Engine - Yamaha XG250 Service Manual

ENGINE REMOVAL ....................................................................................5-1
INSTALLING THE ENGINE ....................................................................5-4
CYLINDER HEAD .......................................................................................5-5
REMOVING THE CYLINDER HEAD ......................................................5-7
CHECKING THE CYLINDER HEAD .......................................................5-7
CHECKING THE TIMING CHAIN GUIDES.............................................5-8
CHECKING THE TIMING CHAIN TENSIONERS ...................................5-8
INSTALLING THE CYLINDER HEAD .....................................................5-9
ROCKER ARM, CAMSHAFT ......................................................................5-12
REMOVING THE ROCKER ARMS AND CAMSHAFT ...........................5-13
CHECKING THE CAMSHAFT ................................................................5-13
CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ........5-14
INSTALLING THE CAMSHAFT AND ROCKER ARMS ..........................5-15
VALVES AND VALVE SPRINGS................................................................5-17
REMOVING THE VALVES......................................................................5-18
CHECKING THE VALVES AND VALVE GUIDES ..................................5-18
CHECKING THE VALVE SEATS............................................................5-20
CHECKING THE VALVE SPRINGS .......................................................5-22
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................................................................5-28
INSTALLING THE PISTON AND CYLINDER .........................................5-28
CLUTCH ......................................................................................................5-30
REMOVING THE CLUTCH .....................................................................5-33
CHECKING THE FRICTION PLATES ....................................................5-33
CHECKING THE CLUTCH PLATES.......................................................5-34
CHECKING THE CLUTCH SPRINGS ....................................................5-34
CHECKING THE CLUTCH HOUSING....................................................5-34
CHECKING THE CLUTCH BOSS...........................................................5-34
CHECKING THE PRESSURE PLATE ....................................................5-35
CHECKING THE CLUTCH PUSH RODS ...............................................5-35
CHECKING THE PRIMARY DRIVE GEAR.............................................5-35
INSTALLING THE CLUTCH....................................................................5-35
OIL PUMP AND BLANCER WEIGHT GEAR .............................................5-38
REMOVING THE BALANCER WEIGHT GEAR AND OIL PUMP...........5-41
CHECKING THE OIL PUMP ...................................................................5-41
CHECKING THE BALANCER WEIGHT GEAR ......................................5-41
ASSENBLING THE BALANCER DRIVE GEAR......................................5-42
INSTALLING THE OIL PUMP .................................................................5-42
INSTALLING THE BALANCER WEIGHT GEAR ....................................5-42
SHIFT SHAFT..............................................................................................5-43

ENGINE

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