Yamaha YFM50S Service Manual page 9

ELECTRICAL SYSTEM................................................................................. 3-33
CHECKING AND CHARGING THE BATTERY....................................... 3-33
CHECKING THE FUSE...........................................................................3-37
ENGINE ...........................................................................................................4-1
EXHAUST PIPE/MUFFLER, BREATHER HOSE AND LEADS ................ 4-1
ENGINE MOUNTING BOLTS ...................................................................4-2
REMOVING THE ENGINE ........................................................................ 4-4
INSTALLING THE ENGINE....................................................................... 4-4
CYLINDER HEAD............................................................................................ 4-5
REMOVING THE CYLINDER HEAD.........................................................4-7
CHECKING THE CAMSHAFT SPROCKET..............................................4-8
CHECKING THE TAPPET COVERS
AND CAMSHAFT SPROCKET COVER................................................... 4-8
CHECKING THE TIMING CHAIN GUIDES............................................... 4-8
CHECKING THE TIMING CHAIN TENSIONER ASSEMBLY ................... 4-8
CHECKING THE CYLINDER HEAD .........................................................4-9
INSTALLING THE CYLINDER HEAD .....................................................4-10
CAMSHAFT, ROCKER ARMS AND VALVES.............................................. 4-12
REMOVING THE ROCKER ARMS AND CAMSHAFT............................ 4-14
REMOVING THE VALVES AND VALVE SPRINGS ...............................4-14
CHECKING THE CAMSHAFT.................................................................4-15
CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ........ 4-15
CHECKING THE VALVES AND VALVE SPRINGS ................................4-17
INSTALLING THE VALVES AND VALVE SPRINGS ..............................4-21
INSTALLING THE CAMSHAFT AND ROCKER ARMS .......................... 4-22
CYLINDER AND PISTON.............................................................................. 4-23
REMOVING THE PISTON ...................................................................... 4-24
CHECKING THE CYLINDER AND PISTON ...........................................4-24
CHECKING THE PISTON RINGS........................................................... 4-26
CHECKING THE PISTON PIN ................................................................4-27
INSTALLING THE PISTON ..................................................................... 4-28
INSTALLING THE CYLINDER ................................................................4-29
C.D.I. MAGNETO........................................................................................... 4-30
REMOVING THE C.D.I. MAGNETO ROTOR .........................................4-31
CHECKING THE PICKUP COIL/STATOR ASSEMBLY.......................... 4-31
INSTALLING THE C.D.I. MAGNETO ROTOR ........................................ 4-32
INSTALLING THE SHIFT LEVER ........................................................... 4-32
CHAPTER 4
ENGINE