2011 Arctic Cat 366SE ATV Service Manual, Page 33Get this manual
Measuring Piston Pin, Connecting Rod Small End, and Piston-Pin Bore
1Measure the piston pin outside diameter at each end and in the centerIf measurement exceeds specifications, the piston pin must be replaced
2Measure the corresponding piston diameter at point 15 mm (0.6 in above the piston skirt at right angle to the piston-pin boreSubtract this measurement from the measurement in step 1The difference (clearance) must be within specifications
Installing Piston Rings
1Install ring expander (4) in the bottom groove of the piston; then install the thin oil rings (3) over the expander making sure the expander ends do not overlapStagger the end gaps of the upper and lower thin oil rings according to the illustrationNOTE: Note the direction of the exhaust side of the piston (5) for correct ring end gap orientation
ATV-1070