Closeup of a fuel filter on a white background.

How To Clean A Fuel Filter On A Lawn Mower?

4 minutes

“Fuel filter” is a broad term covering several different designs and applications. Lawn mowers use a fuel filter specifically designed for their engines. So, when it comes to how to clean a fuel filter on a lawn mower, what do you do?

Instead of cleaning a lawn mower’s fuel filter, you should replace it. Cleaning a fuel filter will mess up its careful design, leading to improper filtering and further issues with the lawn mower.

What Is A Fuel Filter On A Lawn Mower?

Closeup of a fuel filter on a machine.
One kind of fuel filter. This one is for a diesel tractor engine.

A fuel filter is a small device that filters out impurities and foreign objects in fuel. To do this, it uses various materials such as polyester felt and polymer-treated cellulose (paper).

The tiny holes in filters that allow fuel to pass through are measured in microns (one micron equals 40 millionths of an inch, or 0.00004″). A lawn mower filter generally rates between 10-15 microns, meaning it will allow anything through at that size or below.

What Makes A Lawn Mower Fuel Filter Different From Other Fuel Filters?

Lawn mower fuel filters are designed specifically for the engine. Their design focuses on the fuel demand, filtration requirement, and production cost. As a result, lawn mower fuel filters are often small and inexpensive. 

Can I Use Reusable Fuel Filters?

Reusable filters are mostly metal and almost always designed for larger engines, such as those in cars. Modern car engines are far more delicate and expensive, which means more protective, costly parts. A reusable metal filter can cost more than a whole new lawn mower!

Why Shouldn’t I Clean The Fuel Filter On A Lawn Mower?

Polyester felt and Polymer-treated cellulose are very delicate and precise. If a disposable filter is cleaned, the micron rating will be altered, and the design goes out the window. The filter will no longer allow the correct fuel pressure and filtration. 

Can I Use Any Fuel Filter On A Lawn Mower?

You don’t want to use just any fuel filter on a lawn mower because different filters have different ratings. Other kinds of fuel filters will create different fuel pressure and filtration, which can have a negative effect on your lawn mower’s performance or worse.

What Happens When I Use The Wrong Fuel Filter Or Try To Clean It?

Using either the wrong fuel filter or one that has been cleaned out will lead to several problems. Here’s a list of issues you may encounter:

Incorrect Micron Rating

  • Shortened filter life
  • Ineffective filtration

Incorrect Fuel Pressure

  • Poor performance
  • Lower fuel efficiency
  • Engine flooding
  • Increased risk of damage to the carburetor
  • Engine splutter

When To Replace A Fuel Filter

As a filter wears down or gets clogged, the engine will start to show problems. Look for signs like not being able to start the engine, a stalling, spluttering, or backfiring engine, fluctuating engine sound, or excessive carbon buildup. This can mean it’s time to change the fuel filter otherwise your lawn mower could suffer damage that can’t be fixed.

How To Replace A Fuel Filter

If you don’t feel comfortable performing these steps yourself, we recommend contacting a professional. Your owner’s manual may also have some ideas too.

First, make sure your lawn mower is on level ground and in a well-ventilated area. Wear work gloves and safety goggles too. Then, being careful since they involve work with flammable liquid and vapors, follow these steps below:

  1. Switch fuel cut-off valve to OFF position.
  2. Remove the fuel line that returns to the fuel tank from the fuel filter.
  3. Drain the fuel into a fuel can.
  4. Remove all other fuel lines going to the fuel pump from the fuel filter.
  5. Connect the new filter to the fuel tank line.
  6. Connect the new filter to the fuel pump line.
  7. Switch fuel cut-off valve to ON position.
  8. Clean up any spilled fuel.
  9. Refill the fuel tank.
  10. Start the engine to see if it’s working properly.

How To Extend The Life Of A Lawn Mower Fuel Filter

There are several ways to extend the life of a fuel filter. Using a pre-filter such as a funnel with a filter when filling your lawn mower will remove most problems. Regular fuel system maintenance, such as cleaning the fuel lines, will also help.


Keeping an eye and ear on your lawn mower’s behavior will let you know if you need to change your fuel filter. When it comes to how to clean a fuel filter on a lawn mower, it’s better just to replace it. Used fuel filters belong in the trash!

So, when do you plan to change your lawn mower filter? What issues is your lawn mower giving you? Let us know in the comments below!

Also, for any other lawn mower needs, check out our other article about where to find the primer button on a Craftsman lawn mower.

Todd L Miles
Lawn Mowers Enthusiast
I started "Landscape and Lawns Care" to provide clients with lawn care with better service, better products and, most importantly, better ethics. My promise to every customer is to give the greenest grass possible while controlling weeds, insects, and diseases! The most important thing is that I strive to always do the right thing for you, your lawn and your wallet!