Polaris A09BG50AA User Manual page 80

ENGINE
PISTON-TO-CYLINDER
CLEARANCE
40 mm
1. Measure piston outside diameter at a point 40 mm
down from the top of the piston at a right angle to
the direction of the piston pin.
2. Subtract this measurement from the maximum
cylinder measurement obtained in Step 5 above.
Piston to Cylinder Clearance
Std: .0006-.0018I (.015-.045 mm)
Piston O.D.:
Std: 3.6204-3.6215I (91.970-91.985 mm)
PISTON/ROD INSPECTION
Piston Pin Bore
Piston Pin Bore:
.9055-.9057I (23.0-23.006 mm)
3.30
Piston
Piston Pin
1. Measure piston pin bore.
Piston Pin Measurement Locations
Piston Pin O.D.
.9053-.9055I (22.994-23.0 mm)
2. Measure piston pin O.D. Replace piston and/or
piston pin if out of tolerance.
3. Measure connecting rod small end ID.
Piston Ring-to-Groove Clearance
Top Ring Std: .0016-.0031I (.040-.080 mm)
Limit: .0059I (15 mm)
Second Ring Std: .0012-.0028I (.030-.070 mm)
Limit: .0059I (15 mm)
4. Measure piston ring to groove clearance by
placing the ring in the ring land and measuring
with a thickness gauge. Replace piston and rings
if ring-to-groove clearance exceeds service
limits.
Piston
Ring
Feeler Gauge