Yamaha XT660R Service Manual page 236

ENGINE REMOVAL ........................................................................................5-1
EXHAUST PIPES AND MUFFLERS .........................................................5-1
LEADS, CABLES, HOSES, AND IGNITION COIL ....................................5-2
ENGINE..................................................................................................... 5-5
INSTALLING THE ENGINE....................................................................... 5-7
CYLINDER HEAD............................................................................................ 5-8
REMOVING THE CYLINDER HEAD.......................................................5-10
CHECKING THE CYLINDER HEAD .......................................................5-11
CHECKING THE TAPPET COVERS AND CAMSHAFT SPROCKET
COVER ................................................................................................... 5-12
CHECKING THE TIMING CHAIN TENSIONER...................................... 5-12
CHECKING THE CAMSHAFT SPROCKET............................................5-12
INSTALLING THE CYLINDER HEAD .....................................................5-12
ROCKER ARMS AND CAMSHAFT ..............................................................5-16
REMOVING THE ROCKER ARMS AND CAMSHAFT............................ 5-18
CHECKING THE CAMSHAFT.................................................................5-18
CHECKING THE DECOMPRESSION SYSTEM..................................... 5-19
CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ........ 5-20
INSTALLING THE CAMSHAFT AND ROCKER ARMS .......................... 5-21
VALVES AND VALVE SPRINGS.................................................................. 5-23
REMOVING THE VALVES...................................................................... 5-24
CHECKING THE VALVES AND VALVE GUIDES ..................................5-25
CHECKING THE VALVE SEATS ............................................................ 5-27
CHECKING THE VALVE SPRINGS........................................................ 5-29
INSTALLING THE VALVES .................................................................... 5-30
CYLINDER AND PISTON.............................................................................. 5-32
REMOVING THE CYLINDER AND PISTON...........................................5-34
CHECKING THE CYLINDER AND PISTON ...........................................5-34
CHECKING THE PISTON RINGS........................................................... 5-36
CHECKING THE PISTON PIN ................................................................5-37
INSTALLING THE PISTON AND CYLINDER .........................................5-38
CHAPTER 5
ENGINE
ENG