Yamaha YZ250 Owner's Service Manual page 270

CYLINDER HEAD, CYLINDER AND PISTON
EC475000
ASSEMBLY AND INSTALLATION
EC475193
Power valve
1. Install:
9 Power valve 1 1
9 Valve holder 2 2
9 Bolt (valve holder 2) 3
NOTE:
9 Install the power valve 1 with its gouge a fac-
ing upside.
9 Apply the molybdenum disulfide oil on the
power valve 1.
2. Install:
9 Power valve 2 1
9 Link rod 2
9 Plain washer 3
9 Screw (link rod) 4
NOTE:
Install the link rod with the cuts a in its arm
ends fitting over the pins b on the power valves
2.
3. Install:
9 Thrust plate 1
9 Screw (thrust plate) 2
NOTE:
Be sure to install the thrust plate to the cylinder
before installing the valve shaft.
4-27
ENG
6 Nm (0.6 m•kg, 4.3 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)
6 Nm (0.6 m•kg, 4.3 ft•lb)