Piston Removal; Cylinder Inspection - Polaris 2009 Trail Boss 330 Service Manual

PISTON REMOVAL

1. Remove circlip. Note that opening for circlip
access is on the intake side.
2. Remove piston circlip and push piston pin out of
piston. If necessary, heat the crown of the piston
slightly with a propane torch. CAUTION: Do not
apply heat to the piston rings. The ring may lose
radial tension.
3. Remove top compression ring.
*Using a piston ring pliers: Carefully expand ring
and lift it off the piston. CAUTION: Do not expand the
ring more than the amount necessary to remove it
from the piston, or the ring may break.
*By hand: Placing both thumbs as shown, spread the
ring open and push up on the opposite side. Do not
scratch the ring lands.
4. Repeat procedure for second ring.
The oil control ring is a three piece design consisting
of a top and bottom steel rail and a center expander
section.
5. Remove the top rail first followed by the bottom
rail.
6. Remove the expander.

CYLINDER INSPECTION

1. Remove all gasket material from the cylinder
sealing surfaces.
2. Inspect the top of the cylinder for warpage using a
straight edge and feeler gauge.
Cylinder Warpage:
.0020" (.05 mm) MAX
3. Inspect cylinder for wear, scratches, or damage.
4. Inspect cylinder for taper and out of round with a
telescoping gauge or a dial bore gauge. Measure
in two different directions, front to back and side to
side, on three different levels (1/2" down from top,
in the middle, and 1/2" up from bottom).
1/2" Down From Top of Cylinder
X
X
X
1/2" Up From Bottom
ENGINE
Y
Y
Y
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