUITY 1.Bulb and bulb socket Check the bulb and bulb socket for conti- nuity. Replace the bulb and/or bulb socket. CONTINUITY NO CONTINUITY 2.Neutral switch Refer to “SWITCH INSPECTION”.
  • Page 303 – ELEC SIGNAL SYSTEM 2.If the reverse indicator light fails to come NO CONTINUITY 1.Bulb and bulb socket Check the bulb and bulb socket for conti- nuity. Replace the bulb and/or bulb socket. CONTINUITY NO CONTINUITY 2.Reverse switch Refer to “SWITCH INSPECTION”. CONTINUITY Replace the reverse switch.
  • Page 304 – ELEC SIGNAL SYSTEM 3.If the brake light fails to come on: (for New Hampshire and Maine) NO CONTINUITY 1.Bulb and bulb socket Check the bulb and bulb socket for conti- nuity. Replace the bulb and/or bulb socket. CONTINUITY NO CONDITION 2.Brake switch Refer to “SWITCH INSPECTION”.

  • Page 305: Chapter 9. Troubleshooting

    TRBL STARTING FAILURE/HARD STARTING SHTG TROUBLESHOOTING NOTE: The following troubleshooting does not cover all the possible causes of trouble. It should be helpful, however, as a guide to troubleshooting. Refer to the relative procedure in this man- ual for inspection, adjustment and replacement of parts. STARTING FAILURE/HARD STARTING FUEL SYSTEM Fuel tank...

  • Page 306: Compression System

    TRBL STARTING FAILURE/HARD STARTING/POOR IDLE SPEED PERFORMANCE/POOR MEDIUM AND HIGH-SPEED PERFORMANCE SHTG COMPRESSION SYSTEM Cylinder and cylinder head Valve, camshaft and crankshaft Loose spark plug Improperly sealed valve Loose cylinder head or cylinder Improperly contacted valve and valve seat Broken cylinder head gasket Improper valve timing Worn, damaged or seized cylinder Broken valve spring...

  • Page 307: Faulty Drive Train

    TRBL FAULTY DRIVE TRAIN SHTG FAULTY DRIVE TRAIN The following conditions may indicate damaged shaft drive components: Symptoms Possible Causes 1.A pronounced hesitation or “jerky” move- A.Bearing damage. ment during acceleration, deceleration, or sustained speed. (This must not be con- B.Improper gear lash.

  • Page 308: Faulty Gear Shifting

    FAULTY GEAR SHIFTING/ TRBL FAULTY CLUTCH PERFORMANCE SHTG FAULTY GEAR SHIFTING HARD SHIFTING Refer to “CLUTCH SLIPPING/DRAGGING-CLUTCH DRAGGING”. SHIFT PEDAL DOES NOT MOVE Shift shaft Transmission Bent shift shaft Seized transmission gear Shift cam, shift fork Jammed impurities Groove jammed with impurities Incorrectly assembled transmission Seized shift fork Shift guide...

  • Page 309: Overheating

    FAULTY CLUTCH PERFORMANCE/ TRBL OVERHEATING/FAULTY BRAKE SHTG OVERHEATING Engine oil OVERHEATING Improper oil level Ignition system Improper oil viscosity Improper spark plug gap Inferior oil quality Improper spark plug heat range Brake Faulty CDI unit Brake drag Fuel system Improper carburetor main jet (improper setting) Improper fuel level Clogged air filter element...

