2000 Yamaha YFM400FWA(M) Factory Service workshop Manual, Page 66Get this manual
VALVE CLEARANCE ADJUSTMENT ENGINE
INSP ADJ
VALVE CLEARANCE ADJUSTMENT NOTE: The valve clearance must be adjusted when the engine is cool to the touchAdjust the valve clearance when the piston is at the Top Dead Center (T.D.C on the compression stroke1.Remove: Seat Front carrier Front fender Fuel tank Refer to "SEAT, CARRIERS, FENDERS AND FUEL TANK"