Yamaha YZ125(W)/W1 Owner's Service Manual page 258

CYLINDER HEAD, CYLINDER AND PISTON
EC474402
Piston pin and small end bearing
1. Inspect:
9 Piston pin
9 Small end bearing
Signs of heat discoloration ¡ Replace.
2. Measure:
9 Piston pin outside diameter
Use micrometer 1.
Out of limit ¡ Replace.
Piston pin outside diameter:
Standard
14.995~15.000 mm
(0.5904~0.5906 in)
3. Check:
9 Free play (when the piston pin 1 is in
place in the piston 2)
There should be no noticeable for the play.
Free play exists ¡ Replace piston pin
and/or piston.
4. Install:
9 Small end bearing
9 Piston pin
Into the small end of connecting rod.
5. Check:
9 Free play
There should be no noticeable free play.
Free play exists ¡ Inspect the connecting
rod for wear/Replace the pin and/or con-
necting rod as required.
4-22
ENG
<Limit>
14.975 mm
(0.5896 in)