  • Page 310: Unstable Handling

    SHOCK ABSORBER MALFUNCTION/ TRBL UNSTABLE HANDLING/LIGHTING SYSTEM SHTG UNSTABLE HANDLING UNSTABLE HANDLING Wheels Handlebar Deformed wheel Improperly installed or bent Loose bearing Steering Bent or loose wheel axle Incorrect toe-in Excessive wheel runout Bent steering shaft Frame Improperly installed steering shaft Bent Damaged bearing or bearing race Damaged frame...
  • Page 311 YFM250XL WIRING DIAGRAM 1 Main switch 2 Battery 3 Fuse 4 Starter relay 5 Starter motor 6 Rectifier / regulator 7 CDI magneto 8 CDI unit 9 Ignition coil 0 Spark plug A Starting circuit cut-off relay B Rear brake lever switch (GLAY) (GLAY) C Tail light...
  • Page 312 YAMAHA MOTOR CO., LTD. 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U.S.A.
  • Page 313 YFM250XN SUPPLEMENTARY SERVICE MANUAL LIT-11616-14-17 4XE-F8197-11...
  • Page 314 Service Manual together with the following manual. YFM250XL(C) SERVICE MANUAL: 4XE-F8197-10 YFM250XN SUPPLEMENTARY SERVICE MANUAL © 2000 by Yamaha Motor Corporation, U.S.A. First Edition, April 2000 All rights reserved. Any reproduction or unauthorized use without the written permission of Yamaha Motor Corporation, U.S.A.
  • Page 315 EB001000 NOTICE This manual was produced by the Yamaha Motor Company 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, so it is assumed that anyone who uses this book to perform maintenance and repairs on Yamaha machine has a basic understanding of the mechanical ideas and the procedures of machine repair.
  • Page 316 EB002000 HOW TO USE THIS MANUAL MANUAL ORGANIZATION This manual is intended as a handy, easy-to-read reference book for the mechanic. It is divided into chapters, sections and sub-sections. Comprehensive explanations of all installation, removal, dis- assembly, assembly, repair and inspection procedures are laid out with the individual steps in sequential order.
  • Page 317 EB003000 ILLUSTRATED SYMBOLS Illustrated symbols 1 to 9 are printed on the top right of each page and indicate the subject SPEC INFO of each chapter. 1 General information 2 Specifications INSP 3 Periodic inspections and adjustments 4 Engine 5 Carburetion 6 Drive train 7 Chassis 8 Electrical...
  • Page 318 CONTENTS GENERAL INFORMATION ................1 MACHINE IDENTIFICATION ..............1 VEHICLE IDENTIFICATION NUMBER ..........1 MODEL LABEL ................1 SPECIFICATIONS .................... 2 GENERAL SPECIFICATIONS ..............2 MAINTENANCE SPECIFICATIONS ............3 ENGINE ................... 3 CHASSIS ..................4 ELECTRICAL ................... 6 CABLE ROUTING ..................7 PERIODIC INSPECTIONS AND ADJUSTMENTS ........
  • Page 319 ELECTRICAL ....................40 ELECTRICAL COMPONENTS .............. 40 IGNITION SYSTEM ................41 CIRCUIT DIAGRAM ............... 41 TROUBLESHOOTING ..............42 ELECTRIC STARTING SYSTEM ............47 CIRCUIT DIAGRAM ............... 47 STARTING CIRCUIT OPERATION ..........48 TROUBLESHOOTING ..............49 YFM250XN WIRING DIAGRAM...

  • Page 320: General Information

    MACHINE IDENTIFICATION INFO GENERAL INFORMATION MACHINE IDENTIFICATION VEHICLE IDENTIFICATION NUMBER The vehicle identification number 1 is stamped into the left side of the frame. MODEL LABEL The model label 1 is affixed to the frame. This information will be needed to order spare parts.

  • Page 321: Specifications

    SPEC GENERAL SPECIFICATIONS SPECIFICATIONS GENERAL SPECIFICATIONS Item Standard Model code: 4XEA (USA) Dimensions: Overall length 1,940 mm (76.4 in) Overall width 1,005 mm (39.6 in) Overall height 1,118 mm (44.0 in) Seat height 780 mm (30.7 in) Wheelbase 1,170 mm (46.1 in) Minimum ground clearance 150 mm (5.9 in) Minimum turning radius...

  • Page 322: Maintenance Specifications

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Shifter: Shifter type Shift drum and guide bar ---- Guide bar bending limit ---- 0.8 mm (0.032 in) Carburetor: I. D. mark 4XEA 12 ---- Main jet (M.J) ---- Main air jet (M.A.J) ---- Jet needle...

  • Page 323: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Item Standard Limit Rear suspension: Shock absorber travel 85 mm (3.35 in) ---- Suspension spring free length 268 mm (10.55 in) ---- Fitting length 244 mm (9.61 in) ---- Spring rate 39 N/mm (3.9 kg/mm, 222.69 lb/in)/ ---- 0 ~ 85 mm (0 ~ 3.35 in) Optional spring...
  • Page 324 SPEC MAINTENANCE SPECIFICATIONS Tightening torques Tightening torque Parts Part to be tightened Thread size Q’ty Remarks name m·kg ft·lb M10 × 1.25 Front panel wheel and wheel hub M14 × 1.5 Wheel hub and steering knuckle M8 × 1.25 Steering knuckle and brake caliper Bolt M8 ×...

