Checking The Piston Rings - Orion AGB-21G Service Manual

CYLINDER AND PISTON
b. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.
c. Measure piston skirt diameter "P" with the
micrometer.
1 7.0 mm from the bottom edge of the piston.
Standard
d. If out of specification, replace the piston and
piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
Piston-to-cylinder clearance =
Cylinder bore "C" –
Piston skirt diameter "P"
Piston-to-cylinder clearance
0.025
f. If out of specification, rebore or replace the
cylinder, and replace the piston and piston
rings as a set.

CHECKING THE PISTON RINGS

1. Measure:
piston ring side clearance
Out of specification
and piston rings as a set.
NOTE:
Before measuring the piston ring side clear-
ance, eliminate any carbon deposits from the
piston ring grooves and piston rings.
Piston ring side clearance
Top ring
2nd ring
4 - 28
Piston size "P"
53.965 53.975 mm
0.05 mm
Replace the piston
0.04 0.08 mm
<Limit>: 0.12mm
0.04 0.08 mm
<Limit>: 0.12mm