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2009
SERVICE MANUAL
WR125R
WR125X
22B-F8197-E0

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Summary of Contents for Yamaha WR125R 2009

  • Page 1 2009 SERVICE MANUAL WR125R WR125X 22B-F8197-E0...
  • Page 2 EAS20060 WR125R/WR125X 2009 SERVICE MANUAL ©2008 by MBK Industrie First edition, December 2008 All rights reserved. Any reproduction or unauthorized use without the written permission of MBK Industrie is expressly prohibited.
  • Page 3 It is not possible to include all the knowledge of a mechanic in one manual. Therefore, any- one who uses this book to perform maintenance and repairs on Yamaha vehicles should have a basic understanding of mechanics and the techniques to repair these types of vehicles. Repair and mainte- nance work attempted by anyone without this knowledge is likely to render the vehicle unsafe and unfit for use.
  • Page 4 EAS20090 HOW TO USE THIS MANUAL This manual is intended as a handy, easy-to-read reference book for the mechanic. Comprehensive explanations of all installation, removal, disassembly, assembly, repair and check procedures are laid out with the individual steps in sequential order. •...
  • Page 5 EAS20100 1. Serviceable with engine mounted SYMBOLS 2. Filling fluid The following symbols are used in this manual 3. Lubricant for easier understanding. 4. Special tool 5. Tightening torque The following symbols are not relevant to every 6. Wear limit, clearance vehicle.
  • Page 7: Table Of Contents

    EAS20110 TABLE OF CONTENTS GENERAL INFORMATION SPECIFICATIONS PERIODIC CHECKS AND ADJUSTMENTS CHASSIS ENGINE COOLING SYSTEM FUEL SYSTEM ELECTRICAL SYSTEM TROUBLESHOOTING...
  • Page 9: General Information

    GENERAL INFORMATION IDENTIFICATION .................... 1-1 VEHICLE IDENTIFICATION NUMBER ............. 1-1 MODEL LABEL..................1-1 FEATURES...................... 1-2 OUTLINE OF THE FI SYSTEM..............1-2 FI SYSTEM....................1-3 INSTRUMENT FUNCTIONS ..............1-4 IMPORTANT INFORMATION ................. 1-6 PREPARATION FOR REMOVAL AND DISASSEMBLY......1-6 REPLACEMENT PARTS................1-6 GASKETS, OIL SEALS AND O-RINGS ............
  • Page 10: Identification

    IDENTIFICATION EAS20130 IDENTIFICATION EAS20140 VEHICLE IDENTIFICATION NUMBER The vehicle identification number “1” is stamped into the right side of the steering head pipe. EAS20150 MODEL LABEL The model label “1” is affixed to the frame under the seat. This information will be needed to order spare parts.
  • Page 11: Features

    FEATURES EAS20170 FEATURES EAS22B1001 OUTLINE OF THE FI SYSTEM The main function of a fuel supply system is to provide fuel to the combustion chamber at the optimum air-fuel ratio in accordance with the engine operating conditions and the atmospheric temperature. In the conventional carburetor system, the air-fuel ratio of the mixture that is supplied to the combustion chamber is created by the volume of the intake air and the fuel that is metered by the jet used in the respective carburetor.
  • Page 12: Fi System

    FEATURES EAS22B1002 FI SYSTEM The fuel pump delivers fuel to the fuel injector via the fuel filter. The pressure regulator maintains the fuel pressure that is applied to the fuel injector at only 250 kPa (2.50 kgf/cm², 36.3 psi). Accordingly, when the energizing signal from the ECU energizes the fuel injector, the fuel passage opens, causing the fuel to be injected into the intake manifold only during the time the passage remains open.
  • Page 13: Instrument Functions

    FEATURES Odometer and tripmeter modes EAS22B1038 INSTRUMENT FUNCTIONS A brief push (less than one second) on the “RE- SET/SELECT” button switches the display be- Multi-function display tween the odometer mode “ODO” and the EWA22B1019 tripmeter modes “TRIP 1” and “TRIP 2” in the fol- WARNING lowing order: Be sure to stop the vehicle before making...
  • Page 14 FEATURES oil change indicator stops flashing and stays on, release the “RESET/SELECT” button within three seconds; the indicator will go off. If the oil change indicator still flashes after the rest procedure has been completed, repeat the reset procedure completely. Fuel meter 1.
  • Page 15: Important Information

    5. Keep all parts away from any source of fire. EAS20200 REPLACEMENT PARTS Use only genuine Yamaha parts for all replace- ments. Use oil and grease recommended by Yamaha for all lubrication jobs. Other brands may be similar in function and appearance, but...
  • Page 16: Bearings And Oil Seals

    IMPORTANT INFORMATION EAS20230 BEARINGS AND OIL SEALS Install bearings “1” and oil seals “2” so that the manufacturer marks or numbers are visible. When installing oil seals, lubricate the oil seal lips with a light coat of lithium-soap-based grease. Oil bearings liberally when installing, if appropriate.
  • Page 17: Checking The Connections

    CHECKING THE CONNECTIONS EAS20250 CHECKING THE CONNECTIONS Pocket tester 90890-03112 Check the leads, couplers, and connectors for Analog pocket tester stains, rust, moisture, etc. YU-03112-C 1. Disconnect: • Lead • Coupler • If there is no continuity, clean the terminals. •...
  • Page 18 SPECIAL TOOLS EAS20260 SPECIAL TOOLS The following special tools are necessary for complete and accurate tune-up and assembly. Use only the appropriate special tools as this will help prevent damage caused by the use of inappropriate tools or improvised techniques. Special tools, part numbers or both may differ depending on the country. When placing an order, refer to the list provided below to avoid any mistakes.
  • Page 19 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Extension 90890-04082 Compression gauge 90890-03081 Engine compression tester YU-33223 Steering nut wrench 3-22, 4-58 90890-01403 Exhaust flange nut wrench YU-A9472 Spoke nipple wrench (8–9) 3-25 90890-01522 YM-01522 Spoke nipple wrench (10–11) 3-25 90890-01523 YM-01523 Damper rod holder...
  • Page 20 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Fork seal driver attachment (ø41) 4-52 90890-01381 Replacement 41 mm YM-A5142-2 Yamaha bond No. 1215 5-12, 5-33, 90890-85505 5-60 (Three Bond No.1215®) Valve spring compressor 5-18, 5-23 90890-04019 YM-04019 Valve spring compressor attachment...
  • Page 21: Special Tools

    SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Sheave holder 5-31, 5-32, 90890-01701 5-33 Primary clutch holder YS-01880-A Flywheel puller 5-31 90890-01362 Heavy duty puller YU-33270-B Universal clutch holder 5-42, 5-45 90890-04086 YM-91042 Crankcase separating tool 5-63 90890-01135 Crankcase separator YU-01135-B Crankshaft installer pot 5-64...
  • Page 22 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Crankshaft installer bolt 5-64 90890-01275 Bolt YU-90060 Adapter (M12) 5-64 90890-01278 Adapter #3 YU-90063 Spacer (crankshaft installer) 5-64 90890-04081 Pot spacer YM-91044 YM-91044 Radiator cap tester 90890-01325 Radiator pressure tester YU-24460-01 YU-24460-01 Radiator cap tester adapter 90890-01352 Radiator pressure tester adapter...
  • Page 23 SPECIAL TOOLS Reference Tool name/Tool No. Illustration pages Mechanical seal installer 90890-04145 ø30 ø10 Middle driven shaft bearing driver 90890-04058 Bearing driver 40 mm YM-04058 Pressure gauge 90890-03153 YU-03153 Fuel pressure adapter 90890-03186 Ignition checker 8-71 90890-06754 Opama pet-4000 spark checker YM-34487 Digital circuit tester 8-75...
  • Page 24 SPECIAL TOOLS 1-15...
  • Page 25: Specifications

    SPECIFICATIONS GENERAL SPECIFICATIONS ................ 2-1 ENGINE SPECIFICATIONS ................2-2 CHASSIS SPECIFICATIONS ................2-9 ELECTRICAL SPECIFICATIONS ..............2-12 TIGHTENING TORQUES ................2-15 GENERAL TIGHTENING TORQUE SPECIFICATIONS......2-15 ENGINE TIGHTENING TORQUES............2-16 CHASSIS TIGHTENING TORQUES............2-19 LUBRICATION POINTS AND LUBRICANT TYPES ........2-23 ENGINE....................
  • Page 26: General Specifications

    GENERAL SPECIFICATIONS EAS20280 GENERAL SPECIFICATIONS Model Model WR125R 22B1 WR125X 22B2 Dimensions Overall length WR125R 2125 mm (83.7 in) WR125X 2090 mm (82.3 in) Overall width 835 mm (32.9 in) Overall height WR125R 1285 mm (50.6 in) WR125X 1260 mm (49.6 in) Seat height WR125R 930 mm (36.6 in) WR125X 920 mm (36.2 in)
  • Page 27: Engine Specifications

    ENGINE SPECIFICATIONS EAS20290 ENGINE SPECIFICATIONS Engine Engine type Liquid cooled 4-stroke, SOHC Displacement 124.7 cm³ Cylinder arrangement Forward-inclined single cylinder Bore × stroke 52.0 × 58.6 mm (2.05 × 2.31 in) Compression ratio 11.20 :1 Standard compression pressure (at sea level) 550 kPa/600 r/min (5.5 kgf/cm²/600 r/min, 78.2 psi/600 r/min) Minimum–maximum...
  • Page 28 ENGINE SPECIFICATIONS Valve opening temperature 80.5–83.5 °C (176.90–182.30 °F) Valve full open temperature 95.0 °C (203.00 °F) Valve lift (full open) 3.0 mm (0.12 in) Radiator core Width 128.0 mm (5.04 in) Height 258.0 mm (10.16 in) Depth 24.0 mm (0.94 in) Water pump Water pump type Single suction centrifugal pump...
  • Page 29 ENGINE SPECIFICATIONS Tensioning system Automatic Rocker arm/rocker arm shaft Rocker arm inside diameter 9.985–10.000 mm (0.3931–0.3937 in) Limit 10.015 mm (0.3943 in) Rocker arm shaft outside diameter 9.966–9.976 mm (0.3924–0.3928 in) Limit 9.941 mm (0.3914 in) Rocker-arm-to-rocker-arm-shaft clearance 0.009–0.034 mm (0.0004–0.0013 in) Limit 0.074 mm (0.0029 in) Valve, valve seat, valve guide...
  • Page 30 ENGINE SPECIFICATIONS Valve-stem-to-valve-guide clearance (exhaust) 0.025–0.052 mm (0.0010–0.0020 in) Limit 0.100 mm (0.0039 in) Valve stem runout 0.010 mm (0.0004 in) Cylinder head valve seat width (intake) 0.90–1.10 mm (0.0354–0.0433 in) Limit 1.6 mm (0.06 in) Cylinder head valve seat width (exhaust) 0.90–1.10 mm (0.0354–0.0433 in) Limit 1.6 mm (0.06 in)
  • Page 31 ENGINE SPECIFICATIONS Height H 5.0 mm (0.20 in) Offset 0.50 mm (0.0197 in) Offset direction Intake side Piston pin bore inside diameter 14.002–14.013 mm (0.5513–0.5517 in) Limit 14.043 mm (0.5529 in) Piston pin outside diameter 13.995–14.000 mm (0.5510–0.5512 in) Limit 13.975 mm (0.5502 in) Piston-pin-to-piston-pin-bore clearance 0.002–0.018 mm (0.0001–0.0007 in)
  • Page 32 ENGINE SPECIFICATIONS Runout limit C 0.030 mm (0.0012 in) Big end side clearance D 0.110–0.410 mm (0.0043–0.0161 in) Big end radial clearance E 0.004–0.014 mm (0.0002–0.0006 in) Balancer Balancer drive method Gear Clutch Clutch type Wet, multiple-disc Clutch release method Inner push, cam push Clutch lever free play 10.0–15.0 mm (0.39–0.59 in)
  • Page 33 ENGINE SPECIFICATIONS Drive axle runout limit 0.08 mm (0.0032 in) Shifting mechanism Shift mechanism type Shift drum and guide bar Shift fork L thickness 5.76–5.89 mm (0.2268–0.2319 in) Shift fork C, R thickness 4.76–4.89 mm (0.1874–0.1925 in) Decompression device Device type Auto decomp Air filter Air filter element...
  • Page 34: Chassis Specifications

    CHASSIS SPECIFICATIONS EAS20300 CHASSIS SPECIFICATIONS Chassis Frame type Double cradle Caster angle WR125R 27.00° WR125X 25.50° Trail WR125R 107.0 mm (4.21 in) WR125X 78.5 mm (3.09 in) Front wheel Wheel type Spoke wheel WR125R 21 × 1.6 Rim size WR125X 17 × 3 Rim material WR125R Steel WR125X Aluminum...
  • Page 35 CHASSIS SPECIFICATIONS Manufacturer/model WR125R MICHELIN/T63 WR125R PIRELLI/MT21 WR125R PIRELLI/SCORPION A/T WR125R MICHELIN/SIRAC WR125X PIRELLI/SPORT DEMON Wear limit (rear) 1.6 mm (0.06 in) Tire air pressure (measured on cold tires) Loading condition 0–90 kg (0–198 lb) Front 200 kPa (2.00 kgf/cm², 29 psi) Rear 200 kPa (2.00 kgf/cm², 29 psi) Loading condition...
  • Page 36 CHASSIS SPECIFICATIONS Front suspension Type Telescopic fork Spring/shock absorber type Coil spring/oil damper Front fork travel WR125R 240.0 mm (9.45 in) WR125X 210.0 mm (8.27 in) Fork spring free length 520.0 mm (20.47 in) Limit 468.0 mm (18.43 in) Installed length WR125R 517.0 mm (20.35 in) WR125X 514.0 mm (20.24 in) Spring rate K1...
  • Page 37: Electrical Specifications

