2006 Arctic Cat Y-6/Y-12 50cc and 90cc Service Manual, Page 37Get this manual
Piston Assembly NOTE: Whenever piston, rings, or pin is out of tolerance, it must be replaced
2Using the sharpened ring as tool, clean carbon from the ring groovesBe sure to position the ring with its tapered side upOnly use parts-cleaning solvent to clean the third ring groove (oil ring groove) of the piston
! CAUTION
Improper cleaning of the ring grooves by use of the wrong type of ring-groove cleaner will result in severe damage to the piston
CLEANINGINSPECTING PISTON
1Using non-metallic carbon removal tool, remove any carbon buildup from the dome of the piston2Inspect the piston for cracks in the piston pin, dome, and skirt areas3Inspect the piston for seizure marks or scuffingRepair with #400 grit wet-or-dry sandpaper and water or honing oilNOTE: If scuffing or seizure marks are too deep to repair with the sand paper, replace the piston
MEASURING PISTON RING END GAP
1Place each piston ring in the wear portion of the cylinderUse the piston to position each ring squarely in the cylinder2Using feeler gauge, measure each piston ring end gapAcceptable ring end gap must be within specifications