4 - 27
CYLINDER AND PISTON
NOTE:
NOTE:
NOTE:
REMOVING THE PISTON AND PISTON
RINGS
1. Remove:
piston pin circlip
1
piston pin
2
piston
3
Before removing the piston pin circlip, cover the
crankcase opening with a clean towel or rag to
prevent the circlip from falling into the crank-
case cavity.
2. Remove:
top ring
2nd ring
oil ring
When removing the piston ring, open the end
gap of the ring by fingers, and push up the other
side of the ring.
CHECKING THE CYLINDER AND PISTON
1. Check:
piston wall
cylinder wall
Vertical scratches
Rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
2. Measure:
piston-to-cylinder clearance
a. Measure cylinder bore “C” with the cylinder
bore gauge.
Measure cylinder bore “C” by taking side-to-
side and front-to-back measurements of the
cylinder. Then, find the average of the measure-
ments.
Cylinder bore “C”
54.00 54.015 mm
Taper limit ”T” 0.05 mm
Out of round “R” 0.005 mm
”C” = Maximum D
”T” = (Maximum D
1
or D
2
)–
(Maximum D
5
or D
6
)
”R” = (Maximum D
1
, D
3
or D
5
)
– (Minimum D
2
, D
4
or D
6
)
To Next Page
Loading...