Engine - Yamaha WR250F 2017 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...............................6-10
CAMSHAFT ....................................................................................................6-12
REMOVING THE CAMSHAFT .................................................................6-14
CHECKING THE CAMSHAFT..................................................................6-15
CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET ..........6-16
CHECKING THE TIMING CHAIN TENSIONERS ....................................6-16
CHECKING THE DECOMPRESSION SYSTEM......................................6-17
INSTALLING THE CAMSHAFTS .............................................................6-17
CYLINDER HEAD...........................................................................................6-20
REMOVING THE CYLINDER HEAD........................................................6-22
CHECKING THE TIMING CHAIN GUIDE (INTAKE SIDE) ......................6-22
CHECKING THE CYLINDER HEAD ........................................................6-22
INSTALLING THE CYLINDER HEAD ......................................................6-23
VALVES AND VALVE SPRINGS...................................................................6-24
REMOVING THE VALVES.......................................................................6-25
CHECKING THE VALVES AND VALVE GUIDES ...................................6-26
CHECKING THE VALVE SEATS .............................................................6-27
CHECKING THE VALVE SPRINGS.........................................................6-29
CHECKING THE VALVE LIFTERS ..........................................................6-29
INSTALLING THE VALVES .....................................................................6-30
CYLINDER AND PISTON...............................................................................6-32
REMOVING THE PISTON .......................................................................6-33
CHECKING THE CYLINDER AND PISTON ............................................6-33
CHECKING THE PISTON RINGS............................................................6-34
CHECKING THE PISTON PIN .................................................................6-35
INSTALLING THE PISTON AND CYLINDER ..........................................6-35
ELECTRIC STARTER ....................................................................................6-37
CHECKING THE STARTER MOTOR ......................................................6-39
ASSEMBLING THE STARTER MOTOR..................................................6-40

ENGINE

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