2003 Polaris ATV Trail Boss 330 Factory Service Manual, Page 69Get this manual
ENGINE CYLINDER INSPECTION CONT'D 5Record measurementsIf cylinder is tapered or out of round beyond .002, the cylinder must be re-bored oversize, or replacedCylinder Taper Limit: .002 MaxCylinder Out of Round Limit: .002 Max3Measure piston pin bore
Standard Bore Size: 3.0906-3.0913I (78.50-78.520 mm)
PISTON INSPECTION
1Measure piston outside diameter at point mm up from the bottom of the piston at right angle to the direction of the piston pin
Piston Pin Bore: .7095-.7097I (18.007-18.013 mm)