  • Page 325: Electrical

    SPEC MAINTENANCE SPECIFICATIONS ELECTRICAL Item Standard Limit C.D.I.: Magneto model/manufacturer F4T259/MITSUBISHI ---- 189 ~ 231 Ω at 20˚C (68˚F)/ Pickup coil resistance/color ---- White/Green – White/Red 270 ~ 330 Ω at 20˚C (68˚F)/ Charging/rotor rotation direction detection ---- coil resistance/color Red/White/Blue C.D.I.

  • Page 326: Cable Routing

    SPEC CABLE ROUTING CABLE ROUTING Å Do not route the handlebar Ç Fasten the handlebar switch 1 Rear brake lever switch lead 2 Rear brake cable switch assembly lead through assembly lead and rear brake 3 Cable guide the lower bracket cable guide. lever switch lead to the handle- ı...
  • Page 327 SPEC CABLE ROUTING 1 Cable guide B Rear brake breather hose 2 Main switch C Carburetor air vent hose 3 Fuel tank breather hose D CDI magneto lead 4 Taillight Å Route the main switch lead and indicator light lead to the side of 5 Final gear case breather hose 6 Carburetor overflow hose the cable guide.
  • Page 328 SPEC CABLE ROUTING Ç Make sure that the starter motor lead is not Ó Fasten the taillight lead to the box with the plas- slacked. tic clamp. Î Fasten the starter motor lead and wire harness È Route the carburetor overflow hose between the to the frame with the plastic band.
  • Page 329 SPEC CABLE ROUTING Ò Fasten the starter motor lead and wire harness ∏ Route the final gear case breather hose through to the frame with the plastic clamp. the cable guide. ˜ Route the rear brake cable and rear brake Œ...
  • Page 330 SPEC CABLE ROUTING Å Make sure that the battery breather hose is not kinked or bent. 1 Battery breather hose ı Route the rear brake cable through the cable guide on the cyl- 2 Spark plug cap 3 Ignition coil inder.
  • Page 331 SPEC CABLE ROUTING Å Fasten the wire harness to the frame with the plastic clamps. 1 Wire harness ı Make sure the starter motor lead and wire harness do not contact the 2 Starter motor lead 3 Rear brake cable ignition coil.
  • Page 332 SPEC CABLE ROUTING Ï Fasten the battery breather hose to the rear Ô Make sure that the grommet is installed with the fender with the plastic clamp and then insert the mark facing forward. clamp into the hole in the rear fender. Route the taillight lead through the lead holders Ì...

  • Page 333: Periodic Inspections And Adjustments

    INTRODUCTION/ INSP PERIODIC MAINTENANCE/LUBRICATION PERIODIC INSPECTIONS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended inspections and adjust- ments. These preventive maintenance procedures, if followed, will ensure more reliable machine operation and a longer service life. In addition, the need for costly overhaul work will be greatly reduced.
  • Page 334 • Check that the breather hose is working prop- Battery* erly. • Correct if necessary. It is recommended that these items be serviced by a Yamaha dealer. Lithium soap base grease. WARNING Indicates a potential hazard that could result in serious injury or death.

  • Page 335: Engine

    INSP SPARK ARRESTER CLEANING ENGINE SPARK ARRESTER CLEANING 1.Clean: Spark arrester ********************************************* Cleaning steps: WARNING Select a well-ventilated area free of com- bustible materials. Always let the exhaust system cool before performing this operation. Remove the purging bolt 1 . Start the engine and rev it up approximately twenty times while momentarily creating exhaust system back pressure by blocking...

  • Page 336: Chassis

    FRONT BRAKE FLUID LEVEL INSPECTION/ INSP FRONT BRAKE PAD INSPECTION CHASSIS FRONT BRAKE FLUID LEVEL INSPECTION 1.Place the machine on a level surface. NOTE: When inspecting the front brake fluid level, make sure that the top of the master cylinder top is horizontal.

  • Page 337: Brake Hose Inspection

    BRAKE HOSE INSPECTION/ INSP AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) BRAKE HOSE INSPECTION 1.Remove: Front carrier Front fender Refer to “FENDER AND FUEL TANK”. 2.Inspect: Brake hoses 1 Cracks/wear/damage → Replace. 3.Check: Brake hose clamp Loosen → Tighten. 4.Hold the machine in an upright position and apply the front or rear brake.
  • Page 338 INSP AIR BLEEDING (HYDRAULIC BRAKE SYSTEM) 1.Bleed: Brake system ********************************************* Air bleeding steps: a. Add the proper brake fluid to the reservoir. b. Install the diaphragm. Be careful not to spill any fluid or allow the reservoir to overflow. c. Connect the clear plastic hose 1 tightly to the caliper bleed screw 2 .

