Yamaha Wr250r 2008 Manual
Have a look at the manual Yamaha Wr250r 2008 Manual online for free. It’s possible to download the document as PDF or print. UserManuals.tech offer 255 Yamaha manuals and user’s guides for free. Share the user manual or guide on Facebook, Twitter or Google+.
CHAIN DRIVE 4-61 c. Remove the drive chain from the kerosene and completely dry it. CAUTION: ECA14290 This motorcycle has a drive chain with small rubber O-rings “1” between the drive chain side plates. Never use high-pressure water or air, steam, gasoline, certain sol- vents (e.g., benzine), or a coarse brush to clean the drive chain. High-pressure meth- ods could force dirt or water into the drive chain’s internals, and solvents will deterio- rate the O-rings. A coarse brush can also damage the O-rings. Therefore, use only kerosene to clean the drive chain. Do not soak the drive chain in kerosene for more than ten minutes, otherwise the O-rings can be damaged. 4. Check: O-rings “1” Damage → Replace the drive chain. Drive chain rollers “2” Damage/wear → Replace the drive chain. Drive chain side plates “3” Damage/wear → Replace the drive chain.5. Lubricate: Drive chain EAS23460 CHECKING THE DRIVE SPROCKET 1. Check: Drive sprocket Refer to “CHECKING AND REPLACING THE REAR WHEEL SPROCKET” on page 4-9. EAS23470 CHECKING THE REAR WHEEL SPROCKET Refer to “CHECKING AND REPLACING THE REAR WHEEL SPROCKET” on page 4-9. EAS23490 INSTALLING THE DRIVE CHAIN 1. Lubricate: Drive chain 2. Install: Drive chain Drive sprocket Drive sprocket nut (temporarily) 3. Install: Swingarm Refer to “SWINGARM” on page 4-56. Rear wheel Refer to “REAR WHEEL” on page 4-7. 4. Tighten: Drive sprocket nut “1” Recommended lubricant Engine oil or chain lubricant suitable for O-ring chains Recommended lubricant Engine oil or chain lubricant suitable for O-ring chains Drive sprocket nut 95 Nm (9.5 m•kg, 69 ft•lb) TR..
CHAIN DRIVE 4-62 NOTE: While applying the rear brake, tighten the drive sprocket nut. Stake the nut “1”. 5. Adjust: Drive chain slack Refer to “ADJUSTING THE DRIVE CHAIN SLACK” on page 1-26. CAUTION: ECA13550 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.Drive chain slack WR250R 38.0 – 48.0 mm (1.50 – 1.89 in) WR250X 40.0 – 50.0 mm (1.57 – 1.97 in) 1
1 2 3 4 5 6 7 8 9 ENGINE ENGINE REMOVAL .......................................................................................5-1 INSTALLING THE ENGINE .....................................................................5-5 INSTALLING THE SHIFT PEDAL ............................................................5-5 CAMSHAFT....................................................................................................5-6 REMOVING THE CAMSHAFT .................................................................5-8 CHECKING THE CAMSHAFT .................................................................5-8 CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET ..........5-10 CHECKING THE TIMING CHAIN TENSIONERS ....................................5-10 CHECKING THE DECOMPRESSION SYSTEM .....................................5-11 INSTALLING THE CAMSHAFTS .............................................................5-11 CYLINDER HEAD ..........................................................................................5-14 REMOVING THE CYLINDER HEAD .......................................................5-15 CHECKING THE CYLINDER HEAD ........................................................5-15 INSTALLING THE CYLINDER HEAD ......................................................5-15 VALVES AND VALVE SPRINGS ..................................................................5-17 REMOVING THE VALVES.......................................................................5-18 CHECKING THE VALVES AND VALVE GUIDES ...................................5-19 CHECKING THE VALVE SEATS .............................................................5-20 CHECKING THE VALVE SPRINGS ........................................................5-22 CHECKING THE VALVE LIFTERS ..........................................................5-23 INSTALLING THE VALVES .....................................................................5-23 CYLINDER AND PISTON ..............................................................................5-25 REMOVING THE PISTON .......................................................................5-26 CHECKING THE CYLINDER AND PISTON ............................................5-26 CHECKING THE PISTON RINGS ...........................................................5-27 CHECKING THE PISTON PIN .................................................................5-27 INSTALLING THE PISTON AND CYLINDER ..........................................5-28 STARTER MOTOR ........................................................................................5-30 CHECKING THE STARTER MOTOR ......................................................5-32 ASSEMBLING THE STARTER MOTOR..................................................5-33 CLUTCH .........................................................................................................5-34 REMOVING THE CLUTCH ......................................................................5-38 CHECKING THE FRICTION PLATES .....................................................5-38 CHECKING THE CLUTCH PLATES ........................................................5-38 CHECKING THE CLUTCH SPRINGS .....................................................5-39 CHECKING THE CLUTCH HOUSING .....................................................5-39 CHECKING THE CLUTCH BOSS............................................................5-39 CHECKING THE PRESSURE PLATE .....................................................5-39 CHECKING THE CLUTCH PUSH RODS ................................................5-39 CHECKING THE PRIMARY DRIVE GEAR..............................................5-40 CHECKING THE PRIMARY DRIVEN GEAR ...........................................5-40 INSTALLING THE CLUTCH.....................................................................5-40
SHIFT SHAFT ................................................................................................5-43 CHECKING THE SHIFT SHAFT ..............................................................5-44 CHECKING THE STOPPER LEVER .......................................................5-44 INSTALLING THE SHIFT SHAFT ............................................................5-44 OIL PUMP AND BALANCER GEAR .............................................................5-45 REMOVING THE OIL PUMP ...................................................................5-47 CHECKING THE OIL PUMP ....................................................................5-47 ASSEMBLING THE OIL PUMP................................................................5-47 INSTALLING THE OIL PUMP AND BALANCER GEAR ..........................5-48 GENERATOR AND STARTER CLUTCH ......................................................5-50 REMOVING THE GENERATOR ..............................................................5-53 CHECKING THE STARTER CLUTCH .....................................................5-53 INSTALLING THE STARTER CLUTCH ...................................................5-54 INSTALLING THE GENERATOR ............................................................5-54 CRANKCASE .................................................................................................5-56 DISASSEMBLING THE CRANKCASE ....................................................5-59 CHECKING THE TIMING CHAIN, TIMING CHAIN GUIDE, OIL STRAINER, NOZZLE, DELIVERY PIPE ........................................5-59 CHECKING THE CRANKCASE ...............................................................5-59 ASSEMBLING THE CRANKCASE ..........................................................5-59 CRANKSHAFT ASSEMBLY AND BALANCER SHAFT ...............................5-61 REMOVING THE CRANKSHAFT ASSEMBLY ........................................5-62 CHECKING THE CRANKSHAFT ASSEMBLY ........................................5-62 INSTALLING THE CRANKSHAFT ASSEMBLY ......................................5-62 TRANSMISSION ............................................................................................5-64 CHECKING THE SHIFT FORKS .............................................................5-67 CHECKING THE SHIFT DRUM ASSEMBLY...........................................5-67 CHECKING THE TRANSMISSION ..........................................................5-67 INSTALLING THE SHIFT FORKS AND SHIFT DRUM ASSEMBLY .......5-68 INSTALLING THE TRANSMISSION ........................................................5-69
