How To Clean a Lawn Mower Carburetor

How To Clean a Lawn Mower Carburetor : The Ultimate Guide

Cleaning a lawn mower carburetor is not the most glamorous of tasks, but it’s an important one. How often you clean your carburetor depends on how much time and effort you want to put into maintaining your lawn mower. If you’re looking for a quick once-over then we recommend doing this every 3 months or so. However if you prefer to do more maintenance and take care of things like air filters and spark plugs, then cleaning your carburetor should be done at least every season (about 4 times per year). To help make sure that you are following all safety precautions when cleaning the carburetor, we’ve created this step by step guide!

How To Clean a Lawn Mower Carburetor

Step 1. Safety First

Whenever carrying out repair work of any kind, safety should always be your primary concern. For instance, when taking apart a carburetor, the old oil can be highly toxic, ensure you’re working in a well-ventilated area. In case you are working in a garage, ensure that all the windows and doors are open. 


Step 2. Remove the Outer Casing and Air Filter

You’ll need to remove the outer casing of your lawn mower. Also if there is an air filter that has been installed then it should be removed as well. This will enable just enough room for you to carry out all necessary work on the carburetor without damaging anything else in the process.


Step 3. Removing the Carburetor

It is important that you are careful when removing the carburetor, as it can be delicate. The carburetor is normally firmly bolted in place but it comes off easily. Using a nut driver, unbolt it and then drain the fuel line while holding it to the engine. Detach the throttle cables and be ready with a rag or any piece of cloth to wipe any spillage of fuel on the carburetor and the fuel line.


Detach the carburetor from the engine and inspect all connections that run to and from the carburetor’s choke plates and throttle. If you find out that the carburetor is corroded, it’s toast, replace it with a new one. Ensure that there isn’t any dirt or debris left around the area where the carburetor set up will sit, which may cause damage to your lawn mower.


Step 4. Unbolt The Bowl And Clean The Nut

The next thing you’ll need to do is remove the nut from inside of the bowl. How you go about doing this will depend on what type of engine your lawn mower has, but they all work in a similar fashion. The carburetor bowl is held in place by a single nut. First, clean around the bowl with carburetor cleaner then unscrew the nut and remove the bowl.


This nut is usually a jetted hole. Poke a paper clip inside to ensure that the hole is free of any dirt. Presence of simple debris inside this hole will readily make the carburetor stop working properly; cleaning it may fix the problem.


Step 6. Replace The Needle

Inspect the needle that sits inside of the bowl, if it has any corrosion or dirt on it then remove and replace with a new one.


Step 7. Use a carburetor cleaner to get rid of dirt deposits within the carburetor throat

Dirt within the carburetor can block both fuel and air passages thus interrupting its performance. Cleaning the carburetor is necessary for it to work well.

Once you have removed all the parts, clean them by applying a spray cleaner or even gasoline with high amounts of ethanol. These two products will not only clean the carburetor but also remove any gasket or sealant material that was previously used to attach it.

Add a little bit of fuel into the bowl and spray some cleaner on all sides of your mower’s carburetor, one more time from underneath ensuring you get every area of the carburetor.


Step 8. Replacing The Bowl Gasket

After cleaning out all debris, we advise that you replace the main gasket. Simply remove the old one and fit a new one in its place.


 Step 9. Reassemble And Reattach The

If you had taken some photos during the process, let them guide you in putting back the carburetor and reattaching it to the engine. Once everything is back in place, add fuel to the tank and start it up. If you have fixed the problem, it should now start up easily.

A Relatively Easy Issue To Fix

As you can now affirm, cleaning a lawn mower carburetor is that easy and can save you money, time and a lot of frustration. In order to avoid any future problems with your carburetor, you will need to regularly keep an eye on it for dirt or debris buildup in the needle valve seat area. Keeping The Lawn Mower Clean And Taking Care Of It Properly Will Ensure That You Have A Longer Lasting Product Which Will Also Be A Great Help For Your Budget.

When Should You Inspect and Clean a Lawnmower Carburetor?

