Piston Ring Installed Gap; Piston-To-Cylinder Clearance - Polaris ACE 900 2017 Service Manual

ENGINE / COOLING SYSTEM

PISTON RING INSTALLED GAP

1. Place each piston ring
the piston to push the ring squarely into cylinder, as
shown below.
2. Measure installed gap with a feeler gauge
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.
3.66
q w
inside the cylinder . Use
e
at both

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.
Subtract measurement from maximum measurement
obtained in Step 4 of "Cylinder Inspection" procedure.
MEASUREMENT
Piston O.D. (Standard):
3.6592 ± .0003" (92.950 ± .008 mm)
MEASUREMENT
Piston to Cylinder Clearance:
.0014 - .0026" (.035 - .065 mm)
9929422 R02 - 2017-2019 ACE 900 Service Manual
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