2009 Polaris Sportsman 850 XP EFI EPS Service Manual, Page 121Get this manual
ENGINE Cylinder Head Warp Inspection 1Lay straight edge (A) across surface of cylinder head at several different points and
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) max Measure
free length of each spring with Vernier caliper and compare to specification = In mmValve Spring Free Length: Std: 1.861"