Explained: Carburetion VS Fuel Injection

Did You Know | 27 Jul 2018

Explained: Carburetion VS Fuel Injection

Fuel Injected motorcycles are fast taking over carbureted ones, which until the beginning of the new millennium ruled the roost. It wasn’t until 1980 that fuel injection made its way on a street going bike. As things stand today, almost every premium motorcycle comes equipped with an FI system. So while the good old grease monkeys still swear by the reliability, tune-ability and serviceability of carburetors, newer riders believe that fuel injection is better in every way. So how exactly are these two systems work? How exactly are they different and what are their respective virtues and vices? Let’s find out!

Carburetion

Carburetor is the most basic, and until recent times the most prevalent fuelling system used in two-wheelers, especially in India. To explain the basic working of a carburetor, think of it as a tube that feeds an air-fuel mixture into the cylinder from one end, with an air filter attached to another. Now, somewhere in the middle of this tube the air passage area is restricted to increase the velocity of the air passing through. This little area, or part of the carburetor system is known as venturi. By increasing the velocity of the air through the narrow area, a low pressure pocket is created, which in turn facilitates drawing fuel from a jet placed near the venturi through suction. This phenomenon is in line with Bernaulli’s principle which states that the velocity of a fluid (or air) passing through a tube is inversely proportional to the pressure created by it.

The amount of air sucked into the carburetor is decided by a valve at the end of the tube connected to the cylinder. This valve is termed as the throttle valve and is connected to the accelerator grip of your two-wheeler and controls the air-fuel flow through the throttle inputs provided by the rider. When you wring the throttle, the throttle valve opens – allowing a generous flow of air through the carburetor. Conversely, it’s closed when the throttle on the handlebar is fully rolled back.

The fuel jet, which is placed near the venturi draws its fuel directly from the fuel tank via a float chamber, which is a small reservoiur for fuel, with a float valve which cuts fuel supply when it’s full  and resumes it when the jet is drawing fuel from it. The resultant air-fuel mixture is then supplied to the cylinder where combustion takes place.

This is a very basic explanation of how a carburetor works, though modern carburetors including constant velocity or CV carburetors are generally more complex in design. These carburetors make use of components like a diaphragm, needle valve and pilot jet to control the air-fuel mixture. The important point to note here, though, is that this entire setup is rather simple and is fully mechanical with no electronics or sensors coming into play.

Fuel Injection

Unlike carburetors, a Fuel Injection system is comprised of a complex set of electronics and sensors. In carbureted systems the fuel gets drawn from the tank, while in a Fuel Injected system it depends on a fuel pump installed inside the tank for a fine-grained control over fuel flow. The fuel injection nozzle also goes directly inside the combustion chamber. The pressurised fuel is very well atomised as a homogenous mist in case of FI systems, allowing for very efficient and clean combustion.

The fuel supply in case of FI is controlled through an electric brain, or ECU, which constantly makes complex calculations at a very high frequency to deliver the best air-fuel mixture possible. Based on a whole variety of parameters such as engine speed, throttle position, engine temperature and load etc the ECU directs the injectors to let in just the right amount of fuel with every intake stroke to facilitate the most efficient combustion.

Now, while the efficacy of an FI system has been proven to be superior to carburetor, it’s not that the two systems don’t have their distinct advantages and disadvantages. Here, we will discuss the merits and pitfalls of the two systems in brief bullet points.

Advantages of carburetors

  • Carburetors cost less, are simple in operation and easy to repair or replace
  • Carburetors allow the users to tune them to their requirements
  • Since carburetors are not integrated into the engines, they can be serviced or replaced without touching the engine
  • Disadvantages of carburetors

  • Not the most efficient systems, dated design
  • Most carburetors have a slight lag, which results in relatively slow throttle response
  • Certain components like diaphragm are relatively delicate and prone to damage
  • Air fuel mixture fluctuates, affecting engine smoothness
  • Advantages of fuel injection

  • Optimised air-fuel mixture and atomisation allows for cleaner, more efficient combustion
  • Sharper throttle response
  • Better fuel efficiency and marginally more power than carbureted systems
  • They are typically maintenance free and does not break down
  • Disadvantages of fuel injection

  • Substantially more expensive than carburetors
  • Cannot be repaired with simple tools, have to be replaced, which is expensive.
  • Cannot be customised, unless you go for custom ECU maps, which again is expensive
  • So while the advantages of an FI system are pretty clear despite its cost, you’d still be one among millions who still put their faith in the good old carb. Which tech do you prefer, and why? Do let us know your opinions through comments below.

