How To Clean A Carburetor On A Lawn Mower Without Removing It

Machines have a lot of fast-moving parts that work together for the machine to function.

Just like a car, a lawnmower has a machine called carburetor that is responsible for the movement of the blade that cuts the grass.

A carburetor is a device that injects air into the fuel to have internal combustion. The combustion is what will power the blades.

Carburetors are present in large machines like commercial planes and to small ones like your trusty lawnmower.

Today, we discuss how to clean the carburetor in your lawnmower without removing it. This can be a good option if you do not have the technical knowledge and the right tools to do a thorough cleaning which requires removing the carburetor from the machine.

After all, sometimes all it needs is just a bit of cleaning.

Types of lawnmowers

These are the usual types of lawnmowers you can see at your local hardware depot.

  1. Traditional push-reel lawnmower. This one does not use an engine but rather relies on the kinetic energy provided by the turning wheels. A set of 5 to 8 blades work together to provide a basic cut. Do not expect fast or precision cutting with this one.
  2. Walk behind lawnmower. This one is the most popular due to its efficiency. You just push the lawnmower towards the uncut grass and everything is cut nicely and evenly after. The blades are located at the bottom which is powered by a small carburetor.
  3. Ride-on lawmowers. This one is operated similar to a car or a golfcart. Instead of pushing it, you sit on the machine and steer it. Usually, this machine is used on stadiums and large greenfield which requires faster cutting without tiring the person.

Common issues and symptoms of a faulty carburetor

How To Clean A Carburetor On A Lawn Mower Without Removing ItPin

The issue with any gas-power machine is you should regularly use it but not overuse it. Leaving it unused for a long time can lead to complications.

Liquids inside may harden and cause blockage in some parts. The grease may get gunky and cause the moving parts to be stuck.

You will easily know when the carburetor is acting up when it shows the following signs:

  • Weaker engine and performance. If you notice that your lawnmower cannot any more cut evenly or have a hard time cutting denser grasses, the carburetor is definitely in bad shape, and attend to it immediately.
  • Emission of black smoke. This means that the carburetor is consuming unusually high amounts of fuel. You will end up spending more on gasoline. Also, exposure to black smoke could lead to respiratory and dermatological problems.
  • Overheating. Usually, this means that there is a poor mix or ratio of air and fuel. The engine exerts more effort to work.
  • Suddenly shutting down. Simply put, any lawnmower should have no problem being used for an hour or two. When it suddenly shutdowns, it is an obvious sign that your carburetor needs some cleaning or fixing.
  • Jumpy starting. Whether it is started via a push-button or pulling a cord, a lawnmower that has a hard time starting means that the internal parts are not at their optimum status.

Now you know how to spot a faulty carburetor. Let us now talk about whether you should remove it from the lawmower or not.

Why you should not (yet) remove the carburetor when you clean it?

Before you do anything, you should assess your technical know-how with small machines. If you are a mechanic who deals with this problem regularly, then removing the carburetor and putting it back would be easy.

If you are just a casual homeowner, better keep it intact and clean it from there.

You may successfully remove it and clean it, but you may end up having a hard time returning it. What is a clean carburetor if you cannot use it anymore.

Essential tools you need 

Since you are will just be doing a partial cleaning and not disassembling it, you will need these following tools:

  • Screwdriver. This will be used to remove screws. You may use a Philips screwdriver for prying off the filter and other snapped-on parts but you are better off with a plastic card to avoid damaging anything.
  • Rags. This is for wiping off the dirt on and in the carburetor, and keeping your hands clean and non-slip.
  • Flashlight or headlamp. If you are not familiar with the internal parts of a carburetor, you need to inspect it closely first with a flashlight. A headlamp is better to keep both of your hands free.
  • Aerosol cleaner. Now, not every aerosol cleaner can be used interchangeably in different machines. Basically, an aerosol cleaner is a liquid that is suitable to clean electrically-charged, fuel-power, and any running machine without causing rust and discharge.
  • Air-compressor gun. Some parts of the carburetor will have a build-up of grease clumped up with dirt or grass. This is normal. Before you wipe it off manual with a rag, do a clean sweep of the whole machine by blowing strong air to remove some of the dirt.

how to clean lawn mower carburetor Step-by-step

We are assuming that your lawn mower is in nice shape, used regularly, and maintained well.

Any lawn mower that has been left rusting in the garage or been flooded in requires an intensive repairing which requires removing the carburetor.

Cleaning the carburetor without removing it is not a replacement to taking it to your local shop for disassembly and deep cleaning and repair.

It is just a good monthly practice in maintaining it to prolong its lifespan.

Step 1: Turn off the lawnmower

Safety first, always. You do not want any accident just by doing a simple cleaning to your lawnmower.

Midway in the process, you will need to turn on the machine again. Read on to know at what step you should do this.

Step 2: Do an initial check-up

Do An Initial Check-UpPin

Before you start cleaning, take a look of everything to assess how you will proceed with the cleaning. If you see exposed wires, a rat may have chewed on it.

If you see patches of rust, the carburetor may have been exposed to water and was not dried out fast.

Things like these should be taken into account before you do anything whether it is just a simple cleanup or a full-on disassembly.

