Cleaning or replacing your lawn mower’s air filter is simple. First, identify the type of filter you have — paper, foam, or a combination of both — to clean or replace it correctly. Some just need a tap to remove dirt, while others require a thorough wash.
This small but important part prevents dirt and grass clippings from entering the engine. When it becomes clogged, airflow is reduced, causing the engine to work harder, burn more fuel, and even risk damage over time. It’s best to clean a foam filter every 25 hours of use and replace paper filters at least once per season.
In this guide, I’ll explain how to identify your filter type, clean or replace it properly, and troubleshoot common filter-related issues.
| Skill level: Beginner Cost: $0 to $10, depending on the type of filter replacement. If you’re only cleaning the filter, there’s no extra cost. Estimated time: 10 to 20 minutes |
Types of lawn mower air filters
Not all lawn mowers have air filters — electric models don’t need them — but most gas-powered units do. These filters come in three types: paper, foam, or a combination of both.
“Air filters are often inexpensive and an easy method to keep your mower engine running smoothly,” explain the mower experts at the University of Illinois Extension. Understanding which type your mower has will help you keep it in good shape with the right maintenance.
| Filter type | What to know |
| Paper filters | Appearance: Made of pleated paper inside a plastic or rubber frame, similar to a car air filter. When new, they are white or yellowish. Common in: Found in most modern push mowers and riding mowers. Maintenance: Some can be cleaned with compressed air or by tapping them to remove excess dirt, but I suggest replacing it every 25 hours of use or once per mowing season. |
| Foam filters | Appearance: Made of soft, spongy material, usually rectangular or cylindrical. Common in: Found in older push mowers and small gas-powered mowers. Maintenance: Can be washed, dried, and reused multiple times. Replace when the foam is starting to tear, crack, or feel brittle. |
| Dual-element filters | Appearance: A combination of a paper filter with a foam pre-filter wrapped around it. The foam layer helps block larger debris before it reaches the paper filter. Common in: Used in high-performance mowers and some riding mowers. Maintenance: The foam pre-filter can be cleaned and reused until it tears or no longer returns to its original shape after being squeezed. However, the paper element must be replaced if it gets too dirty. |
Read more: Best Lawn Mower Maintenance Practices
What you’ll need
- Screwdriver (if needed to remove the air filter cover)
- Dish soap or mild detergent (for foam filters only)
- Clean water
- Engine oil (for foam filters only)
- Paper towels or a clean rag
- Compressed air (for paper filter, optional)
- Air filter
First, a word on safety
Before you start cleaning or replacing your lawn mower’s air filter, pay attention to a couple of simple safety tips.
Make sure the mower is turned off and give it a few minutes to cool down. Next, disconnect the spark plug wire, which is the thick rubber-coated wire connected to the front or side of the engine. Simply pull the rubber boot off the spark plug and move it aside. These simple steps prevent the mower from accidentally starting while you work.
Read more: 9 Best Gas Lawn Mowers
Step 1: Locate your air filter
On push mowers, the air filter is inside a plastic or metal cover on the side of the engine. Most are rectangular or square, but some small engines have a cylindrical cover instead. The cover is usually secured with clips, screws, or a wing out.
For riding mowers, the air filter is typically located on top of the engine, under a large cover. To find it, open the mower’s hood or engine cover. The air filter housing is larger and more visible than on push mowers, and it’s held in place by clips, screws or a latch.
Read more:
Step 2: Remove your old air filter
Before removing the air filter, it’s important to prevent dirt from getting into the engine. Start by using a dry cloth or small brush to eliminate loose dirt and debris around the cover. This prevents dirt from falling into the carburetor when you take out the filter.
If it’s secured with screws or a wing nut, use a screwdriver or wrench to remove it. If it has clips, carefully unclip them. Once the cover is off, remove the filter slowly to avoid shaking off built-up dirt into the carburetor. If the filter is stuck, gently wiggle it; never force it out.
Read more: 10 Best Lawn Mowers for Small Yards
Step 3: Clean your old filter
Now that you’ve removed the air filter, it’s time to clean or replace it, depending on its type.
Paper air filters
Start by inspecting your paper filter for oil stains, holes, or light blockage when held up; if any are found, replace it. In general, paper filters need to be replaced once per season or more often in dusty conditions.
To remove loose dirt, hold the filter with the open end facing down and gently tap it on a hard surface. If you have compressed air, you can also blow air from inside to push out the dust. Never wash a paper air filter. Water weakens the fibers, making it less effective.
