Polaris 850 PRO-RMK 155 2.6" QD 2021, Manual

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9850060 R02 - 2020-2021 850 AXYS™ Long Track Snowmobile Service Manual
© Copyright Polaris Inc.
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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.
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
q
.
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.
ENGINE / COOLING / EXHAUST