2005 Polaris Sportsman 400/500 Service Manual, Page 90Get this manual
Piston Ring-to-Groove Clearance Top Ring Std: .0016-.0031I (.040-.080 mm) Limit: .0059I (15 mm) Second Ring Std: .0012-.0028I (.030-.070 mm) Limit: .0059I (15 mm) 4Measure piston ring to groove clearance by placing the ring in the ring land and measuring with thickness gaugeReplace piston and rings if ring-to-groove clearance exceeds service limits
below specified limit, file ring ends until gap is within specified rangeNOTE: Always check piston ring installed gap after re-boring cylinder or when installing new ringsA re-bored cylinder should always be scrubbed thoroughly with hot soapy water, rinsed, and dried completelyWipe cylinder bore with an oil rag immediately to remove residue and prevent rust
CRANKCASE DISASSEMBLY
NOTE: The recoil starter, starter motor, starter drive, flywheel, stator, cam chain and sprockets can be serviced with the engine in the frame
PISTON RING INSTALLED GAP
1Place each piston ring inside cylinder using piston to push ring squarely into place as shown at right