Yamaha YZ250(W)/W1 Owner's Service Manual page 276

CYLINDER HEAD, CYLINDER AND PISTON
7. Install:
9 O-ring 1
9 Side holder 2
9 Screw (side holder) 3
9 YPVS breather hose 4
NOTE:
9 Apply the lithium soap base grease on the O-
rings.
9 Install the side holder with its projection a
facing upward.
8. Install:
9 Gasket (power valve cover) 1
9 Power valve cover 2
9 Screw (power valve cover) 3
NOTE:
9 Install the gasket with its cut a facing down-
ward and the seal print side toward the power
valve cover.
9 Install the power valve cover so that the arrow
mark b faces upward.
EC475233
Piston ring and piston
1. Install:
9 Piston ring 1
NOTE:
9 Take care not to scratch the piston or damage
the piston ring.
9 Align the piston ring gap with the pin 2.
9 After installing the piston ring, check the
smooth movement of it.
2. Install:
9 Gasket (cylinder) 1
9 Small end bearing 2
9 Dowel pin 3
NOTE:
9 Apply the engine oil onto the bearing (crank-
shaft and connecting rod) and connecting rod
big end washers.
9 Install the gasket with the seal print side toward
the crankcase.
4-29
ENG
4 Nm (0.4 m•kg, 2.9 ft•lb)
4 Nm (0.4 m•kg, 2.9 ft•lb)