Lawn Mower Fuel Filter: When To Change It?

The fuel filter in your lawnmower is a small but essential component that prevents dirt, dust, and debris from entering the carburetor and clogging the engine's fuel system. It is designed to strain the gas before it reaches the carburetor, ensuring that the gas is clean and can flow and burn properly. Over time, the fuel filter can become clogged, leading to poor engine performance and even engine failure.

The frequency with which you should change your lawn mower's fuel filter depends on several factors, including the type of filter, your usage patterns, and the condition of your lawnmower. In-line fuel filters, commonly found in larger lawn tractors and riding lawn mowers, should be replaced at least once a year, preferably as part of your spring or fall maintenance routine. If you use your lawn mower frequently, it is recommended to change the filter more often, such as after every 100 hours of operation.

For walk-behind lawn mowers with in-tank filters, the replacement interval is typically much longer, and these filters may only need to be changed by an experienced technician every few years or when they become severely clogged. However, it is always a good idea to inspect and clean your fuel filter periodically to ensure optimal performance and prevent unexpected breakdowns.

By staying on top of fuel filter maintenance and keeping your lawn mower in good condition, you can avoid the hassle of a stalled engine and enjoy a well-manicured lawn all season long.

Fuel filter location

The fuel filter in a lawnmower is 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 and disturb the gas-air mixture, leading to poor engine performance.

The exact location of the fuel filter varies from one machine to another. However, it is generally located either inside the fuel tank or fitted into the fuel line between the tank and the fuel pump. Some fuel tanks have internal, non-serviceable fuel filters.

The replaceable kind of fuel filter is a small plastic canister with pleated material inside, or a thin, 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

When to Check and Clean

At least once a year, preferably after each mowing season. If you've been mowing in dusty conditions, it's a good idea to do this more frequently.

Step-by-Step Guide

• Park your mower in a flat area and let the engine cool completely.
• Drain all the gas from the tank with a siphon or run the mower dry outside.
• Disconnect the wire from the spark plug to prevent accidental engine start during the process.
• Locate the fuel line and use pliers to release the spring clips holding it to the gas tank spigot and filter.
• Pull the fuel line off the spigot and remove the filter.
• If you have a canister-style filter, examine the transparent plastic casing and the pleated material inside. If you notice debris or severe discolouration, replace it with a new filter. These filters cannot be conveniently cleaned.
• For tube-style filters, inspect the meshed end for dirt or debris. If it appears dirty, carefully rinse it with water until it's clear or install a new filter.

Additional Tips:

• Fuel filters are typically located inside or attached to the fuel line or inside the gas tank.
• Remember to wear safety eyewear and ensure there are no open flames or fire sources nearby when working with fuel.

How to replace a lawn mower fuel filter

When to Replace

Lawn mower fuel filters should be replaced at least once a year, or after each mowing season. If you're unsure whether your fuel filter needs replacing, you can check for debris by looking through the transparent plastic casing of the filter. If you can see debris inside or it is severely discoloured, you will need a new filter.

Step-by-Step Guide to Replacing a Lawn Mower Fuel Filter

• Park your mower in a flat area, such as inside your garage, and let the engine cool completely.
• Drain all the gas from the tank with a siphon, or simply run the mower dry outside.
• Disconnect the wire from the spark plug so that the engine doesn't accidentally start while you're working on it.
• Locate the fuel line and, using 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, once the old filter is removed, push the ends of the fuel line segments onto the spigots of the new 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, simply remove the old filter and pop in the new one, making sure to orient it the same way as the old one.
• Reconnect the fuel line and replace the spring clamps.

Safety Precautions

• Wear safety eyewear to protect your eyes from liquid fuel or fuel vapours.
• Have a dry cloth handy to hold the filter and catch any dripping fuel.
• Make sure you are in a safe area with no open flames or fire sources.
• If your filter is installed inside the tank, you will need to drain the tank before you can remove the filter for inspection or replacement.
• If your tank is equipped with a valve, shut the fuel valve before removing the filter. If your tank does not have a valve, clamp the gas line using a fuel line clamp. Do not pinch the fuel line as this could cause damage.

How often should a lawn mower fuel filter be replaced?

The fuel filter in your lawnmower is a disposable component that clogs up over time and needs to be replaced. The frequency with which you should replace it depends on the type of filter you have, how often you mow your lawn, and the condition of your lawn mower.

Some smaller, walk-behind lawn mowers have an in-tank filter that should only be changed by an experienced technician. This type of filter is designed to catch the coarsest debris and may take years to clog up.

Larger lawn tractors and riding lawn mowers typically have an in-line fuel filter that bisects the fuel line running from the gas tank to the carburetor. According to the Tractor Supply Company (TSC), you should replace this type of filter at least once a year. Some people prefer to do it as part of their spring maintenance, while others change it before storing their mower for the fall. If you use your lawn mower frequently, TSC recommends changing the filter more often—at least once every 100 hours of operation.

In addition to the type of filter and frequency of use, the condition of your lawn mower can also be an indicator of when to replace the fuel filter. If your lawn mower is running poorly, it could be a sign that the fuel filter is clogged. Impurities in the gasoline, dust, or debris in the gas tank can fill up the fuel filter and impede gas flow. A rusty gas tank, for example, can cause rust particles to break off and clog the filter.

Visual inspection can also help determine if the fuel filter needs to be replaced. If you have a transparent in-line fuel filter, you can check for any gunk, dust, or discolouration of the filter's paper filament. However, it's worth noting that a filter can be clogged even if it looks normal. Therefore, if you're unsure or suspect an issue, it's generally recommended to change the filter to ensure optimal performance.

Why fuel filters fail

Fuel filters are designed to strain gas before it reaches the carburetor in your lawn mower or other equipment. They prevent foreign particles from clogging your engine's fuel system. However, fuel filters can fail, and when they do, it can cause significant problems for your engine. Here are some reasons why fuel filters fail:

Clogged Filter

One of the most common reasons for fuel filter failure is a clogged filter. Over time, the filter can become clogged with dirt, dust, debris, and other particles that it has filtered out of the fuel. This can restrict the flow of fuel to the engine, leading to poor engine performance, hesitation, misfiring, stalling, and a decrease in power and acceleration. A clogged filter can also cause low fuel pressure, which can result in a lean fuel condition and engine misfire.

Dirty or Contaminated Fuel

Using dirty or contaminated fuel can also cause fuel filter failure. If the fuel is not properly filtered before it reaches the engine, it can clog the fuel filter and prevent it from functioning properly. This can lead to a restricted fuel flow and engine performance issues.

Faulty Fuel Pump

A faulty fuel pump can also contribute to fuel filter failure. If the fuel pump is not working properly, it may not be able to deliver the correct amount of fuel to the engine, placing undue pressure on the fuel filter. This can cause the fuel filter to become clogged or restricted, leading to engine performance issues.

Normal Wear and Tear

Like any other component, fuel filters are subject to normal wear and tear. Over time, they can become less effective at filtering out particles, which can lead to a build-up of contaminants in the fuel system. Therefore, it is important to replace fuel filters at regular intervals, as recommended by the manufacturer. For lawn mowers, this is typically once a year or after each mowing season.

Incorrect Installation

Improper installation of a fuel filter can also lead to its failure. If the fuel filter is not installed correctly, it may not be able to function properly, leading to a restricted fuel flow and engine performance issues. It is important to refer to the owner's manual or a professional for guidance on installing a fuel filter.

Frequently asked questions