  • Page 339: Chassis

    CHAS FRONT WHEEL CHASSIS FRONT WHEEL TIRE AIR PRESSURE Cold Tire Pressure Front Rear 1 Wheel cap 7 Spacer 20 kPa 25 kPa 2 Cotter pin 8 Oil seal Standard (0.20 kg/cm (0.25 kg/cm 3 Axle nut 9 Bearing 2.9 psi) 3.6 psi) 4 Plain washer 0 Front wheel hub...

  • Page 340: Removal

    CHAS FRONT WHEEL REMOVAL 1.Place the machine on a level surface. 2.Loosen: Nuts (front wheel) Apply the front brake. 3.Block the rear wheels, and elevate the front wheels by placing the suitable stand under the frame. 4.Remove: Nuts 1 (front wheel) Front wheel 2 5.Remove: Wheel cap...

  • Page 341: Inspection

    CHAS FRONT WHEEL 8.Remove: Front brake disc 1 INSPECTION 1.Inspect: Wheel hub 1 Cracks/damage → Replace. – 22 –...

  • Page 342: Front Brake

    CHAS FRONT BRAKE FRONT BRAKE 1 Brake master cylinder reservoir cap 0 Brake disc 2 Brake master cylinder reservoir diaphragm holder A Caliper bleed screw 3 Brake master cylinder reservoir diaphragm B Retaining bolt 4 Brake master cylinder C Brake caliper 5 Brake master cylinder kit D Pad shim 6 Copper washer...

  • Page 343: Brake Pad Replacement

    CHAS FRONT BRAKE CAUTION: Disc brake components rarely require dis- assembly. DO NOT: Disassemble components unless abso- lutely necessary. Use solvents on internal brake compo- nents. Use contaminated brake fluid for clean- ing. Use only clean brake fluid. Allow brake fluid to come in contact with the eyes, otherwise eye injury may occur.
  • Page 344 CHAS FRONT BRAKE 5.Remove: Brake pads 1 (with pad shim 2) Pad spring 3 NOTE: When pad replacement is required, also replace the pad spring and shim. Replace the pads as a set if either is found to be worn to the wear limit a. Wear limit a: 1.0 mm (0.04 in) 6.Install:...

  • Page 345: Caliper Disassembly

    CHAS FRONT BRAKE 7.Install: Retaining bolts Front brake caliper Retaining bolt: 18 Nm (1.8 m • kg, 13 ft • lb) Bolt (front brake caliper): 30 Nm (3.0 m • kg, 22 ft • lb) 8.Install: Front wheel 9.Inspect: Brake fluid level Refer to “FRONT BRAKE FLUID LEVEL INSPECTION”.

  • Page 346: Master Cylinder Disassembly

    CHAS FRONT BRAKE 4.Remove: Union bolt 1 Copper washers 2 Brake hose 3 NOTE: Place the open end of the hose into a con- tainer and pump the oil fluid out carefully. 5.Remove: Caliper body 1 Caliper bracket 2 NOTE: Before removing the caliper body from the bracket, disconnect the dust boot from the guide shaft on the bracket.

  • Page 347: Inspection And Repair

    CHAS FRONT BRAKE 1.Remove: Brake lever 1 Union bolt 2 Copper washers 3 Brake hose 4 NOTE: Hold a container under the master cylinder and under the hose end to collect remaining brake fluid. 2.Remove: Brake master cylinder reservoir cap 1 Brake master cylinder reservoir diaphragm holder Brake master cylinder reservoir diaphragm...
  • Page 348 CHAS FRONT BRAKE 1.Inspect: Caliper piston 1 → Scratches/rust/wear Replace caliper assembly. Caliper cylinder 2 Wear/scratches → Replace caliper assem- bly. Caliper body 3 Cracks/damage → Replace. Oil delivery passage (caliper body) Blow out with compressed air. WARNING Replace the piston seal whenever the cali- per is disassembled.
  • Page 349 CHAS FRONT BRAKE 6.Measure: Brake pads (thickness) a Out of specification → Replace. NOTE: When pad replacement is required, also replace the pad spring and shims. Replace the pads as a set if either is found to be worn to the wear limit a . Wear limit a : 1.0 mm (0.04 in) 7.Inspect:...

