2008 Arctic Cat 400/500/650/700 ATV Service Manual, Page 213Get this manual
5Bend the washer tabs and remove the two cap screws securing the sprocket to the camshaft; then drop the sprocket off the camshaftWhile holding the chain, slide the sprocket and camshaft out of the cylinder head CC009D
NOTE: Loop the chain over the cylinder and secure it to keep it from falling into the crankcase