Yamaha TZ250M1 Owner's Service Manual page 119

CYLINDER HEAD, CYLINDER AND PISTON
3. Remove:
• Piston ring 1
NOTE:
Take care not to scratch the piston and dam-
age the piston ring.
EC474000
INSPECTION
EC474110
Cylinder head
1. Remove:
• Carbon deposits
Use #400~600 grit wet sandpaper.
2. Inspect:
• Cylinder head water jacket
Crust of minerals/Rust ≥ Remove.
• Cylinder head contact surface
Wear/Damage ≥ Replace.
• Recess of insert portion a
The contact surface b of the insert portion
is recessed below the aluminum portion c
≥ Replace.
EC474210
Cylinder
1. Remove:
• Carbon deposits
Use a rounded scraper 1.
NOTE:
Do not use a sharp instrument. Avoid scratch-
ing the aluminum.
2. Inspect:
• Cylinder inner surface
Score marks ≥ Repair or replace.
Use #400~600 grit wet sandpaper.
C C CAUTION:
Do not rebore the cylinder.
4-21
ENG