8 Reasons Your Motorcycle is Backfiring (Plus How to Fix It) 


Motorcycle exhaust pipes

Most people have heard a motorcycle backfiring. That loud popping sound that rings in your ears for a moment afterwards. If you’ve heard this sound first-hand, then you’ve come to the right place. When your motorcycle backfires, it could lead to you inadvertently damaging your motorcycle. 

There are many possible reasons that could cause a motorcycle to backfire, from broken spark plugs or clogged jets to an inadequate exhaust pipe. Luckily, most of the fixes for these issues are simple when you know what you’re looking for. By understanding the factors that lead to backfiring, you can stop and prevent it from happening. 

Here are the 8 reasons your motorcycle is backfiring:

  1. The carburetor is dirty
  2. The motorcycles jets are clogged
  3. The motorcycle is fitted with the incorrect exhaust
  4. The fuel filter is dirty
  5. Filling the motorcycle tank with low-grade fuel
  6. The motorcycle is using too much fuel
  7. The exhaust pipe is too short
  8. A faulty spark plug

#1 Your Motorcycle’s Carburetor is To Blame 

When your bike backfires, you should always check your carburetor first. Your motorcycle’s carburetor is used in the process of fuel transfer when you’re riding. If your carburetor is dirty, fuel will not be able to flow through it the way it usually does. This could result in backfiring. 

How to Fix It

The fix for this issue is rather simple, you just need to clean your carburetor to ensure that it can function properly and allow fuel to flow smoothly through it. To do this, you might want to use a carburetor cleaner. This reason is closely linked to the next one on our list – keep reading! 

#2 Your Motorcycle’s Jets are Clogged 

Your motorcycle’s carburettor consists of four different jets, which make it possible for you to ride your bike when you turn your throttle. However, over time as these become clogged with dirt and debris, they can malfunction, causing your motorcycle to backfire. 

How to Fix It

If this is the reason your motorcycle is backfiring, you’ll need to unclog the four different jets – namely the pilot jet, main jet, jet needle, and needle jet. To do this, you can use a specially designed carburetor cleaner, which usually has a spray can with a nozzle attached. 

#3 Your Motorcycle Doesn’t Have the Proper Exhaust 

One of the main reasons that motorcycles backfire is because some motorcyclists try to cut corners by purchasing aftermarket exhausts and not tuning the engine correctly. This is a bad idea, as it could result in your motorcycle backfiring. These aftermarket parts are advertised as enhancing the performance of your bike, but they often do the opposite! 

How to Fix It

The first fix is slightly obvious: try to stay away from aftermarket parts. It is always recommended that, when working on or repairing your motorcycle, you use parts from the original equipment manufacturer, also known as OEM parts. 

If you’re looking to fix this issue anyway, you’ll need to have your motorcycle tuned to suit the specific aftermarket exhaust you have equipped it with. Doing this can help prevent your motorcycle from backfiring, even if you insist on using aftermarket parts. 

#4 Your Fuel Filter is Dirty 

If your motorcycle’s fuel filter is dirty or too old, it could be struggling to handle its designated workload. This could result in your motorcycle backfiring, luckily the fix is a rather easy one! 

How to Fix It

To fix this, you should take a look at your motorcycle’s fuel filter. Once you assessed it and found it is, in fact, dirty and in need of replacing, you’re halfway there. By replacing this part your motorcycle will stop backfiring!

#5 You’re Using Low-Grade Fuel

When it comes down to your motorcycle, the type of fuel – and the quality thereof – really does make a difference. A common cause for the backfiring of motorcycles is the use of lower-grade fuel. The higher the quality of the fuel you use, the better your motorcycle’s engine will perform. The opposite is true too, the lower the quality, the more issues you’ll have. 

How to Fix It

By being mindful of the fuel you use and switching to a different fuel, you should be able to get your motorcycle to stop backfiring if it was caused by this. As we can see so far in this list, trying to cut corners to save some bucks can often lead to a motorcycle backfiring in different ways. 

#6 You’re Using Too Much Fuel 

Fuel is necessary for the combustion that takes place within your motorcycle’s cylinder. While the amount necessary for this to take place is substantial, you need to find the balance that’s correct for your motorbike

When you’re riding your bike, air and fuel have to be mixed in certain proportions. When these proportions are disrupted by, say, using too much fuel, you could potentially disrupt the combustion process. Not only could this result in backfiring, but it could lead to you inadvertently damaging your motorcycle’s engine. 

How to Fix It

To prevent that dreaded popping sound of your motorbike due to the incorrect amounts of oil, you should be mindful to only fill your bike with the right amount of fuel necessary to facilitate the combustion process.

If you haven’t used your motorcycle recently, you may need to clean the carburetor to ensure your fuel isn’t being tainted. 

#7 Your Exhaust Is Too Short And Doesn’t Fit the Legal Requirements 

Let me explain! Earlier in this article, we looked at the possible effects that aftermarket exhausts could have on your motorcycle. Another possible reason your exhaust could cause your motorcycle to backfire is that it is too short. In fact, there are laws designed to regulate the length of motorcycle exhausts to prevent motorcycles from backfiring, among other safety concerns. 

How to Fix It

As a general rule of thumb, you should ensure that your motorcycle’s exhaust pipe is at least 12 inches long. By doing this, you can safely rule out the possibility of a short exhaust pipe leading to habitual backfiring. This length will also be in line with a majority of the laws surrounding motorcycle exhaust pipe lengths across the world. 

If your exhaust pipe is not tight enough, this could also be a factor leading to your motorcycle backfiring. You should keep this in mind and monitor it over time.  

#8 A Faulty Spark Plug is to Blame 

If you have a faulty spark plug, it could result in bad ignition timing for your motorcycle. This, in turn, could result in your motorcycle backfiring. 

How to Fix It

Luckily, if a spark plug is to blame, it’s a quick and easy fix. However, that doesn’t mean you shouldn’t consider the above-discussed points as any less serious. Any of these issues could lead to your motorcycle backfiring, so it would be advantageous to be aware of these factors as they could lead to you damaging your motorcycle. 

Conclusion

Backfiring can unnecessarily damage your motorcycle and there are many possible reasons that your motorcycle has been backfiring.

By figuring out the reason, you can not only stop the backfiring from happening but prevent it from happening in the future.

From faulty spark plugs to aftermarket parts, we looked at all of the different reasons and how to fix them, so now that backfiring should become a thing of the past. 

Happy Riding!

Robert Blake

Hi, I'm Robert and I've been riding motorcycles for nearly 2 decades. The intention of this blog is to give reliable up to date information to other motorcyclists who are looking for answers about all different aspects of motorcycling. All the information is either from my personal experience or investigational work I have carried out myself. Happy Riding!

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