lawn mower fuel filter

Should A Lawn Mower Fuel Filter Be Full?

A lawn mower is a complex piece of equipment and made up from various components. The fuel filter may be a small part of the lawn mower but it has a very important job. The lawn mower fuel filter cleans the fuel before it heads to the combustion chamber so you should make sure that it is always working perfectly. If gas is not getting to the fuel filter, you need to act quickly.

The job of your fuel filter is to remove impurities and dirt from the fuel before it moves into the combustion chamber to be ignited. The lawn mower fuel filter location may vary from model to model but as a general rule, it is typically located either in the fuel tank or along the fuel line.

A lot of people wonder ‘is a fuel filter supposed to be full?’ At worst, they will believe that being full is a bad thing and empty the lawn mower gas filter without realising that this could be detrimental to the health of the mower.

It is important that there is always a good amount of fuel inside the filter. In fact, an empty filter or a fuel filter not filling up properly is one of the many lawn mower fuel filter symptoms that tell you there could be a problem.

If the filter is not working correctly, this will affect the overall performance of your lawnmower. One major issue that a lot of homeowners face is that the mower stops working as well as it once did but not many people think to look at the push mower fuel filter as being the culprit.

One of the most common lawn mower issues is that dirt and debris gets into the combustion chamber where it then becomes difficult to ignite the fuel. When this happens, you can almost guarantee that it is because the lawn mower fuel filter isn’t full; tending to this problem will likely make the world of difference.

But this still doesn’t explain why the filter must be full. One could be forgiven for thinking that if it is full, it needs replacing. But this isn’t the case. If the fuel filter is not full this can cause the mower to stall simply because the lawn mower is not getting gas. The reasons for this is that even though there needs to be enough fuel in the combustion chamber, there must also be a back up of fuel in the filter. This will ensure that there is always a good supply to the engine.

When the filter becomes clogged, this means that fuel cannot sit inside and as a result, your engine may become deprived, causing it to cut out.

Do I Need To Replace The Filter With A New One?

When you first purchase your lawn mower, you will probably be amazed at the level of performance, but over time, this may decrease. You may find yourself with a mower that doesn’t do half of what it once did. But this could mean that there is a lawn mower fuel filter problem.

Regularly replacing the filter is a great way to avoid issues from arising in the first place and will help you to ensure that your mower keeps running smoothly. You may be able to change the filter yourself but some models have an internal filter that will need to be serviced by a professional. In any case, these are some of the benefits of staying on top of replacing the fuel filter.

  • If water gets into the engine of your mower then it is only a matter of time before the entire thing packs up. Engines are not designed to work well with water and over time, if it is allowed to enter, white rust will appear and degrade the components eventually rendering the engine useless. However, regularly changing the fuel filter will ensure that water cannot get in.
  • Another thing that you want to keep out of the system, particularly in the fuel filter, is oxygen. This can take up a lot of space and will result in deposits forming on the inside of the filter. This can be very difficult to clean but can be avoided through regular changes.
  • The engine system is very delicate, despite what you might believe and any exposure to air can significantly damage the parts. A fresh fuel filter can prevent this from happening.

If you have never done it before, replacing the fuel filter on a lawnmower may feel like something of a challenge, but this is something that most homeowners will be able to do. If you’re worried that you won’t know what to do or are asking yourself questions like which way does a fuel filter go and how do I replace a fuel filter then don’t worry, we’ve got you covered.  Take a look at the following steps to ensure that you get it right.

  • Before you start, take a careful look over your user manual. While we can give you general tips, each mower is different and the manufacturer will offer specific advice for the model.
  • You will need to ensure that you are wearing the correct personal protective equipment such as safety goggles and avoid wearing loose clothing that could become stuck in the lawn mower as you work.
  • Some fuel filters are located within the gas tank and this will require you to empty it first. You can either wait until the mower naturally runs out of fuel through use or drain it into a suitable container.
  • For mowers whose fuel filter is on the fuel line, you will need to clamp the line and then drain the fuel before removing the second end of the fuel line.
  • Clean the filter with a dry cloth and then, in an area with good light, hold it up to and look for any debris. If you cannot see straight through the filter, it will need replacing.
  • When you insert the new filter, make sure that you tighten the metal clips on either side to keep it in place. Once the filter is secure, remove any clamps on the fuel line and check that there are no leaks.

