2008 Arctic Cat 400/500/650/700 ATV Service Manual, Page 111Get this manual
5Bend the washer tabs and remove the two cap screws securing the sprocket to the camshaft
7Noting the timing marks for installing purposes, drop the sprocket off the camshaftWhile holding the cam chain, slide the sprocket and camshaft out of the cylinder headAccount for an alignment pinNOTE: Loop the chain over the cylinder and secure it with wire to keep it from falling into the crankcase