How to Clean a Carburetor on a Lawn Mower Without Removing It

Sooner or later, your lawnmower is going to need some maintenance. A tool like that needs to be consistently kept up and must stay in good working order. One of those maintenance tasks is cleaning your lawn mower’s carburetor.

To clean your lawn mower carburetor without removing it, first check all the hose connections. Then, remove the air filter cover and spray aerosol carburetor cleaner into the open carb. Then, remove any hard deposits and replace the filter cover. 

By cleaning your lawn mower’s carburetor regularly, you can avoid interruptions in yard maintenance. A dirty carburetor will shut down your lawn mowers engine quickly. No one wants their Saturday afternoon chores to take any longer than they have to.

What Does the Carburetor Do?

The carburetor is an important piece of your lawn mower’s engine. It is responsible for keeping the engine running cleanly and at the power capacity it was built for. Keeping it clean is a fantastic preventative measure.

The carburetor’s basic function is to regulate the amount of fuel and air being pumped into the engine. Internal combustion engines need a specific mixture of the two in order to function correctly. If your carburetor is dirty, it will not be able to do this.

Dirt and oil deposits can build up inside the carburetor. When this happens, oxygen is not properly fed into the engine. This can result in too much fuel flooding the motor and not burning off.

How Do You Know If Your Carburetor Needs Cleaning?

You will know that your carburetor needs cleaning if your engine is running rough. This means that it either has difficulty starting or staying running. This can become a problem especially if you are trying to cut exceptionally thick grass.

You will know that your carburetor is dirty if when you run over a difficult piece of lawn, your lawn mower’s engine stops. This is a sign that your mower’s engine is running too rich. This means that it is getting too much fuel and not enough oxygen to actually burn it off.

Your carburetor could also need cleaning if the mower has difficulty starting. However, there are many factors that could be coming into play with a mower that won’t start. Cleaning the carburetor may just be one solution.

Step 1: Check All Connections to the Carburetor

Before you begin, check all of the hoses and couplings that attach to the carburetor itself. These should all be secure and tightened at their respective connection points. If there is any loose connection, be sure to tighten it and check your mower again.

One of the issues that could arise from a loose hose is air not reaching the carburetor itself. This would essentially mimic the same symptoms as a dirty carburetor. The bottom line is that air is not getting to the engine.

It is probably a good idea to go around your mower’s engine and check the connections anyway. Bumping and frequent use can easily knock wires and hoses loose. By checking them regularly, you can avoid doing any unnecessary maintenance.

Step 2: Remove the Air Filter Cover

To access the carburetor, remove the black plastic air filter cover. This will expose both the carburetor and the air filter. These are both necessary parts for your engine’s continued health.

Check the air filter itself while you have the cover off. The air filter should be relatively clean but keep in mind that it can also function with some dirt. You don’t have to replace the air filter just because it is a little bit dirty.

Make sure that you keep any parts or screws separate from any others. These will be necessary when you put the engine back together. The last thing you want is to get to the end and realize you’ve lost a screw.

Step 3: Use an Aerosol Cleaner

Once you have the air filter cover off and the inside of the carburetor exposed, you can clean it. It is also a good opportunity to take a look around and get a good idea of how the whole mechanism works. This will help you in the future when you need to diagnose a problem.

Spray an aerosol carburetor cleaner into the exposed inside of the carb. Make sure, however, that you do this outside or in a well-ventilated area. The chemicals in many carb cleaners are corrosive and can be dangerous to inhale.

Be sure that you don’t use too much carb cleaner when spraying. Excess cleaner can contribute to build-up and deposits that will only make the problem worse. A little bit of the aerosol spray will go a long way.

Step 4: Remove Any Excess Dirt

After you have sprayed the cleaner, let it sit for 15 to 20 minutes. This will allow the cleaner to loosen any debris or deposits that may have clung to the inside of the carb. This is an incredibly important step and should not be skipped.

The corrosive nature of the carburetor cleaner is what helps it break down anything that might be blocking the airflow. This is why it is important that you let the cleaner sit and do its job before attempting to loosen any deposits.

If you do not wait for the carburetor cleaner to break the deposits down, you could damage the carburetor while cleaning it. Prying excess dirt from the mechanism could create chips and divots that can affect the flow of the air.

Step 5: Replace the Air Filter Cover

After you have sprayed the carburetor and removed any excess deposits or dirt, replace the air filter cover. Make sure that you screw down all the same connection points and that you are not left over with any spare parts.

Also, be sure that you check any wires or cables you may have accidentally disconnected. This is a common occurrence and can cause even more confusion. There is nothing worse than finishing a fix and having it be worse than when you started.

After you have replaced the air filter, start the engine and listen to it intently. Listen for any catches, knocks or chugs that might tell you there is a problem. Your engine should start up smoothly and easily if your carburetor has been thoroughly cleaned.

Related Questions

Will vinegar clean a carburetor?

You may be asking yourself if you can use any other household cleaner or item to clean your carburetor. While vinegar will clean excess dirt, it is not safe to use in your mower’s engine. The corrosive properties of vinegar have a tendency to make their way into the engine.

What is the main ingredient in carburetor cleaner?

The standard main ingredient for carburetor cleaner is Methyl Ethyl Ketone. This compound uses chemical reactions to liquify solids. This is incredibly important for things like carburetor cleaners since they are so dependent on breaking down deposits.

Is there a difference between the carburetor cleaner and brake cleaner?

The main difference between most carburetor cleaners and brake cleaners is that many brake cleaners don’t use any oil. Most carburetor cleaners have some kind of oil compound in them to help facilitate lubrication. Brake cleaners will not have this and should not be used as a substitute.