2008 Arctic Cat ATVs factory service and repair manual, Page 226Get this manual
13With the cam lobes directed down (toward the piston), maneuver the camshaftlsprocket assembly through the chain and towards its seating position; then loop the chain over the sprocket APiston still at top-dead-center
BCamshaft lobes directed down (toward the piston)
CCamshaft alignment marks parallel to the valve cover mating surfaceDRecessed side of the sprocket directed toward the cam lobes
ECamshaft alignment pin and sprocket alignment
hole (smallest) are aligned
of the above factors are not as stated, go back to step and carefully proceed
mNOTE: Note the position of the alignment marks on the end of the camshaftThey must be parallel with the valve cover mating surfaceIf rotating the camshaft is necessary for alignment, do not allow the chain and sprocket to rotate and be sure the cam lobes are in the down position