  • Page 350: Caliper Assembly

    CHAS FRONT BRAKE NOTE: Tighten the bolts (brake disc) in stage using a crisscross pattern. Bolt (brake disc): 16 Nm (1.6 m • kg, 12 ft • lb) CALIPER ASSEMBLY WARNING All internal parts should be cleaned in new brake fluid only. Internal parts should be lubricated with brake fluid when installed.
  • Page 351 CHAS FRONT BRAKE 3.Install: Brake caliper 1 (temporarily) Copper washers 2 Brake hose 3 Union bolt 4 Union bolt: 27 Nm (2.7 m • kg, 19 ft • lb) CAUTION: When installing the brake hose on the cali- per, make sure that the brake pipe touches the projection a on the brake caliper.
  • Page 352 CHAS FRONT BRAKE 6.Fill: Reservoir tank Recommended brake fluid: DOT 4 NOTE: If DOT 4 is not available, 3 can be used. CAUTION: Brake fluid may erode painted surfaces or plastic parts. Always clean up spilled fluid immediately. WARNING Use only the designated quality brake fluid: otherwise, the rubber seals may deteriorate, causing leakage and poor brake performance.

  • Page 353: Master Cylinder Assembly

    CHAS FRONT BRAKE MASTER CYLINDER ASSEMBLY WARNING All internal parts should be cleaned in new brake fluid only. Internal parts should be lubricated with brake fluid when installed. Recommended brake fluid: DOT 4 Replace the piston seals and dust seals whenever a brake master cylinder is dis- assembled.
  • Page 354 CHAS FRONT BRAKE 3.Install: Copper washers Brake hose Union bolt Union bolt: 27 Nm (2.7 m • kg, 19 ft • lb) NOTE: Tighten the union bolt while holding the brake hose as shown. Check that the brake hose does not touch other parts (throttle cable, wire harness, leads, etc.) by turning the handlebar left and right, and correct if necessary.
  • Page 355 CHAS FRONT BRAKE Refill with the same type of brake fluid: mixing fluids may result in a harmful chemical reaction and lead to poor per- formance. Be careful that water does not enter the master cylinder when refilling. Water will significantly lower the boiling point of the fluid and may result in vapor lock.

  • Page 356: Rear Wheels/Rear Brake And Rear Axle

    CHAS REAR WHEELS/REAR BRAKE AND REAR AXLE REAR WHEELS/REAR BRAKE AND REAR AXLE 1 Rear axle 2 Bearing 3 Oil seal 4 Wheel hub 5 Axle nut × TIRE SIZE: AT22 10-10 TIRE WEAR LIMIT: 2.0 mm (0.08 in) × C RIM SIZE: 8 10AT RIM RUNOUT LIMIT:...

  • Page 357: Front Shock Absorber And Front Arm

    CHAS FRONT SHOCK ABSORBER AND FRONT ARM FRONT SHOCK ABSORBER AND FRONT ARM 1 Front shock absorber 2 Steering knuckle 3 Lower arm 4 Bushing – 38 –...

  • Page 358: Rear Shock Absorber And Swingarm

    CHAS REAR SHOCK ABSORBER AND SWINGARM REAR SHOCK ABSORBER AND SWINGARM 1 Rear shock absorber 8 Swingarm 2 Thrust cover 9 Rubber boot 3 Locknut 0 Final gear case protector 4 Pivot shaft 5 Collar 6 Oil seal 7 Taper roller bearing SWINGARM FREE PLAY LIMIT: End: 1.0 mm (0.04 in) Side: 1.0 mm (0.04 in)

  • Page 359: Electrical

    – ELEC ELECTRICAL COMPONENTS EB800000 ELECTRICAL ELECTRICAL COMPONENTS 1 Reverse indicator light 8 Rectifier/regulator E Headlight 2 Neutral indicator light 9 CDI unit F Ignition coil 3 Main switch 0 Taillight 4 Rear brake lever switch A Battery 5 Handlebar switch B Starting circuit cut-off relay 6 Fuses C Reverse switch...

  • Page 360: Ignition System

    – ELEC IGNITION SYSTEM EB802000 IGNITION SYSTEM CIRCUIT DIAGRAM – 41 –...

