Yamaha Motor YZ250 N/LC 2001 Manuel D'atelier Du Proprietaire page 256

CYLINDER HEAD, CYLINDER AND PISTON
5. Check:
9Free play
There should be no noticeable free play.
Free play exists
rod for wear/Replace the pin and/or con-
necting rod as required.
EC474502
Piston ring
1. Install:
9Piston ring
Into the cylinder.
Push the ring with the piston crown.
2. Measure:
9End gap
Use a thickness gauge 1.
Out of limit
Ring end gap (installed):
Standard
0.40~0.55 mm
(0.016~0.022 in)
3. Measure:
9Side clearance
Use a thickness gauge 1.
Out of limit
Side clearance:
Standard
0.030~0.065 mm
(0.0012~0.0026 in)
NOTE:
Check at several points.
4-23
ENG
Inspect the connecting
Replace.
<Limit>
0.95 mm
(0.037 in)
Replace piston and/or ring.
<Limit>
0.1 mm
(0.004 in)