How To Find, Clean and Replace a Lawn Mower Fuel Filter

The summer I turned 14, I got a job cutting grass at a children’s camp. I shared this task with a few other teenagers, using an old Honda walk-behind mower.

One day when it was another guy’s turn, the mower abruptly sputtered to a stop. No one could figure out why. Luckily, my dad taught me about lawn mower fuel filters the year before.

It turned out the fuel filter hadn’t been checked or changed in nearly five years! It was completely clogged, stopping the mower dead in its tracks. The camp maintenance crew didn’t have a fresh filter on hand, but a quick rinse under the tap made the old one as good as new. The mower was up and running again in less than 15 minutes.

If you use a lawn mower or any small engine machinery regularly, it’s wise to learn about fuel filters. Here’s what you need to know.

What Is the Lawn Mower Fuel Filter?

It’s a small device that prevents dirt, dust and debris from entering the carburetor. Gas needs to be clean to flow and burn properly, and fuel filters make this happen.

Without a fuel filter, any debris that got into the gas tank could eventually flow through the fuel line to the carburetor. There, it would disturb the gas-air mixture and lead to poor engine performance.

Where Is the Lawn Mower Fuel Filter?

Exact location varies from one machine to the next, but it’s generally inside or attached to the fuel line, or inside the gas tank.

Lawn mower fuel filters can be replaceable or non-replaceable.

The replaceable kind is a small plastic canister with pleated material inside, or a thin and straw-like tube-style device with a fine mesh at one end. The canister style connects to one end of the fuel line, while the straw style slides inside the fuel line where it connects to the gas tank.

The non-replaceable kind is a metal mesh in the bottom of the gas tank where it empties into the fuel line.

How To Check and Clean a Lawn Mower Fuel Filter

• Begin by parking your mower in a flat area, like inside your garage. Let the engine cool completely.
• Drain all the gas from the tank with a siphon, or simply run the mower dry. (Always do the latter outside.)
• Disconnect the wire from the spark plug so the engine doesn’t accidentally start while you’re working on it.
• Locate the fuel line. With pliers, release the spring clips holding the line to the gas tank spigot and filter.
• Pull the fuel line off the spigot and remove the filter.
• For canister-style filters, look through the transparent plastic casing and examine the pleated material inside. Can you see debris inside, or is it severely discolored? If so, you need a new filter. There’s no way to conveniently clean canister-style filters, but they’re cheap and easy to replace.
• For tube-style filters, look closely at the meshed end. Do you see dirt or debris inside? If so, rinse it out carefully with water until it’s clear, or buy and install a new filter.

How To Replace a Lawn Mower Fuel Filter

Once you have your new lawn mower fuel filter or cleaned the old one, installation only takes only a few minutes. You’ll need pliers and a plastic container to catch any gas sitting in the bottom of the tank or in the fuel line.

• Follow the steps above in the “How To Check and Clean a Lawn Mower Filter” section.
• For canister-style filters, once you’ve removed the old filter, push the ends of the fuel line segments onto the spigots of the filter and use pliers to replace the spring clips.
• Be sure to install the canister-style filter in the correct direction, usually indicated by an arrow on the casing pointing in the direction of fuel flow.
• For tube-style filters, once you’ve pulled the old one out, pop in the new one. Be sure to orient it the same way the old one was.
• Reconnect the fuel line, replace the spring clamps and you’re good to go.

How Often Should I Replace a Lawn Mower Fuel Filter?

At least once a year. In the 20 years I’ve been mowing grass, I’ve never cleaned or changed the fuel filter more often than that, usually after each mowing season. Some years I’ve forgotten to do it, but it’s never been a problem. Still, be sure to add this to your annual maintenance checklist. 

Where To Buy Replacement Lawn Mower Fuel Filters

Whenever I need a lawn mower fuel filter, I order it from Amazon. They offer great selection and fast delivery. Check your owner’s manual or look closely at your old filter to get the right part number.