Polaris 340 LX 2007 Service Manual page 104

Piston Ring Installed Gap
Position the ring 1/2" (1.3 cm) from the top of the cylinder
using the piston to push it squarely into place. Measure
installed gap with a feeler gauge at both the top and
bottom of the cylinder.
NOTE: A difference in end gap indicates cylinder
taper. The cylinder should be measured for excessive
taper and out-of-round. Replace rings if the installed
end gap exceeds the service limit. Always check
piston ring installed gap after re-boring a cylinder or
when installing new rings.
Piston rings are installed with marking or beveled side up.
Bearing Fit
Any time crankshaft bearing failure occurs and the case is
reused, check the bearing fit into the case halves using the
following procedure.
With case halves cleaned, press a replacement bearing
into each of the main bearing journals to determine a basic
amount of press fit.
Do a comparison check of all journals by manually forcing
the bearing into the bearing seats noting if any are
noticeably loose or tight. Normal hand installation will be
an indication of the recommended interference fit. If the
bearing falls out of the case when the case is inverted, or
if the crankcase bearing surface is severely galled or
damaged, the crankcase assembly should be replaced.
= In. / mm.
Bearing Interference Fit: .001-.002" (.026-.051mm)
Main Bearing
Clean crankshaft thoroughly and oil main and connecting
rod bearings with Polaris engine oil. Carefully 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.
Connecting Rod Lower Bearing
Measure connecting rod big end side clearance 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.
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
9923396 - 2007-2012 EDGE/Widetrak LX Service Manual
©2011 Polaris Sales Inc.
Engine Systems
= In. / mm.
Connecting Rod Side Clearance:
.012"-.016" (.30-.40mm)
Maximum Clearance Differential
.002" (.051mm)
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5.5