Piston / Piston Ring Inspection; Piston Ring Removal; Piston Ring Installed Gap - Polaris Sportsman 850 Service Manual

PISTON / PISTON RING INSPECTION

1. Measure piston ring to ring land clearance with a
thickness gauge (A) inserted between bottom edge
of ring (B) and piston ring land (C). Replace both
piston and rings if clearance exceeds service limit.
2. Repeat for 2nd ring.

PISTON RING REMOVAL

1. Carefully remove top compression ring
using a ring removal pliers.
CAUTION
Do not expand the ring more than necessary to remove
it from the piston or the ring may break or lose radial
tension.
Carefully expand ring and lift it off the piston.
2. Repeat procedure for second ring
3. Remove (3 piece) oil control ring
first, then bottom rail, then the expander.

PISTON RING INSTALLED GAP

1. Place each piston ring
piston to push the ring squarely into cylinder.
2. Measure installed gap with a feeler gauge
the top and bottom of the cylinder.
A difference between top and bottom end gap
q
measurements is a general indication of cylinder taper
by hand or
(wear). The cylinder should be measured for taper and
3. If the installed gap measurement exceeds the service
limit, replace the rings.
Always check piston ring installed gap when installing
w
.
e
. Remove top rail
ENGINE / COOLING SYSTEM
q
inside the cylinder . Use the
NOTE
out of round.
MEASUREMENT
Piston Ring Installed Gap
Top: 0.014" ± 0.008" (0.36 ± 0.20 mm)
Second: 0.014" ± 0.008" (0.36 ± 0.20 mm)
Oil Control Rails:
0.0196" ± 0.010" (0.50 ± 0.25 mm)
IMPORTANT
new rings and/or a new cylinder.
3
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at both
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