    TCI (digital) Advancer type Throttle position sensor and electrical Ignition timing (B.T.D.C.) 10.0°/1400 r/min Engine control unit Model/manufacturer WR125R 22B00/YAMAHA WR125X 22B10/YAMAHA Ignition coil Model/manufacturer 2JN/YAMAHA Minimum ignition spark gap 6.0 mm (0.24 in) 2.16–2.64 Ω at 20 °C (68 °F)
  • Page 38 High beam indicator light Coolant temperature warning light Engine trouble warning light Electric starting system System type Constant mesh Starter motor Model/manufacturer 5D7/YAMAHA Power output 0.20 kW 0.0315–0.0385 Ω Armature coil resistance Brush overall length 7.0 mm (0.28 in) Limit 3.50 mm (0.14 in)
  • Page 39 ELECTRICAL SPECIFICATIONS Headlight relay Model/manufacturer ACM33211 M05/MATSUSHITA 96.0 Ω Coil resistance Radiator fan Model/manufacturer SSW6101/PANASONIC Running rpm 4800 r/min Fan motor relay Model/manufacturer ACM33211 M05/MATSUSHITA 96.0 Ω Coil resistance Fuses Main fuse 20.0 A Headlight fuse 15.0 A Signaling system fuse 7.5 A Ignition fuse 7.5 A...
  • Page 40: Tightening Torques

    TIGHTENING TORQUES EAS20320 TIGHTENING TORQUES EAS20330 GENERAL TIGHTENING TORQUE SPECIFICATIONS This chart specifies tightening torques for stan- dard fasteners with a standard ISO thread pitch. Tightening torque specifications for special com- ponents or assemblies are provided for each chapter of this manual. To avoid warpage, tight- en multi-fastener assemblies in a crisscross pat- tern and progressive stages until the specified tightening torque is reached.
  • Page 41: Engine Tightening Torques

    30 Nm (3.0 m·kgf, 22 ft·lbf) Camshaft retainer bolt 7 Nm (0.7 m·kgf, 5.1 ft·lbf) Timing chain guide (intake side) 10 Nm (1.0 m·kgf, 7.2 ft·lbf) bolt Yamaha bond No.1215 Timing chain tensioner bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) (Three Bond No.1215...
  • Page 42 TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Air filter case bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Air induction system reed valve 10 Nm (1.0 m·kgf, 7.2 ft·lbf) bolt Exhaust pipe nut 20 Nm (2.0 m·kgf, 14 ft·lbf) Muffler bolt 27 Nm (2.7 m·kgf, 19 ft·lbf) Muffler clamp bolt...
  • Page 43 TIGHTENING TORQUES Generator cover tightening sequence: 3,11 2,10 Clutch cover tightening sequence: 2,12 3,13 Crankcase tightening sequence: 2,13 3,14 A. Left crankcase B. Right crankcase 2-18...
  • Page 44: Chassis Tightening Torques

    TIGHTENING TORQUES EAS20350 CHASSIS TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Engine front lower bracket nut 67 Nm (6.7 m·kgf, 48 ft·lbf) Engine front lower mounting nut 67 Nm (6.7 m·kgf, 48 ft·lbf) Engine rear lower mounting nut 67 Nm (6.7 m·kgf, 48 ft·lbf) Engine rear upper bracket bolt 33 Nm (3.3 m·kgf, 24 ft·lbf)
  • Page 45 TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Clutch lever nut 7 Nm (0.7 m·kgf, 5.1 ft·lbf) Front brake hose union bolt 30 Nm (3.0 m·kgf, 22 ft·lbf) Front brake hose holder bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Fuel tank front bracket and frame 10 Nm (1.0 m·kgf, 7.2 ft·lbf) bolt...
  • Page 46 TIGHTENING TORQUES Thread Item Q’ty Tightening torque Remarks size Rear wheel sprocket bolt 35 Nm (3.5 m·kgf, 25 ft·lbf) Rear brake caliper bleed screw 6 Nm (0.6 m·kgf, 4.3 ft·lbf) Rear brake pad pin 13 Nm (1.3 m·kgf, 9.4 ft·lbf) Rider footrest/sidestand bracket 62 Nm (6.2 m·kgf, 45 ft·lbf) assembly bolt...
  • Page 47 TIGHTENING TORQUES A. WR125R B. WR125X Front wheel axle pinch bolts 1. Insert the front wheel axle from the right side of the vehicle and tighten it to 58 Nm (5.8 m·kgf, 42 ft·lbf). 2. Tighten each bolt to 9 Nm (0.9 m·kgf, 6.5 ft·lbf) in the order of pinch bolt “2” → pinch bolt “1” → pinch bolt “2”...
  • Page 48: Lubrication Points And Lubricant Types

    LUBRICATION POINTS AND LUBRICANT TYPES EAS20360 LUBRICATION POINTS AND LUBRICANT TYPES EAS20370 ENGINE Lubrication point Lubricant Oil seal lips Bearings Cylinder head bolt seats, cylinder head bolt threads and washers Water pump assembly O-rings Cylinder head cover gasket Connecting rod big end Piston pin Cylinder inner surface, piston, ring grooves, and piston rings Balancer O-rings...
  • Page 49 Clutch boss nut seat, nut thread, and lock washer Main axle and pinion gears Drive axle and wheel gears Shift drum assembly Shift forks and shift fork guide bar Shift shaft Yamaha bond Crankshaft position sensor/stator coil lead grommet No.1215 (Three Bond No.1215®) Yamaha bond Crankcase mating surfaces No.1215 (Three Bond...
  • Page 50: Chassis

    LUBRICATION POINTS AND LUBRICANT TYPES EAS20380 CHASSIS Lubrication point Lubricant Swingarm dust cover lips Swingarm pivot shaft bushing (outer surface) and swingarm bushings (in- ner surface) Pivot shaft Oil seal lips (swingarm and connecting rod) Swingarm spacer and connecting rod spacer (outer surface) Chain tensioner spacers outer surface Steering bearings, bearing outer races, and bearing cover lip Oil seal lips (front wheel and speed sensor)
  • Page 51 LUBRICATION POINTS AND LUBRICANT TYPES 2-26...
  • Page 52: Lubrication System Chart And Diagrams

    LUBRICATION SYSTEM CHART AND DIAGRAMS EAS20390 LUBRICATION SYSTEM CHART AND DIAGRAMS EAS20400 ENGINE OIL LUBRICATION CHART 2-27...
  • Page 53 LUBRICATION SYSTEM CHART AND DIAGRAMS 1. Oil pump 2. Oil filter element 3. Crankshaft 4. Camshaft 5. Main axle 6. Drive axle 2-28...
  • Page 54: Lubrication Diagrams

    LUBRICATION SYSTEM CHART AND DIAGRAMS EAS20410 LUBRICATION DIAGRAMS 2-29...
  • Page 55 LUBRICATION SYSTEM CHART AND DIAGRAMS 1. Clutch push lever 2. Main axle 3. Drive axle 4. Crankshaft 5. Oil filter 6. Oil pump assembly 7. Oil strainer A. To cylinder head 2-30...
  • Page 56 LUBRICATION SYSTEM CHART AND DIAGRAMS 2-31...
  • Page 57 LUBRICATION SYSTEM CHART AND DIAGRAMS 1. Camshaft 2. Crankshaft 3. Main axle 4. Drive axle 2-32...
  • Page 58: Cooling System Diagrams

    COOLING SYSTEM DIAGRAMS EAS20420 COOLING SYSTEM DIAGRAMS 2-33...
  • Page 59 COOLING SYSTEM DIAGRAMS 1. Radiator cap 2. Water pump breather hose 3. Coolant reservoir hose 4. Coolant reservoir breather hose 5. Coolant reservoir 6. Water pump 7. Radiator outlet hose 8. Radiator 9. Radiator inlet hose 2-34...
  • Page 60: Cable Routing

    CABLE ROUTING EAS20430 CABLE ROUTING 2-35...
  • Page 61 CABLE ROUTING 1. Clutch cable 2. Meter assembly 3. Front brake hose 4. Throttle cable 5. Front brake light switch lead 6. Right handlebar switch lead 7. Left handlebar switch lead 8. Clutch switch lead 9. Speed sensor lead 10. Front left turn signal lead 11.
  • Page 62 CABLE ROUTING 2-37...
  • Page 63 CABLE ROUTING 1. Wire harness 2. Throttle cable 3. Battery breather hose 4. Spark plug lead 5. Horn 6. Coolant temperature sensor lead 7. Clutch cable 8. Main switch lead 9. Right handlebar switch lead 10. Front brake light switch lead 11.
  • Page 64 CABLE ROUTING 2-39...
  • Page 65 CABLE ROUTING 1. Wire harness 2. Air filter case silencer hose 3. Battery breather hose 4. Brake fluid reservoir hose 5. Rear brake hose 6. Rear brake light switch 7. Air induction system hose (air filter case to reed valve assembly) 8.
  • Page 66 CABLE ROUTING 2-41...
  • Page 67 CABLE ROUTING 1. Front brake hose 2. Clutch cable 3. Radiator fan motor coupler 4. Radiator fan motor lead 5. Ignition coil lead 6. Fuel injector coupler 7. Throttle body sensor assembly coupler 8. Auxiliary light coupler 9. Auxiliary light bulb 10.
  • Page 68 CABLE ROUTING 2-43...
  • Page 69 CABLE ROUTING 1. Tail/brake light 2. License plate light 3. Neutral switch lead 4. Sidestand switch lead 5. Crankshaft position sensor/stator coil lead 6. Ground lead 7. Sidestand switch 8. Neutral switch 9. ECU (engine control unit) 10. Generator cover 11.
  • Page 70 CABLE ROUTING 2-45...
  • Page 71 CABLE ROUTING 1. Clutch cable 2. Wire harness 3. Throttle cable 4. Fuse box 5. Starter relay 6. Ground lead 7. Starter motor lead 8. Sidestand switch lead 9. Crankshaft position sensor/stator coil lead 10. Neutral switch lead 11. Throttle body sensor assembly lead 12.
  • Page 72 CABLE ROUTING 2-47...
  • Page 73 CABLE ROUTING 1. Headlight relay 2. Radiator fan motor relay 3. Starting circuit cut-off relay 4. Rear brake light switch coupler 5. Ground lead (short lead to the frame) 6. Rectifier/regulator 7. Couplers (tail/brake light, license plate light, rear left turn signal light, and rear right turn signal light) 8.
  • Page 74 CABLE ROUTING WR125R WR125X 2-49...
  • Page 75 CABLE ROUTING 1. Front brake hose 2. Front brake hose guide 3. Front fork protector 4. Front fork protector guide 5. Front brake hose holders – ° A. 4 B. White paint mark C. Yellow paint mark 2-50...
  • Page 76 CABLE ROUTING WR125X WR125R 2-51...
  • Page 77 CABLE ROUTING 1. Speed sensor lead 2. Front fork protector 3. Front fork protector guide 4. Speed sensor lead holder 5. Front mudguard A. White paint mark B. Yellow paint mark 2-52...
  • Page 78 CABLE ROUTING 2-53...
  • Page 79: Periodic Checks And Adjustments

    PERIODIC CHECKS AND ADJUSTMENTS PERIODIC MAINTENANCE ................3-1 INTRODUCTION ..................3-1 PERIODIC MAINTENANCE CHART FOR THE EMISSION CONTROL SYSTEM ................3-1 GENERAL MAINTENANCE AND LUBRICATION CHART ....... 3-1 ENGINE ......................3-4 ADJUSTING THE VALVE CLEARANCE ..........3-4 ADJUSTING THE EXHAUST GAS VOLUME ........... 3-5 ADJUSTING THE ENGINE IDLING SPEED ..........
  • Page 80 ELECTRICAL SYSTEM................. 3-27 CHECKING AND CHARGING THE BATTERY........3-27 CHECKING THE FUSES ................ 3-27 REPLACING THE HEADLIGHT BULB............ 3-27 ADJUSTING THE HEADLIGHT BEAM ........... 3-27...
  • Page 82: Periodic Maintenance

    UK, a mileage-based maintenance, is performed instead. • From 30000 km (17500 mi), repeat the maintenance intervals starting from 6000 km (3500 mi). • Items marked with an asterisk should be performed by a Yamaha dealer as they require special tools, data and technical skills.
  • Page 83 PERIODIC MAINTENANCE ODOMETER READING CHECK OR MAINTENANCE ANNUAL ITEM 1000 km 6000 km 12000 km 18000 km 24000 km CHECK (600 mi) (3500 mi) (7000 mi) (10500 mi) (14000 mi) √ √ √ √ √ • Check for cracks or damage. 6 * Brake hoses •...
  • Page 84 PERIODIC MAINTENANCE EAUM2070 • The air filter needs more frequent service if you are riding in unusually wet or dusty areas. • Hydraulic brake service • Regularly check and, if necessary, correct the brake fluid level. • Every two years change the brake fluid. •...
  • Page 85: Engine

    ENGINE EAS20472 ENGINE EAS20520 ADJUSTING THE VALVE CLEARANCE The following procedure applies to all of the valves. • Valve clearance adjustment should be made on a cold engine, at room temperature. • When the valve clearance is to be measured or c.
  • Page 86: Adjusting The Exhaust Gas Volume

    ENGINE EAS20600 ADJUSTING THE EXHAUST GAS VOLUME Be sure to set the CO density level to standard, and then adjust the exhaust gas volume. 1. Remove: • Seat Refer to “GENERAL CHASSIS” on page 4-1. 2. Set the main switch to “OFF”. 3.
  • Page 87: Adjusting The Engine Idling Speed

    ENGINE 7. After selecting “CO”, press the “MODE” but- 1. Start the engine and let it warm up for several ton. minutes. 8. Check that “C1” appears on the LCD of the FI 2. Connect: diagnostic tool, and then press the “MODE” •...
  • Page 88: Checking The Spark Plug

    ENGINE 1. Check: M MMM M MMM M MMM M MMM M MMM Handlebar end • Throttle cable free play “a” a. Slide back the rubber cover “1”. Out of specification → Adjust. b. Loosen the locknut “2”. Throttle cable free play c.
  • Page 89: Checking The Ignition Timing

    ENGINE 4. Check: • Electrode “1” Damage/wear → Replace the spark plug. • Insulator “2” Abnormal color → Replace the spark plug. Normal color is medium-to-light tan. 5. Clean: • Spark plug (with a spark plug cleaner or wire brush) 6.
  • Page 90: Measuring The Compression Pressure

    ENGINE The ignition timing is not adjustable. L LLL L LLL L LLL L LLL L LLL 4. Remove: • Digital tachometer • Timing light 5. Install: • Timing mark accessing screw (along with the O-ring 6. Measure: • Compression pressure EAS20710 MEASURING THE COMPRESSION Out of specification →...
  • Page 91: Checking The Engine Oil Level

