43
Measuring Piston-Ring End Gap
(Installed)
1. Place each piston ring in the wear portion of the
cylinder. Use the piston to position each ring
squarely in the cylinder.
2. Using a feeler gauge, measure each piston-ring
end gap. Acceptable ring end gap must be within
specifications.
CC995
Measuring Piston Pin, Connecting
Rod Small End, and Piston-Pin Bore
1. Measure the piston pin outside diameter at each
end and in the center. If measurement exceeds
specifications, the piston pin must be replaced.
ATV-1070
2. Inspect and measure the connecting rod small end.
If the measurement exceeds specifications, the
connecting rod must be replaced (see Center
Crankcase Components in this section).
3. Insert an inside dial indicator into the piston-pin
bore. Take two measurements to ensure accuracy.
The diameter must not exceed specifications. If
the diameter exceeds specifications, the piston
must be replaced.
ATV-1069
Measuring Piston Skirt/
Cylinder Clearance
1. Measure the cylinder front to back in six places.
CC397D
2. Measure the corresponding piston diameter at a
point 15 mm (0.6 in.) above the piston skirt at a
right angle to the piston-pin bore. Subtract this
measurement from the measurement in step 1. The
difference (clearance) must be within specifica-
tions.
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.
NOTE: Note the direction of the exhaust side of
the piston (5) for correct ring end gap orientation.