  • Page 361: Troubleshooting

    – ELEC IGNITION SYSTEM EB802010 TROUBLESHOOTING IF THE IGNITION SYSTEM FAILS TO OPERATE (NO SPARK OR INTERMITTENT SPARK): Procedure Check: 8.Main switch 1.Fuse 9.Pickup coil resistance 2.Battery 10. Charging/rotor rotation direction detection 3.Spark plug coil resistance 4.Ignition spark gap 11. Wiring connection 5.Spark plug cap resistance (the entire ignition system) 6.Ignition coil resistance...
  • Page 362 – ELEC IGNITION SYSTEM C0NTINUITY INCORRECT Spark plug gap: 0.6 ~ 0.7 mm (0.024 ~ 0.028 in) CORRECT Repair or replace the spark plug. 4.Ignition spark gap Disconnect the spark plug cap from the spark plug. Connect the dynamic spark tester 1 as shown.
  • Page 363 – ELEC IGNITION SYSTEM C0NTINUITY Tester (+) lead → Orange lead terminal 6.Ignition coil resistance Tester (–) lead → Ignition coil base Disconnect the ignition coil connector from the wire harness. Connect the pocket tester (Ω × 1) to the ignition coil.
  • Page 364 – ELEC IGNITION SYSTEM C0NTINUITY 9.Pickup coil resistance Disconnect the CDI magneto coupler from the wire harness. Connect the pocket tester (Ω × 100) to the pickup coil terminal. Tester (+) lead → White/Green terminal 1 Tester (–) lead → White/Red terminal 2 Check the pickup coil for the specified OUT OF SPECIFICATION resistance.
  • Page 365 – ELEC IGNITION SYSTEM C0NTINUITY POOR CONNECTION 11. Wiring connection Check the connections of the entire ignition system. Refer to “CIRCUIT DIAGRAM”. Properly connect the ignition system. CORRECT Replace the CDI unit. – 46 –...

  • Page 366: Electric Starting System

    – ELEC ELECTRIC STARTING SYSTEM EB803000 ELECTRIC STARTING SYSTEM CIRCUIT DIAGRAM – 47 –...

  • Page 367: Starting Circuit Operation

    – ELEC ELECTRIC STARTING SYSTEM STARTING CIRCUIT OPERATION The starting circuit on this model consists of the starter motor, starter relay, starting circuit cut-off relay, rear brake lever switch, and neu- tral switch. If the main switch is on and engine stop switch is in the RUN position, the starter motor can be operated only if: The transmission is in neutral (the neutral...

  • Page 368: Troubleshooting

    – ELEC ELECTRIC STARTING SYSTEM EB803020 TROUBLESHOOTING IF THE STARTER MOTOR FAILS TO OPERATE: Procedure Check: 7.Engine stop switch 1.Fuse 8.Neutral switch 2.Battery 9.Rear brake lever switch 3.Starter motor 10. Start switch 4.Starting circuit cut-off relay 11. Wiring connection 5.Starter relay (the entire starting system) 6.Main switch NOTE:...
  • Page 369 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY WARNING 3.Starter motor A wire that is used as a jumper lead must Connect the battery positive terminal 1 have the equivalent capacity or more as and starter motor lead 2 using a jumper that of the battery lead, otherwise the lead 3 jumper lead may burn.
  • Page 370 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY 5.Starter relay Remove the starter relay from the wire har- ness. Connect the pocket tester (Ω × 1) and the battery (12 V) to the starter relay terminals. L/W L/B Battery (+) terminal → Blue/White terminal 1 NO CONTINUITY Battery (–) terminal →...
  • Page 371 – ELEC ELECTRIC STARTING SYSTEM C0NTINUITY 9.Rear brake lever switch INCORRECT Refer to “SWITCH INSPECTION”. CORRECT Replace the rear brake lever switch. INCORRECT 10.Start switch Refer to “SWITCH INSPECTION”. CORRECT Replace the handlebar switch (left). EB803028 POOR CONNECTION 11.Wiring connection Check the connections of the entire starting system.
  • Page 372 YAMAHA MOTOR CO., LTD. 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U.S.A.