    ENGINE 8. Install: -20 -10 10 20 30 40 50 ˚C • Spark plug SAE 10W-30 Spark plug SAE 10W-40 13 Nm (1.3 m·kgf, 9.4 ft·lbf) SAE 10W-50 9. Connect: SAE 15W-40 • Spark plug cap SAE 20W-40 EAS28920 SAE 20W-50 CHECKING THE ENGINE OIL LEVEL 1.
  • Page 92 ENGINE • O-ring • Engine oil drain plug Engine oil drain plug 32 Nm (3.2 m·kgf, 23 ft·lbf) 8. Fill: • Crankcase (with the specified amount of the recom- mended engine oil) Engine oil quantity Total amount 1.15 L (1.22 US qt, 1.01 Imp.qt) Without oil filter element replace- ment 0.95 L (1.00 US qt, 0.84 Imp.qt)
  • Page 93: Adjusting The Clutch Cable Free Play

    ENGINE d. Start the engine after solving the problem(s) d. Tighten the locknut. and check the engine oil pressure again. e. Place the rubber cover in its original position. e. Tighten the oil check bolt to specification. If the specified clutch cable free play cannot be Oil check bolt obtained on the handlebar end of the cable, use 7 Nm (0.7 m·kgf, 5.1 ft·lbf)
  • Page 94: Checking The Throttle Body Joint And Air Filter Case Joint

    ENGINE 1. Remove: • Seat • Seat Refer to “GENERAL CHASSIS” on page 4-1. • Seat bracket EAS22B1003 Refer to “GENERAL CHASSIS” on page 4-1. CHECKING THE THROTTLE BODY JOINT 2. Remove: AND AIR FILTER CASE JOINT • Air filter case cover “1” 1.
  • Page 95: Checking The Exhaust System

    ENGINE Below the minimum level mark → Add the recommended coolant to the proper level. EAS21080 CHECKING THE EXHAUST SYSTEM 1. Check: ECA22B1004 NOTICE • Exhaust pipe “1” • Adding water instead of coolant lowers the • Muffler “2” Cracks/damage → Replace. antifreeze content of the coolant.
  • Page 96: Changing The Coolant

    ENGINE 3. Install: 4. Drain: • Fuel tank cover assembly • Coolant Refer to “GENERAL CHASSIS” on page 4-1. (from the engine and radiator) 5. Remove: EAS21130 • Coolant reservoir cap “1” CHANGING THE COOLANT • Coolant reservoir “2” 1. Remove: •...
  • Page 97 ENGINE EWA13040 WARNING • If coolant splashes in your eyes, thorough- ly wash them with water and consult a doc- tor. • If coolant splashes on your clothes, quickly wash it away with water and then with soap and water. •...
  • Page 98: Chassis

    CHASSIS EAS21140 EWA22B1013 CHASSIS WARNING A soft or spongy feeling in the brake pedal EAS21200 can indicate the presence of air in the brake ADJUSTING THE REAR DISC BRAKE system. Before the vehicle is operated, the 1. Check: air must be removed by bleeding the brake •...
  • Page 99: Checking The Front Brake Pads

    CHASSIS EWA22B1014 WARNING • Use only the designated brake fluid. Other brake fluids may cause the rubber seals to deteriorate, causing leakage and poor brake performance. • Refill with the same type of brake fluid that is already in the system. Mixing brake fluids may result in a harmful chemical reaction, leading to poor brake performance.
  • Page 100: Checking The Rear Brake Hose

    CHASSIS 3. Hold the vehicle upright and apply the front 2. Remove: brake several times. • Owner’s tool kit “1” 4. Check: • Brake fluid reservoir bolt “2” • Brake hose Brake fluid leakage → Replace the damaged hose. Refer to “FRONT BRAKE” on page 4-19. EAS21290 CHECKING THE REAR BRAKE HOSE 1.
  • Page 101: Adjusting The Drive Chain Slack

    CHASSIS Loosening the bleed screw will release the pres- Place the vehicle on a suitable stand so that the sure and cause the brake lever to contact the rear wheel is elevated. throttle grip or the brake pedal to fully extend. 2.
  • Page 102: Lubricating The Drive Chain

    CHASSIS Recommended lubricant Engine oil or chain lubricant suitable for O-ring chains EAS21510 CHECKING AND ADJUSTING THE STEERING HEAD 1. Stand the vehicle on a level surface. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. Place the vehicle on a suitable stand so that the front wheel is elevated.
  • Page 103: Checking The Front Fork

    CHASSIS Steering nut wrench 90890-01403 Exhaust flange nut wrench YU-A9472 Lower ring nut (initial tightening torque) 38 Nm (3.8 m·kgf, 27 ft·lbf) L LLL L LLL L LLL L LLL L LLL Set the torque wrench at a right angle to the 5.
  • Page 104: Checking The Tires

    CHASSIS Spring preload Spring preload adjusting positions ECA13590 NOTICE Minimum Never go beyond the maximum or minimum Standard adjustment positions. 1. Remove: Maximum • Rear mudguard “1” L LLL L LLL L LLL L LLL L LLL EAS21660 CHECKING THE TIRES The following procedure applies to both of the tires.
  • Page 105 No guarantee con- cerning handling characteristics can be giv- en if a tire combination other than one 1. Tire tread depth approved by Yamaha is used on this vehicle. 2. Side wall 3. Wear indicator Front tire Size WR125R 80/90–21 M/C 48P...
  • Page 106: Checking The Wheels

    CHASSIS Rear tire After a tire or wheel has been changed or re- Size placed, always balance the wheel. WR125R 110/80–18 M/C 58P WR125R 110/80–18 M/C 58S WR125R 110/80–18 M/C 58R EAS21680 CHECKING AND TIGHTENING THE SPOKES WR125X 140/70–17 M/C 66H The following procedure applies to all of the Manufacturer/model spokes.
  • Page 107: Checking And Lubricating The Cables

    CHASSIS EAS21710 LUBRICATING THE BRAKE PEDAL Lubricate the pivoting point and metal-to-metal moving parts of the pedal. Recommended lubricant Lithium-soap-based grease EAS21720 LUBRICATING THE SIDESTAND Lubricate the pivoting point and metal-to-metal moving parts of the sidestand. EAS21690 CHECKING AND LUBRICATING THE Recommended lubricant CABLES Lithium-soap-based grease...
  • Page 108 ELECTRICAL SYSTEM EAS21750 ELECTRICAL SYSTEM EAS21760 CHECKING AND CHARGING THE BATTERY Refer to “ELECTRICAL COMPONENTS” on page 8-59. EAS21770 CHECKING THE FUSES Refer to “ELECTRICAL COMPONENTS” on page 8-59. EWA13320 WARNING EAS21780 REPLACING THE HEADLIGHT BULB Since the headlight bulb gets extremely hot, 1.
  • Page 109 ELECTRICAL SYSTEM L LLL L LLL L LLL L LLL L LLL 3-28...
  • Page 110 ELECTRICAL SYSTEM 3-29...
  • Page 111 CHASSIS GENERAL CHASSIS..................4-1 REMOVING THE REAR SIDE COVERS ..........4-5 INSTALLING THE AIR FILTER CASE ............4-5 FRONT WHEEL....................4-6 REMOVING THE FRONT WHEEL (DISC)..........4-10 DISASSEMBLING THE FRONT WHEEL..........4-10 CHECKING THE FRONT WHEEL ............4-10 ASSEMBLING THE FRONT WHEEL............4-11 INSTALLING THE FRONT WHEEL (DISC) ..........
  • Page 112 HANDLEBAR ....................4-41 REMOVING THE HANDLEBAR.............. 4-43 CHECKING THE HANDLEBAR .............. 4-43 INSTALLING THE HANDLEBAR ............4-43 FRONT FORK....................4-46 REMOVING THE FRONT FORK LEGS..........4-50 DISASSEMBLING THE FRONT FORK LEGS ........4-50 CHECKING THE FRONT FORK LEGS ..........4-51 ASSEMBLING THE FRONT FORK LEGS ..........
  • Page 114: General Chassis

    GENERAL CHASSIS EAS21830 GENERAL CHASSIS Removing the seat and covers 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf)
  • Page 115 GENERAL CHASSIS Disassembling the fuel tank cover Order Job/Parts to remove Q’ty Remarks Fuel tank top cover Fuel overflow hose Fuel tank front side cover Fuel tank rear side cover For assembly, reverse the disassembly pro- cedure.
  • Page 116 GENERAL CHASSIS Removing the battery and battery box 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Fuel tank cover assembly...
  • Page 117 GENERAL CHASSIS Removing the air filter case 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 1 Nm (0.1 m kgf, 0.7 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Seat bracket/Fuel tank cover assembly...
  • Page 118: Removing The Rear Side Covers

    GENERAL CHASSIS 3. Tighten: EAS22B1037 REMOVING THE REAR SIDE COVERS • Air filter case joint clamp screw 1. Remove: • Rear side covers Air filter case joint clamp screw 1 Nm (0.1 m·kgf, 0.7 ft·lbf) To remove a rear side cover “1”, remove the pro- 4.
  • Page 119: Front Wheel

    FRONT WHEEL EAS21870 FRONT WHEEL Removing the front wheel and brake disc (WR125R) 58 Nm (5.8 m kgf, 42 ft Ibf) • • 9 Nm (0.9 m kgf, 6.5 ft Ibf) • • 13 Nm (1.3 m kgf, 9.4 ft Ibf) •...
  • Page 120 FRONT WHEEL Removing the front wheel and brake disc (WR125X) 58 Nm (5.8 m kgf, 42 ft Ibf) • • 9 Nm (0.9 m kgf, 6.5 ft Ibf) • • 30 Nm (3.0 m kgf, 22 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf)
  • Page 121 FRONT WHEEL Disassembling the front wheel (WR125R) Order Job/Parts to remove Q’ty Remarks Oil seal Bearing Spacer For assembly, reverse the disassembly pro- cedure.
  • Page 122 FRONT WHEEL Disassembling the front wheel (WR125X) Order Job/Parts to remove Q’ty Remarks Collar Oil seal Bearing Spacer For assembly, reverse the disassembly pro- cedure.
  • Page 123: Removing The Front Wheel (Disc)

    FRONT WHEEL EAS21890 REMOVING THE FRONT WHEEL (DISC) 1. Stand the vehicle on a level surface. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. 2. Elevate: • Front wheel Place the vehicle on a suitable stand so that the L LLL L LLL L LLL...
  • Page 124: Assembling The Front Wheel

    FRONT WHEEL Radial wheel runout limit 1.0 mm (0.04 in) Lateral wheel runout limit 0.5 mm (0.02 in) L LLL L LLL L LLL L LLL L LLL EAS21990 INSTALLING THE FRONT WHEEL (DISC) 1. Install: • Front brake disc 5.
  • Page 125 FRONT WHEEL 4. Measure: • Collar “1” (WR125R) Make sure that the projections “a” on the speed Out of specification → Adjust. sensor fit over the stopper “b” on the outer tube. Installed depth “a” 8 mm (0.31 in) 7. Tighten: •...
  • Page 126: Rear Wheel

    REAR WHEEL EAS22020 REAR WHEEL Removing the rear wheel, rear brake disc, and rear wheel sprocket 16 Nm (1.6 m kgf, 11 ft Ibf) • • 90 Nm (9.0 m kgf, 65 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 127 REAR WHEEL Removing the rear wheel, rear brake disc, and rear wheel sprocket 16 Nm (1.6 m kgf, 11 ft Ibf) • • 90 Nm (9.0 m kgf, 65 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 128 REAR WHEEL Disassembling the rear wheel (WR125R) Order Job/Parts to remove Q’ty Remarks Oil seal Bearing Spacer For assembly, reverse the disassembly pro- cedure. 4-15...
  • Page 129 REAR WHEEL Disassembling the rear wheel (WR125X) Order Job/Parts to remove Q’ty Remarks Oil seal Bearing Spacer For assembly, reverse the disassembly pro- cedure. 4-16...
  • Page 130: Removing The Rear Wheel (Disc)

    REAR WHEEL • Oil seals EAS22040 REMOVING THE REAR WHEEL (DISC) Refer to “CHECKING THE FRONT WHEEL” 1. Stand the vehicle on a level surface. on page 4-10. EWA13120 2. Check: WARNING • Tire Securely support the vehicle so that there is •...
  • Page 131: Assembling The Rear Wheel

    REAR WHEEL b. Clean the rear wheel drive hub with a clean cloth, especially the surfaces that contact the sprocket. c. Install the new rear wheel sprocket. Rear wheel sprocket bolt 35 Nm (3.5 m·kgf, 25 ft·lbf) Tighten the bolts in stages and in a crisscross pattern.
  • Page 132: Front Brake

    FRONT BRAKE EAS22210 FRONT BRAKE Removing the front brake pads 30 Nm (3.0 m kgf, 22 ft Ibf) • • 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) • • Order Job/Parts to remove Q’ty...
  • Page 133 FRONT BRAKE Removing the front brake master cylinder 30 Nm (3.0 m kgf, 22 ft Ibf) • • 9 Nm (0.9 m kgf, 6.5 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Brake fluid Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM”...
  • Page 134 FRONT BRAKE Removing the front brake caliper 30 Nm (3.0 m kgf, 22 ft Ibf) • • 30 Nm (3.0 m kgf, 22 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Brake fluid Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM”...
  • Page 135 FRONT BRAKE Disassembling the front brake caliper 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Brake pad pin Front brake pad Brake pad spring Brake pad support Front brake caliper bracket Brake caliper piston...
  • Page 136: Introduction

    FRONT BRAKE e. Measure the deflection 1.5 mm (0.06 in) EAS22220 INTRODUCTION (WR125R) or 2.0 mm (0.09 in) (WR125X) be- EWA14100 low the edge of the brake disc. WARNING Disc brake components rarely require disas- sembly. Therefore, always follow these pre- ventive measures: •...
  • Page 137: Replacing The Front Brake Pads

    FRONT BRAKE 2. Install: • Brake pads • Brake pad spring • Brake pad support Always install new brake pads, a new brake pad spring, and a new brake pad support as a set. M MMM M MMM M MMM M MMM M MMM a.
  • Page 138: Removing The Front Brake Caliper

