2007 Yamaha Apex Factory Service Manual, Page 183Get this manual

2007 Yamaha Apex Factory Service Manual, Page 183

VALVES AND VALVE SPRINGS 6Measure: Valve stem runout Out of specificationReplace the valveNOTE: When installing new valve,
(0.035 0.043 in) Exhaust: 0.9 1.1 mm (0.035 0.043 in) Measurement steps: Apply Mechanic's blueing dye (Dykem) onto the valve
faceS Install the valve into the cylinder headS Press the valve through the valve guide and onto the valve seat to make clear
patternS Measure the valve seat widthNOTE: Where the valve seat and valve face contacted one another, the blueing will have