How to Clean a Motorcycle Carburetor?

This article may contain affiliate links. As an Amazon Associate we earn from qualifying purchases.

It is common to see people cleaning dirt off their motorcycle’s body as it comes with several benefits. One of them is that it is simply hygienic. A clean motorcycle is also visually appealing. Of course, cleaning the bike’s outside body is integral. What many people do not know is that the inside parts should also be cleaned.

A motorcycle has several internal parts that should all be cleaned. However, we would like to focus specifically on the carburetor. Of course, cleaning it can be a bit tricky, especially for newbies. To simplify things, here is everything you need to know about a motorcycle’s carburetor and how to clean it.

If you want to learn how to clean a dirt bike carburetor, please read the linked tutorial.

What is a Carburetor – Where is it Located?

The carburetor is an integral part of every motorcycle. It is a highly sensitive precision gadget that is located between the airbox and engine. Its role is to blend air and fuel in the right proper portions. The result of this mixing process is what causes internal combustion in the engine.

That is just a slight overview of the combustion process through the carburetor. Let us break down step by step how the motorcycle carburetor makes all of this happen. Here is how a motorcycle carburetor works.

For you to understand how it works, you need to have in mind that there are various types of carburetors. In this explanation, we are going to look at one of the simplest designs. This particular carburetor features a large vertically-placed air pipe. Furthermore, it has a horizontal pipe joined onto it on the side.

The air usually flows down the vertical pipe when the bike is in use.  As it flows downwards, it passes through a space called a venturi. A venturi is a narrow “kink-like” section that is responsible for speeding up the air. As the airspeed is increased, the pressure falls.  A decrease in pressure causes air to be drawn into the fuel pipe (the pipe on the side).

As the fuel joins the main pipe, the choke and throttle come into play.  These are valves located close to the venturi.  The choke is located at the top while the throttle is placed below the venturi.

The choke is the valve responsible for regulating the amount of airflow. The choke is usually closed when more fuel is needed in the carburetor. This then makes the air flow down the pipe, causing the venture to suck in more fuel, which is what is needed.

The throttle, on the other hand, regulates the flow of air and the supply of fuel from the side. In the event that it is fully open, both of these components will flow freely. As they increase, more power is generated, thereby leading to increased bike speeds. Basically, it is the throttle that is responsible for making a bike accelerate.

One thing we have forgotten to go into great detail into is the fuel pipe (the pipe on the side). In most cases, you will find a float feed chamber inside it. This a “somewhat” mini fuel tank with a valve and float.

It is this chamber that feeds fuel to the carburetor. When this happens, the fuel level decreases, and the float goes down with the fuel level. If the float reaches a certain level, the valve in this tank is opened.

This is what causes the fuel from the main tank to go inside this chamber (mini-tank). When it is full, then float rises, and the valve is closed. The process then continues from there.

Why You Need to Clean the Carburetor on a Motorcycle?

Here are some benefits of cleaning your motorcycle carburetor.

Greater Fuel Efficiency

For every motorcycle to move from one place to another, combustion needs to take place. One of the crucial facilitators of this is fuel. Basically, fuel needs to move from the gas tank to the engine. In the event that there are unwanted substances like grease and sludge, fuel will not get into the engine.

Even if the fuel does reach the engine, it will not be in the right quantity. This is what then leads to lower fuel efficiency and thereby translates to a lot of wastage. That is why you need to clean the carburetor frequently to get rid of such items. In the process, you will improve the bike’s fuel efficiency.

The Engine and Motorcycle As a Whole Function Better

One of the things that can make your bike function properly and run smoothly is a clean carburetor. If you have never cleaned it, try it today, and you will notice the great difference in your rides. With a doubt, they will be better than any other rides you have been on.

The Motorcycle’s Acceleration is Improved

There are instances where you may find trouble accelerating your bike. One of the reasons that can because this is the presence of dirt blocking the fuel pipe. This then results in less fuel reaching the engine. If the carburetor is properly cleaned, the fuel pipe is unclogged. As a result, the bike’s acceleration is improved greatly.