Remember, if you lawnmower is still under warranty, make sure to ask the company whether your machine is eligible for a clean-up.

Step 2.1: Take photos of the carburetor before you do anything

You may not see this step in other guides but you need to have photos of the machine before you do anything.

The reason for this is to have a reference later on what the machine should look like when you put everything back in case you fumble in putting back the parts together after.

Also, this is good for warranty purposes to show that your machine has acquired damage and unusual wear-and-tear even under normal usage.

Step 3: Remove air filter then clean it

Remove Air Filter Then Clean ItPin

All the air that is sucked inside goes through the air filter. Unless you are using your lawnmower in a clean and empty room, your filter will have a lot of dirt and sediments on it.

You can just use a damp rag if there is minimal dirt but use the blow function of your vaccuum to remove the dirt.

If the air filter on your lawnmower can be removed, it is better to remove it and clean it on its own.

This way, you can clean both sides and leave it for it to dry. You can now proceed without waiting for the air filter to dry.

Step 4: Closely look at the insides with a flashlight or a headlamp

Other people skip this and just glance at the internals. With a flaslight or a headlamp, you can focus on all the parts one-by-one to you know what you are dealing with.

You do not want any surprises like an exposed wire which you can leave unattended if you have not seen it with a flashlight.

Also, most carburetors have a dark paint or gets dark over time. You miss out the rust, moss, or other discoloration inside if you do not use a flashlight.

Step 5: Look at the connecting wires in the carburetor

Look At The Connecting Wires In The CarburetorPin

Wires are important, but they are delicate. Any slight tug of it could snap it and render the machine useless (for a while until you get a replacement wire or patch it up).

It can also cause serious injuries when an exposed wire touches another wire or some dried grass (which are flammable).

This is also a good practice in being a better homeowner and a “DIY mechanic.” You will be familiarized with how a machine works.

After all, once you understand the machine of a lawnmower, you will be familiarized with other machines like electric generators, motorbikes, and electric fans.

A common issue of a failing carburetor are old spark plugs. The coating may have worn out due to aging and does not receive electricity optimally.

Step 6: Remove all the dirt with an air-compressor gun

Over the days (or months) you have used with your lawnmower, there could be a build up of dirt and gunk inside and outside the carburetor.

Some are placed in hard-to-reach areas so instead of squeezing your hands in, why not use an air-compressor gun?You can easily dislodge any debris with this tool. However, you should not use it with the highest setting or even use an industrial air-compressor gun that are meant for heavier cleaning.

Step 7: Spray the insides with an aerosol cleaner

Spray The Insides With An Aerosol CleanerPin

Do not be confused to use water in cleaning your carburetor. That would just ruin the machine for good. An aerosol cleaner is a machine-friendly that sticks to the surface for longer protection.

Now, this step requires turning on the machine. The reason is you need the cleaner to go through the machine so that even the internal parts are cleaned.

On the center of the carburetor, spray in pulse the lawn mower carburetor cleaner like this one while the machine is running. You can do this in 10-15 pulses and leave the machine running for a minute to ensure maximum coverage.

Turn off the engine and spray the carburetor’s throat thoroughly. The lower plate will also have dirt so give it a good spray after.

Step 8: Remove all the gunk and deposits manually

Remove All The Gunk And Deposits ManuallyPin

After blowing off the dirt with the air-compressor gun and spraying the aerosol cleaner, now is the time to use your hands and manually clean off leftover dirt.

Make sure your rag is damp, and not soaking wet, to easily wipe off any solid dirt. Also, after every wipe of a major dirt, rinse the rag and squeeze out the water to avoid spreading the dirt further on the carburetor.

Step 9: Inspect everything before finishing

When everything is done, make sure to check everything and spot-check important parts using a flashlight. You can see the photos you have taken earlier to see if everything is matching.

Test it and let it run for 5 to 10 minutes to see if anything has been affected by the cleaning. Usually, you will notice a smoother start (no chugging sound or shaking).

Additional tips

Here are some final tips for you to consider before cleaning the carburetor

  • Maintain a regular schedule of partial cleaning (like this article is saying) and deep cleaning (removing the carburetor).
  • Before you take the lawn mower that won’t start for repair or cleaning to the shop, make sure you know what the problem is. Some shops will exaggerate the problem and ask for a more expensive service fee.
  • Use the right aerosol cleaner. A general purpose cleaner is fine in most situations but if you want the best cleaner, get the one dedicated to lawnmowers or small carburetors. The cleaner for your over or your bathroom’s disinfectant spray are not suitable for this type of cleaning.


At first, cleaning the carburetor can be intimidating. After all, not everyone is proficient with machines or have previous experience with it. This guide is to give you an overview of how the process works.

However, as some lawnmowers are built differently and some have different usage, the process may vary.

In some gas-powered weed eater trimmers, you may have the same issues. So you can do the same checks like the above. The differences may be that you have a 2-cycle or 4-cycle engine.

Always remember that cleaning without removing the carburetor is not a replacement to deep-cleaning the carburetor by removing it and even dismantling the parts.

Maintain your lawnmower and it will serve you and even your kids well.

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