2007-2011 Polaris IQ Snowmobiles Service Manual, Page 227Get this manual
Engine and Cooling Systems Connecting Rod Lower Bearing Piston Needle Bearing
1Clean the end of the connecting rod and inspect inner bore with magnifying glassLook for any surface irregularities including pitting, wear, or dents2Run fingernail around the inside of the rod and check for rough spots, galling, or wear3Oil and install needle bearing and pin in connecting rod4Rotate pin slowly and check for rough spots or any resistance to movement5Slide pin back and forth through bearing while rotating and check for rough spots
Measure connecting rod big end side clearance with feeler gauge on both sides of the connecting rodThe side clearance on either side of the connecting rod cannot exceed the connecting rod side clearance specificationThe difference between the two clearance measurements cannot exceed the maximum clearance differential specification6With pin and bearing centered in rod, twist ends back and forth in all directions to check for excessive axial play7Pull up and down evenly on both ends of pin to check for radial play8Replace pin and bearing if there is any resistance to rotation or excessive axial or radial movementIf play or roughness is evident with new pin and bearing, replace the connecting rod