2008 Polaris Sportsman 500 EFI/X2/Touring/500 H.O. Service Manual, Page 83Get this manual
ENGINE Combustion Chamber
3Heat cylinder head in an oven or use hot plate to bring cylinder head temperature to 212o (100o C)
CAUTION
Do not use torch to heat cylinder head or warpage may result from uneven heatingHead temperature can be checked with pyrometer or welding temperature stickWear the appropriate safety equipment for working with heated metalFollow the manufacturers instructions provided in the Valve Seat Reconditioning KitAbrasive stone seat reconditioning equipment can also be usedKeep all valves in order with their respective seatClean all accumulated carbon deposits from combustion chamber and valve seat area with soft wire brush
Valve Seat Reconditioning