How to adjust the valve of Yamaha 6500 generator, rescue expert! thank you

Either remove the cylinder head cover, remove the spark plug, pull the dial (starting handle), let the piston reach the highest point, and then adjust the throttle clearance. Their clearance is about 0. 10 mm for the intake valve, 0. 15 mm for the exhaust valve, and 0.05 mm for an A4 paper. This tool is just two ring wrenches. I hope it works for you.