Engine - Yamaha YZ 2019 Series Owner's Service Manual

ENGINE REMOVAL ..........................................................................................5-1
REMOVING THE SILENCER .....................................................................5-5
REMOVING THE EXHAUST PIPE 2 ..........................................................5-5
REMOVING THE DRIVE SPROCKET .......................................................5-5
REMOVING THE ENGINE .........................................................................5-5
CHECKING THE SILENCER AND EXHAUST PIPE ..................................5-6
CHANGING THE SILENCER FIBER..........................................................5-6
INSTALLING THE ENGINE ........................................................................5-7
INSTALLING THE BRAKE PEDAL.............................................................5-8
INSTALLING THE DRIVE SPROCKET ......................................................5-8
INSTALLING THE EXHAUST PIPE AND MUFFLER .................................5-9
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...........................................................................................5-19
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......................................................................5-27
CYLINDER AND PISTON ...............................................................................5-29
REMOVING THE PISTON........................................................................5-30
CHECKING THE CYLINDER AND PISTON.............................................5-30
CHECKING THE PISTON RINGS ............................................................5-31
CHECKING THE PISTON PIN .................................................................5-31
INSTALLING THE PISTON AND CYLINDER ..........................................5-32
ELECTRIC STARTER.....................................................................................5-34
CHECKING THE STARTER MOTOR ......................................................5-36
ASSEMBLING THE STARTER MOTOR ..................................................5-37
CLUTCH..........................................................................................................5-39
REMOVING THE CLUTCH ......................................................................5-42

ENGINE

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