    FRONT BRAKE Brake pad pin 18 Nm (1.8 m·kgf, 13 ft·lbf) LOCTITE® Front brake caliper bolt 30 Nm (3.0 m·kgf, 22 ft·lbf) LOCTITE® 4. Check: • Brake fluid level Below the minimum level mark “a” → Add the M MMM M MMM M MMM M MMM...
  • Page 139: Assembling The Front Brake Caliper

    FRONT BRAKE • Brake caliper cylinders “2” • Brake hose union bolt “3” Scratches/wear → Replace the brake caliper Front brake caliper bolt assembly. 30 Nm (3.0 m·kgf, 22 ft·lbf) • Brake caliper body “3” Brake hose union bolt Cracks/damage → Replace the brake caliper 30 Nm (3.0 m·kgf, 22 ft·lbf) assembly.
  • Page 140: Removing The Front Brake Master Cylinder

    FRONT BRAKE EWA13540 EAS22490 REMOVING THE FRONT BRAKE MASTER WARNING CYLINDER • Use only the designated brake fluid. Other brake fluids may cause the rubber seals to deteriorate, causing leakage and poor Before removing the front brake master cylinder, brake performance. drain the brake fluid from the entire brake sys- tem.
  • Page 141 FRONT BRAKE 3. Fill: • Brake master cylinder reservoir • Install the brake master cylinder holder with the (with the specified amount of the recom- arrow mark “a” pointing forward. mended brake fluid) • Align the end of the brake master cylinder hold- er with the punch mark “b”...
  • Page 142 FRONT BRAKE Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” on page 3-19. 4-29...
  • Page 143: Rear Brake

    REAR BRAKE EAS22550 REAR BRAKE Removing the rear brake pads 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • 13 Nm (1.3 m kgf, 9.4 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Rear wheel Refer to “REAR WHEEL” on page 4-13. Brake pad clip Brake pad pin Rear brake pad...
  • Page 144 REAR BRAKE Removing the rear brake master cylinder 4 Nm (0.4 m kgf, 2.9 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) • • 22 Nm (2.2 m kgf, 16 ft Ibf) •...
  • Page 145 REAR BRAKE Removing the rear brake master cylinder 4 Nm (0.4 m kgf, 2.9 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) • • 22 Nm (2.2 m kgf, 16 ft Ibf) •...
  • Page 146 REAR BRAKE Disassembling the rear brake master cylinder 17 Nm (1.7 m kgf, 12 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Brake hose joint Brake master cylinder kit Brake master cylinder body For assembly, reverse the disassembly pro- cedure.
  • Page 147 REAR BRAKE Removing the rear brake caliper 30 Nm (3.0 m kgf, 22 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Brake fluid Refer to “BLEEDING THE HYDRAULIC BRAKE SYSTEM” on page 3-19. Rear wheel Refer to “REAR WHEEL” on page 4-13. Rear brake hose union bolt Copper washer Rear brake hose...
  • Page 148 REAR BRAKE Disassembling the rear brake caliper 13 Nm (1.3 m kgf, 9.4 ft Ibf) • • 6 Nm (0.6 m kgf, 4.3 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Brake pad pin clip Brake pad pin Rear brake pad Brake pad spring Brake pad support...
  • Page 149: Introduction

    REAR BRAKE EAS22560 INTRODUCTION Brake disc thickness limit EWA14100 4.0 mm (0.16 in) WARNING Disc brake components rarely require disas- 5. Adjust: sembly. Therefore, always follow these pre- • Brake disc deflection ventive measures: Refer to “CHECKING THE FRONT BRAKE •...
  • Page 150: Removing The Rear Brake Caliper

    REAR BRAKE EAS22590 REMOVING THE REAR BRAKE CALIPER Always install new brake pads, a new brake pad spring, and a new brake pad support as a set. Before disassembling the brake caliper, drain M MMM M MMM M MMM M MMM M MMM the brake fluid from the entire brake system.
  • Page 151: Checking The Rear Brake Caliper

    REAR BRAKE b. Remove the brake caliper piston dust seal EAS22650 ASSEMBLING THE REAR BRAKE CALIPER and brake caliper piston seal. EWA22B1008 L LLL L LLL L LLL L LLL L LLL WARNING • Before installation, all internal brake com- EAS22640 CHECKING THE REAR BRAKE CALIPER ponents should be cleaned and lubricated...
  • Page 152: Removing The Rear Brake Master Cylinder

    REAR BRAKE 3. Install: • Brake pads • Brake pad spring • Brake pad support • Brake pad pin • Brake pad pin clip • Brake caliper Refer to “REPLACING THE REAR BRAKE PADS” on page 4-36. 4. Fill: • Brake fluid reservoir 7.
  • Page 153: Assembling The Rear Brake Master Cylinder

    REAR BRAKE EAS22730 EWA13090 ASSEMBLING THE REAR BRAKE MASTER WARNING CYLINDER • Use only the designated brake fluid. Other EWA13520 brake fluids may cause the rubber seals to WARNING deteriorate, causing leakage and poor • Before installation, all internal brake com- brake performance.
  • Page 154 HANDLEBAR EAS22840 HANDLEBAR Removing the handlebar 9 Nm (0.9 m kgf, 6.5 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 9 Nm (0.9 m kgf, 6.5 ft Ibf) •...
  • Page 155 HANDLEBAR Removing the handlebar 9 Nm (0.9 m kgf, 6.5 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 9 Nm (0.9 m kgf, 6.5 ft Ibf) •...
  • Page 156: Handlebar

    HANDLEBAR EAS22860 REMOVING THE HANDLEBAR Temporarily tighten the nuts. 1. Stand the vehicle on a level surface. EWA13120 3. Install: WARNING • Handlebar “1” Securely support the vehicle so that there is • Upper handlebar holders “2” no danger of it falling over. Upper handlebar holder bolt 2.
  • Page 157 HANDLEBAR 23˚ ± 5˚ 6. Install: L LLL L LLL L LLL L LLL L LLL • Clutch lever 9. Install: • Clutch switch “1” • Left handlebar switch “1” Align the projection “a” on the clutch switch with Align the projection “a” on the left handlebar the slit “b”...
  • Page 158 HANDLEBAR 11.Install: • Front brake master cylinder “1” • Front brake master cylinder holder “2” Front brake master cylinder hold- er bolt 9 Nm (0.9 m·kgf, 6.5 ft·lbf) • Install the brake master cylinder holder with the arrow mark “a” pointing forward. •...
  • Page 159: Front Fork

    FRONT FORK EAS22950 FRONT FORK Removing the front fork legs (WR125R) 23 Nm (2.3 m kgf, 17 ft Ibf) • • 22 Nm (2.2 m kgf, 16 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) • •...
  • Page 160 FRONT FORK Removing the front fork legs (WR125X) 22 Nm (2.2 m kgf, 16 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) • • 23 Nm (2.3 m kgf, 17 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 161 FRONT FORK Disassembling the front fork legs 20 Nm (2.0 m kgf, 14 ft Ibf) • • 28 Nm (2.8 m kgf, 20 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks The following procedure applies to both of the front fork legs.
  • Page 162 FRONT FORK Disassembling the front fork legs 20 Nm (2.0 m kgf, 14 ft Ibf) • • 28 Nm (2.8 m kgf, 20 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Inner tube bushing Outer tube For assembly, reverse the disassembly pro- cedure.
  • Page 163: Removing The Front Fork Legs

    FRONT FORK 3. Remove: EAS22960 REMOVING THE FRONT FORK LEGS • Front fork leg The following procedure applies to both of the front fork legs. EAS22980 DISASSEMBLING THE FRONT FORK LEGS 1. Stand the vehicle on a level surface. The following procedure applies to both of the EWA13120 WARNING front fork legs.
  • Page 164: Checking The Front Fork Legs

    FRONT FORK • Outer tube Damper rod holder Bends/damage/scratches → Replace. 90890-01460 EWA13650 T-handle WARNING 90890-01326 Do not attempt to straighten a bent inner T-handle 3/8" drive 60 cm long tube as this may dangerously weaken it. YM-01326 2. Measure: •...
  • Page 165 FRONT FORK Damper rod bolt • When assembling the front fork leg, be sure to 28 Nm (2.8 m·kgf, 20 ft·lbf) replace the following parts: LOCTITE® –Inner tube bushing –Outer tube bushing –Oil seal While holding the damper rod with the damper –Dust seal rod holder “2”...
  • Page 166 FRONT FORK 5. Install: 7. Install: • Oil seal “1” • Dust seal “1” (with the fork seal driver weight “2” and fork (with the fork seal driver “2”) seal driver attachment “3”) Fork seal driver weight ECA14220 90890-01367 NOTICE Replacement hammer Make sure the numbered side of the oil seal YM-A9409-7...
  • Page 167: Installing The Front Fork Legs

    FRONT FORK Tighten the lower bracket pinch bolts to specifi- cation twice, each time in the order of lower pinch bolt → upper pinch bolt. Do not loosen the bolts after tightening them to specification. 10.Install: • Spring • Spring seats •...
  • Page 168: Steering Head

    STEERING HEAD EAS23090 STEERING HEAD Removing the headlight assembly and meter assembly 7 Nm (0.7 m kgf, 5.1 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...
  • Page 169 STEERING HEAD Removing the headlight assembly and meter assembly 7 Nm (0.7 m kgf, 5.1 ft Ibf) 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...
  • Page 170 STEERING HEAD Removing the lower bracket 140 Nm (14.0 m kgf, 100 ft lbf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 1st 38 Nm (3.8 m kgf, 27 ft lbf) • • 2nd 4 Nm (0.4 m kgf, 2.9 ft lbf) •...
  • Page 171: Removing The Lower Bracket

    STEERING HEAD M MMM M MMM M MMM M MMM M MMM EAS23110 REMOVING THE LOWER BRACKET a. Remove the bearing races from the steering 1. Stand the vehicle on a level surface. head pipe with a long rod “1” and hammer. EWA13120 b.
  • Page 172 STEERING HEAD • Upper ring nut “3” • Lock washer “4” Refer to “CHECKING AND ADJUSTING THE STEERING HEAD” on page 3-21. 3. Install: • Upper bracket • Steering stem nut Temporarily tighten the steering stem nut. 4. Install: • Front fork legs Refer to “FRONT FORK”...
  • Page 173: Rear Shock Absorber Assembly

    REAR SHOCK ABSORBER ASSEMBLY EAS23160 REAR SHOCK ABSORBER ASSEMBLY Removing the rear shock absorber assembly 43 Nm (4.3 m kgf, 31 ft Ibf) 59 Nm (5.9 m kgf, 43 ft Ibf) • • • • 59 Nm (5.9 m kgf, 43 ft Ibf) •...
  • Page 174: Handling The Rear Shock Absorber Assembly (Wr125R)

    REAR SHOCK ABSORBER ASSEMBLY EAS22B1041 EAS23230 HANDLING THE REAR SHOCK ABSORBER REMOVING THE REAR SHOCK ABSORBER ASSEMBLY (WR125R) ASSEMBLY 1. Stand the vehicle on a level surface. EWA22B1020 WARNING EWA13120 WARNING This rear shock absorber assembly contains highly compressed nitrogen gas. Before Securely support the vehicle so that there is handling the rear shock absorber assembly, no danger of it falling over.
  • Page 175 REAR SHOCK ABSORBER ASSEMBLY Recommended lubricant Lithium-soap-based grease 2. Install: • Oil seals “1” (to the connecting rod) Installed depth “a” 0 mm (0 in) 2. Connecting rod A. Left side B. Right side 3. Install: • Relay arms “1” Be sure to face the “L”...
  • Page 176: Swingarm

    SWINGARM EAS23330 SWINGARM Removing the swingarm 80 Nm (8.0 m kgf, 58 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Refer to “GENERAL CHASSIS”...
  • Page 177 SWINGARM Removing the swingarm 80 Nm (8.0 m kgf, 58 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Bushing For installation, reverse the removal proce- dure.
  • Page 178: Removing The Swingarm

    SWINGARM EAS23350 EWA13770 REMOVING THE SWINGARM WARNING 1. Stand the vehicle on a level surface. Do not attempt to straighten a bent pivot EWA13120 shaft. WARNING Securely support the vehicle so that there is no danger of it falling over. 2.
  • Page 179 SWINGARM 2. Swingarm A. Left side B. Right side 3. Adjust: • Drive chain slack Refer to “ADJUSTING THE DRIVE CHAIN SLACK” on page 3-20. Drive chain slack 40.0–50.0 mm (1.57–1.97 in) ECA13550 NOTICE A drive chain that is too tight will overload the engine and other vital parts, and one that is too loose can skip and damage the swing- arm or cause an accident.
  • Page 180: Chain Drive

    CHAIN DRIVE EAS23400 CHAIN DRIVE Removing the drive chain 23 Nm (2.3 m kgf, 17 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Swingarm Refer to “SWINGARM” on page 4-63. Drive sprocket cover Drive sprocket retainer Drive sprocket...
  • Page 181: Removing The Drive Chain

    CHAIN DRIVE EAS23410 REMOVING THE DRIVE CHAIN 1. Stand the vehicle on a level surface. EWA13120 WARNING Securely support the vehicle so that there is no danger of it falling over. Place the vehicle on a suitable stand so that the rear wheel is elevated.
  • Page 182: Checking The Drive Sprocket

    CHAIN DRIVE b. Correct 1. Drive chain roller 2. Drive sprocket EAS23470 CHECKING THE REAR WHEEL SPROCKET Refer to “CHECKING AND REPLACING THE REAR WHEEL SPROCKET” on page 4-17 EAS28800 INSTALLING THE DRIVE CHAIN 1. Lubricate: L LLL L LLL L LLL L LLL L LLL...
  • Page 183 CHAIN DRIVE Drive chain slack 40.0–50.0 mm (1.57–1.97 in) ECA13550 NOTICE A drive chain that is too tight will overload the engine and other vital parts, and one that is too loose can skip and damage the swing- arm or cause an accident. Therefore, keep the drive chain slack within the specified lim- its.
  • Page 184 CHAIN DRIVE 4-71...
  • Page 185: Engine