Foam filters
Begin by checking for any tears or excessive dirt buildup. If these are present, replace your foam filter. If the foam is intact, it can be washed and reused. Use warm water and dish soap to remove dirt and grease. After washing, rinse and squeeze (don’t wring) until the water runs clear.
Let it dry in a well-ventilated area for at least 24 hours. Avoid direct sunlight or heat sources, as they can damage the foam. Once dry, pour a small amount of clean engine oil onto the filter and then squeeze it to distribute the oil evenly. Finally, wipe off excess oil; too much oil can clog the engine.
My tip: I use a Ziplock bag to apply oil on my cleaned foam filter. To do this, place your foam filter in a Ziplock bag, add a small amount of clean engine oil, seal the bag, and gently squeeze it to distribute the oil evenly. This is a great way to keep your hands clean.
Dual element filters
Start by separating the foam pre-filter (the outer layer) from the paper filter (the inner layer). Next, you’ll check each and clean or replace them according to my instructions above.
Read more: 9 Best Lawn Mowers Under $300
Step 4: Clean the filter housing
Before installing a new or cleaned filter, take a moment to clean the filter compartment. A clean compartment helps your filter work more effectively.
Use a dry rag or a small brush to clean out any dust, grass, or grime inside the housing. If you see a lot of oil or gas inside, there could be a bigger issue. The mower may have been tipped over, letting oil into the filter, or the carburetor might be flooded and leaking fuel.
Read more: 9 Best Lawn Mowers for Big Yards
Step 5: Install your new or cleaned filter
If you’re installing a paper filter or foam filter, simply insert it directly into the housing, ensuring it’s in the correct orientation to fit snugly. For a dual-element filter, start by placing the foam pre-filter over the paper filter. Once they are fitted together, insert them as a single unit into the housing, ensuring everything is properly seated.
Once the filter is in place, reattach the cover and secure it with any screws, wing nuts, or clips. Lastly, reconnect the spark plug wire by pushing the rubber boot back onto the spark plug.
Read more: 9 Best Lawn Mowers Under $500
Troubleshooting air filter problems
Neglecting your mower’s air filter can lead to various engine issues. The following chart outlines common air-filter-related problems, their potential causes, and recommended solutions to help you troubleshoot and maintain your mower efficiently.
| Problem | Solution |
| The engine struggles to start | Clean or replace the filter. Replace if soaked in oil or gas. Ensure proper installation. |
| The engine runs rough or stalls | Clean or replace the filter. Squeeze excess oil from the foam filter. Secure the air filter cover. |
| Black smoke from the exhaust | Replace the air filter. Check the carburetor for a stuck choke or dirty jets and clean or adjust as needed. |
| Loss of power or poor performance | Clean or replace the air filter. Squeeze the foam filter over a clean rag or paper towel to remove excess oil. |
| Fuel smell from the air filter | Replace the fuel-soaked filter. Avoid excessive priming. Check for carburetor flooding. |
| Excessive dirt or debris in the filter too quickly | Clean or replace the filter more often. Ensure the filter housing is securely sealed. |
Dealing with mower issues can be frustrating, but you don’t have to worry about it. A lawn care expert can keep your yard looking great so you can enjoy a beautiful lawn without the hassle of mowing and maintenance.
Read more: How to repair a lawn mower
FAQ about lawn mower air filters
Check the filter every 25 hours of use or once a month, and clean out any dirt from the housing with a dry cloth to keep airflow clear. Avoid oil or fuel contamination by not overfilling and always tilting the mower with the spark plug facing up. If the filter gets oily or soaked with fuel, it may point to a problem. Store the mower in a clean, dry place to protect the filter from dust and moisture.
No, you should never run your lawn mower without an air filter. The air filter prevents dirt, dust, and debris from entering the engine. While you may be able to run the mower for a few seconds, doing so for an extended period will damage the engine and shorten the mower’s lifespan.
As a general rule, clean a foam filter every 25 hours of operation and replace paper filters at least once per season. Mowing in dusty conditions may require more frequent maintenance, so always check your owner’s manual for specific recommendations.
Yes, a clean air filter improves fuel efficiency by ensuring proper airflow into the engine, which helps maintain the correct air-to-fuel ratio. Other important maintenance tasks include changing the oil and sharpening your blades, which enhance your mower’s efficiency and performance.
Find a professional in your area
Keeping your lawn mower’s air filter clean is a simple yet required maintenance task. However, if you’re short on time or need expert care, Lawn Love can connect you with trusted professionals in your area. Whether you need mowing, yard cleanup, or garden care, let the experts handle it so you can simply enjoy your lawn.
Sources:
“Mower Maintenance.” University of Illinois Extension
Main Photo Credit: atipong | Adobe Stock
Related Posts:
