Although lawn mowers have far less complex combustion engines than motor vehicles, the equipment’s engine still has a few items that require regular maintenance. The lawn mower air filter is one of those components. Because you probably regularly check the gasoline and motor oil levels, it’s easy to stay on top of maintaining those components. But without a clean and functioning air filter, the mower may not run. The fix is easy, though; just wash the foam filter with soap and water between replacements.
The filter protects the mower’s engine from dust that naturally flies up while you are mowing. Because of its job, the air filter is supposed to become dirty, but you can make it work more efficiently by cleaning it every few times you mow, especially after working in dusty conditions. Wash or replace your air filter as part of the process of winterizing the lawn mower, too.
A lawn mower with a combustion engine has a carburetor, where air and gasoline mix to generate power. As the carburetor pulls in air through the intake system, the air filter ensures the air that reaches the carburetor is free of dust and debris. Introducing such items would shorten the life of the engine. Additionally, if you don’t keep the air filter on the lawn mower clean, the air intake system cannot efficiently pull in air. A dirty air filter could cause the engine to sputter or leave you with a lawn mower that won’t start.
How to clean a foam air filter
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To start, allow the lawn mower engine to cool down before checking the air filter. You should also disconnect the spark plug wire before working on the engine for safety. A foam air filter looks like a sponge. You can replace the foam lawn mower air filter less often than a paper filter, especially if you keep it clean regularly.
If your lawn mower has a fuel primer button that you push before starting the mower, the foam air filter should be in this area of the engine. It’ll be behind a plastic covering that should pop out of place without needing any tools. However, some models may have one or two screws holding the covering in place.
If the foam filter has damage, it’s time to replace it. Otherwise, you can wash it. You may want to wear disposable gloves. Rinse the foam with water from a garden hose or a bucket. The foam will collect grease over time, so adding a little dishwashing soap while rinsing can help remove the grease. Squeeze the foam and continue rinsing it several times until it looks clean. Wring excess liquid from the foam before wrapping it in paper towels and squeezing it to soak up the remaining water. Then allow it to fully dry for about an hour in the sun before reassembling the filter cover.
How to clean a paper air filter
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A paper filter doesn’t last as long as a foam filter, but you may be able to clean it a couple of times before needing to replace it. A paper filter sits behind a plastic cover on the side or top of the engine compartment. Paper air filters for lawn mowers can be round or rectangular. The paper looks like a series of accordion folds that catch dust and debris before they enter the carburetor. Though it has microscopic holes that allow air to pass through, it blocks dust particles.
After removing the paper filter, inspect it for damage. If any accordion folds are wet or have holes or splits, replace the filter rather than clean it. If you believe it is usable, gently shake it or tap it against a hard object to loosen any solid debris. You also can blow on it to loosen unwanted particles and cause them to fall away. Some people use a hand wand on a vacuum cleaner to pull dust and debris from the paper filter’s accordion folds.
If the paper filter looks greasy or has caked dust, these soils almost certainly block the microscopic holes. Shaking dust and debris loose probably won’t improve the filter’s performance. You’ll have better luck buying a new filter.
