Yamaha YZ250F(E), Owner'S Service Manual

Page: 191 / 356

5
ENGINE
ENGINE REMOVAL .........................................................................................5-1
REMOVING THE SILENCER.....................................................................5-6
REMOVING THE EXHAUST PIPE 2..........................................................5-6
REMOVING THE DRIVE SPROCKET .......................................................5-6
REMOVING THE ENGINE .........................................................................5-7
CHECKING THE SILENCER AND EXHAUST PIPE..................................5-7
CHANGING THE SILENCER FIBER .........................................................5-7
INSTALLING THE ENGINE........................................................................5-8
INSTALLING THE BRAKE PEDAL ............................................................5-9
INSTALLING THE DRIVE SPROCKET......................................................5-9
INSTALLING THE EXHAUST PIPE AND MUFFLER...............................5-10
CAMSHAFT ....................................................................................................5-11
REMOVING THE CAMSHAFT .................................................................5-13
CHECKING THE CAMSHAFT..................................................................5-14
CHECKING THE TIMING CHAIN AND CAMSHAFT SPROCKET ..........5-15
CHECKING THE TIMING CHAIN TENSIONERS ....................................5-15
CHECKING THE DECOMPRESSION SYSTEM......................................5-16
INSTALLING THE CAMSHAFTS .............................................................5-16
CYLINDER HEAD ...........................................................................................5-18
REMOVING THE CYLINDER HEAD........................................................5-20
CHECKING THE TIMING CHAIN GUIDE (INTAKE SIDE) ......................5-20
CHECKING THE CYLINDER HEAD ........................................................5-20
INSTALLING THE CYLINDER HEAD ......................................................5-21
VALVES AND VALVE SPRINGS ...................................................................5-22
REMOVING THE VALVES.......................................................................5-23
CHECKING THE VALVES AND VALVE GUIDES ...................................5-24
CHECKING THE VALVE SEATS .............................................................5-25
CHECKING THE VALVE SPRINGS.........................................................5-27
CHECKING THE VALVE LIFTERS ..........................................................5-27
INSTALLING THE VALVES .....................................................................5-28
CYLINDER AND PISTON ...............................................................................5-30
REMOVING THE PISTON .......................................................................5-31
CHECKING THE CYLINDER AND PISTON ............................................5-31
CHECKING THE PISTON RINGS............................................................5-32
CHECKING THE PISTON PIN .................................................................5-33
INSTALLING THE PISTON AND CYLINDER ..........................................5-33