1985-1995 Polaris ATV and Light Utility Hauler Service Manual, Page 299Get this manual
ENGINES Magnum Engine DisassemblyInspection 6Measure valve guide inside diameter at the top middle and end of the guide using small hole gauge and micrometerMeasure in two directions, front to back and side to side7Subtract valve stem measurement to obtain stem to guide clearanceNOTE: Be sure to measure each guide and valve combination individually8Replace valve andor guide if clearance is excessiveNOTE: If valve guides are replaced, valve seats must be reconditioned
Combustion Chamber
Clean all accumulated carbon deposits from combustion chamber and valve seat area with soft wire brush
Valve Seat Inspection
Inspect valve seat in cylinder head for pitting, burnt spots, roughness, and uneven surfaceIf any of the above conditions exist, the valve seat must be reconditionedSee Valve Seat Reconditioning, page 7.76If the valve seat is cracked the cylinder head must be replaced