1999-2002 TRX400EX Fourtrax Service Manual, Page 90Get this manual
CYLINDER HEADVALVE Loosen the cam chain tensioner lifter plugRemove the two bolts, cam chain tensioner lifter and gasket
Becarefulnotto let the sprocket bolts fall into the crankcase,
Remove the cam sprocket boltRotate the crankshaft counterclockwise one tu rn and remove the other cam sprocket bolt
Remove the cam sprocket from the camshaft flangeAttach piece of wire to the cam chain to prevent it from falling into the crankcaseLift the camshaft and remove itRemove the cam sprocket from the cam chain