How to Clean a Lawn Mower Carburetor

One of the common issues most lawn mower owners will face at some point is a dirty carburetor. Problems such as debris getting through the fuel system and bad gas can turn a perfectly running lawn mower engine into a spluttering nightmare within a few minutes. So, rather than struggling with your lawn mower, let’s go over how to clean a lawn mower carburetor and get your lawn mower running like usual.

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How to Clean a Lawn Mower Carburetor (The Overview)

There are two easy ways to clean a lawn mower carburetor. The first is to use a carburetor spray to remove fuel gum and residue. The second is to remove the carburetor jet to clear any blockage. For this method, you’ll need to remove the fuel cup, the fuel float, and the carburetor jet. Then, with the jet out of the way, you can clear the blockage.

Symptoms of a Dirty Lawn Mower Carburetor

A lawn mower with a dirty carburetor will show signs that it is struggling, and the engine won’t perform as usual. Here are some common signs of a dirty lawn mower carburetor you should look for.

Do You Have to Remove a Lawn Mower Carburetor to Clean It?

Lawn mower carburetors usually become blocked with a build-up of debris or fuel gum which restricts the flow of fuel through the carburetor jet. In many cases, you can leave the carburetor attached to your lawn mower and just remove the jet to clear the blockage or use a carburetor spray. So, no, you don’t always have to remove the carburetor completely to clean it.

Where is a Lawn Mower Carburetor

Before you can even begin, you first need to know where the carburetor is. The carburetor is linked to the air filter and cylinder head. To help you out, I’ve written an article on how to find the carburetor on a mower.

How to Clean a Lawn Mower Carburetor Without Removing It (2 Methods)

Cleaning the carburetor on a riding lawn mower carburetor is just the same as push mower carburetor cleaning. The only difference is the shape and size of the carburetor. However, the principles of how they work and the components they use are the same.

So, let’s take a look at how to use carburetor cleaner on a lawn mower using two methods.

Cleaning a Lawn Mower Carburetor Jet (Method 1)

To clean a blockage in a lawn mower carburetor jet, you’ll need to remove the bottom of the carburetor to access the jet. Here are the steps you’ll need to follow.

Detach the spark plug cable from the spark plug
Remove the bolt located on the underside of the carburetor fuel cup
Remove the fuel cup from within the carburetor
Remove the pin holding the fuel float and needle into place
Remove the fuel float and needle from the carburetor
Remove the securing screw holding the jet in place
Remove the carburetor jet from the carburetor
Using a thin wire, clear the blockage in the jet
Reinstall the carburetor jet
Secure the jet in place
Reinstall the fuel float, needle, and pin
Reinstall the fuel cup and fuel cup bolt
Reconnect the spark plug

What You’ll Need to Clear a Blocked Carburetor Jet

Cleaning a Lawn Mower Carburetor with a Carburetor Cleaning Spray (Method 2)

If you’re not confident taking your carburetor apart, then you can use a carburetor cleaner to clean fuel gum and residue from your lawn mower carburetor. This is a product that removes fuel gum and residue on contact. It might not be as effective as method one when clearing a blockage, but it will do a pretty good job. With this method, you won’t need to remove any parts of the carburetor. All you need to do is gain access to the inside of the carburetor via the air filter. Here are the steps to using a lawn mower carburetor cleaning spray.

Remove the air filter cover
Remove the air filter
Start your lawn mower
Spray a short burst of the carburetor cleaner into the carburetor opening
Allow the engine to run for 1 minute to burn off the cleaner
Repeat the spray/burning process several times
Install the air filter and air filter cover

What You’ll Need to Clean a Carburetor Using Spray

Does Carburetor Cleaning Spray Work?

Carburetor cleaning spray is effective depending on the problem you’re dealing with. When you use a carburetor cleaning spray, you only clean one section of the carburetor, which includes the throttle valve, throttle opening, and the jet. So, if the problem lies within this section of the carburetor, then a spray will work. But if the issue with your carburetor is before this area, say, a sticky fuel float or a blockage in the jet, then a cleaning spray won’t work.

To tackle these kinds of problems, you’ll need to remove the fuel cup and address the issue directly. Or, if you’re dealing with a blockage in the carburetor jet, you’ll have to remove the jet from your mower and clean it by hand, as I explained in method 1.

How to Avoid Carburetor Cleaning

There are a few steps that you can take to avoid carburetor cleaning altogether. These include a few simple tools, additives, and keeping up with maintenance. Here are some steps I use to keep carburetor cleaning to a minimum.