How do you adjust Yamaha 135LC valve clearance?

To adjust the valve clearance on a Yamaha 135LC, first, ensure the engine is cold and remove the side cover. Rotate the engine to the TDC (Top Dead Center) position on the compression stroke for the cylinder you are adjusting. Use a feeler gauge to measure the clearance between the valve stem and rocker arm, adjusting the clearance by loosening the lock nut and turning the adjustment screw as necessary. Finally, recheck with the feeler gauge and reassemble the parts once the desired clearance is achieved.