Generic Trigger SM 50ccm - Installation of Piston

- 92 -
Measure the roundness of inner wall（bore diameter difference between X and Y direction ）.
Allowable limit：0.04mm。
Measure the cylindricity of inner wall（bore diameter difference at the upper , middle and lower part in X or Y
direction）.
Allowable limit：0.05mm。
Inspect the flatness of the cylinder surface.
Allowable limit：0.05mm。
Measure the bore diameter of connecting rod small end.
Allowable limit：15.06mm。
11.4.1 Installation of piston
Install the guide pin.
Evenly spread machine oil on each piston ring and
piston and correctly install the piston ring by
aligning it with the guide pin on the piston.
Note：
The piston should not be scratched and the
piston ring should not be broken.
The piston ring should be assembled with its
marked side upward.
upper
middle
lower
middle
rule
r
Testing gauge
cylinder
bore diameter of connecting rod small end
guide
p
iston
Top ring
second
ring