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What Is A Carburetor And What Does It Do? [Answered]

What Is A Carburetor And What Does It Do? [Answered]

A clear understanding of your engine's operation is key to ensuring that you can take care of your car. The Carburetor is one of the essential components of an engine system as it plays a significant role in providing the required energy.

By definition, a carburetor is a device that assists in the mixing of air and fuel to enhance fuel combustion in the engine. The fuel combustion is what provides the required energy to propel the vehicle. Notably, the amount of the mixture of air and fuel that the engine requires depends on several factors, including the speed and the distance that the vehicle covers.

Technically, the Carburetor plays a significant role in the proper functioning of a vehicle, which is why you need to ensure that your Carburetor is always in perfect condition. Read on to learn more about the magic of the Carburetor.

mechanic with carburetor

How Does A Carburetor Work?

A carburetor works on Bernoulli's principles which state that the faster the air moves, the lower static pressure it possesses with higher dynamic pressure. While the accelerator does not directly control the fuel flow, it actuates the carburetor process that directs the airflow to the engine. The airspeed, and hence the pressure, determines the amount of fuel that gets into the airstream.

To make it easy to answer the question, what does a carburetor do? Here is a summary of how it works;

  • Air enters the Carburetor through a narrow opening on the top that widens again.
  • As the air flows through the narrow region known as the venturi, the speed increases, drawing gasoline from a tube protruding into the one side of the venturi called the jet.
  • Once the fuel and the air pass through the venturi, they encounter the throttle plate, which opens and closes to regulate the amount of air that gets to the engine.

Parts Of A Carburetor And Their Functions

One way to clearly understand the functioning of a carburetor is to understand all its parts and how they function. Here are some of the essential parts of a carburetor.

The Inlet Hose

The inlet hose is responsible for delivering gasoline from the fuel lines to the float chamber. It is through this inlet that gasoline goes into the Carburetor.

Needle Valve

The needle valve is situated in the float chamber and is sometimes referred to as the gasoline valve. It has a triangle shape that enhances its function of opening and closing the inlet hose.


As the name suggests, a buoy is a component that floats on a liquid, and its function is to dictate the position of the floating needle based on the volume of gas in the float chamber. When the volume of the gasoline in the chamber is higher, the buoyancy position gets higher, pushing the needle up. The reverse is also correct.

The Float Chamber

The float chamber works as a transit space. It is where gasoline is stored to be channeled to the engine. The pressure must equal atmospheric pressure for the float chamber to hold gasoline from the fuel line.

Main Jet

The main jet joins the float chamber with a venturi. The diameter of the main jet is adjusted to conform to the engine capacity to ensure that the mixture of air and gasoline is always stable.

The Air Vent

The air vent connects the float chamber to the outside to keep the pressure float chamber stable based on the air pressure outside. It is through the air vent that the volume of gasoline getting to the venture becomes ideal.

Economizer Jet

The main objective of the economizer jet is to ensure that the gasoline is better mixed with air. One characteristic of this component of the Carburetor is that it works when the engine is at idle speed.

The Slow Jet

The slow jet connects the intake manifold to the float chamber. Its function is to flow gasoline when the engine is at idle speed.

The Venturi

The venturi describes a space with a narrow diameter intake channel. The objective of the venturi is to accelerate the speed of the air passing through it. If the air inside the venturi is faster, the pressure will be low, and it is this difference in pressure that leads to the gasoline flowing out via the main jet.

The Choke Valve

The choke valve resembles the throttle valve, and their functions are similar as its main objective is to close the air ducts that enter the engines. The difference is that the choke valve is located before the venturi. Hence when the choke valve is closed, the piston sucks excessive gasoline from the float chamber, making the air-fuel mixture richer.

So, What Is The Function Of A Carburetor?

With a good understanding of the different components of a carburetor, you shouldn't have a hard time explaining the functions of the Carburetor.

The function of a carburetor is to mix fuel and air in a correct ratio to enhance fuel combustion. It contains the throttle and the choke that assists with regulating the fuel and mixture. Further, the Carburetor has a fuel feed chamber responsible for regulating the amount of fuel drawn into the engine.

Types Of Carburetor

There are several types of Carburetors based on the flow of air. These types of carburetors include;

Updraft Carburetor

In the updraft carburetor, the air gets inside through the bottom, meaning the airflow is upward. The major disadvantage of this Carburetor type is that it has a small mixing tube, so it cannot supply the mixture of air and oxygen when the vehicle is at high speed.

The Downdraft Carburetor

The downdraft carburetor has a mechanism where the air-fuel mixture flows downwards. These carburetors have a large mixing tube, hence downplaying the disadvantage of the updraft carburetor. Even if the engine speed is very high, it will still get enough supply of air and fuel.

Constant Choke Carburetor

As the name suggests, consistency is always given priority in this type of Carburetor, and consistency is given top priority.

Nonetheless, the difference between the pressure responsible for triggering the flow of fuel-air mixtures varies depending on the engine requirements.

Constant Vacuum Carburetor

The constant vacuum carburetor, also known as the variable choke carburetor, is a type of Carburetor when the air and fuel flow areas are different and are dictated by the engine's requirement.

Other types of carburetors include

  • The multiple venturi carburetor
  • Solex carburetor
  • Bike carburetor

What Is A Carburetor Backfire Flame Arrestor

A carburetor backfires flame arrestor is a system designed to prevent the ignition of gasoline if the engine backfires. Since the engine may backfire for various reasons, any vehicle or boat fueled with gasoline must have a functional backfire flame arrestor on the Carburetor. A good backfire flame arrestor must be in perfect and serviceable condition.

men orange carburetor

Why Should You Clean Your Carburetor Regularly?

The Carburetor is one of the most vital parts of an engine that is extensively utilized by the engine. Consequently, over the years, the choke and the carburetors become clogged with dirt, gum, varnish, etc.,, which interferes with the normal functioning of the engine.

The best way to ensure the engine operates normally is to clean it regularly. It would help to be professional when cleaning your Carburetor to avoid damaging it. Always keep the cleaner away from the battery terminals and electrical connections. Further, keep your hand upright when spraying the can.


A carburetor is an essential part of an engine, and being able to answer the question, what does a carburetor do will ensure that you are abreast with the functioning of your machine. Further, this knowledge will enable you to take good care of your engine.