Introduction: How to Change the Air Filter on a Dirt Bike

The air filter is one of the most important components on an off-highway motorcycle. The filter captures dirt and debris and keeps it from getting sucked into the motor during operation. This can be problematic for two reasons. First, dirt and debris causes excessive wear on the internal moving components of the motor, such as, the pistons and rings. Second, a clogged filter allows less air into the motor, which will result in sluggish performance. This maintenance task is very simple. With the aid of these instructions, even a beginner can do it. The entire process takes between five and fifteen minutes. 

Step 1: Materials Required

•Dirt Bike Owner’s Manual
•10mm socket and ratchet or 10mm combination wrench
•Clean rag
•Silicone Grease
•New Air filter
•Dish Soap
•Air filter oil (if needed)

Step 2: Remove the Seat

1)  First, locate the airbox on your dirt bike. On most dirtbikes, the airbox is located under the seat.

2) Loosen and remove the two bolts that hold the seat in place using a 10mm socket or combination wrench.

3) Lift the seat off the bike.

Step 3: Remove the Old Air Filter

1) Remove the wingnut which holds the air filter in place.

2) Remove the air filter.

3) Separate the filter from the plastic support cage.

Caution: Be careful not to damage the cage. Doing so will result in an improper seal and can cause engine damage.

Step 4: Clean the Airbox

1) Wipe out the airbox using the clean rag.

2) Allow the airbox to dry.

Step 5: Install the New Filter

1) If necessary, apply air filter oil to the new filter.

Note: I use No-Toil air filters which come pre-oiled. Not all air filters come pre-oiled.

2) Apply grease to the part of the filter that touches the airbox.

3) Fit the new filter over the plastic support cage.

Caution: Be careful not to rip the new air filter while fitting it over the cage. Doing so can result in engine damage.

4) Apply a thin layer of waterproof grease to the base of the filter. 

4) Insert the new air filter into the housing.

5) Tighten the wingnut to hold the new air filter in place.

6) Replace the seat.

Step 6: Clean the Old Filter

If the old filter is still serviceable, you can clean it and reuse it. It is not always necessary to replace your filter when it becomes dirty.

1) Apply the dish soap to the old filter.

2) Wet the filter.

3) Knead the filter in your hands, working up a good lather.

4) Rinse the filter.

5) Allow the filter to dry.

6) Apply air filter oil to the clean filter.

Step 7: Congratulations!

You have successfully changed the air filter on your dirt bike. I recommend cleaning your air filter whenever it is dirty, usually after riding. Once your air filter becomes unserviceable, then it must be replaced. Air filter maintenance is vital to the performance of your engine. By doing this task regularly, you will have the benefits of better engine performance and less wear on your motor. This simple task can save you a lot of money in repairs later. Now that you have completed this task, grab a helmet and go for a ride.