How Often Should You Clean The Filter?

There is no clear answer on how frequently you should be cleaning your fuel filter but one thing that is for certain is that you should stay on top of this job. Of course, the more you use your lawn mower, the more maintenance you are going to need to perform. But even when the mower will be out of action for a while, you still need to make sure that it is well-looked after.

For example, using a fuel stabiliser when you won’t use the lawn mower for a significant period of time can be very beneficial for your equipment. This works to prevent too much air exposure to the components, therefore, prolonging their lifespan.

However, during the summer months when you are using the mower much more frequently, you will need to keep an eye on the filter. It isn’t difficult to tell when it might need a clean as you’ll notice that it isn’t filling up and the performance of the mower will likely be affected.

As part of your routine lawn mower care, you should get into the habit of cleaning the filter.

How To Clean A Lawn Mower Fuel Filter

Learning how to properly clean your mowers fuel filters will help your equipment last much longer. If you are unsure what you are doing, our simple steps will help you to get the job done correctly. Once you have done it a few times, changing the lawn mower fuel filter will become second nature.

1. Relieve Fuel Lines Of Pressure

This step is important for the safety of the mower and of yourself, so make sure that you don’t omit this. Begin by finding the fuel pump fuse and take this out. Now turn on the engine and let it run for two minutes; you can run it longer if you like but two minutes should be the minimum.

Also make sure that while you are doing this, the lawn mower is in an open location with plenty of airflow. Outside is the best option.

2. Remove Spark Plug

Next, you will need to remove the spark plug and while you do this, you have the opportunity to check this component over too. If it needs to be replaced, now is the time to do it.

Begin by disconnecting the battery terminals, starting with the negative one as this will remove any fire hazards should the fuel ignite during the process.

3. Disconnect Fuel Line

You’ll now need to disconnect the fuel lines that connect the fuel filter to the combustion chamber. You may need tools to help you do this and typically a crew wrench will be your best bet. Be aware that this could be a dangerous job so you should always wear the appropriate PPE that we discussed earlier in this article.

4. Remove Fuel Filter

Next, you will remove the fuel filter from its seat. In most cases, there will be arrows to show where the filter goes but before you take it out, make sure that you look at the lawn mower fuel filter location so that when it comes to replacing it, you won’t be left scratching your head.

5. Drain Fuel Residue

It is important to ensure that you drain all of the fuel from the filter and this can be done by gently tapping it on either end. You will need a suitable container to drain the fuel into such as a draining tray.

6. Clean The Fuel Filter

To clean the fuel filter, you will need to use a carburetor spray. This can be sprayed on the inside of the filter as well as around the exterior. You don’t need to do much more than this, as the spray will do most of the hard work for you. However, it is important to remember that the filter needs time to dry and you should leave it in the open air for at least an hour before attempting to reinstall it.

Why Is My Fuel Filter Always Empty?

If your lawn mower’s fuel filter is always empty then this is a sign that there may be a problem. Typically, this signifies that there is a blockage in the filter and simply cleaning it could solve the problem. However, upon inspecting the filter, if you cannot see directly through it, it may be time to replace it with a new one.

However, another common reason that the fuel filter is always empty is because there is a hole in it. Again, this issue can only be solved through a replacement.


All gas lawn mowers have a fuel filter and this is an important part of the setup. Without it, the fuel could not be cleaned before entering the combustion chamber. It is important that the fuel filter is filled with fuel as this poses as a back-up for the engine and shows that the system is running fluidly.

Andrew Fisher

Andrew Fisher

Andrew is a dedicated father of three who really takes pride in his lawn and garden. You'll find Andrew behind the scenes of almost everything Edge Your Lawn produces. When he's not helping readers find all the information they need, he's in his backyard working on his lawn and garden landscaping. This year he hopes to build an outdoor deck and sort out his veg patches.

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