How to Replace the Air Filter on a Lawn Mower

Two hands with gloves on changing lawnmower air filter

The air filter is the first line of defense your lawn mower’s engine has against airborne dirt and debris. Because protecting your engine from damaging airborne particulates is so important for engine health, it is recommended that you check your lawn mower’s air filter two or three times a season. How often you actually change it depends on the state of the filter — if the filter is dirty, replace it — but a good rule of thumb is to replace the mower’s air filter at least once a season.

The most common questions for anyone trying to decide if a filter needs changing are: How do I know if my lawn mower’s air filter needs replacing? And what happens if I don’t change it? The telltale signs of an air filter needing replacing, and the eventual consequences of not changing a bad filter are:

  • Engine sputtering
  • Complete loss of power
  • Weak starts or failure to start at all
  • Black smoke from the exhaust
  • Higher fuel consumption

If you’ve noticed any of these symptoms, or if you want to get out ahead of a potential problem, follow the steps below to properly check and replace a push mower’s air filter.

1. Remove Protective Housing

First things first, where is the air filter on your lawn mower? Most push lawn mowers, including Toros, have air filters located on the side of the machine that is covered by a protective housing. Wipe down the outside of the housing before you remove it to ensure no debris is introduced into the engine.

2. Knock Clean & Inspect

Remove the paper air filter and gently knock off any loose debris before holding it up in good light. If the filter is difficult to see through, it’s time for a replacement. Even if it isn’t hard to see through yet, replacing the filter before it gets too dirty can help keep your lawn mower’s engine running at its best.

Some lawn mowers have a foam pre-filter to catch larger debris like grass clippings. Brush away anything stuck on the outside when you check your air filter and replace the foam whenever you change out paper filters.

3. Replace If Necessary

If your air filter needs replacing, double check you are getting the correct part for your lawn mower. For Toro lawn mowers, you can make sure you pick up the right replacement air filter at or visiting your local dealer in person. Remember to either bring the filter or complete model number to ensure you purchase the correct part.

Before installing the new filter, wipe down the inside of the housing with a clean cloth. Then install the replacement filter just how the old filter was seated before putting in a new pre-filter (if applicable).

NOTE: Don’t use solvents when cleaning the filter housing, as they can damage the new filter and leave your engine with less protection.

4. Reattach Housing

If the filter is installed correctly, the housing should reattach easily. If the housing doesn’t fit tightly back in place, make sure the filter is seated correctly.

Keeping the air filter on your lawn mower clean is one of the easiest ways to make sure the engine is performing at its best. If you’ve noticed more difficult starts or diminishing engine health, replacing your air filter is a great first step to take in getting your machine back in prime shape.

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