    ENGINE ENGINE REMOVAL ..................5-1 REMOVING THE ENGINE ................ 5-5 INSTALLING THE ENGINE............... 5-5 INSTALLING THE RIDER FOOTREST/BRAKE PEDAL BRACKET ASSEMBLY ....................5-5 INSTALLING THE SHIFT PEDAL ............. 5-6 INSTALLING THE MUFFLER AND EXHAUST PIPE........ 5-6 CYLINDER HEAD.................... 5-7 REMOVING THE CYLINDER HEAD............5-9 CHECKING THE CYLINDER HEAD ............
  • Page 186 CLUTCH ......................5-38 REMOVING THE CLUTCH ..............5-42 CHECKING THE FRICTION PLATES............. 5-42 CHECKING THE CLUTCH PLATES ............5-43 CHECKING THE CLUTCH SPRINGS............. 5-43 CHECKING THE CLUTCH HOUSING ............ 5-43 CHECKING THE CLUTCH BOSS............5-43 CHECKING THE PRESSURE PLATE ............ 5-44 CHECKING THE CLUTCH PUSH LEVER AND SHORT CLUTCH PUSH ROD ................
  • Page 187 TRANSMISSION.................... 5-65 CHECKING THE SHIFT FORKS............. 5-68 CHECKING THE SHIFT DRUM ASSEMBLY.......... 5-68 CHECKING THE TRANSMISSION ............5-68 CHECKING THE LONG CLUTCH PUSH ROD........5-69 ASSEMBLING THE MAIN AXLE AND DRIVE AXLE ......5-69 INSTALLING THE SHIFT FORKS AND SHIFT DRUM ASSEMBLY ....................
  • Page 188: Engine Removal

    ENGINE REMOVAL EAS23711 ENGINE REMOVAL Removing the muffler and exhaust pipe 27 Nm (2.7 m kgf, 19 ft Ibf) • • 18 Nm (1.8 m kgf, 13 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) • •...
  • Page 189 ENGINE REMOVAL Disconnecting the leads and couplers 7 Nm (0.7 m kgf, 5.1 ft Ibf) 62 Nm (6.2 m kgf, 45 ft Ibf) • • • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 16 Nm (1.6 m kgf, 11 ft Ibf) •...
  • Page 190 ENGINE REMOVAL Disconnecting the leads and couplers 7 Nm (0.7 m kgf, 5.1 ft Ibf) 62 Nm (6.2 m kgf, 45 ft Ibf) • • • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 16 Nm (1.6 m kgf, 11 ft Ibf) •...
  • Page 191 ENGINE REMOVAL Removing the engine 46 Nm (4.6 m kgf, 33 ft Ibf) • • 67 Nm (6.7 m kgf, 48 ft Ibf) • • 46 Nm (4.6 m kgf, 33 ft Ibf) • • 33 Nm (3.3 m kgf, 24 ft Ibf) •...
  • Page 192: Removing The Engine

    ENGINE REMOVAL EAS22B1039 REMOVING THE ENGINE Engine front upper mounting nut 1. Remove: 67 Nm (6.7 m·kgf, 48 ft·lbf) • Engine ECA22B1028 • Engine rear bracket bolts “9” NOTICE Engine rear bracket bolt When removing the engine, be careful not to 33 Nm (3.3 m·kgf, 24 ft·lbf) pull on or damage the wire harness and bat- tery breather hose with the engine.
  • Page 193: Installing The Shift Pedal

    ENGINE REMOVAL 2. Check: Muffler clamp bolt • Brake pedal position 18 Nm (1.8 m·kgf, 13 ft·lbf) Refer to “ADJUSTING THE REAR DISC BRAKE” on page 3-17. Brake pedal position 12.0 mm (0.47 in) EAS22B1027 INSTALLING THE SHIFT PEDAL 1. Install: •...
  • Page 194: Cylinder Head

    CYLINDER HEAD EAS24100 CYLINDER HEAD Removing the cylinder head 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 22 Nm (2.2 m kgf, 16 ft Ibf) • • 13 Nm (1.3 m kgf, 9.4 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...
  • Page 195 Clutch cable holder Timing chain tensioner Timing chain tensioner gasket Camshaft sprocket Decompression cam Cylinder head Cylinder head gasket Dowel pin Timing chain guide (exhaust side) For installation, reverse the removal proce- dure. * Yamaha bond No. 1215 (Three Bond No.1215®)
  • Page 196: Removing The Cylinder Head

    CYLINDER HEAD EAS24130 REMOVING THE CYLINDER HEAD To prevent the timing chain from falling into the 1. Align: crankcase, fasten it with a wire “1”. • “I” mark “a” on the generator rotor (with the stationary pointer “b” on the genera- tor cover) M MMM M MMM...
  • Page 197: Checking The Camshaft Sprocket And Timing Chain Guide

    CYLINDER HEAD EAS22B1004 CHECKING THE CAMSHAFT SPROCKET AND TIMING CHAIN GUIDE 1. Check: • Camshaft sprocket More than 1/4 tooth wear “a” → Replace the camshaft sprocket, timing chain and crank- shaft as a set. 2. Check: • Cylinder head Damage/scratches →...
  • Page 198: Checking The Decompression System

    CYLINDER HEAD d. Make sure that the timing chain tensioner rod comes out of the timing chain tensioner hous- ing smoothly. If there is rough movement, re- place the timing chain tensioner. e. Install the timing chain tensioner cap. L LLL L LLL L LLL L LLL...
  • Page 199 “d” on the cylin- threads. der head. d. Install the timing chain onto the camshaft sprocket, and then install the camshaft Yamaha bond No. 1215 sprocket onto the camshaft. 90890-85505 (Three Bond No.1215®) Timing chain tensioner bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf)
  • Page 200 CYLINDER HEAD 5. Turn: • Crankshaft (several turns counterclockwise) 6. Check: • “I” mark “a” Align the “I” mark on the generator rotor with the stationary pointer “b” on the generator cover. • “I” mark “c” Align the “I” mark on the camshaft sprocket with the stationary pointer “d”...
  • Page 201: Camshaft

    CAMSHAFT EAS23730 CAMSHAFT Removing the rocker arms and camshaft 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks...
  • Page 202: Checking The Camshaft

    CAMSHAFT EAS23840 EAS23880 CHECKING THE CAMSHAFT CHECKING THE ROCKER ARMS AND 1. Check: ROCKER ARM SHAFTS • Camshaft lobes The following procedure applies to all of the Blue discoloration/pitting/scratches → Re- rocker arms and rocker arm shafts. place the camshaft. 1.
  • Page 203: Installing The Camshaft And Rocker Arms

    CAMSHAFT 5. Calculate: 4. Install: • Rocker-arm-to-rocker-arm-shaft clearance • Rocker arms • Rocker arm shafts “1” Calculate the clearance by subtracting the rock- er arm shaft outside diameter from the rocker • Make sure that the cutout “a” in each rocker arm inside diameter.
  • Page 204 VALVES AND VALVE SPRINGS EAS24270 VALVES AND VALVE SPRINGS Removing the valves and valve springs Order Job/Parts to remove Q’ty Remarks Cylinder head Refer to “CYLINDER HEAD” on page 5-7. Rocker arms/Camshaft Refer to “CAMSHAFT” on page 5-14. Valve cotter Upper spring seat Valve spring Intake valve...
  • Page 205: Valves And Valve Springs

    VALVES AND VALVE SPRINGS EAS24280 REMOVING THE VALVES The following procedure applies to all of the valves and related components. Before removing the internal parts of the cylinder head (e.g., valves, valve springs, valve seats), make sure the valves properly seal. 1.
  • Page 206 VALVES AND VALVE SPRINGS b. Install the new valve guide with the valve Valve-stem-to-valve-guide clear- guide installer “2” and valve guide remover ance (intake) “1”. 0.010–0.037 mm (0.0004–0.0015 Valve guide position (intake) Limit 17.0–17.4 mm (0.669–0.685 in) 0.080 mm (0.0032 in) Valve guide position (exhaust) Valve-stem-to-valve-guide clear- 14.0–14.4 mm (0.551–0.567 in)
  • Page 207: Checking The Valve Seats

    VALVES AND VALVE SPRINGS 3. Eliminate: EAS24300 CHECKING THE VALVE SEATS • Carbon deposits The following procedure applies to all of the (from the valve face and valve seat) valves and valve seats. 4. Check: 1. Eliminate: • Valve face •...
  • Page 208: Checking The Valve Springs

    VALVES AND VALVE SPRINGS 4. Lap: • Valve face • Valve seat After replacing the cylinder head or replacing the valve and valve guide, the valve seat and valve face should be lapped. M MMM M MMM M MMM M MMM M MMM a.
  • Page 209: Installing The Valves

    VALVES AND VALVE SPRINGS Free length (intake) Spring tilt (intake) 41.71 mm (1.64 in) 2.5°/1.8 mm Limit Spring tilt (exhaust) 39.62 mm (1.56 in) 2.5°/1.8 mm Free length (exhaust) 41.71 mm (1.64 in) Limit 39.62 mm (1.56 in) EAS24340 INSTALLING THE VALVES The following procedure applies to all of the valves and related components.
  • Page 210 VALVES AND VALVE SPRINGS • Valve “3” • Valve spring “4” • Upper spring seat “5” (into the cylinder head) • Make sure each valve is installed in its original place. • Install the valve springs with the larger pitch “a” facing up.
  • Page 211: Cylinder And Piston

    CYLINDER AND PISTON EAS24350 CYLINDER AND PISTON Removing the cylinder and piston 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Cylinder head Refer to “CYLINDER HEAD” on page 5-7. Cylinder Cylinder gasket Dowel pin Piston pin clip Piston pin...
  • Page 212: Removing The Piston

    CYLINDER AND PISTON EAS24380 REMOVING THE PISTON When removing a piston ring, open the end gap 1. Remove: with your fingers and lift the other side of the ring • Piston pin clips “1” over the piston crown. • Piston pin “2” •...
  • Page 213: Checking The Piston Rings

    CYLINDER AND PISTON EAS24430 “C” = maximum of D –D CHECKING THE PISTON RINGS 1. Measure: “T” = maximum of D or D - maximum of D • Piston ring side clearance or D Out of specification → Replace the piston “R”...
  • Page 214: Checking The Piston Pin

    CYLINDER AND PISTON 3. Measure: 3. Measure: • Piston ring end gap • Piston pin bore inside diameter “b” Out of specification → Replace the piston Out of specification → Replace the piston. ring. Piston pin bore inside diameter 14.002–14.013 mm (0.5513– The oil ring expander end gap cannot be mea- 0.5517 in) sured.
  • Page 215 CYLINDER AND PISTON 2. Install: a. Top ring • Piston “1” b. Upper oil ring rail • Piston pin “2” c. Oil ring expander d. Lower oil ring rail • Piston pin clips “3” e. 2nd ring f. 20 mm (0.79 in) •...
  • Page 216: Generator And Starter Clutch

    GENERATOR AND STARTER CLUTCH EAS22B1006 GENERATOR AND STARTER CLUTCH Removing the generator and starter clutch 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 14 Nm (1.4 m kgf, 10 ft Ibf) •...
  • Page 217 GENERATOR AND STARTER CLUTCH Removing the generator and starter clutch 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 14 Nm (1.4 m kgf, 10 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf)
  • Page 218: Removing The Generator

    GENERATOR AND STARTER CLUTCH EAS24490 ECA13880 REMOVING THE GENERATOR NOTICE 1. Remove: To protect the end of the crankshaft, place an • Generator cover appropriate sized socket between the fly- wheel puller set center bolt and the crank- Loosen each bolt 1/4 of a turn at a time, in stag- shaft.
  • Page 219: Checking The Starter Clutch

    GENERATOR AND STARTER CLUTCH EAS24570 EAS24600 CHECKING THE STARTER CLUTCH INSTALLING THE STARTER CLUTCH 1. Check: 1. Install: • Starter clutch rollers “1” • Starter clutch assembly • Starter clutch spring caps “2” • Starter clutch bolts “1” • Starter clutch springs “3” Starter clutch bolt Damage/wear →...
  • Page 220 90890-01701 Primary clutch holder YS-01880-A 3. Apply: • Sealant (to the crankshaft position sensor/stator as- sembly lead grommet) Yamaha bond No. 1215 90890-85505 (Three Bond No.1215®) 4. Install: • Generator cover Generator cover bolt 10 Nm (1.0 m·kgf, 7.2 ft·lbf) Tighten the generator cover bolts in the proper tightening sequence as shown.
  • Page 221: Electric Starter

    ELECTRIC STARTER EAS24780 ELECTRIC STARTER Removing the starter motor 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Starter motor Starter motor lead Disconnect. For installation, reverse the removal proce- dure. 5-34...
  • Page 222 ELECTRIC STARTER Disassembling the starter motor Order Job/Parts to remove Q’ty Remarks O-ring Starter motor yoke O-ring Armature assembly Starter motor front cover/brush holder set Brush Brush spring For assembly, reverse the disassembly pro- cedure. 5-35...
  • Page 223: Checking The Starter Motor

    ELECTRIC STARTER EAS24790 CHECKING THE STARTER MOTOR Pocket tester 1. Check: 90890-03112 • Commutator Analog pocket tester Dirt → Clean with 600 grit sandpaper. YU-03112-C 2. Measure: • Commutator diameter “a” Armature coil Out of specification → Replace the starter Commutator resistance “1”...
  • Page 224: Assembling The Starter Motor

    ELECTRIC STARTER 7. Check: • Gear teeth Damage/wear → Replace the starter motor. 8. Check: • Bearing • Oil seal Damage/wear → Replace the starter motor front cover/brush holder set. EAS24800 ASSEMBLING THE STARTER MOTOR 1. Install: • Starter motor front cover/brush holder set “1” •...
  • Page 225: Clutch

    CLUTCH EAS25061 CLUTCH Removing the clutch cover 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) •...
  • Page 226 CLUTCH Removing the clutch 70 Nm (7.0 m kgf, 50 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Locknut Clutch spring Pressure plate...
  • Page 227 CLUTCH Removing the clutch 70 Nm (7.0 m kgf, 50 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Conical spring washer For installation, reverse the removal proce- dure.
  • Page 228 CLUTCH Removing the push lever Order Job/Parts to remove Q’ty Remarks Exhaust pipe Refer to “ENGINE REMOVAL” on page 5-1. Clutch push lever Clutch push lever spring Circlip Oil seal Bearing For installation, reverse the removal proce- dure. 5-41...
  • Page 229: Removing The Clutch

