2007-2011 Polaris IQ Snowmobiles Service Manual, Page 224Get this manual
Engine and Cooling Systems Cylinder Measurement
Inspect each cylinder for wear, scratches, or damageIf no damage is evident, measure the cylinder for taper and out of round with telescoping gauge or dial bore gaugeMeasure the bore 12" from the top of the cylinder; in line with the piston pin and 90 to the pin to determine if the bore is out of roundRepeat the measurements at the middle and bottom of the cylinderUse the chart below and record all measurements
Crankshaft Runout Inspection
Cylinder Measurement Worksheet
TOP MIDDLE BOTTOM 1Support the crankshaft in set of "V" blocks as shown2Use dial indicator to measure the runout at the following locations: PTO endFirst taper after bearing flat MAG end12" from bearing flat3Runout deflection cannot exceed .0025" (.07mm)4If the runout deflection exceeds the maximum specification, crankshaft trueing may correct the deflection