2007-2008 Polaris IQ Snowmobiles Service Manual, Page 125Get this manual
Engine and Cooling Systems Piston Inspection
Check piston for scoring or cracks in piston crown or pin areaExcessive carbon buildup below the ring lands is an indication of piston, ring or cylinder wearOn Fuji engines, measure piston outside diameter at point that is 12" (12.7mm) up form the bottom of the skirt at 90 angle to the direction of the piston pinPiston rings are installed with marking or beveled side up
Reed Valve Inspection
123456Loosen he hose clamps Remove the carburetor or the throttle body from the intake bootsRemove the intake boot fasteners and hose holders (if applicable)Remove the intake assemblySeparate the intake boot(s) from the reed cageSeparate the reed stuffer(s) from the reed cage and inspect the reeds before they are removed from the reed cage
NOTE: Measure the air gap between the fiber reed and the reed blockThe air gap should not exceed .015" (.38mm)If clearance is excessive DO NOT attempt to reverse the reeds to reduce the air gapAlways replace them if damaged or wornCheck each fiber reed for white stress marks or missing materialThe air gap should not exceed .015" (.30mm)