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    Comments (73)

    Oduvan4ikHads

    12 Jul 2021

    Oduvan4ikHads

    17 Jul 2021

    Shaikh mustaq Hasan muneer

    03 Aug 2021

    If we thought about future fuel injection system is good because the petrol prices increasing day by day. If people drive their bikes with rules and regulations then they will not face the problem of cost of fuel injection system.

    Kiran

    03 Aug 2021

    carburettors bikes are good.is e carburator bikes are low maintenance

    Douglas Makonya

    18 Aug 2021

    Thank you

    Oduvan4ikHads

    26 Aug 2021

    Error 523 [url=https://support.cloudflare.com/hc/en-us/articles/115003011431-Troubleshooting-Cloudflare-5XX-errors#523error]origin is unreachable[/url]

    ChristineHads

    03 Sep 2021

    ChristineHads

    03 Sep 2021

    Edmark Florentino

    29 Sep 2021

    Can help me to get a company job about automotive industry.

    Carburator

    30 Sep 2021

    Low price,simple

    Al Muntakim Anik

    11 Oct 2021

    I prefer FI engine, because it's sound is very good.

    Samson

    12 Oct 2021

    I prefer EFI system. because, once you buy the EFI system vehicle you will not run to the Garage for maintenance off course most of the spares are expensive than Carburetor but this one is efficient, get more power, fuel economy and easy to know the malfunction.

    J Sravani

    14 Oct 2021

    =D

    hykfeRKXa

    15 Oct 2021

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    15 Oct 2021

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    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

    Sithu Hpone Maw

    28 Oct 2021

    For me,I prefer the good old carburettor,since it is simplar than the FI system,it can be easily repaired too,btw thank you for the knowledge!

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    01 Nov 2021

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    29 Nov 2021

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    Rajib

    20 Dec 2021

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    28 Dec 2021

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    28 Dec 2021

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    08 Jan 2022

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    08 Jan 2022

    MOwbKnDip

    Subash kumar

    17 Jan 2022

    Mujhe bhi chahiye

    Subash Kumar

    17 Jan 2022

    Mujhe bhi chahiye

    Ranjit

    19 Jan 2022

    Nice

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    19 Jan 2022

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    19 Jan 2022

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    Samuel Muyodi

    24 Jan 2022

    Very much useful information

    Andrew Tafadzwa

    12 Feb 2022

    Very good

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    21 Feb 2022

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    21 Feb 2022

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    Kumaresan T

    03 Mar 2022

    Fuel Injection system is the best one. It reduces the fuel wastage which is most important for countries like our India. Thank you!

    ECDC

    06 Mar 2022

    I still prefer carburetor, because I can repair it myself in the garage.

    Rohit kumar

    14 Mar 2022

    Good

    Chandan

    14 Mar 2022

    My bike theft has taken placemeri bike chori ho gai 7.2.2022 ko

    AMAN YADAB

    21 Mar 2022

    I love to ride bikes equipped with F.I technology specially my love TVs Apache rtr 200 4V

    Rajesh Kumar

    04 Apr 2022

    TVS Apache RTR

    Srinivasan Reghuraman

    18 Apr 2022

    Thank you for the crisp article of how the two work. I think carburetors were not given a chance to evolve into versions that could overcome their shortcomings. A critical working part of the motorcycle has become unnecessarily expensive now.

    Oteje Adeniyi Samuel

    28 Apr 2022

    I prefer carburator, in much case injector engine can not be operating without battery while in carburator if battery fail you can use starting rope to operate the engine.

    SfsuCkGvhT

    03 May 2022

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    03 May 2022

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    Mainak Debnath

    04 May 2022

    Old is gold

    Zakir Khan

    07 May 2022

    ?

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    11 May 2022

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    11 May 2022

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    Deepak Kumar

    16 May 2022

    Super

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    17 May 2022

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    Lakhan

    24 May 2022

    Yes

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    30 May 2022

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    Mesfin Assefa

    07 Jun 2022

    I prefer injection type, because it can save full usage for long time until it need replaced.

    Deepu Singh

    12 Jun 2022

    Kuch nhi Chang hua fuel injector bekuf bna rhe ho sb log bina change kiye hi bta rhe ho

    Chris Carrier

    15 Jun 2022

    Great article, thank you.

    ARNOLD SAUNGWEME

    21 Jun 2022

    i like carb

    Ashraf ansari

    06 Jul 2022

    Hello

    Pratod Dixit

    20 Jul 2022

    I prefer Carb. Why spend Rs.10000 more if I as end user is not getting significantly higher mileage ? I am an inventor and have invented "password protection anti theft security for bikes" in 1995. Would be great if bike manufacturer implements password protection on bikes

    Ritesh negi

    25 Jul 2022

    Very bed bike apache 200 =%=%Frequent stops on the way

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    28 Jul 2022

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