Quick Starting of the Engine

The carburetor directly affects the functioning of the engine. The carburetor is, in turn, affected by the way in which the fuel and air move towards each other. In the event that you have a dirty carburetor, this flow would be affected negatively.

That is why it is important to clean your carburetor to allow for the smooth flow of these components. As a result, your engine will start quickly.

How Often Should You Clean the Carburetor on a Motorcycle?

There is no problem with cleaning your carburetor almost as much as you clean the body of your bike. It will just go a long way in improving its functionality. All in all, you should try as much as possible to clean it after every six months.

This will make sure that every dirt and unwanted substance is cleared out. It is through this that you will reap the full benefits of riding on a clean carburetor.

How Do You Know Motorcycle Carburetor Needs Cleaning?

Here are some signs that indicate your motorcycle’s carburetor needs cleaning.

Problems in Starting the Engine

When your bike is cranking, but it is not starting, the carburetor is probably unclean. This is so because a dirty carburetor limits the flow of air and fuel, as earlier stated. As a result, you will feel a turnover (crank) but no actual start.

Overflow of Fuel

If there is too much dirt in the fuel pipe, the valve that controls fuel entry is prevented from closing. As a result, there is an overflow of fuel into the carburetor.

This then causes the air-to-fuel ratio to be completely messed up. This is what wets the spark plugs. If this happens, it is time to get your carburetor cleaned.

It is running rich

When your bike is releasing a lot of dark smoke, your carburetor is most likely dirty. Typically, you will find that there is an excess flow of fuel in the engine and not enough air.

This is what we call running rich. If this happens, clean your carburetor as soon as possible.

It is running lean

When an engine is running lean, it means that there is too much air in the carburetor and not enough fuel. This then causes popping sounds to be produced in the intake.

In the event of such, it is good to have your carburetor cleaned.

Can You Use WD40 to Clean Motorcycle Carburetor?

“WD-49” is an abbreviation that stands for Water Displacement, 40th Formula. The WD-40 cleaner is a spray that can be used to effectively clean a motorcycle’s carburetor.

It usually contains a solvent formula that breaks away any tough carbon contaminants. This way, you will be left with a sparkling clean carburetor.

Can You Use Brake Cleaner to Clean a Motorcycle Carburetor?

A break cleaner is a pressurized spray used to clear away dirt on the brake and clutch assemblies. It does this by dissolving these unwanted substances. Most of the time, you will find that they leave no residue at all.

So the question is, can you use it to clean a motorcycle carburetor? The answer to this question is yes. Basically, it is okay for you to use a brake cleaner to clean a motorcycle carburetor.

Make sure that you avoid using the non-chlorinated brake cleaner. It is known to leave a very bad residue on the carburetor. Furthermore, it is not as effective as the chlorinated ones


Having to go through bike issues due to a dirty carburetor can really be frustrating. You may find that the bike is taking a long time to start. In other cases, you find that the bike is not functioning properly.

Or maybe there is an overflow of fuel in the carburetor. All these issues can be avoided by cleaning your carburetor frequently. In most instances, it should not go past six months before cleaning the carburetor.

Both the WD40 and brake cleaner are great for cleaning your carburetor. However, before doing anything, read the instructions on the can carefully.

Josh Berry - MotoShark Editor
Josh Berry
I'm a off-road enthusiast, extreme sport fan and the editor of MotoShark. If you have any questions or suggestions regarding this article, please leave a comment or contact me.

1 Response

  1. Tyler Johnson says:

    That’s good to know that you should clean the carburetor every six months or so. I feel like that would be a good way to make sure that it runs properly, and that the bike as a whole runs for as long a possible. I’ll have to make sure I clean up the carburetor if I decide to buy some parts to fix up my old bike.

Leave a Reply

Your email address will not be published. Required fields are marked *