Lower Connecting Rod Bearing Inspection; Main Bearing Inspection - Polaris 850 MATRYX INDY XC 129 2021 Manual

LOWER CONNECTING ROD BEARING
INSPECTION
Measure the side clearance for the big end of the
connecting rod with a feeler gauge on both sides of the
connecting rod. The side clearance on either side of the
connecting rod cannot exceed the connecting rod side
clearance specification. The difference between the two
clearance measurements cannot exceed the maximum
clearance differential specification.
MEASUREMENT
Connecting Rod Side Clearance:
0.030 in (0.762 mm)
Rotate the connecting rod on the crankshaft and feel for
any rough spots. Check radial end play in rod by
supporting rod against one thrust washer and alternately
applying up and down pressure. Replace bearing, pin,
and thrust washers if side clearance is excessive or if
there is any up and down movement detectable in the big
end bearing.
9850064 R03 - 2021 650 / 850 Matryx Trail Performance / Crossover Snowmobile Service Manual
© Copyright Polaris Inc.
ENGINE / COOLING / EXHAUST

MAIN BEARING INSPECTION

Clean the crankshaft, oil main, and connecting rod
bearings thoroughly with Polaris engine oil. Carefully
q
check each main bearing on the crankshaft.
Due to extremely close tolerances, the bearings must be
inspected visually and by feel. Look for signs of
discoloration, scoring or galling. Turn the outer race of
each bearing. The bearings should turn smoothly and
quietly. The inner race of each bearing should fit tightly
on the crankshaft. The outer race should be firm with
minimal side to side movement and no detectable up and
down movement. Replace any loose or rough bearings.
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