2010 Polaris Sportsman 850 Service Manual, Page 127Get this manual

2010 Polaris Sportsman 850 Service Manual, Page 127

ENGINE Cylinder Head Warp Inspection 1Lay straight edge (A) across surface of cylinder head at several different points and
parts or place them in rack as you remove themValve Spring Compressor: PV-1253 (or PV-4019 with adapter PV-43513-A) 123Compress
valve spring and remove split keepers (B)Remove compressor, then remove top retainer, spring, and seal (C)Discard sealsRepeat
for all remaining valvesClean combustion chamber and head gasket surface = In mmCylinder Head Warp Limit: .004" (.10 mm)