To clean a lawn mower air filter, remove the filter first. If it is a paper filter, you can dust it off or replace it entirely. If it is a plastic or foam air filter, you can wash it in soapy water and then replace it.
Your lawn mower filter is the lungs of your powered mower. And when air induction is blocked or limited, your mower may not start. Whether a foam or paper filter, a clean air filter is crucial for your lawn mower’s engine to function optimally.
Over time, filters can get soaked in oil or clogged with dirt, dust, and debris, affecting the performance of your mower. This guide will walk you through cleaning your lawn mower air filter, from disconnecting the spark plug wire for safety to using an air compressor to remove loose dirt.
In about an hour, you’ll have a clean filter ready to help your mower work efficiently.
Understanding the Importance of a Clean Air Filter
Air filters play a vital role in the operation of your lawn mower. They trap dirt, dust, and debris, preventing these particles from entering the mower’s engine. A clean air filter ensures that your lawn mower engine gets a steady flow of clean air, essential for efficient combustion and optimal performance.
The Role of Air Filters in Lawn Mowers
Whether it’s a foam or paper air filter, the job remains to filter the engine’s air. As the mower operates, the air is drawn in, passing through the air filter before reaching the engine. This process ensures that only clean air, free from dirt and debris, enters the engine.
Consequences of a Dirty Air Filter
A dirty air filter can have severe consequences for your lawn mower. When clogged with dirt and dust, the air filter restricts airflow to the engine.
This can lead to poor fuel efficiency, reduced power, and even engine damage. Therefore, regular cleaning or replacing the air filter is crucial to lawn mower maintenance. It not only keeps your mower running smoothly but also extends its lifespan.
Identifying the Type of Your Lawn Mower’s Air Filter
Knowing the type of air filter in your lawn mower is the first step toward proper maintenance. Lawn mowers typically use either a foam air filter or a paper filter. Although some of the newer mowers use a disposable air filer, meaning you have to replace it once it is dirty or blocked.
Foam Air Filters vs Paper Filters

Foam air filters are reusable and can be cleaned with soap and water. After cleaning the foam filters, they’re often oiled to trap more dust and debris.
On the other hand, paper filters have accordion folds that trap microscopic particles. They’re not washable and should be replaced when dirty.
Identifying your lawn mower air filter type helps you understand the cleaning or replacement process. Whether it’s a foam filter or a paper filter, regular maintenance ensures your mower’s air intake system remains clean, promoting optimal engine performance.
Preparing for the Cleaning Process
Before you start cleaning your lawn mower air filter, there are a few preparatory steps to ensure safety and ease of access to the filter.
Safety First: Disconnecting the Spark Plug Wire
The first step is to disconnect the spark plug wire. This is a crucial safety measure to prevent the mower from accidentally starting while you’re working on it.
Simply pull the wire away from the spark plug. Now, you can proceed with cleaning without worrying about the mower starting unexpectedly.
Accessing the Air Filter Housing
Next, you need to access the air filter. The air filter is typically in a plastic cover on the side of the mower’s engine. Depending on your lawn mower model, you may need to unscrew or unclip the cover to access the air filter.
Once the cover is removed, you’ll see the air filter – a foam air filter or a paper filter.
With the spark plug wire disconnected and the air filter housing open, you’re ready to clean or replace your lawn mower air filter.
Cleaning a Foam Air Filter
Foam air filters are common in many lawn mowers due to their durability and reusability. Here’s how to clean a lawn mower with a foam filter.
Removing Excess Dirt from the Foam Filter

Start by removing the foam filter from the air housing. Use compressed air or a vacuum cleaner to blow or suck out the loose debris from the filter. Be gentle to avoid tearing the foam.
For stubborn dirt lodged in the microscopic holes, gently tap the filter on a flat surface.
Washing the Foam Filter with Liquid Soap
Next, prepare a mixture of warm water and liquid soap. Submerge the foam filter in this solution and gently squeeze it to remove the grease and remaining dirt. Avoid wringing the filter, as it can cause damage.
Rinsing and Drying the Foam Filter
Rinse the foam filter under clean water until all soap is removed. Squeeze out the excess water and then let the filter air dry. The filter must be bone dry before reinstallation to prevent engine damage.
Cleaning your foam air filter regularly ensures your lawn mower operates efficiently, reducing wear and tear and keeping your lawn looking great.
Maintaining a Paper Air Filter
Unlike foam filters, paper air filters are not designed to be cleaned. Instead, they need to be replaced when they become dirty. Here’s how to maintain a paper air filter.
When to Replace a Paper Air Filter
A paper air filter should be replaced when it becomes visibly dirty or after about 25 hours of use, whichever comes first. If you mow in dusty conditions, you may need to replace the filter more often.
A dirty filter restricts airflow to the carburetor, reducing your mower’s performance. Regular replacement ensures your mower is working correctly. Something to note here, is that paper filters generally come in standard sizes. A brand of mowers quite often share the same paper filter across multiple models, making them easy to source and replace.
Installing a New Paper Filter

First, remove the old filter from the air filter housing to install a new paper filter. Then, insert the new filter, ensuring it fits snugly in the housing. The accordion folds of the paper element should face outwards. Once the new filter is in place, replace the cover.
Final Steps in the Air Filter Maintenance Process
Once your lawn mower air filter is clean or a new one is ready to be installed, there are a few final steps to complete the maintenance process.
Oiling the Clean Filter (If Required)
If you’re using a foam filter, it may need to be oiled after cleaning. This helps the filter trap more dust and debris.
To oil the filter, apply a small amount of motor oil, then squeeze it to distribute it evenly. Use a paper towel to remove any excess motor oil. Be careful not to over-oil the filter, which can cause the engine to smoke. If you accidentally drench the filler in oil, the best idea is to take it out and clean it again.
Reinstalling the Air Filter in the Lawn Mower
With the filter clean and dry (and oiled if necessary), it’s time to reinstall or replace it. Place the filter back in the air filter housing, ensuring it fits snugly. Then, replace the cover. If using a paper filter, ensure the accordion folds face outwards.
Regular Maintenance for Optimal Lawn Mower Performance
Regular maintenance is vital to keeping your lawn mower running smoothly and efficiently. This includes routine checks and care for your lawn mower air filters.
Routine Checks for a Clean and Functioning Air Filter
Whether you have a foam or paper filter, checking its condition regularly is essential. Look for signs of excessive dirt or damage.
A foam pre-filter or main filter should be cleaned when visibly dirty. On the other hand, a paper filter should be replaced when it’s dirty. Regular checks ensure your mower’s air intake system remains clean, promoting optimal engine performance.
Understanding the Role of Regular Maintenance in Lawn Mower Longevity
Regular maintenance maximizes the lifespan and performance of your lawn mower. Keeping the air filter clean ensures that your mower’s engine gets a steady flow of clean air, essential for efficient combustion. This reduces wear and tear on the engine, helping your mower last longer.
Remember, a well-maintained lawn mower performs better, making mowing your lawn easier and more enjoyable.
Conclusion: Ensuring the Longevity of Your Lawn Mower
Maintaining your lawn mower’s air filter is critical to ensuring its longevity. Regular cleaning or replacement keeps your mower running efficiently, whether a foam pre-filter or a paper filter. Use paper towels to remove excess oil and a garden hose to rinse the remaining water.
Remember to replace the filter when necessary. Regular maintenance, including checking the carburetor and oil levels, helps your walk-behind mower perform its best.
So, take the time to clean your lawn mower and keep it in top shape. It’s a small effort that pays off in the long run.