Yamaha TZ250M1 Owner's Service Manual page 122

CYLINDER HEAD, CYLINDER AND PISTON
EC474520
Piston ring
1. Install:
• Piston ring
Into the cylinder.
Push the ring with the piston crown.
2. Measure:
• End gap
Use a thickness gauge 1.
Out of limit ≥ Replace.
]
Ring end gap (installed):
Standard
0.22~0.37 mm
(0.009~0.015 in)
3. Measure:
• Side clearance
Use a thickness gauge 1.
Out of limit ≥ Replace piston and/or ring.
]
Side clearance:
Standard
0.02~0.06 mm
(0.0008~0.0024 in)
NOTE:
• Insert the thickness gauge deep in the piston
ring groove. Then measure the clearance with
both sliding surfaces being flush with each
other.
• Check at several points.
EC474720
Combination of piston and cylinder
1. Check:
*
• Cylinder mark a
Cylinder mark a a
4-24
ENG
<Limit>
0.59 mm
(0.023 in)
<Limit>
0.1 mm
(0.004 in)
A
B
C