A lawn tractor relies heavily on its carburetor to run efficiently and at peak power. If the carburetor is clogged, fouled or varnished, it will not only affect how the tractor runs, it may even cause the engine to fail to start. In this case, cleaning the carburetor is a necessity, especially if the tractor hasn’t been running for an extended period of time or if the carburetor was exposed to dirty or low-quality fuel. Fortunately, you can clean your tractor’s carburetor with an assortment of basic tools and some spare time.
Drain the gas from the lawn tractor’s fuel tank. Manually remove the fuel from the tank using a small siphon or hand pump. Once all of the fuel has been removed, detach the fuel line from the carburetor. If the tractor’s air filter obstructs your access to the carburetor, remove it as well. A screwdriver and/or small wrenches will be needed to disconnect the fuel line and remove the air filter.
Remove the bolts connecting the intake manifold to the lawn tractor’s engine block. The exact size of the bolts and number of bolts will vary according to the make and model of lawn tractor. Turn the bolts on the intake manifold counterclockwise to remove them. If the bolts are tight, spray with penetrating oil and wait a few minutes before retrying.
Disconnect the governor spring and throttle assembly from the tractor’s carburetor. Remove all other linkages, such as speed control and automatic stop switch, that may be attached to your specific carburetor. Pay close attention to how all wires, springs and linkages are connected to the carburetor, as they must be replaced in exactly the same position upon reassembly.
Remove the bolts holding the carburetor in place. Many lawn tractor carburetors are held in place by two bolts. After removing the bolts, the carburetor should simply lift free.
Place the carburetor on a clean work area. Look at the bowl on the bottom of the carburetor. You will see a single bolt holding the bowl in place. Remove the bolt from the bowl. Allow any gas remaining in the bowl or carburetor to drain out and remove the bowl, as well as the O-ring between the bowl and main body of the carburetor.
Turn the float inside the carburetor so that it is completely open. This will reveal the inlet needle, which is a small rod with a cone-shaped tip. Remove the small clip that holds the needle in place, as well as the inlet needle itself.
Remove the float from the carburetor. Use needle-nose pliers to carefully grasp the hinge pin that fastens the float to the carburetor. Once the hinge pin is free, remove the float. Also, loosen and remove the bolts that connect intake pipe to the carburetor. Remove the intake pipe and place it out your way.
Remove the small screw attaching the throttle plate to the carburetor. You need a small screwdriver to loosen and remove the small screw. Remove both the throttle plate and throttle shaft from the tractor’s carburetor.
Spray the assorted carburetor parts as well as the body of the carburetor with commercial carburetor cleaner. Allow the cleaner to soak for a few minutes and then scrub each individual part with a clean, microfiber cloth. Continue scrubbing until the carburetor and all its parts are completely clean.
Reassemble the lawn tractor’s carburetor. Simply reverse the methods used to disconnect and remove the parts. It is important to reconnect each part in exactly the same position as it was prior to removal.