2003 Arctic Cat ATVs from 250cc to 500cc Service Manual, Page 370Get this manual
23Rotate the crankshaft until the second cap screw securing the sprocket to the camshaft can be installed; then install the cap screw and tighten to 1.5 kg-m (11 ft-Ib)Bend the tab to secure the cap screw24Rotate the crankshaft until the first cap screw (from step 16) securing the sprocket to the camshaft can be addressed; then tighten to 1.5 kg-m (11 ft-Ib)Bend the tab to secure the cap screw25Loosen the four adjuster screw jam nuts; then loosen the four adjuster screws on the rocker arms in the valve cover26Apply thin coat of Three Bond Sealant (pn 0636-070) to the mating surfaces of the cylinder head and valve cover 29In crisscross pattern starting from the center and working outward, tighten the cap screws securely30Adjust valvetappet clearance using the following procedure NOTE: Use Valve Clearance 0444-078) for this procedureAdjuster
ATurn the engine over until the piston reaches top dead center on the compression strokeBPlace the valve adjuster onto the jam nut securing the tappet adjuster screw; then rotate the valve adjuster dial clockwise until the end is seated in the tappet adjuster screw