Engine - Yamaha WR250F Owner's Service Manual

ENGINE REMOVAL .........................................................................................6-1
REMOVING THE SILENCER.....................................................................6-6
REMOVING THE EXHAUST PIPE 2..........................................................6-6
REMOVING THE DRIVE SPROCKET .......................................................6-6
REMOVING THE ENGINE .........................................................................6-7
CLEANING THE SPARK ARRESTER .......................................................6-7
CHECKING THE SILENCER AND EXHAUST PIPE..................................6-8
INSTALLING THE ENGINE........................................................................6-8
INSTALLING THE BRAKE PEDAL ............................................................6-9
INSTALLING THE DRIVE SPROCKET......................................................6-9
INSTALLING THE EXHAUST PIPE AND MUFFLER.................................6-9
CAMSHAFT ....................................................................................................6-11
REMOVING THE CAMSHAFT .................................................................6-13
CHECKING THE CAMSHAFT..................................................................6-14
CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET ..........6-15
CHECKING THE TIMING CHAIN TENSIONERS ....................................6-15
CHECKING THE DECOMPRESSION SYSTEM......................................6-16
INSTALLING THE CAMSHAFTS .............................................................6-16
CYLINDER HEAD...........................................................................................6-18
REMOVING THE CYLINDER HEAD........................................................6-20
CHECKING THE TIMING CHAIN GUIDE (INTAKE SIDE) ......................6-20
CHECKING THE CYLINDER HEAD ........................................................6-20
INSTALLING THE CYLINDER HEAD ......................................................6-21
VALVES AND VALVE SPRINGS...................................................................6-22
REMOVING THE VALVES.......................................................................6-23
CHECKING THE VALVES AND VALVE GUIDES ...................................6-24
CHECKING THE VALVE SEATS .............................................................6-26
CHECKING THE VALVE SPRINGS.........................................................6-27
CHECKING THE VALVE LIFTERS ..........................................................6-28
INSTALLING THE VALVES .....................................................................6-28
CYLINDER AND PISTON...............................................................................6-30
REMOVING THE PISTON .......................................................................6-31
CHECKING THE CYLINDER AND PISTON ............................................6-31
CHECKING THE PISTON RINGS............................................................6-32
CHECKING THE PISTON PIN .................................................................6-33
INSTALLING THE PISTON AND CYLINDER ..........................................6-33
ELECTRIC STARTER ....................................................................................6-35
CHECKING THE STARTER MOTOR ......................................................6-37
ASSEMBLING THE STARTER MOTOR..................................................6-38

ENGINE

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