2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 139Get this manual
CAMSHAFT, ROCKER ARMS AND VALVES
CAMSHAFT AND ROCKER ARM REMOVAL 1.Remove: Camshaft NOTE: Screw in M10 bolt into the thread hole on the camshaft, and pull out the camshaft
2.Remove: Rocker arm shafts (intake and exhaust) Rocker arms NOTE: Use slide hammer to remove the rocker arm shaftsSlide hammer set: PNYU-01083-A Slide hammer bolt (M6): PN90890-01083 Weight: PN90890-01084