    CLUTCH EAS25070 REMOVING THE CLUTCH Measure the friction plate at four places. 1. Remove: • Clutch cover Friction plate 1 thickness 2.90–3.10 mm (0.114–0.122 in) Loosen each bolt 1/4 of a turn at a time, in stag- Wear limit es and in a crisscross pattern. After all of the 2.80 mm (0.110 in) bolts are fully loosened, remove them.
  • Page 230: Checking The Clutch Plates

    CLUTCH EAS25110 CHECKING THE CLUTCH PLATES The following procedure applies to all of the clutch plates. 1. Check: • Clutch plate Damage → Replace the clutch plates as a set. 2. Measure: • Clutch plate warpage (with a surface plate and thickness gauge “1”) Out of specification →...
  • Page 231: Checking The Pressure Plate

    CLUTCH EAS25170 CHECKING THE PRESSURE PLATE Install the conical spring washer as shown in the 1. Check: illustration. • Pressure plate Cracks/damage → Replace. EAS22B1007 CHECKING THE CLUTCH PUSH LEVER AND SHORT CLUTCH PUSH ROD 1. Check: • Clutch push lever •...
  • Page 232 CLUTCH 4. Tighten: • Clutch boss nut “1” Clutch boss nut 70 Nm (7.0 m·kgf, 50 ft·lbf) While holding the clutch boss “2” with the univer- sal clutch holder “3”, tighten the clutch boss nut. 8. Install: Universal clutch holder 90890-04086 •...
  • Page 233 CLUTCH • With the clutch push lever fully pushed in di- rection “c”, turn the short clutch push rod “3” in or out until the projection “a” aligns with the mark “b”. • Hold the short clutch push rod to prevent it from moving, and then tighten the locknut to specification.
  • Page 234: Oil Pump

    OIL PUMP EAS24911 OIL PUMP Removing the oil pump 4 Nm (0.4 m kgf, 2.9 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Clutch housing Refer to “CLUTCH” on page 5-38. Refer to “BALANCER GEARS”...
  • Page 235 OIL PUMP Disassembling the oil pump Order Job/Parts to remove Q’ty Remarks Oil pump housing cover Oil pump driven gear Oil pump inner rotor Oil pump outer rotor Oil pump housing For assembly, reverse the disassembly pro- cedure. 5-48...
  • Page 236: Checking The Oil Pump

    OIL PUMP EAS24960 CHECKING THE OIL PUMP Inner-rotor-to-outer-rotor-tip 1. Check: clearance • Oil pump drive gear Less than 0.150 mm (0.0059 in) • Oil pump driven gear Limit 0.23 mm (0.0091 in) • Oil pump housing Outer-rotor-to-oil-pump-housing • Oil pump housing cover clearance Cracks/damage/wear →...
  • Page 237: Installing The Oil Pump

    OIL PUMP 3. Check: • Oil pump operation Refer to “CHECKING THE OIL PUMP” on page 5-49. EAS25020 INSTALLING THE OIL PUMP 1. Install: • Oil pump assembly Oil pump assembly screw 4 Nm (0.4 m·kgf, 2.9 ft·lbf) ECA22B1011 NOTICE After tightening the screws, make sure the oil pump turns smoothly.
  • Page 238: Shift Shaft

    SHIFT SHAFT EAS25410 SHIFT SHAFT Removing the shift shaft and stopper lever 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Clutch housing Refer to “CLUTCH” on page 5-38. Shift pedal Refer to “ENGINE REMOVAL” on page 5-1. Shift shaft Circlip Shift shaft spring...
  • Page 239: Checking The Shift Shaft

    SHIFT SHAFT EAS25420 CHECKING THE SHIFT SHAFT 1. Check: • Shift shaft Bends/damage/wear → Replace. • Shift shaft spring Damage/wear → Replace. EAS25430 CHECKING THE STOPPER LEVER 1. Check: • Stopper lever 3. Install: Bends/damage → Replace. • Shift shaft “1” Roller turns roughly →...
  • Page 240: Balancer Gears

    BALANCER GEARS EAS22B1008 BALANCER GEARS Removing the primary drive gear and balancer gears 60 Nm (6.0 m kgf, 43 ft Ibf) • • 50 Nm (5.0 m kgf, 36 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Clutch housing Refer to “CLUTCH”...
  • Page 241: Removing The Primary Drive Gear And Balancer Gears

    BALANCER GEARS EAS22B1009 EAS22B1011 REMOVING THE PRIMARY DRIVE GEAR INSTALLING THE PRIMARY DRIVE GEAR AND BALANCER GEARS AND BALANCER GEARS 1. Loosen: 1. Install: • Primary drive gear nut “1” • Balancer driven gear “1” • Lock washer Place an aluminum plate “a” between the bal- •...
  • Page 242 BALANCER GEARS • Place an aluminum plate “b” between the bal- ancer drive gear “3” and the balancer driven gear “4”, and then tighten the primary drive gear nut. 3. Bend the lock washer tab along a flat side of the nut.
  • Page 243: Crankcase

    CRANKCASE EAS25540 CRANKCASE Separating the crankcase 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) •...
  • Page 244 CRANKCASE Separating the crankcase 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 32 Nm (3.2 m kgf, 23 ft Ibf) • • 20 Nm (2.0 m kgf, 14 ft Ibf) •...
  • Page 245 CRANKCASE Removing the oil seal and bearings 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Crankshaft/Balancer Refer to “CRANKSHAFT” on page 5-62. Transmission Refer to “TRANSMISSION” on page 5-65. Oil seal Bearing retainer Bearing For installation, reverse the removal proce- dure.
  • Page 246: Separating The Crankcase

    CRANKCASE EAS22B1012 ECA22B1021 SEPARATING THE CRANKCASE NOTICE 1. Remove: Tap on one side of the crankcase with a soft- • Crankcase bolts face hammer. Tap only on reinforced por- tions of the crankcase, not on the crankcase Loosen each bolt 1/4 of a turn at a time, in stag- mating surfaces.
  • Page 247: Installing The Bearing Retainer

    CRANKCASE • Oil seal Yamaha bond No. 1215 Damage/wear → Replace. 90890-85505 (Three Bond No.1215®) EAS22B1016 INSTALLING THE BEARING RETAINER 1. Install: • Bearing retainer “1” Do not allow any sealant to come into contact with the oil gallery. • Install the bearing retainer “1” with its “OUT”...
  • Page 248 CRANKCASE 2,13 3,14 A. Left crankcase B. Right crankcase 5-61...
  • Page 249: Crankshaft

    CRANKSHAFT EAS25960 CRANKSHAFT Removing the crankshaft and balancer Order Job/Parts to remove Q’ty Remarks Separate. Crankcase Refer to “CRANKCASE” on page 5-56. Balancer Crankshaft For installation, reverse the removal proce- dure. 5-62...
  • Page 250: Removing The Crankshaft

    CRANKSHAFT EAS22B1017 REMOVING THE CRANKSHAFT 1. Remove: • Crankshaft “1” • Remove the crankshaft with the crankcase separating tool “2”. • Make sure the crankcase separating tool is centered over the crankshaft. ECA22B1006 2. Measure: NOTICE • Big end side clearance •...
  • Page 251 CRANKSHAFT Crankshaft installer pot 90890-01274 Installing pot YU-90058 Crankshaft installer bolt 90890-01275 Bolt YU-90060 Adapter (M12) 90890-01278 Adapter #3 YU-90063 Spacer (crankshaft installer) 90890-04081 Pot spacer YM-91044 ECA22B1022 NOTICE To avoid scratching the crankshaft and to ease the installation procedure, lubricate the oil seal lips with lithium-soap-based grease and each bearing with engine oil.
  • Page 252: Transmission

    TRANSMISSION EAS26241 TRANSMISSION Removing the transmission, shift drum assembly, and shift forks Order Job/Parts to remove Q’ty Remarks Separate. Crankcase Refer to “CRANKCASE” on page 5-56. Shift fork guide bar Spring Shift drum assembly Shift fork-R Shift fork-C Shift fork-L Drive axle assembly Main axle assembly Long clutch push rod...
  • Page 253 TRANSMISSION Disassembling the main axle Order Job/Parts to remove Q’ty Remarks 2nd pinion gear 6th pinion gear 3rd/4th pinion gear Circlip Toothed washer 5th pinion gear Main axle/1st pinion gear For assembly, reverse the disassembly pro- cedure. 5-66...
  • Page 254 TRANSMISSION Disassembling the drive axle Order Job/Parts to remove Q’ty Remarks Washer 2nd wheel gear 6th wheel gear Washer 1st wheel gear Spacer 5th wheel gear Circlip Toothed washer 4th wheel gear 3rd wheel gear Drive axle For assembly, reverse the disassembly pro- cedure.
  • Page 255: Checking The Shift Forks

    TRANSMISSION EAS26260 EAS26270 CHECKING THE SHIFT FORKS CHECKING THE SHIFT DRUM ASSEMBLY The following procedure applies to all of the shift 1. Check: forks. • Shift drum groove Damage/scratches/wear → Replace the shift 1. Check: • Shift fork cam follower “1” drum assembly.
  • Page 256: Checking The Long Clutch Push Rod

    TRANSMISSION EAS29020 ASSEMBLING THE MAIN AXLE AND DRIVE AXLE 1. Install: • Toothed washer “1” • Circlip “2” • Be sure to install the circlip so that its sharp edge “a” is facing away from the toothed wash- er and gear. 3.
  • Page 257 TRANSMISSION The embossed marks on the shift forks should face towards the right side of the engine and be in the following sequence: “R”, “C”, “L”. 2. Check: • Transmission Rough movement → Repair. • Apply engine oil to each gear and bearing thor- oughly.
  • Page 258 TRANSMISSION 5-71...
  • Page 259: Cooling System

    COOLING SYSTEM RADIATOR ...................... 6-1 CHECKING THE RADIATOR..............6-3 INSTALLING THE RADIATOR..............6-3 THERMOSTAT ....................6-4 CHECKING THE THERMOSTAT.............. 6-5 INSTALLING THE THERMOSTAT............6-5 WATER PUMP....................6-6 DISASSEMBLING THE WATER PUMP............ 6-8 CHECKING THE WATER PUMP .............. 6-8 ASSEMBLING THE WATER PUMP............6-8 INSTALLING THE WATER PUMP ............
  • Page 260: Radiator

    RADIATOR EAS26380 RADIATOR Removing the radiator 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 16 Nm (1.6 m kgf, 11 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) •...
  • Page 261 RADIATOR Removing the radiator 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 16 Nm (1.6 m kgf, 11 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 8 Nm (0.8 m kgf, 5.8 ft Ibf) •...
  • Page 262: Checking The Radiator

    RADIATOR EAS26390 CHECKING THE RADIATOR 1. Check: • Radiator fins Obstruction → Clean. Apply compressed air to the rear of the radia- tor. Damage → Repair or replace. Straighten any flattened fins with a thin, flat-head screwdriver. b. Apply the specified pressure for ten seconds and make sure there is no drop in pressure.
  • Page 263: Thermostat

    THERMOSTAT EAS26440 THERMOSTAT Removing the thermostat 18 Nm (1.8 m kgf, 13 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Coolant Refer to “CHANGING THE COOLANT” on page 3-15.
  • Page 264: Checking The Thermostat

    THERMOSTAT 2. Check: EAS26450 CHECKING THE THERMOSTAT • Thermostat cover 1. Check: Cracks/damage → Replace. • Thermostat 3. Check: Does not open at 80.5–83.5 °C (176.9–182.3 • Radiator inlet hose °F) → Replace. Cracks/damage → Replace. EAS26480 INSTALLING THE THERMOSTAT 1.
  • Page 265: Water Pump

    WATER PUMP EAS26500 WATER PUMP Removing the water pump 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Drain. Coolant Refer to “CHANGING THE COOLANT” on page 3-15. Refer to “GENERAL CHASSIS” on page Fuel tank cover assembly 4-1.
  • Page 266 WATER PUMP Disassembling the water pump 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Water pump housing cover Water pump housing cover gasket Impeller shaft retainer Impeller shaft Water pump housing plate...
  • Page 267: Disassembling The Water Pump

    WATER PUMP EAS26510 ECA14080 DISASSEMBLING THE WATER PUMP NOTICE 1. Remove: Never lubricate the water pump seal surface • Water pump seal “1” with oil or grease. Remove the water pump seal from the inside of Install the water pump seal with the special tools the water pump housing “2”.
  • Page 268: Installing The Water Pump

    WATER PUMP • Impeller shaft retainer “3” 3. Check: • Cooling system Impeller shaft retainer bolt Leaks → Repair or replace all faulty parts. 10 Nm (1.0 m·kgf, 7.2 ft·lbf) 4. Measure: LOCTITE® • Radiator cap opening pressure Below the specified pressure → Replace the radiator cap.
  • Page 269: Fuel System

    FUEL SYSTEM FUEL TANK..................... 7-1 REMOVING THE FUEL TANK ..............7-2 REMOVING THE FUEL PUMP ..............7-2 CHECKING THE FUEL PUMP BODY............7-2 INSTALLING THE FUEL PUMP..............7-2 INSTALLING THE FUEL TANK..............7-3 CHECKING THE FUEL PRESSURE ............7-3 THROTTLE BODY................... 7-5 REMOVING THE THROTTLE BODY............
  • Page 270: Fuel Tank

    FUEL TANK EAS26620 FUEL TANK Removing the fuel tank 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 7 Nm (0.7 m kgf, 5.1 ft Ibf) •...
  • Page 271: Removing The Fuel Tank

    FUEL TANK EAS26630 ECA14720 REMOVING THE FUEL TANK NOTICE 1. Extract the fuel in the fuel tank through the • Do not drop the fuel pump or give it a fuel tank filler hole with a pump. strong shock. 2. Disconnect: •...
  • Page 272: Installing The Fuel Tank

    FUEL TANK EAS22B1034 INSTALLING THE FUEL TANK 1. Install: • Fuel tank rear bracket “1” Make sure that the hole “a” in the fuel tank rear bracket is on the left side of the vehicle. EAS27010 CHECKING THE FUEL PRESSURE 1.
  • Page 273 FUEL TANK d. Start the engine. e. Measure the fuel pressure. Output pressure 250.0 kPa (2.50 kgf/cm², 36.3 psi) Out of specification → Replace the fuel pump. L LLL L LLL L LLL L LLL L LLL...
  • Page 274: Throttle Body

