Yamaha TZ250M1 Owner's Service Manual page 123

CYLINDER HEAD, CYLINDER AND PISTON
2. Check:
*
• Piston mark a
Piston mark a a (color)
B (orange)
3. Combination:
Combine the piston and cylinder by the fol-
(
lowing chart.
Cylinder mark
A
B
C
NOTE:
When you purchase a cylinder, you cannot
designate a specific one. Choose the piston
that matches the above chart.
EC474821
Power valve
1. Inspect:
• Power valve 1
Wear/Damage ≥ Replace.
Carbon deposits ≥ Remove.
• Valve shaft 2
• Solid bush 3
• Oil seal 4
Wear/Damage ≥ Replace.
EC474901
Power valve hole on cylinder
1. Remove:
• Carbon deposits
From power valve hole surface a.
NOTE:
Do not use a sharp instrument. Avoid scratch-
ing the aluminum.
EC475000
ASSEMBLY AND INSTALLATION
EC475180
Power valve
1. Install:
• Power valve 1
• Bolt (power valve) 2
GT
NOTE:
Install the power valve at cut-away faced a for
down side.
4-25
ENG
A (red)
C (green)
Piston mark (color)
A(red)
B(orange)
C (green)
9 Nm (0.9 mdkg, 6.5 ftdlb)