If you have had problems with your lawn mower suddenly dying on you, then chances are that it is the carburetor which needs some attention.

Another sign to look for would be a decrease in fuel economy of your machine and if this is happening then something may need cleaning or replacing within the carburetor.

Before winter sets in, you should also look to clean your carburetor. You can do this by removing the bowl and then taking it apart, cleaning any rough edges that have been exposed due to using a tool such as an ice scraper on it during winter months.


4 Signs Your Carburetor Needs Cleaning

1. When Your Car Is Not Starting

If you’re having problems with starting your mower, then this could be a sign that the problem lies within its carburetor. A dirty carburetor affects performance of the car engine. This is because the presence of too much dirt in the carburetor prevents proper passage of air and fuel combination into the engine. By implication, this would most often lead to a “turn over” and your car would likely not start.

2 . When Your Engine Is Running Lean

Have you ever heard of what it means for an engine to “run lean”? Well, an engine is said to be running lean if there is an imbalance in the ratio of fuel and air. An engine “runs lean” when the balance of fuel and air gets thrown off. Typically, there’s a 12:1 or 15:1 ratio of air to fuel, and when there’s too much air or not enough fuel, it causes sneezing or popping sounds in the intake. This can also be a sign that it is time to get your carburetor cleaned.

 3. When Your Engine Is Running Rich

When an engine runs “rich,” it’s the exact opposite of running lean, meaning there’s excess fuel and not enough air. When this happens, black smoke comes from the exhaust. In a situation where an engine is running rich, the most obvious sign is black smoke emitting from the exhaust. When you notice this, be sure to clean your car carburetor as this is another sign that you most likely have a dirty carburetor at hand.

 4. When Your Engine Is Flooded

 If there is dirt or debris in the fuel bowl, it can block the needle valve and prevent it from closing. As a result, the fuel would begin to overflow into the carburetor and then flow out of the bowl vents. The air-to-fuel ratio would be distorted and the spark plugs would become wet.

Can I spray WD 40 on my lawn mower carburetor?

Yes, A common household product can be used to clean your mower’s carburetor. Although it will not effectively remove dirt and dust deposits, it can dissolve gasoline and oil residue in the bowl of the lawnmower which is why we recommend that you use this sparingly when cleaning out a clogged up or dirty carburetor. To use this product, you will need to remove the small bowl from your lawnmower’s carburetor so that it can be sprayed directly onto the inside of the nozzle and throttle plate area.

Be sure to clean around these areas as well in order for WD-40 to work effectively. After allowing time for this product to work, replace the bowl and your lawn mower should start up without any problems.

How To Clean A Carburetor Without Removing It?

If you’re a lawnmower user, you’ve probably heard one of the itching questions most lawnmower users ask, on how to clean a carburetor without removing it. The reason why this may seem pretty necessary is that, when it comes to handling a carburetor, you should know that there are tiny parts of the carburetor that could easily get lost when you take it apart. Moreover, it is quite a simple mechanism to clean a carburetor without removing it at all. This method is however mainly used for cleaning the carburetor of a motorcycle and that is what we’ll be sharing with you.


  1. You have to start by removing the bowls at the bottom of the carburetor.
  2. Then you spray some carburetor cleaner up inside the carburetor and wait for some minutes.
  3. You will have to spray it again to make sure it fully covers the carburetor area.
  4. Replace the bowls at the bottom of the carburetor
  5. Start the engine and assess its performance.

How do I know my lawn mower needs a new carburetor?

If your engine is sputtering or stalling while you are operating it then there might be something wrong with your Carburetor’s inner parts. You may also notice that your engine is acting sluggish and the mower seems to be losing power even though it has a full gas tank, this can mean there’s something clogging up the Carburetor throat or float needle valve.

If you have tried starting your lawnmower after filling it with gasoline but nothing happens, then chances are that you need to clean or repair your Carburetors.

Keep in mind that if there is not enough gasoline reaching the engine then it won’t start up even though a spark plug has been used and turned on, this is because fuel needs to be pushed into the combustion chamber of an engine for it to run smoothly.