How to Clean a Motocross Air Filter

Motocross dirt bikes, like all motorcycles, rely on an air filter to prevent dirt and debris from being sucked into the engine during a race. These filters are usually made from a foam element that allows air to pass through while trapping dirt particles in the process. Extremely dusty track conditions can eventually clog the air filter, decreasing the dirt bike’s performance by reducing the amount of air being pulled into the engine. Most manufacturers recommend a complete cleaning of the air filter after every race, a job that can be done by any dirt bike owner in a short time


1) Remove the seat and radiator shrouds from the dirt bike by using a socket wrench.

2) Remove the bolt from the center of the air filter, located between the frame’s seat rails on the carburetor inlet, by using a socket wrench. Alternatively, remove the air filter housing cover or loosen the clamp attaching the air filter to the carburetor inlet by using a screwdriver. Pull the air filter away from the carburetor.

3) Place a clean, lint-free shop towel in the carburetor inlet to prevent dirt and debris from entering the carburetor and engine while you are cleaning the air filter.

4) Pull the air filter element off the inner frame, if any. Check the element for tears or holes. Replace the element if it is damaged in any way.

5) Place the air filter element into a plastic container filled with warm water and mild dish soap. Soak the element in the soapy water for five minutes, then gently shake the element while submerged to dislodge trapped dirt. Remove the element from the container and squeeze out excess water. Do not wring or twist the element.

6) Allow the air filter element to air dry completely. Alternatively, place the air filter element in front of a fan to hasten the drying process.

7) Spray the air filter element with an air filter oil until the entire element is evenly saturated with oil. Let the oil soak into the element for five minutes, then squeeze out the excess oil. The air filter element should be moist but not dripping.

8) Remove the shop towel from the carburetor inlet. Reinstall the inner frame into the air filter element, if any. Reinstall the air filter onto the carburetor inlet or air filter housing.

9) Reinstall the radiator shroud and seat onto the dirt bike.

Extra tips:

* Solvent-based cleaning sprays made specifically for motorcycle air filters can be used on most dirt bike air filters. Air filter removal and installation directions specific to your dirt bike can be found in a factory service manual. These manuals can be purchased from a local motorcycle dealership or repair center.

* Do not use gasoline to clean a dirt bike’s air filter, especially if the filter uses a foam element. The foam element can be weakened or become brittle, dramatically reducing the service life of the air filter. The use of gasoline also will create a potential fire hazard that can cause the filter to ignite.

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