What is Fuel Injection System?

Published On 11-May-2020 08:29am , By Raihan Opu

Fuel Injection System is comparatively a newer technology to the Bangladeshi mass bikers. Over the years we used to get the fuel injection systems in the high-end 150cc performance motorcycles. But these days due to the emission regulations in many countries fuel-injected bikes are coming in good numbers in our country. Today we will talk about some of the key features of the Fuel Injection System.


In a fuel injection featured engine instead of a carburetor it has an electronically controlled fuel feeding system called Electronic Fuel Injection System. Here instead of a carburetor, the fuel injection is done electronically through injectors into the combustion chamber of the engine. Like any other bike, the air into the engine comes through the air filter & then through the intake manifold. Here the fuel is sprayed into the manifold through the injectors which are controlled by the Electronic Control Unit (ECU). The quantity of fuel & the injection timing is controlled digitally by the ECU.


The purpose of the ECU is to measure the engine temperature, oxygen level to burn the fuel, air intake, throttle response, & many other things which are measured through many sensors in a fuel injection featured bike. The fuel injection system is a high-tech system for us as we are used to riding 4-stroke carburetor motorcycles for the best part of 25 years. In fact, in the early days, we used to see Fuel Injection system in the bikes like Yamaha R15 series & Honda CBR series in common both of which are performance sport bike in the 150cc segment.

For the past 3.5 years, we can see the same system in bikes like the Yamaha FZS series. The fuel injection system has literally increased the capability & efficiency of the motorcycle engines in the 150-165cc category, which something you can feel if you have ridden the bikes on the hill districts of Bangladesh.

Yamaha FZS FI V3 Review

Let’s have a look at some of the advantages & disadvantages of the Fuel Injection System in the bellow mentioned clauses. PROS:

  • In the fuel injection system, the ECU unit calculates a precise amount of fuel & air mixture, so it ensures maximum fuel efficiency compared to a carburetor bike of the same category.
  • Engine vibration and knocking are reduced at a certain level, so the engine becomes more refined.
  • For low capacity bikes like 150-165cc, having the FI system helps to have a more comfortable ride while riding the bike on the hill tracks.
  • It is good for the environment as a Fuel Injected bike engine creates less carbon dioxide, carbon monoxide, nitrogen dioxide & other harmful gases.
  • No need to adjust the carburetor of the engine as the ECU of the bike itself does the précised measurement of fuel after measuring lots of parameters through its sensors.
  • No cold start issues. During winter we face the issue that we need to give many self-start before the ignition coil starts to operate with the Fi system in place that isn't a problem anymore.



  • It is a complex system so not every mechanic can work on it & you need special tools to clean the injectors and trained technician to do the job.
  • Fuel Injection System needs the best quality fuel available (at least RON 90). Bad quality fuel might not give the best feedback to the biker.
  • The fuel injection system is an expensive thing to service, repair, or further change but as with more & more bikes are coming in Bangladesh with Fuel Injection & companies like Yamaha Bangladesh now has around 61 service centre with offers the service & clearing of Fuel Injection system while 57 of those service centre has YDT( Yamaha Diagnostic Tools) for check-up of the engine.

fi service centre

The Bangladeshi motorcycle market is mostly dependent on the Japanese or Indian motorcycle market. Those two countries are working a lot on emission. Hence the government is pushing for the development of Fuel Injected motorcycles to make those more fuel-efficient & at the same time making the engines less harmful for the environment.

Also Read: Check Yamaha Showroom 

Currently, some of the 110-125cc bikes have been launched with FI-System in India due to BS-VI emission regulations, something which might also come in Bangladesh in the near future. so, although an expensive technology currently in the near future most bikes in Bangladesh might come with Fuel Injection System with it.

Published by Raihan Opu