2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 82Get this manual
ENGINE 4Measure free length of spring with Vernier caliperCheck spring for squarenessCompare to specificationsReplace spring if either measurement is out of specification seat area (B)NOTE: The valves cannot be re-faced or end groundValves must be replaced if worn, bent, or damagedMeasure valve stem in several places
Valve Stem Diameter: Intake: .2343-.2348" (5.950-5.965 mm) Exhaust: .2341-.2346" (5.945-5.960 mm) 5Measure diameter of valve stem with micrometer in three places and in two different directions (six measurements total)Compare to specificationsRemove valve sealsCAUTION: Replace seals whenever the cylinder head is disassembledHardened, cracked or worn valve seals will cause excessive oil consumption and carbon buildup
Valve Inspection
1Remove all carbon from valve with soft wire wheel