Yamaha YP250R 2005, Service Manual

Page: 192 / 370

ENG
CHAPTER 5
ENGINE
ENGINE REMOVAL ........................................................................................ 5-1
LEADS, HOSES, EXHAUST PIPE AND MUFFLER ................................. 5-1
ENGINE..................................................................................................... 5-3
INSTALLING THE ENGINE....................................................................... 5-4
CYLINDER HEAD ............................................................................................ 5-5
REMOVING THE CYLINDER HEAD......................................................... 5-7
CHECKING THE CYLINDER HEAD ......................................................... 5-8
CHECKING THE CAMSHAFT SPROCKET .............................................. 5-9
CHECKING THE TIMING CHAIN TENSIONER........................................ 5-9
INSTALLING THE CYLINDER HEAD ....................................................... 5-9
CAMSHAFT AND ROCKER ARMS .............................................................. 5-13
REMOVING THE ROCKER ARMS AND CAMSHAFT............................ 5-14
CHECKING THE CAMSHAFT................................................................. 5-14
CHECKING THE ROCKER ARMS AND ROCKER ARM SHAFTS ........ 5-15
INSTALLING THE CAMSHAFT AND ROCKER ARMS .......................... 5-17
VALVES AND VALVE SPRINGS .................................................................. 5-19
REMOVING THE VALVES...................................................................... 5-20
CHECKING THE VALVES AND VALVE GUIDES .................................. 5-21
CHECKING THE VALVE SEATS ............................................................ 5-23
CHECKING THE VALVE SPRINGS........................................................ 5-25
INSTALLING THE VALVES .................................................................... 5-26
CYLINDER AND PISTON .............................................................................. 5-29
REMOVING THE PISTON ...................................................................... 5-30
CHECKING THE CYLINDER AND PISTON ........................................... 5-30
CHECKING THE PISTON RINGS........................................................... 5-32
CHECKING THE PISTON PIN ................................................................ 5-33
INSTALLING THE PISTON AND CYLINDER ......................................... 5-34