ENGINE REMOVAL 5-1 EAS23710 ENGINE REMOVAL Removing the exhaust pipe Order Job/Parts to remove Q’ty Remarks Seat side cover (left/right) Refer to“GENERAL CHASSIS” on page 4-1. Air scoop (left/right) Refer to“GENERAL CHASSIS” on page 4-1. 1 Muffler protector 1 2 EXUP pulley cover 1 3 Side cover right stay 1 4 EXUP cable 2 5 Muffler 1 6 Exhaust pipe 1 7 Exhaust pipe gasket 1 8 Muffler gasket 1 For installation, reverse the removal proce- dure. 23 4 5 67 8 1 T R..7 Nm (0.7 m • kg, 5.1 ft • Ib) T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..42 Nm (4.2 m • kg, 30 ft • Ib) T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..20 Nm (2.0 m • kg, 14 ft • Ib) T R..20 Nm (2.0 m • kg, 14 ft • Ib)
ENGINE REMOVAL 5-2 Removing the shift pedal, leads and hoses Order Job/Parts to remove Q’ty Remarks CoolantDrain. Refer to“CHANGING THE COOLANT” on page 3-18. Radiator Refer to“RADIATOR” on page 6-1. Starter motor Refer to“STARTER MOTOR” on page 5-30. 1 Shift pedal 1 2 Drive sprocket cover 1 3 Gasket 1 4 Drive sprocket nut 1 5 Drive sprocket 1 6 Speed sensor coupler 1 Disconnect. 7 Coolant temperature sensor coupler 1 Disconnect. 8 Generator coupler 2 Disconnect. 9 Crankshaft position sensor coupler 1 Disconnect. 10 Horn lead coupler 1 Disconnect. 11 Fuse box 1 12 Side cover stay 1 13 Ground lead 1 14 Neutral switch lead 1 Disconnect. 15 Ignition coil lead coupler 1 Disconnect. 95 Nm (9.5 m • kg, 69 ft • Ib) 12 3 4 56 7 8 910 11 121513 14 T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..18 Nm (1.8 m • kg, 13 ft • Ib) T R.. T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
ENGINE REMOVAL 5-3 For installation, reverse the removal proce- dure. Removing the shift pedal, leads and hoses Order Job/Parts to remove Q’ty Remarks 95 Nm (9.5 m • kg, 69 ft • Ib) 12 3 4 56 7 8 910 11 121513 14 T R..10 Nm (1.0 m • kg, 7.2 ft • Ib) T R..18 Nm (1.8 m • kg, 13 ft • Ib) T R.. T R..10 Nm (1.0 m • kg, 7.2 ft • Ib)
ENGINE REMOVAL 5-4 Order Job/Parts to remove Q’ty Remarks NOTE: Use a suitable stand to supported the engine side. Engine oilDrain. Refer to“CHANGING THE ENGINE OIL” on page 3-11. 1 Engine mounting bolt (front upper) 1 2 Engine mounting bolt (front) 1 3 Engine mounting bolt (front lower) 1 4 Down tube bolts (front upper) 2 5 Down tube bolts (rear lower) 2 6 Down tube 1 7 Pivot shaft 1 8 Engine assembly 1 For installation, reverse the removal proce- dure. 1 2 3 4 5 67 8 T R..85 Nm (8.5 m • kg, 62 ft • Ib) T R..67 Nm (6.7 m • kg, 48 ft • Ib) T R..56 Nm (5.6 m • kg, 41 ft • Ib) T R..113 Nm (11.3 m • kg, 82 ft • Ib)
ENGINE REMOVAL 5-5 EAS23720 INSTALLING THE ENGINE 1. Install: Engine assembly “1” Pivot shaft “2” Down tube “3” Down tube bolt (rear lower side) “4” Down tube bolt (front upper side) “5” Engine mounting bolt (front lower side) “6” Engine mounting bolt (front) “7” Engine mounting bolt (front upper side) “8” NOTE: Do not fully tighten the bolts. (Temporarily tight- en) 2. Tighten: Pivot shaft nut Downtube nut (rear lower side) Engine mounting nut EAS32D1009 INSTALLING THE SHIFT PEDAL 1. Install: Shift pedal NOTE: Install the shift pedal so that pedal top face “a” is 5 mm (0.20 in) lower than the footrest top face. Pivot shaft nut 85 Nm (8.5 m•kg, 62 ft•lb) Downtube nut (rear lower side) 113 Nm (11.3 m•kg, 82 ft•lb) Downtube nut (front upper side) 113 Nm (11.3 m•kg, 82 ft•lb) Engine mounting nut (front lower side) 56 Nm (5.6 m•kg, 41 ft•lb) Engine mounting nut (front upper side) 67 Nm (6.7 m•kg, 48 ft•lb) Engine mounting nut (front) 56 Nm (5.6 m•kg, 41 ft•lb) 7 8 6 4 1 3 2 5 TR.. Shift pedal bolt 18 Nm (1.8 m•kg, 13 ft•lb) a. 5 mm (0.20 in) TR.. a
CAMSHAFT 5-6 EAS23730 CAMSHAFT Removing the cylinder head cover Order Job/Parts to remove Q’ty Remarks Side cover (left/right)Refer to “GENERAL CHASSIS” on page 4-1. Fuel tank Refer to “FUEL TANK” on page 7-1. CoolantDrain. Refer to “CHANGING THE COOLANT” on page 3-18. Engine oilDrain. Refer to “CHANGING THE ENGINE OIL” on page 3-11. 1 Throttle cable 2 2 Throttle body 1 3 Clutch cable 1 Disconnect. 4 Ignition coil coupler 1 Disconnect. 5 Cylinder head cover breather hose 1 6 Ignition coil assembly 1 7 Spark plug 1 8 Cylinder head cover 1 9 Cylinder head cover gasket 1 For installation, reverse the removal proce- dure. 12 9 4 5 6 7 3 8T R..13 Nm (1.3 m • kg, 9.4 ft • Ib) T R..12 Nm (1.2 m • kg, 8.7 ft • Ib)