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9930588 R02 - 2017-2020 RZR 900 900/S 900/S4 1000/S 1000/S4 Service Manual
© Copyright Polaris Industries Inc.
3.61
PISTON RING TO GROOVE CLEARANCE
INSPECTION
1. Measure piston ring to groove clearance
q
by
placing the ring in the ring land and measuring with a
thickness (feeler) gauge. Replace piston and rings if
ring-to-groove clearance exceeds service limits.
MEASUREMENT
Piston Ring to Groove Clearance:
Top Ring: 0.0012 - 0.0037" (.030 - .095 mm)
Second Ring: 0.0012 - 0.0030" (.030 - .076 mm)
Service Limit: .0047" (.12 mm)
PISTON RING INSTALLED GAP
1. Place each piston ring
q
inside the cylinder
w
. Use
the piston to push the ring squarely into cylinder, as
shown below.
2. Measure installed gap with a feeler gauge
e
at both
the top and bottom of the cylinder.
NOTICE
A difference between top and bottom end gap
measurements is a general indication of cylinder taper
(wear). The cylinder should be measured for taper and
out of round.
3. If the installed gap measurement exceeds the
service limit, replace the rings.
MEASUREMENT
Piston Ring Installed Gap:
Top Ring: .008 - .014" (.20 - .36 mm)
Service Limit: .020" (.50 mm)
Second Ring: .015 - .025" (.37 - .63 mm)
Service Limit: .028" (.70 mm)
Oil Control Rails: .010 - .040" (.25 - 1.02 mm)
Service Limit: .059" (1.50 mm)
NOTICE
Always check piston ring installed gap when installing
new rings and/or a new cylinder.
PISTON-TO-CYLINDER CLEARANCE
Measure piston outside diameter at a point 13 mm up
from the bottom of the piston, at a right angle to piston
pin bore.
ENGINE / COOLING SYSTEM