![background image](/i/yamaha/160811/yamaha-yw50at-2001/h/yamaha-yw50at-2001-075.png)
4-4
ENG
PISTON PIN AND PISTON REMOVAL
1. Remove:
8
Piston pin clip
1
NOTE:
Before removing the piston pin clip, cover the
crankcase with a clean rag so you will not acci-
dentally drop the clip into the crankcase.
2. Remove:
8
Piston pin
1
8
Piston
2
8
Piston pin bearing
3
c
C
Do not use a hammer to drive the piston pin
out.
CYLINDER HEAD INSPECTION
1. Eliminate:
8
Carbon deposits
Use a rounded scrapper
1
.
2. Inspect:
8
Cylinder head warpage
Out of specification
→
Re-surface.
*************************************
Warpage measurement and re-surfacement
steps:
8
Attach a straight edge
1
and a thickness
gauge
2
on the cylinder head.
8
Measure the warpage limit.
Warpage limit:
0.03 mm(0.0012 in)
8
If the warpage is out of specification, reface
the cylinder head.
NOTE:
Rotate the head severai tires to avoid remov-
ing too much material from one side.
*************************************
CYLINDER HEAD, CYLINDER, PISTON
2
1