How do you adjust the valves on a Honda rancher 420?

To adjust the valves on a Honda Rancher 420, first ensure the engine is cold and remove the seat and side covers for access. Rotate the engine to TDC (top dead center) on the compression stroke for the cylinder you're adjusting, and use a feeler gauge to measure the clearance between the rocker arm and the valve stem. Adjust the clearance using a 10mm wrench and a flathead screwdriver to loosen the locknut and turn the adjustment screw as needed, then re-tighten the locknut. Repeat for the other cylinder, if necessary, and reassemble the components once finished.