1999 Polaris SLH, SLTH, SLX, SLTX, PRO785 Factory Service Manual, Page 173Get this manual
ENGINECOOLING DisassemblyllnspectionPolaris Engines
Piston InspectionMeasurement
1 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 wear2Measure piston outside diameter at pOint 10 mm (38") up from bottom of skirt at 90 angle to the direction of the piston pinRecord the measurement for each pistonNOTE: The piston must be measured at this point to provide accurate piston-to-cylinder clearance measurement3 Subtract this measurement from the minimum cylinder measurement recorded previouslyIf clearance exceeds the service limit, determine if piston or cylinder is worn and recondition or replace as necessary
1 Position each piston ring 12" (1.3 cm) from the top of the cylinder using the piston to push it squarely into place Measure installed gap with feeler gauge at both the top and bottom of the cylinderNOTE: difference in end gap indicates cylinder taperThe cylinder should be measured for excessive taper and out of roundReplace rings if the installed end gap exceeds the service limitNOTE: Always check piston ring installed gap after reboring cylinder or when installing new rings