Upper Crankcase Preparation; Piston Ring Installation - Polaris RZR 900 2017 Service Manual

ENGINE / COOLING SYSTEM

UPPER CRANKCASE PREPARATION

NOTICE
Always replace plain bearings when the crankcase or
connecting rods have been disassembled. Refer to
bearing selection procedures.
1. Remove all traces of crankcase sealer from the
crankcase mating surfaces. Inspect the surfaces
closely for nicks, burrs or damage.
2. Clean bolt hole threads to remove any oil or
crankcase sealant.
3. Inspect crankcase bearing bores. Replace the
crankcase assembly if a bearing bore is galled or if
bearing inserts have rotated in the case.
4. Be sure alignment pins are in place where used.
5. Refer to Engine Oil Flow Chart page
beginning of this chapter and trace the oil paths
through the crankcase and cylinder.
6. Flush all oil passages with solvent and then warm
soapy water. Rinse with clear, warm water and dry
with compressed air.
7. Be sure passages are clean and dry before
assembling the upper crankcase.
3.120

PISTON RING INSTALLATION

Apply clean engine oil to all ring surfaces and ring lands
upon installation. Always check piston ring installed gap
before rings are installed on piston (see Piston Ring
Installed Gap (1000) page 3.116). Clean accumulated
carbon from piston ring grooves and oil ring lube holes
if piston has been in service.
at the
q
Top Ring
w
Second Ring
e
Upper Rail
1. Place oil control ring expander in oil ring groove.
Rotate expander in groove until butt ends are on
PTO side of piston (see illustration below).
Ends must butt squarely together and must not overlap.
2. Install lower rail with end gap positioned on the
intake side of piston.
9930588 R02 - 2017-2020 RZR 900 900/S 900/S4 1000/S 1000/S4 Service Manual
NOTICE
r
Spring Expander
t
Lower Rail
NOTICE
© Copyright Polaris Industries Inc.