How to Tune Up Small Gas Engines

Remove the protective cowling and rope starter assembly from the top of the engine. Remove the magnetic spark plug ignition device from the side of the motor's aluminum flywheel.

Clean the contacts on both sides of the spark plug ignition device with clean rags dampened by gasoline or cleaning solvent. Protect hands at all times with rubber gloves.

Remove and replace old spark plug with a new spark plug. Replacement plugs can be purchased at local automotive or lawn equipment supply companies.

Remove foam air cleaner from air cleaner assembly. Soak air cleaner in gasoline or other cleaning solvent. Rinse the home air cleaner thoroughly to remove all dirt, grime, and debris from the filter. Allow to dry.

While air cleaner and air cleaner assembly are deep tax from the motor, spray carburetor cleaner into the motor's carburetor. Usually inspect carburetor to ensure that all carbon and varnish deposits have been removed by the carburetor cleaner.

Squirt a small amount of motor oil on the foam filter. Squeeze the oil into the foam filter, and then replace the air filter in the air filter assembly.

Remove the oil crank case drain plug from the underside of the motor. Allow the old oil to collect in a disposable plastic container. Replace oil drain plug once all of the old oil has drained from the engine crank case. Fill oil crank case with new SAE 30w Non-detergent oil, according to manufacturer's instructions.

Replace all remaining parts in the reverse order.