    THROTTLE BODY EAS26970 THROTTLE BODY Removing the throttle body 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 2 Nm (0.2 m kgf, 1.4 ft Ibf) •...
  • Page 275 THROTTLE BODY Removing the throttle body 7 Nm (0.7 m kgf, 5.1 ft Ibf) • • 12 Nm (1.2 m kgf, 8.7 ft Ibf) • • 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • 2 Nm (0.2 m kgf, 1.4 ft Ibf) •...
  • Page 276: Removing The Throttle Body

    THROTTLE BODY EAS22B1020 REMOVING THE THROTTLE BODY 1. Remove: • Throttle body ECA22B1007 NOTICE Do not remove the throttle body sensor as- sembly “1” from the throttle body. 2. Install: • Throttle body joint Align the projection “a” on the throttle body joint with the slot “b”...
  • Page 277 THROTTLE BODY...
  • Page 278: Air Induction System

    AIR INDUCTION SYSTEM EAS27040 AIR INDUCTION SYSTEM...
  • Page 279 AIR INDUCTION SYSTEM 1. Air induction system hose (air filter case to reed valve assembly) 2. Air induction system reed valve assembly 3. Air induction system hose (reed valve assembly to exhaust pipe) 7-10...
  • Page 280 AIR INDUCTION SYSTEM Removing the air induction system reed valve assembly 10 Nm (1.0 m kgf, 7.2 ft Ibf) • • Order Job/Parts to remove Q’ty Remarks Air induction system hose (reed valve assembly to exhaust pipe) Air induction system reed valve assembly Air induction system hose (air filter case to reed valve assembly) For installation, reverse the removal proce-...
  • Page 281: Checking The Air Induction System

    AIR INDUCTION SYSTEM EAS27060 CHECKING THE AIR INDUCTION SYSTEM Air induction The air induction system burns unburned ex- haust gases by injecting fresh air (secondary air) into the exhaust pipe, reducing the emission of hydrocarbons. 1. Check: • Hoses Loose connections → Connect properly. Cracks/damage →...
  • Page 282 AIR INDUCTION SYSTEM 7-13...
  • Page 283: Electrical System

    ELECTRICAL SYSTEM IGNITION SYSTEM ..................8-1 CIRCUIT DIAGRAM .................. 8-1 TROUBLESHOOTING ................8-3 ELECTRIC STARTING SYSTEM ..............8-5 CIRCUIT DIAGRAM .................. 8-5 STARTING CIRCUIT CUT-OFF SYSTEM OPERATION ......8-7 TROUBLESHOOTING ................8-8 CHARGING SYSTEM..................8-11 CIRCUIT DIAGRAM ................8-11 TROUBLESHOOTING ................8-13 LIGHTING SYSTEM ..................
  • Page 284 ELECTRICAL COMPONENTS..............8-59 CHECKING THE SWITCHES ..............8-61 CHECKING THE BULBS AND BULB SOCKETS ........8-64 CHECKING THE FUSES ................ 8-65 CHECKING AND CHARGING THE BATTERY........8-65 CHECKING THE RELAYS ..............8-67 CHECKING THE TURN SIGNAL RELAY ..........8-68 CHECKING THE DIODE ................. 8-69 CHECKING THE SPARK PLUG CAP .............
  • Page 286: Ignition System

    IGNITION SYSTEM EAS27090 IGNITION SYSTEM EAS27100 CIRCUIT DIAGRAM...
  • Page 287 IGNITION SYSTEM 1. Crankshaft position sensor 3. Main switch 5. Main fuse 6. Battery 14.Engine stop switch 20.Lean angle sensor 22.ECU (engine control unit) 23.Ignition coil 24.Spark plug 60.Ignition fuse 63.Sidestand switch...
  • Page 288: Troubleshooting

    IGNITION SYSTEM EAS27120 TROUBLESHOOTING The ignition system fails to operate (no spark or intermittent spark). • Before troubleshooting, remove the following part(s): 1. Battery cover 2. Rear fender 3. Fuel tank NG → 1. Check the fuses. (Main and ignition) Replace the fuse(s).
  • Page 289 IGNITION SYSTEM NG → 9. Check the engine stop switch. The engine stop switch is faulty. Replace Refer to “CHECKING THE the right handlebar switch. SWITCHES” on page 8-61. OK ↓ NG → 10.Check the sidestand switch. Refer to “CHECKING THE Replace the sidestand switch.
  • Page 290: Electric Starting System

    ELECTRIC STARTING SYSTEM EAS27160 ELECTRIC STARTING SYSTEM EAS27170 CIRCUIT DIAGRAM...
  • Page 291 ELECTRIC STARTING SYSTEM 3. Main switch 5. Main fuse 6. Battery 7. Starter motor 8. Starter relay 9. Starting circuit cut-off relay 10.Diode 11.Neutral switch 13.Start switch 14.Engine stop switch 60.Ignition fuse 62.Clutch switch 63.Sidestand switch...
  • Page 292: Starting Circuit Cut-Off System Operation

    ELECTRIC STARTING SYSTEM EAS27180 STARTING CIRCUIT CUT-OFF SYSTEM OPERATION If the engine stop switch is set to “ ” and the main switch is set to “ON” (both switch circuits are closed), the starter motor can only operate if at least one of the following conditions is met: •...
  • Page 293: Troubleshooting

    ELECTRIC STARTING SYSTEM EAS27190 TROUBLESHOOTING The starter motor fails to turn. • Before troubleshooting, remove the following part(s): 1. Battery cover 2. Battery 3. Headlight assembly 4. Fuel tank NG → 1. Check the fuses. (Main and ignition) Replace the fuse(s). Refer to “CHECKING THE FUS- ES”...
  • Page 294 ELECTRIC STARTING SYSTEM NG → 8. Check the main switch. Refer to “CHECKING THE Replace the main switch. SWITCHES” on page 8-61. OK ↓ NG → 9. Check the engine stop switch. The engine stop switch is faulty. Replace Refer to “CHECKING THE the right handlebar switch.
  • Page 295 ELECTRIC STARTING SYSTEM 8-10...
  • Page 296: Charging System

    CHARGING SYSTEM EAS27200 CHARGING SYSTEM EAS27210 CIRCUIT DIAGRAM 8-11...
  • Page 297 CHARGING SYSTEM 2. AC magneto 4. Rectifier/regulator 5. Main fuse 6. Battery 8-12...
  • Page 298: Troubleshooting

    CHARGING SYSTEM EAS27230 TROUBLESHOOTING The battery is not being charged. • Before troubleshooting, remove the following part(s): 1. Seat 2. Battery cover NG → 1. Check the fuse. (Main) Replace the fuse. Refer to “CHECKING THE FUS- ES” on page 8-65. OK ↓...
  • Page 299 CHARGING SYSTEM 8-14...
  • Page 300: Lighting System

    LIGHTING SYSTEM EAS27240 LIGHTING SYSTEM EAS27250 CIRCUIT DIAGRAM 8-15...
  • Page 301 LIGHTING SYSTEM 3. Main switch 5. Main fuse 6. Battery 22.ECU (engine control unit) 33.License plate light 34.Tail/brake light 41.Headlight relay 43.Pass switch 44.Dimmer switch 47.Headlight 48.Auxiliary light 51.Meter light 53.High beam indicator light 58.Signaling system fuse 59.Headlight fuse 60.Ignition fuse 8-16...
  • Page 302: Troubleshooting

    LIGHTING SYSTEM EAS27260 TROUBLESHOOTING Any of the following fail to light: headlight, high beam indicator light, taillight, license plate light, auxiliary light or meter light. • Before troubleshooting, remove the following part(s): 1. Battery cover 2. Fuel tank NG → 1.
  • Page 303 LIGHTING SYSTEM NG → 8. Check the entire lighting system wiring. Properly connect or repair the lighting sys- Refer to “CIRCUIT DIAGRAM” on tem wiring. page 8-15. OK ↓ Replace the ECU or meter assembly. 8-18...
  • Page 304: Signaling System

    SIGNALING SYSTEM EAS27270 SIGNALING SYSTEM EAS27280 CIRCUIT DIAGRAM 8-19...
  • Page 305 SIGNALING SYSTEM 3. Main switch 5. Main fuse 6. Battery 11.Neutral switch 22.ECU (engine control unit) 28.Fuel sender 31.Rear brake light switch 32.Front brake light switch 34.Tail/brake light 35.Rear right turn signal light 36.Rear left turn signal light 37.Front right turn signal light 38.Front left turn signal light 39.Turn signal relay 40.Horn...
  • Page 306: Troubleshooting

    SIGNALING SYSTEM EAS27290 TROUBLESHOOTING • Any of the following fail to light: turn signal lights, brake light or indicator lights. • The horn fails to sound. • The fuel meter fails to operate. • The speedometer fails to operate. • Before troubleshooting, remove the following part(s): 1.
  • Page 307 SIGNALING SYSTEM NG → 2. Check the horn. Refer to “CHECKING THE HORN” Replace the horn. on page 8-73. OK ↓ NG → 3. Check the entire signaling system wiring. Properly connect or repair the signaling Refer to “CIRCUIT DIAGRAM” on system wiring.
  • Page 308 SIGNALING SYSTEM NG → 2. Check the turn signal switch. The turn signal switch is faulty. Replace Refer to “CHECKING THE the left handlebar switch. SWITCHES” on page 8-61. OK ↓ NG → 3. Check the turn signal relay. Refer to “CHECKING THE RE- Replace the turn signal relay.
  • Page 309 SIGNALING SYSTEM The speedometer fails to operate. NG → 1. Check the speed sensor. Refer to “CHECKING THE SPEED Replace the speed sensor. SENSOR” on page 8-74. OK ↓ NG → 2. Check the entire signaling system wiring. Properly connect or repair the signaling Refer to “CIRCUIT DIAGRAM”...
  • Page 310: Cooling System

    COOLING SYSTEM EAS27300 COOLING SYSTEM EAS27310 CIRCUIT DIAGRAM 8-25...
  • Page 311 COOLING SYSTEM 3. Main switch 5. Main fuse 6. Battery 19.Coolant temperature sensor 22.ECU (engine control unit) 29.Radiator fan motor relay 30.Radiator fan motor 52.Coolant temperature warning light 58.Signaling system fuse 60.Ignition fuse 61.Radiator fan motor fuse 8-26...
  • Page 312: Troubleshooting

    COOLING SYSTEM EAS27320 TROUBLESHOOTING • The radiator fan motor fails to turn. • The coolant temperature warning light fails to come on. • Before troubleshooting, remove the following part(s): 1. Battery cover 2. Fuel tank NG → 1. Check the fuses. (Main, ignition, signaling system, and radiator fan motor) Replace the fuse(s).
  • Page 313 COOLING SYSTEM 8-28...
  • Page 314: Fuel Injection System

    FUEL INJECTION SYSTEM EAS27330 FUEL INJECTION SYSTEM EAS27340 CIRCUIT DIAGRAM 8-29...
  • Page 315 FUEL INJECTION SYSTEM 1. Crankshaft position sensor 3. Main switch 5. Main fuse 6. Battery 14.Engine stop switch 16.Intake air pressure sensor 17.Intake air temperature sensor 18.Throttle position sensor 19.Coolant temperature sensor 20.Lean angle sensor 21.Self-diagnosis signal coupler 22.ECU (engine control unit) 23.Ignition coil 25.FID (fast idle solenoid) 26.Fuel injector...
  • Page 316: Ecu Self-Diagnostic Function

    FUEL INJECTION SYSTEM EAS27350 ECU SELF-DIAGNOSTIC FUNCTION The ECU is equipped with a self-diagnostic function in order to ensure that the fuel injection system is operating normally. If this function detects a malfunction in the system, it immediately operates the en- gine under substitute characteristics and illuminates the engine trouble warning light to alert the rider that a malfunction has occurred in the system.
  • Page 317: Self-Diagnostic Function Table

    FUEL INJECTION SYSTEM Engine trouble warning light indication and fuel injection system operation Warning light indica- Fuel injection opera- ECU operation Vehicle operation tion tion Warning provided Flashing* when unable to start Operation stopped Cannot be operated engine Operated with substi- tute characteristics in Can or cannot be oper- Remains on...
  • Page 318 FUEL INJECTION SYSTEM Self-Diagnostic Function table Able / un- Fault Able / un- Item Symptom able to code No. able to start drive No normal signals are received Crankshaft position from the crankshaft position sen- Unable Unable sensor sor. Intake air pressure Intake air pressure sensor: open sensor Able...
  • Page 319: Troubleshooting Method

    FUEL INJECTION SYSTEM Able / un- Fault Able / un- Item Symptom able to code No. able to start drive Faulty ECU memory. (When this ECU internal malfunc- malfunction is detected in the tion ECU, the fault code number might Unable Unable (memory check error)
  • Page 320 FUEL INJECTION SYSTEM FI diagnostic tool 90890-03182 Setting the normal mode The engine speed, coolant temperature, and fault codes, if detected, can be displayed on the LCD of the FI diagnostic tool when the tool is connected to the vehicle and is set to the normal mode. 1.
  • Page 321 FUEL INJECTION SYSTEM 5. Set the main switch to “OFF” to cancel the normal mode. 6. Disconnect the FI diagnostic tool and connect the self-diagnosis signal coupler. Setting the diagnostic mode 1. Set the main switch to “OFF” and the engine stop switch to “ ”.
  • Page 322 FUEL INJECTION SYSTEM Diagnostic code table Fault Diagnostic code Symptom Probable cause of malfunction code No. • Malfunction in wire harness ECU coupler. • Malfunction in crankshaft position sensor coupler. No normal signals are re- • Open or short circuit in wire harness. ceived from the crankshaft •...
  • Page 323 FUEL INJECTION SYSTEM Fault Diagnostic code Symptom Probable cause of malfunction code No. • Malfunction in wire harness ECU coupler. • Malfunction in coolant temperature sensor coupler. Coolant temperature sen- • Open or short circuit in wire harness. sor: open or short circuit •...
  • Page 324 FUEL INJECTION SYSTEM Fault Diagnostic code Symptom Probable cause of malfunction code No. Power supply to the fuel in- • Malfunction in the charging system. Refer jection system is not nor- — to “CHARGING SYSTEM” on page 8-11. mal. Faulty ECU memory. (When this malfunction is •...
  • Page 325 FUEL INJECTION SYSTEM Diag- nostic Item FI diagnostic tool display Checking method code Sidestand switch Extend and retract the side- stand (with the transmis- • Stand retracted sion in gear). • Stand extended EEPROM fault code dis- — play • No history •...
  • Page 326 FUEL INJECTION SYSTEM Diag- nostic Item Actuation Checking method code When the “MODE” button is pressed, the fuel injector is actuated five times at one- second intervals, and the Check the operating sound Fuel injector “WARNING” LED on the FI of the injector five times.
  • Page 327: Troubleshooting Details

