What is the Difference Between Carburettor & Fuel Injection?

Bikers are often heavily invested in the functioning and make of their vehicle. Thus, there have been massive ongoing debates regarding the riding experience in motorbikes powered by carburettor and fuel injection engines.

Now, how is carburetion different from fuel injection? Does the fuel delivery technique impact engine performance? Will fuel injection systems completely wipe out carburettors in the future? Let’s have a detailed look at them both.


The first carburetor was developed by Karl Benz.

Until recent times, the carburetor was the most common and basic fuel delivery system in two-wheelers. The setup of a carburetor is quite simplistic and mechanical and does not make any use of sensors or electronics. For example, the Discover is a 100 cc bike from Bajaj and comes equipped with a carburetor.

Additional Read: 10 Easy Ways to Increase Your Bike Mileage

How Carburettor Works

The inlet pipe of a carburetor feeds an air-fuel mixture into the cylinder while an air filter is attached to the outlet. In the venturi, the tube tapers to restrict air passage, which increases the velocity with which the air moves through it.

Following Bernoulli's principle, the increased velocity results in a low-pressure condition, which uses suction to draw out fuel from a jet near the venturi. The air-fuel mixture gets supplied to the cylinder where the combustion takes place.

A valve, called the throttle valve, is present at the end of the tube and is connected to the cylinder. It controls the air sucked into the carburetors. The throttle valve is connected to the accelerator of your bike. Thus, revving up the throttle increases the airflow, thereby delivering more fuel, while rolling it back does vice versa.

Carburetor Pros

  • Since a carburetor has a purely simplistic and mechanical build, it does not cost a lot.
  • Maintenance and replacement of carburetors is not an expensive affair.
  • Tuning and setting of carburetors are possible while on the go. Plus, it can be quickly serviced.
  • It can be opened as an individual unit without disturbing the engine.

Carburettor Cons

  • The diaphragm of a carburetor is delicate and can tear easily. Also, the carburetor design is obsolete.
  • The open nature of the carburettor, it loses its efficiency due to pumping losses caused by evaporation.
  • While carburetors are precise, they are not accurate. A carburetor’s accuracy may be hampered by air or fuel temperature changes or atmospheric pressure changes.
  • Low temperatures may make it difficult to start a bike that is powered by a carburetor.
Additional Read: Best Fuel Injection Bikes in India

Fuel Injection

Fuel injectors are considered to be far superior to carburetors as they make use of sensors and electronics that automate most of the tasks.

How Fuel Injection Works

In this fuel delivery system, a fuel injection nozzle is fed directly inside the combustion chamber, while the air intake is measured using an air sensor. Upon entering the pressure pump, the fuel and air are subjected to pressure and get atomized into a homogenous mist, which allows for clean and efficient combustion.

The supply of the fuel-air mist is controlled by an ECU, which makes use of dynamic, complex calculations to deliver the best air-fuel mixture based on factors like load, engine speed, engine temperature, throttle position, etc.

Fuel Injection Pros

  • Optimum fuel delivery with a consistent air to fuel ratio, which may be modified on a case-to-case basis as computed by the ECU.
  • Increased fuel efficiency and higher power output.
  • Greater throttle sensitivity, which offers a quicker response to acceleration.

Fuel Injection Cons

  • Servicing and maintenance of a fuel injection system are expensive.
  • If the ECU fails, the entire fuel delivery system will fail, rendering your bike useless.
  • The replacement of fuel injection systems is expensive.

Which One Takes the Cake

Even though the advantages of a fuel injection system greatly outweigh the humble carburetor, the costs involved in repairing, maintaining, and replacing fuel injection can be quite a deterrent. Using poor quality fuel can damage a fuel injection system, which is a common cause for concern lately.

Carburetors, on the other hand, are reliable, inexpensive, and easier to maintain. A good practice could be opting for a carburetor for small capacity bikes, that is, less than 250 cc.

Conversely, if you are availing of a 2-wheeler loan to purchase your dream bike then throw in a little extra money and go all in for a fuel injection system.


Fuel Injection Vs Carburetor Which is Better in Bikes?

A carburetor may not be the best choice in terms of versatility. That's why it was phased out of the automotive industry in the 1990s.  For instance, a carburetor can not work in diesel vehicles, whereas a fuel injection can be used in both diesel and petrol vehicles (both electronic and mechanical).

Which Gives More Mileage Carburetor or Fuel Injection?

A carburetor can not properly measure the air-fuel ratio with changing air pressure and fuel temperature causing poor fuel economy and performance. A fuel injection system with electronic fuel induction can tweak fuel delivery and ensure the right amount of fuel is delivered to avoid fuel wastage. It gives better fuel efficiency and maximum mileage.

Is Fuel Injection Better Than a Carburetor?

Given the carburetor’s inability to measure and adjust air-fuel ratio as per the engine conditions, and its inflexible nature, it is not an ideal machine for your vehicle. While a fuel injection system offers better maintenance, and performance. It is used for both petrol and diesel vehicles in electronic and mechanical variations.

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