Yamaha YZ250 Handbuch Seite 270

CYLINDER HEAD, CYLINDER AND PISTON
3. Combination:
Combine the piston and cylinder by the fol-
lowing chart.
Cylinder mark
A
B
C
D
NOTE:
When you purchase a cylinder, you cannot des-
ignate its size. Choose the piston that matches
the above chart.
EC474841
Power valve
1. Inspect:
9 Power valve 1, 2 1
Wear/Damage ¡ Replace.
Carbon deposits ¡ Remove.
9 Valve holder 1 2
9 Link lever 3
9 Pulley 4
9 Valve shaft 5
9 Link rod 6
9 Plain washer 7
Wear/Damage ¡ Replace.
9 Spring 1, 2 8
Broken ¡ Replace.
EC474901
Power valve hole on cylinder
1. Remove:
9 Carbon deposits
From power valve hole surface a.
NOTE:
Do not use a sharp instrument. Avoid scratching
the aluminum.
4-26
ENG
Piston mark (color)
A (red)
B (orange)
C (green)
D (purple)