  • Page 373: Yfm250Xn Wiring Diagram

    YFM250XN WIRING DIAGRAM 1 CDI magneto 2 Rectifier/regulator 3 Main switch 4 Battery 5 Fuse 6 Starter relay 7 Starter motor 8 Starting circuit cut-off relay W/L W/R 9 CDI unit 0 Ignition coil A Spark plug (BLACK) B Neutral indicator light W/L O C Reverse indicator light (BLACK)
  • Page 374 YFM250XP SUPPLEMENTARY SERVICE MANUAL LIT-11616-15-03 4XE-F8197-12...
  • Page 375 YFM250XL(C) SERVICE MANUAL: LIT-11616-12-01 (4XE-F8197-10) YFM250XN SUPPLEMENTARY SERVICE MANUAL: LIT-11616-14-17 (4XE-F8197-11) YFM250XP SUPPLEMENTARY SERVICE MANUAL  2001 by Yamaha Motor Corporation, U.S.A. First Edition, June 2001 All rights reserved. Any reproduction or unauthorized use without the written permission of Yamaha Motor Corporation, U.S.A.
  • Page 376 EB001000 NOTICE This manual was produced by the Yamaha Motor Company 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, so it is assumed that anyone who uses this book to perform maintenance and repairs on Yamaha machine has a basic understanding of the mechanical ideas and the procedures of machine repair.
  • Page 377 HOW TO USE THIS MANUAL CONSTRUCTION OF THIS MANUAL This manual consists of chapters for the main categories of subjects. (See “Illustrated symbols”) 1st title 1: This is a chapter with its symbol on the upper right of each page. 2nd title 2: This title appears on the upper of each page on the left of the chapter sym- bol.
  • Page 378 EB003000 ILLUSTRATED SYMBOLS Illustrated symbols 1 to 9 are printed on the SPEC top right of each page and indicate the subject INFO of each chapter. 1 General information 2 Specifications 3 Periodic checks and adjustments 4 Engine 5 Carburetion 6 Drive train 7 Chassis 8 Electrical...
  • Page 379 CONTENTS SPECIFICATIONS ................... 1 GENERAL SPECIFICATIONS ..............1 MAINTENANCE SPECIFICATION ............2 ENGINE ....................2 CHASSIS ....................3 ELECTRICAL ..................3 CABLE ROUTING ..................4 PERIODIC CHECKS AND ADJUSTMENTS ..........12 INTRODUCTION ..................12 PERIODIC MAINTENANCE/LUBRICATION INTERVALS ...... 12 CHASSIS ....................14 ADJUSTING THE FRONT BRAKE ............

  • Page 380: Specifications

    SPEC GENERAL SPECIFICATIONS SPECIFICATIONS GENERAL SPECIFICATIONS Item Standard Model code: 4XEE (USA) Brake: Front brake type Dual disc brake operation Right hand operation Rear brake type Drum brake (fully sealed) operation Left hand and right foot operation Electrical: Ignition system DC.C.D.I.

  • Page 381: Maintenance Specification

    SPEC MAINTENANCE SPECIFICATIONS MAINTENANCE SPECIFICATIONS ENGINE Item Standard Limit Cylinder head: Warp limit ---- 0.03 mm (0.001 in) Measuring point Lines indicate straightedge measurement. Piston: Piston to cylinder clearance 0.04 ~ 0.06 mm 0.15 mm (0.0016 ~ 0.0024 in) (0.0059 in) Piston size “D”...

  • Page 382: Chassis

    SPEC MAINTENANCE SPECIFICATIONS CHASSIS Item Standard Limit Rear suspension: Shock absorber travel 85 mm (3.35 in) ---- Suspension spring free length 268 mm (10.55 in) ---- Fitting length 244 mm (9.61 in) ---- Spring rate 39 N/mm (3.9 kg/mm, ---- 222.69 lb/in)/0 ~ 85 mm (0 ~ 3.35 in) Optional spring ----...

