The Honda GX 160 is a horizontal-shaft engine, rated at 4.8 horsepower. It features an overhead valve design, cast-iron sleeve and electronic ignition system. To promote engine longevity and consistent performance, the Honda GX 160 employs a mechanical governor, designed to limit the engine's rpm. Improper adjustment of the engine's governor will cause excessive revving at full throttle, which might cause damage to the engine. Adjusting the governor to the proper factory setting is an easy task with the proper tools.
Switch the engine's round-shaped kill switch to the "Off" position. It is located on the side of the pull starter housing.
Remove the black spark plug wire from the spark plug. It located on the cylinder head valve cover and labelled "OHV."
Remove the two nuts that secure the bottom of the fuel tank to the engine block, using an appropriate size socket. Use an appropriate size socket to remove the small bolt securing the front side portion of the fuel tank, located between the air filter housing and exhaust muffler.
Lift the fuel tank carefully and position it toward the pull starter side of the engine. This will expose the angled lever connected to the internal governor mechanism. Use an appropriate size scrap piece of wood or series of bricks to support the gas tank. Do not let the gas tank hang off the engine by the fuel line.
Loosen the governor arm from the shaft protruding from the engine block. Use a 6mm wrench to hold the small nut, while turning the small bolt counterclockwise with an appropriate size socket.
Wrap a rubber band around the throttle arm and secure the rubber band to the air filter assembly. Tension the rubber band enough to keep the throttle arm in the wide-open throttle position.
Rotate the governor shaft fully clockwise and tighten the governor arm, using an appropriate size socket and 6mm wrench. Remove the rubber band from the throttle arm and air cleaner assembly.
Secure the fuel tank to the engine and reconnect the spark plug wire to finish the adjustment process.