    FUEL INJECTION SYSTEM LCD Display Symptom Probable cause of malfunction • Set the main switch to “OFF” once, and then set the FI diagnostic tool to the CO adjustment mode or the diagnostic mode. Commands from the FI di- • Vehicle battery is insufficiently charged. ERROR_4 agnostic tool are not ac- •...
  • Page 328 FUEL INJECTION SYSTEM Fault code No. Symptom Intake air pressure sensor: open or short circuit detected. Diagnostic code No. Intake air pressure sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the coupler for any pins Set the main •...
  • Page 329 FUEL INJECTION SYSTEM Fault code No. Symptom Throttle body malfunction (clogged intake air pressure sensor hole or improperly installed throttle body sensor assembly). Intake air system malfunction (correct pressure is not supplied to throttle body sensor assembly) Diagnostic code No. Intake air pressure sensor Order Item/components and probable Check or maintenance job...
  • Page 330 FUEL INJECTION SYSTEM Fault code No. Symptom Throttle position sensor: open or short circuit detected. Diagnostic code No. Throttle position sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the coupler for any pins Set the main •...
  • Page 331 FUEL INJECTION SYSTEM Fault code No. Symptom Stuck throttle position sensor detected. Diagnostic code No. Throttle position sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Defective throttle body sensor assem- • Execute the diagnostic mode. Start the en- bly (throttle position sensor).
  • Page 332 FUEL INJECTION SYSTEM Fault code No. Symptom Coolant temperature sensor: open or short circuit detect- Diagnostic code No. Coolant temperature sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Installed condition of coolant tempera- Check for looseness or pinching. Set the main ture sensor switch to “ON”.
  • Page 333 FUEL INJECTION SYSTEM Fault code No. Symptom Intake air temperature sensor: open or short circuit de- tected. Diagnostic code No. Intake air temperature sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the couplers for any pins Set the main •...
  • Page 334 FUEL INJECTION SYSTEM Fault code No. Symptom Latch up detected. No normal signal is received from the lean angle sensor. Diagnostic code No. Lean angle sensor Order Item/components and probable Check or maintenance job Reinstatement cause method The vehicle has overturned. Raise the vehicle upright.
  • Page 335 FUEL INJECTION SYSTEM Fault code No. Symptom Primary lead of the ignition coil: open circuit detected. Diagnostic code No. Ignition coil Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the connector and cou- Start the en- •...
  • Page 336 FUEL INJECTION SYSTEM Fault code No. Symptom Fuel injector: open or short circuit detected. Diagnostic code No. Fuel injector Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the couplers for any pins Start the en- •...
  • Page 337 FUEL INJECTION SYSTEM Fault code No. Symptom Lean angle sensor: open or short circuit detected. Diagnostic code No. Lean angle sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the coupler for any pins Set the main •...
  • Page 338 FUEL INJECTION SYSTEM Fault code No. Symptom No normal signals are received from the speed sensor. Diagnostic code No. Speed sensor Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the coupler for any pins Start the en- •...
  • Page 339 FUEL INJECTION SYSTEM Fault code No. Symptom Power supply to the fuel injection system is not normal. Diagnostic code No. — — Order Item/components and probable Check or maintenance job Reinstatement cause method Connections • Check the coupler for any pins Start the en- •...
  • Page 340: Fuel Pump System

    FUEL PUMP SYSTEM EAS27550 FUEL PUMP SYSTEM EAS27560 CIRCUIT DIAGRAM 8-55...
  • Page 341 FUEL PUMP SYSTEM 3. Main switch 5. Main fuse 6. Battery 14.Engine stop switch 22.ECU (engine control unit) 27.Fuel pump 60.Ignition fuse 8-56...
  • Page 342: Troubleshooting

    FUEL PUMP SYSTEM EAS27570 TROUBLESHOOTING If the fuel pump fails to operate. • Before troubleshooting, remove the following part(s): 1. Battery cover 2. Fuel tank NG → 1. Check the fuses. (Main and ignition) Replace the fuse(s). Refer to “CHECKING THE FUS- ES”...
  • Page 343 FUEL PUMP SYSTEM 8-58...
  • Page 344: Electrical Components

    ELECTRICAL COMPONENTS EAS27972 ELECTRICAL COMPONENTS 8-59...
  • Page 345 ELECTRICAL COMPONENTS 1. Main switch 2. Clutch switch 3. Front brake light switch 4. Starter relay 5. Ignition coil 6. Coolant temperature sensor 7. Fuel pump assembly 8. Throttle body sensor assembly (intake air pressure sensor, intake air temperature sensor, throttle position sensor) 9.
  • Page 346: Checking The Switches

    ELECTRICAL COMPONENTS EAS27980 CHECKING THE SWITCHES Ch Br/W Br/W PASS (BLUE) Br/L R/W R/W Sb/W Br/L (RED) 8-61...
  • Page 347 ELECTRICAL COMPONENTS 1. Clutch switch 2. Pass switch 3. Dimmer switch 4. Horn switch 5. Turn signal switch 6. Rear brake light switch 7. Sidestand switch 8. Neutral switch 9. Front brake light switch 10. Main switch 11. Engine stop switch 12.
  • Page 348 ELECTRICAL COMPONENTS Check each switch for continuity with the pocket tester. If the continuity reading is incorrect, check the wiring connections and, if necessary, replace the switch. ECA14370 NOTICE Never insert the tester probes into the coupler terminal slots “a”. Always insert the probes from the opposite end of the coupler, taking care not to loosen or damage the leads.
  • Page 349: Checking The Bulbs And Bulb Sockets

    ELECTRICAL COMPONENTS EAS27990 EWA22B1003 CHECKING THE BULBS AND BULB WARNING SOCKETS Since the headlight bulbs get extremely hot, keep flammable products and your hands Do not check any of the lights that use LEDs. away from them until they have cooled down.
  • Page 350: Checking The Fuses

    ELECTRICAL COMPONENTS Checking the condition of the bulb sockets 3. Replace: The following procedure applies to all of the bulb • Blown fuse sockets. M MMM M MMM M MMM M MMM M MMM a. Set the main switch to “OFF”. 1.
  • Page 351 ELECTRICAL COMPONENTS • DO NOT SMOKE when charging or han- dling batteries. • KEEP BATTERIES AND ELECTROLYTE OUT OF REACH OF CHILDREN. • Avoid bodily contact with electrolyte as it can cause severe burns or permanent eye injury. FIRST AID IN CASE OF BODILY CONTACT: EXTERNAL •...
  • Page 352: Checking The Relays

    ELECTRICAL COMPONENTS Loose connection → Connect properly. tery charger lead clip may generate heat in the contact area and a weak clip spring may 12.Connect: cause sparks. • Battery leads • If the battery becomes hot to the touch at (to the battery terminals) any time during the charging process, dis- ECA22B1019...
  • Page 353: Checking The Turn Signal Relay

    ELECTRICAL COMPONENTS Starter relay 2. Negative battery terminal 3. Positive tester probe 4. Negative tester probe Result Continuity (between “3” and “4”) R R/W Radiator fan motor relay 1. Positive battery terminal 2. Negative battery terminal 3. Positive tester probe 4.
  • Page 354: Checking The Diode

    ELECTRICAL COMPONENTS Pocket tester 90890-03112 Analog pocket tester YU-03112-C Br/W The pocket tester or the analog pocket tester readings are shown in the following table. No continuity b. Set the main switch to “ON”. Positive tester probe → c. Measure the turn signal relay input voltage. blue/black “1”...
  • Page 355: Checking The Ignition Coil

    ELECTRICAL COMPONENTS Resistance 5.0 kΩ M MMM M MMM M MMM M MMM M MMM a. Remove the spark plug cap from the spark plug lead. b. Connect the pocket tester (Ω × 1k) to the spark plug cap as shown. Pocket tester 90890-03112 c.
  • Page 356: Checking The Crankshaft Position Sensor

    ELECTRICAL COMPONENTS Refer to “TROUBLESHOOTING” on page M MMM M MMM M MMM M MMM M MMM a. Connect the pocket tester (Ω × 100) to the 8-3. crankshaft position sensor coupler as shown. Minimum ignition spark gap Pocket tester 6.0 mm (0.24 in) 90890-03112 Analog pocket tester...
  • Page 357: Checking The Starter Motor Operation

    ELECTRICAL COMPONENTS EAS28150 CHECKING THE STATOR COIL 1. Disconnect: • Stator coil coupler (from the wire harness) 2. Check: • Stator coil resistance Out of specification → Replace the crank- shaft position sensor/stator assembly. Stator coil resistance c. Set the main switch to “ON”. 0.448–0.672 Ω...
  • Page 358: Checking The Horn

    ELECTRICAL COMPONENTS • Positive tester probe → Charging voltage horn terminal “1” 14 V at 5000 r/min • Negative tester probe → horn terminal “2” M MMM M MMM M MMM M MMM M MMM a. Set the engine tachometer to the spark plug lead.
  • Page 359: Checking The Speed Sensor

    ELECTRICAL COMPONENTS M MMM M MMM M MMM M MMM M MMM Sender unit resistance (full) a. Connect the pocket tester (DC 20 V) to the 19.0–21.0 Ω at 20 °C (68 °F) speed sensor coupler as shown. Sender unit resistance (empty) 137.0–143.0 Ω...
  • Page 360: Checking The Coolant Temperature Sensor

    ELECTRICAL COMPONENTS c. Measure the radiator fan motor movement. e. Measure the coolant temperature sensor re- sistance. L LLL L LLL L LLL L LLL L LLL L LLL L LLL L LLL L LLL L LLL EAS28260 CHECKING THE COOLANT TEMPERATURE 3.
  • Page 361 ELECTRICAL COMPONENTS • Positive tester probe → yellow terminal “3” • Negative tester probe → gray/black terminal “2” d. While slowly opening the throttle, check that the throttle position sensor output voltage is Gy/R Y Gy/B increased. Voltage does not change or it changes abruptly →...
  • Page 362: Checking The Fid (Fast Idle Solenoid)

    ELECTRICAL COMPONENTS EAS22B1026 CHECKING THE FID (FAST IDLE SOLENOID) 1. Disconnect: • FID (fast idle solenoid) coupler 2. Check: • FID (fast idle solenoid) resistance Out of specification → Replace the throttle body. FID (fast idle solenoid) resistance 31.5–38.5 Ω M MMM M MMM M MMM...
  • Page 363: Troubleshooting

    TROUBLESHOOTING TROUBLESHOOTING..................9-1 GENERAL INFORMATION ............... 9-1 STARTING FAILURES................9-1 INCORRECT ENGINE IDLING SPEED ............ 9-1 POOR MEDIUM-AND-HIGH-SPEED PERFORMANCE ......9-2 FAULTY GEAR SHIFTING................ 9-2 SHIFT PEDAL DOES NOT MOVE ............9-2 JUMPS OUT OF GEAR................9-2 FAULTY CLUTCH ..................9-2 OVERHEATING ..................
  • Page 364: Troubleshooting

    TROUBLESHOOTING Electrical system EAS28451 TROUBLESHOOTING 1. Battery • Discharged battery EAS28460 • Faulty battery GENERAL INFORMATION 2. Fuse(s) • Blown, damaged or incorrect fuse The following guide for troubleshooting does not • Improperly installed fuse cover all the possible causes of trouble. It should 3.
  • Page 365: Poor Medium-And-High-Speed Performance

    TROUBLESHOOTING • Flooded throttle body • Improperly assembled transmission • Faulty air induction system EAS28550 JUMPS OUT OF GEAR Electrical system 1. Battery Shift shaft • Discharged battery • Incorrect shift pedal position • Faulty battery • Improperly returned stopper lever 2.
  • Page 366: Overcooling

    TROUBLESHOOTING 2. Engine oil • Damaged brake hose • Incorrect oil level • Oil or grease on the brake disc • Incorrect oil viscosity • Oil or grease on the brake pad • Inferior oil quality • Incorrect brake fluid level EAS28660 Cooling system FAULTY FRONT FORK LEGS...
  • Page 367: Faulty Lighting Or Signaling System

    TROUBLESHOOTING 7. Wheel(s) • Faulty turn signal switch • Broken or loose spoke • Incorrect turn signal bulb • Damaged wheel bearing Turn signal remains lit • Bent or loose wheel axle • Faulty turn signal relay • Excessive wheel runout •...
  • Page 368 EAS28740 57. Speed sensor EAS28750 WIRING DIAGRAM COLOR CODE 58. Signaling system fuse Black 59. Headlight fuse WR125R/WR125X 2009 Brown 60. Ignition fuse 1. Crankshaft position sensor Chocolate 61. Radiator fan motor fuse 2. AC magneto Dark green 62. Clutch switch 3.
  • Page 371 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WIRING DIAGRAM SCHÉMA DE CÂBLAGE SCHALTPLAN SCHEMA ELETTRICO DIAGRAMA ELÉCTRICO B Gy/B Gy/R R Y/G O/B Y/R Y/B G/W L/Y Gy Br/W G/R Gy/B R Gy/B R/B L/B Br/W P/W Gy/B Gy/R R/B L/B...
  • Page 372 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WR125R/WR125X 2009 WIRING DIAGRAM SCHÉMA DE CÂBLAGE SCHALTPLAN SCHEMA ELETTRICO DIAGRAMA ELÉCTRICO (BLACK) (BLACK) ( RED ) ( RED ) CLUTCH SWITCH WIRE HARNESS SUB-LEAD PASS (BLACK) (GREEN) (BLACK) (GREEN) (BLACK) (GREEN) (BLACK) (GREEN)

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Wr125x 2009

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