2004-2007 Yamaha ATV Raptor 50 YMF50S Service Manual, Page 59Get this manual
ADJUSTING THE TIMING CHAIN TENSIONER ADJUSTING THE VALVE CLEARANCE
5Install: camshaft sprocket cover C.D.Imagneto cover Refer to "CYLINDER HEAD" in chapter 4
ADJUSTING THE VALVE CLEARANCE NOTE: The valve clearance must be adjusted when the engine is cool to the touch Adjust the valve clearance when the piston is at the Top Dead Center (TDC) on the compression stroke1