96
Measuring Piston Pin (Outside
Diameter) and Piston-Pin Bore
1. Measure the piston pin outside diameter at each end
and in the center. If measurement is not within speci-
fications, the piston pin must be replaced.
ATV-1070
2. Insert an inside dial indicator into the piston-pin
bore. The diameter must not exceed specifications.
Take two measurements to ensure accuracy.
ATV-1069
Measuring Piston Skirt/Cylinder
Clearance
1. Measure the cylinder front to back in six places.
CC127D
2. Measure the corresponding piston diameter at the
recommended point above the piston skirt at a right
angle to the piston-pin bore. Subtract this measure-
ment from the measurement in step 1. The difference
(clearance) must not exceed specifications.
Installing Piston Rings
1. Install ring expander (4) in the bottom groove of the
piston; then install the thin oil rings (3) over the
expander making sure the expander ends do not
overlap. Stagger the end gaps of the upper and lower
thin oil rings according to the illustration.
ATV-1085B
NOTE: Note the direction of the exhaust side of the
piston (5) for correct ring end gap orientation.
2. The ring with the orientation mark (MTOP or TOP)
should be installed in the second (middle) groove
and the ring with the orientation mark (M or O)
should be installed in the first (top) groove.
ATV-1024A
ATV-1024B
CAUTION
Incorrect installation of the piston rings will result in
engine damage.
