Piston Markings; Piston Inspection - Polaris 850 MATRYX INDY XC 129 2021 Manual

PISTON MARKINGS

The dots found on the piston skirts indicate the official
location to measure the diameter of the piston.
NOTICE
Intake side of piston shown.
Pistons are directional (intake vs. exhaust), but can be
placed in either cylinder. The arrow will point toward the
exhaust side.
9850064 R03 - 2021 650 / 850 Matryx Trail Performance / Crossover Snowmobile Service Manual
© Copyright Polaris Inc.
ENGINE / COOLING / EXHAUST

PISTON INSPECTION

NOTICE
A micrometer is the only recommended tool to
accurately measure piston diameter.
Check piston for scoring or cracks in piston crown or pin
area. Excessive carbon buildup below the ring lands is
an indication of piston, ring or cylinder wear.
Using a micrometer, measure the piston outside
diameter at a 90° angle to the direction of the piston pin
and at the specified measuring point
MEASUREMENT
Piston Measuring Point:
0.98 in (25 mm) from the bottom of the piston skirt
Subtract this measurement from the minimum cylinder
measurement (90° to the pin). If clearance exceeds the
service limit piston/cylinder overhaul may be required.
3
q
.
3.81