2001 Polaris Sportsman 400-500 DUSE and H.O. Service Manual, Page 56Get this manual
MAINTENANCE
VALVE CLEARANCE
Inspect and adjust valve clearance while the engine is cold and the piston positioned at Top Dead Center (TDC) on compression stroke1Remove the seat2Remove body panels and fuel tank as necessary to gain access to valve cover3Remove the spark plug high tension lead and remove the spark plugCAUTION: Place clean shop towel into the spark plug cavity to prevent dirt from entering4Remove rocker cover bolts, cover and gasketNOTE: It may be necessary to tap cover lightly with soft-faced hammer to loosen it from the cylinder head5Remove timing inspection plug from recoil housingCAUTION: Failure to position the crankshaft at TDC on compression stroke will result in improper valve adjustment6Rotate engine slowly with recoil rope, watching the intake valve(s) open and closeNOTE: At this point watch the camshaft sprocket locating pin and slowly rotate engine until locating pin is facing upward, directly in line with the crankshaft to camshaft center line as shownThe camshaft lobes should be pointing downward