Valve adjustment on a Kohler 16-horsepower engine is usually necessary once a year in order to ensure proper air intake into the engine and keep it running efficiently. You may avoid the inconvenience and expense of taking your engine to a small engine repair shop. Instead, adjust the Kohler's valves yourself by way of the valves' rocker arms — even if you have never attempted valve adjustment on a small engine previously.
Ensure the Kohler engine is turned off. Find the iron valve cover on the side of the engine, next to the spark plug and carburetor bowl. Remove the four bolts securing the valve cover using a socket wrench. Pull the cover off once the bolts are removed.
Examine the two valves beneath the Kohler's valve cover. The rocker arms over these valves must be adjusted. There is one rocker arm at the top and one at the bottom, and each has a bolt at its center. The middle of each bolt has a Torx screw that must be adjusted with a Torx screwdriver. Use this screwdriver to loosen the Torx screw in the top rocker arm.
Attempt to slide a feeler gauge under the left side of the top rocker arm. The rocker arm must be loose enough to slide the feeler gauge under its side, yet tight enough that the feeler gauge cannot easily slip around beneath the arm. Hold the feeler gauge in place as you adjust the rocker arm's center bolt with a socket wrench. Turn the bolt clockwise with the wrench to tighten it until the feeler gauge no longer slips around, or loosen the bolt with counterclockwise turns until the feeler gauge can just barely slip under the rocker arm.
Tighten the Torx screw on the top rocker arm,again using your Torx screwdriver.
Repeat the process on the lower rocker arm. The valves on the Kohler engine will be properly adjusted when the feeler gauge snugly slides under each rocker arm.
Set the valve cover back into place and reinsert its bolts with the socket wrench.