Beginning 1 April 2020, India will move from Bharat Stage IV (BSIV) to Bharat Stage VI (BSVI) emission norms to mitigate the rising pollution in the country. The move from BS4 to BS6 emission standards are so strict that the mechanical changes to two-wheelers or bikes are far more extensive. The BS6 emission norms are so extreme that accurate fuelling is important. Most bike manufacturers have ditched the affordable carburetor to a more precise, but expensive fuel-injection system.

Difference Between Fuel Injection and Carburetor in Bikes - Acko

However, what is the difference between fuel injection and carburetor in bikes? In this article, learn about the different fuelling systems of bikes.

Difference Between Carburetor and Fuel Injection:

Since the invention of the internal combustion engine, automobile engineers have strived to find effective ways to deliver air and fuel to the combustion engine. The device which controls the ratio of air-fuel mixture entering the engine is known as a carburetor, a fuel injection system also does the same. Then what is the difference between carburetor and fuel injection?

In simple terms, a carburetor helps the air-fuel mixture to enter the combustion chamber. All this is done through mechanical parts. The fuel injection system also helps the combustion chamber to get air-fuel mixture, but with the aid of electronics and sensors, and not through mechanical parts.

Carburetor Engine: How Does It Work

The only or primary job of a carburetor is to mix fuel and air in a certain ratio and feed it to the combustion chamber. The device intercepts the flow of air to the combustion chamber, mixes fuel and delivers it to the engine. When the throttle of the bike is squeezed, the airflow to the carburetor increases causing suction of air and the delivery of fuel increases accordingly resulting in increased acceleration.

In technical terms, think of the carburetor as a tube that regulates or rather restricts the fuel delivery to increase the velocity of the air. This part which restricts the fuel is known as Venturi. With the increase in velocity of air, a low-pressure space is created, which facilitates drawing of fuel from a jet located near the venturi. This creates a concoction of air-fuel mixture that burns inside the combustion chamber. This is known as the Vacuum Venturi Effect.

Advantages of Carburetor:

While fuel injection systems may have replaced the conventional carburetors, there are advantages of carburetors as well. Below are the advantages:

  • They are less expensive and can be easily repaired or replaced.
  • Users can tune the carburetor according to their requirement, more power or more mileage.
  • Made of light materials and hence are generally long-lasting.
  • They are integrated separately from the engine, hence they can be easily removed and serviced or replaced without impacting the engine.

Disadvantages of Carburetor:

Some of the reasons why carburetors have made way for fuel injection systems are due to its disadvantages. Here are the disadvantages of a carburetor:

  • Not fuel-efficient as a fuel injection system.
  • There is a certain amount of lag resulting in a slow response from the throttle body.
  • Carburetors parts are prone to wear and tear which requires frequent replacements.
  • The mixture ratio of air-fuel might not always be the same and needs to be tuned regularly.
  • Possibility of dust entering the carburetor’s chamber resulting in blockages.
  • Diaphragm components are delicate which can be prone to damage easily.

Also, read: Top 15 Reasons to Ride a Bike

Fuel Injection (FI): How Does It Work

Fuel injection system comprises a complex set of electronic components and sensors. The system depends on a fuel pump to control the flow of fuel to the combustion chamber. This fuel pump is located inside the fuel tank of the bike. The supply of fuel to the combustion chamber is enabled through an Electronic Control Unit (ECU). This electric brain constantly monitors and makes complex calculations to deliver the best possible air-fuel mixture.

The complex calculations include parameters such as throttle position, engine speed, engine temperature and load, among others. The nozzle of the fuel injection system goes right into the chamber of the cylinder. Hence, the ECU directs the injectors to control the amount of fuel to enable the most efficient mode of combustion.

Advantages of Fuel Injection:

Here are the advantages of fuel injection system on bikes:

  • Accurate air-fuel mixture and atomisation.
  • Cleaner and more efficient combustion.
  • Sharper and quicker throttle response.
  • Better fuel efficiency or mileage.
  • Compared to carburetors, FI systems are maintenance-free and less prone to damages.
  • Can easily be tuned through ECU mapping.

Disadvantages of Fuel Injection:

However, fuel injection systems also have disadvantages. Here are some of the advantages of FI:

  • Expensive compared to conventional carburetors.
  • Requires complex tools to tune the FI system through custom ECU mapping.
  • Needs expensive tools to repair it, which leads to higher costs.
  • If the ECU fails, the bike will not start and you might be left stranded.

Also, read: Tips to Get Maximum Fuel Efficiency from Your Bike

Carburetor Vs. Fuel Injection Engine in Bike: Which is Better

You might be wondering which is better when it comes to comparing carburetor vs. fuel injection in bikes. Below are some of the differences between the two:

  • Versatility: Carburetors are phased out since they are comparatively more pollutant compared to FI systems.
  • Performance: The ECU is constantly working on complex calculations to offer the best performance of the engine. The carburetors struggle when it comes to ever-changing fuel temperature and air pressure.
  • Mileage: FI system provides an accurate measurement of fuel and air resulting in higher performance of the engine which leads to better fuel management and mileage. The ECU can be mapped for a higher power ratio if you require.
  • Maintenance: This is the only category where the carburetor is better compared to the fuel injection system. Carburetors can easily be repaired or replaced while FI systems require professional help which can lead to higher costs.

So, which is better? Fuel injection has an upper hand when it comes to performance, fuel efficiency, and better throttle response. While the FI system may cost you more, the long-term aspects of the FI system are better than a carburetor. That said, old school auto enthusiasts swear by the carburetor technology as they like to fiddle and work on them to derive the required results.

FAQs About Carburetor and Fuel Injection System:

Below are some of the frequently asked questions about carburetors and FI system:

Why has the fuel injection system replaced the carburetor on bikes?

The biggest reason is that the FI system is less pollutant compared to carburetor technology apart from being fuel-efficient, and offers better throttle response and overall performance from the engine.

Do bikes with fuel injection require two-wheeler insurance?

Whether you are an old school auto enthusiast or modern electronic believer, two-wheeler insurance is required to protect the bike against any unforeseen circumstances.

Which gives more mileage carburetor or fuel injection?

Fuel injection system makes complex calculations which include fuel temperature, throttle response, etc to ensure the right amount of fuel is injected into the combustion chamber. This way the use of fuel is a lot more effective resulting in better mileage.

Can I get higher power through the FI system?

Yes, you can map the ECU to get the most of the power from the bike’s engine; however, this requires professionals and the mapping kits are usually expensive.

What are the signs of fuel injector failure?

Some of the signs that indicate a FI failure are starting issues, poor idling and performance, increased fuel consumption, engine not reaching the intended RPM (Rotation Per Minute) and increased smoke from the exhaust are some of the signs that your FI system is having trouble.

Related Articles:


Read informative Two Wheeler Insurance Articles at Acko.

Read all our insurance & non insurance related articles here.