Carburetors are moving parts that are essential for machines to function. They can be found in vehicles, planes, motorcycles, and even airplanes. Carburetors are devices that mix air and fuel to create combustion. Their job is to ensure the air and fuel ratio is regulated, helping to control the speed of the engine. 

In a lawnmower, the carburetor is a major part and it moves the fast-rotating blade that mows the lawn. It does all the hard work when you mow your lawn. 

Why do carburetors sometimes stop working? 

If your lawnmower is not working properly, the most likely cause will be the carburetor. Carburetors are susceptible to blockages, whether they are being used regularly or have been standing idle for a while. 

The blockages are usually caused by dirt that has accumulated within the carburetor. Besides general dust from using the lawnmower, the carburetor can also clog from gasoline or oil deposits. 

Common issues and symptoms of a faulty lawnmower

  • You are struggling to get your lawnmower started, or it won’t start at all
  • Your lawnmower shuts down suddenly as you mow the lawn
  • There is overheating, and you notice the engine is over-exerting
  • Your lawnmower is emitting black smoke
  • You notice your lawnmower is not working optimally and is not cutting patches of dense grass or is cutting the grass unevenly

How to clean a carburetor on a lawnmower?

An old carburetor will not work optimally, even when cleaned. Unless your lawn mower’s carburetor is very old and needs replacing, you can usually clean it without needing to remove it. A clean should remove the build-up that causes most of the above problems. 

You should maintain your carburetor at least once a month during the summer months when it’s used regularly. You should also maintain it at the beginning of summer after it has stood in your garage over winter.

If your lawnmower has been unused for ages, or its carburetor was flooded, then you need to remove the carburetor to repair it. Unless you know how to do this, it’s best to have this done at a lawnmower repair shop.

Tools & materials you need

  • Aerosol spray cleaner
  • Air blow gun or vacuum with blow function
  • A tool kit that contains a set of screwdrivers
  • If you don’t have good lighting, you must need a flashlight 
  • Some rags

Step-by-step procedure to clean carburetor or lawnmower

Never attempt cleaning the carburetor with the lawnmower engine running. Make sure it is completely cool before starting.

Early check-up to assess the condition

Do an early check of the working parts of your lawnmower. See there are no exposed wires or rust patches. These will indicate that the carburetor needs more than just cleaning and will need to be disassembled for proper repair. If your lawnmower is new, it should still have a warranty that would cover you for a clean-up and maybe even some repairs. 

Take initial snaps of the carburetor

Before undertaking any tasks on the lawn mower, take some photos of its engine. This may seem like an unimportant step, but a photo can serve as proof of any unusual wear-and-tear under the warranty cover. Also, you may need some reference to ensure you have put everything together properly once you have completed the clean.

Remove air filter for cleaning

Use a screwdriver to open the cover of the air filter. This also exposes the carburetor, and you can remove its cover and linkage.

The air filter keeps all dirt and sediment from going into the working parts of your lawnmower. Since you are using it on the lawn, it will have collected lots of dirt. If you can, remove the air filter and clean it all around. If it’s very dirty, start with the air gun to remove most of the dirt. Then go in with a damp rag, making sure to remove all dust deposits. Leave the air filter aside to dry. 

Carefully look at the insides with a torch

Use a flashlight to make a closer inspection of the carburetor. Carburetors are usually painted in a dark color, and the inside of your lawnmower is a dark place. Look out for discolorations, rust, moss, or exposed wires. Exposed wires may need to be replaced or fixed because they can cause injuries or fire. 

Eliminate all the dirt with an air compressor gun

Remove all visible dirt with a rag. You will notice your carburetor has dirt in some hard to reach places. Use the air blow gun to get into those, but not in a very high setting.

Spray the insides with an aerosol cleaner

At this point, you need to turn on the engine, so it can be cleaned with the aerosol cleaner. As the machine runs, the cleaner will be distributed into the internal parts. As it cleans it also offers long-term protection. Never use water, as it will ruin the engine. 

The aerosol cleaner is sprayed into the midpoint of the carburetor. You need about 10 -15 squirts, and then let the engine run for 1 distribute throughout the engine. Turn the engine off, and spray the lower plate and throat of the carburetor. 

Eliminate all the gunk and deposits physically

Use the rag to remove all left-over dirt. The rag must be damp, and as you wipe, rinse it off to avoid spreading the dirt.  

Replace cover and linkage

Replace the carburetor’s cover and linkage properly. Then fit the air filter in the correct position and tightly screw it in place. 

Examine everything before finalizing

Use your flashlight to inspect the inside of your lawnmower. Make sure you have replaced all parts properly and that there are no open wires. Now you can turn on the lawn mower again to make sure that the carburetor is clean and running smoothly. 

Your lawnmower is now well-maintained and ready to tackle the task at hand.