  • Page 383: Cable Routing

    SPEC CABLE ROUTING CABLE ROUTING 1 Rear brake lever switch lead È Do not route the handlebar Ë Fasten the handlebar switch 2 Rear brake cable switch assembly lead through assembly lead and rear brake 3 Cable guide the lower bracket cable guide. lever switch lead to the handle- 4 Front brake hose É...
  • Page 384 SPEC CABLE ROUTING 1 Cable guide É Insert the carburetor air vent hose, rear brake 2 Main switch breather hose, and final gear case breather hose 3 Fuel tank breather hose into the air duct after routing them through the fuel 4 Carburetor overflow hose tank grommet.
  • Page 385 SPEC CABLE ROUTING 1 Tail/brake light È Make sure that the starter motor lead has no 2 Final gear case breather hose slack. 3 Front brake light switch lead É Fasten the starter motor lead and wire harness 4 Carburetor air vent hose to the frame with the plastic band.
  • Page 386 SPEC CABLE ROUTING Í Fasten the tail/brake light lead to the storage box Ò Fasten the rear brake cable and rear brake with the plastic clamp. breather hose to the swingarm with the plastic Î Fasten the starter motor lead and wire harness clips.
  • Page 387 SPEC CABLE ROUTING 1 Battery breather hose È Make sure that the battery breather hose is not 2 Rear brake cable kinked or bent. 3 Spark plug cap É Route the rear brake cable through the cable 4 Ignition coil guide on the cylinder.
  • Page 388 SPEC CABLE ROUTING 1 Rectifier/regulator È Fasten the battery + lead and starter motor lead 2 CDI unit to the rear fender with the plastic clamps. 3 Starting circuit cut-off relay lead É Install the starter circuit cut-off relay onto the tab 4 Starter relay lead with its terminal side facing down.
  • Page 389 SPEC CABLE ROUTING Í Make sure that the grommet is installed with the mark facing forward. Î 5 mm (0.2 in) – 10 –...
  • Page 390 SPEC CABLE ROUTING 1 Rear brake cable Ê Make sure the starter motor lead and wire har- 2 Throttle cable ness do not contact the ignition coil. 3 Wire harness Ë Fasten the wire harness, starter motor lead, and 4 Starter motor lead ignition coil lead to the frame with the plastic 5 Tail/brake light lead locking tie.

  • Page 391: Periodic Checks And Adjustments

    INTRODUCTION/PERIODIC MAINTENANCE/ LUBRICATION INTERVALS EB300000 PERIODIC CHECKS AND ADJUSTMENTS INTRODUCTION This chapter includes all information necessary to perform recommended inspections and adjust- ments. These preventive maintenance procedures, if followed, will ensure more reliable vehicle operation and a longer service life. The need for costly overhaul work will be greatly reduced. This information applies to vehicles already in service as well as to new vehicles that are being prepared for sale.
  • Page 392 • Check specific gravity. Battery* • Check that the breather hose is working properly. • Correct if necessary. * It is recommended that these items be serviced by a Yamaha dealer. ** Lithium-soap-based grease NOTE: Recommended brake fluid: DOT 4 Brake fluid replacement: 1.When disassembling the master cylinder or caliper, replace the brake fluid.

  • Page 393: Chassis

    ADJUSTING THE FRONT BRAKE/ ADJUSTING THE REAR BRAKE LIGHT SWITCH CHASSIS ADJUSTING THE FRONT BRAKE 1.Check: Brake lever free play a Out of specification → Bleed the front brake system. Refer to “AIR BLEEDING (HYDRAULIC BRAKE SYSTEM)”. (Manual No.: 4XE-F8197-11) Brake lever free play (at brake lever end): 0 mm (0 in)

  • Page 394: Electrical

    – ELEC CHECKING THE SWITCH ELECTRICAL CHECKING THE SWITCH CHECKING THE SWITCH Use a pocket tester to check the terminals for continuity. If the continuity is faulty at any point, replace the switch. Pocket tester: P/N. YU-03112, 90890-03112 NOTE: Set the pocket tester to “0” before starting the test.

  • Page 395: Signal System

    – ELEC SIGNAL SYSTEM EB806000 SIGNAL SYSTEM CIRCUIT DIAGRAM – 16 –...

  • Page 396: Checking The Signal System

    – ELEC SIGNAL SYSTEM CHECKING THE SIGNAL SYSTEM 1.If the tail/brake light fails to come on: 1.Bulb and bulb socket NO CONTINUITY Check the bulb and bulb socket for continu- ity. CONTINUITY Replace the bulb and/or bulb socket. NO CONTINUITY 2.Brake light switches Refer to “CHECKING THE SWITCH”.
  • Page 397 YAMAHA MOTOR CO., LTD. 2500 SHINGAI IWATA SHIZUOKA JAPAN PRINTED IN U.S.A.

  • Page 398: Yfm250Xp Wiring Diagram

    YFM250XP WIRING DIAGRAM 1 A.C. magneto 2 Rectifier/regulator 3 Main switch 4 Battery 5 Fuse 6 Starter relay W/G R R W/G 7 Starter motor W/R W/L W/L W/R 8 Starting circuit cut-off relay 9 CDI unit (BLACK) 0 Ignition coil W/R R R/B A Spark plug W/L O...

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