Troy-Bilt self-propelled lawn mowers allow you to mow lawns under an acre and are easy to push on slopes because the front wheels turn by themselves. If your self-propelled mover starts acting strange or will not start up, there are many pieces on the lawn mower that can be fixed at home. Pieces like spark plugs and air filters can be replaced with new ones that will make the lawn mower's engine start and run more efficiently, and the belt that drives the wheels can be checked..
Replace the spark plug. The plug is located on under a black hose on the engine. Unscrew the plug with an adjustable wrench. Look at the number on the side of plug. Replace the plug with a new one that has the same number.
Place new gasoline into the engine. If gasoline has been inside the engine over winter, it will begin to break down. Drain the bad gas out of the engine by unplugging the gas tank plug and draining it into a container. Replug the tank and pour new gasoline into the engine
Replace the air filter. The air filter is located under the black square plate on the side of the engine. Unscrew the plate with a Phillips screwdriver. Pop the old filter out with your hand. Place a new filter into position and screw the plate back into position.
Replace the rear flap if it is torn or if part of was ripped off. Lift the rear door that is located underneath the mower's handle. Using your hand, push the flap off the mower by pulling it to the left. This will disconnect the flap hook. Slide a new flap into the flap hook and then into the hole in the other side.
Replace the self-propelled mower's drive belt if the self-propelled wheels will not engage the self-propelled mode. Unscrew the two screws holding the self-propelled drive cover in place. Push the sides of the cover inward and pull the cover off. There is only one belt inside of here, so you will see it immediately. Find the tension screw, the piece that is keeping the belt in place. With the screwdriver, loosen the screw until the belt goes limp. Pull the belt off of the engine pulley and transmission pulley to free it from the mower. Place the belt around the engine pulley and transmission pulley. Screw the tension screw tight. Snap the drive cover back into position and screw it tight.