Dirt Bike Backfires: 6 Possibles Reasons with Fixes

While riding a bike, if a dirt bike backfires, then it can increase a rider’s tension. But wait, being a rider, you should be ready for this and you must know the different causes with their solutions.

Backfire can be a result of a wrong mixing ratio of air-to-fuel that affects the emission system. Excess fuel or air can be the reason for your dirt bike’s backfiring. The heat produced at the exhaust causes fuel ignition, resulting in incomplete combustion.

Many people are there in this world. You do not like the loud sound, especially when it comes from a dirt bike, and it is so irritating that no one can stand it.

You will also not feel good when your bike backfires; then, the sound will trouble others.

I am sure that you are searching for this. Why does my Dirt Bike backfire on the internet to get rid of this? It is a great intention not to go the other people for fun and enjoy the adventure. Taking steps to resolve the issue and keep the bike in good condition will help you.

Now we will discuss the common issues why backfires happen on a dirt bike. But before that, we will know what precisely a backfire is. We have described it here if you don’t know in what condition you should change your clutch.

What is called a “backfire”?

Due to emission system malfunction in a dirt bike engine, a high level of the air-fuel mixture results in incomplete combustion. Thus heat of exhaust ignites the fuel. It is called a backfire.

Standard ignition happens inside the combustion chamber, and if there is no ignition, it means the engine will stop has an interruption.

The backfire explosion happens during the intake or exhaust, producing a loud sound which makes an irritating noise.

You can see a flame from the exhaust due to the partial compression. The rider can feel a jerk during the ride.

Suppose you are going for a ride on your lovely dirt bike, but a loud sound scares you. What was that? What kind of sound is your bike producing? These questions may arise in your mind; we are talking about backfiring. This article is about “Why Does My Dirt Bike Backfires?”. 

Before going deeply, you need to know what Backfiring is. If there is a high amount of air or fuel in the combustion chamber, this could lead to an explosion. But, if it doesn’t happen, your dirt bike starts producing noise.

All over, in a simple word, we can say that backfiring means the malfunctioning of the emission system due to the wrong ratio of the air-fuel mixture. Let’s see in detail what the causes of backfires are. 

What are the different reasons for backfire?

If you have a dirt bike and an emission system malfunctions, just like a leak in the exhaust running leech or running, Lean backfire occurs.

If the engine is running rich, then the consumption of fuel will be more than the air. And if the engine runs lean, air combustion will be more than the fuel.

In both cases, the result is incomplete combustion due to the improper ratio of the air-fuel mixture. In this situation, the fuel is ignited by the heat produced by the exhaust, which causes loud and irritating noise.

Stock muffler, assembled in the bike, is designed to ensure the complete and proper function of the engine.

If there is a difference in pipe design and other specifications, it can result in increased airflow to the bike, which causes the bike to fire in the exhaust.

Also, many different causes of backfire, like weak fuel pumps, clogged fuel filters, and low fuel pressure, all of these three of these issues directly affect the air-fuel ratio.

1. Backfire on Deceleration?

Backfires are a result of unburnt fuel clogging the exhaust pipe.

A high flow of fresh air increases the temperature of the exhaust pipe and can destroy those garbages and produce sounds as something explodes into the pipe.  

2. Dirt Bike Backfiring On Acceleration

There are a lot of reasons that produce backfiring on acceleration. The first and most common cause is the lousy ratio of air-to-fuel mixture that forces the ignition process to occur in the intake or exhaust.

It also happens when there is a leakage in the exhausting system or wrong catalytic converters. 

When the dirt bike starts backfiring on acceleration, its causes are low compression, leaks in the fuel tank or air filters, broken valves or damaged carburettor.

Check these parts one by one, and you will get the leading cause of Backfiring. 

3. Dirt Bike Backfire When Kickstarted

When starting your dirt bike, if it starts backfiring instead of running, what causes it to do so?

Suppose you start your dirt bike for the first time of the day, fuel mixtures take time to reach the combustion chamber, where these fuels burn and generate fires to start the dirt bike.

When you put on the valve, the air-fuel mixture slips towards the chamber to complete everything from burning to firing.

Still, if insufficient time is given to the process, very low amount fuels start burning in the chamber, and low fuel or mixture is one reason behind backfires.

To prevent backfires while kickstarting, wait 10-15 mins after putting the valve on; this much time is enough for the combustion. 

4. Dirt Bike Backfires When Trying To Kickstart

This problem is similar to the above issue. But the only difference is you are trying to kickstart. You must know that start your dirt bike with a kickstart; you need to wait for a perfect time to kick it.

It might be possible that you have forgotten to fill the air-fuel mixture or forgot to put it on the valve. In both cases, the dirt bike backfires.

You must want to know why this happens; when less mixture is present, one of the parts of the mixture reaches the exhausting pipe and produces pop sounds, which means it backfires.

On the other hand, the valve allows fuel to flow into the chamber; maybe you didn’t notice it. So, the previous burnt fuel coming out from the pipes backfires. Before trying to kickstart, check these two systems. 

5. Dirt Bike Backfire Through Carburator

We have already discussed that a lean running bike is a sign of backfiring.

When extremely lean carburettor mixtures are present in the bike, it causes backfiring. When this lean mixture flows, it burns slowly in the combustion chamber or can remain unburnt.

This unburnt fuel is inside the chamber until the next stroke is given to it, fresh fuel joins the chamber, and the previous one pushes out via exhausting pipes.

Here is the malfunctioning through carbs; replace this carb, or this could burn your whole bike. If it doesn’t work, carburettor monitoring the mixture ratio means backfires are not so far away. 

To prevent such backfires through the carb, remove the carburettor and then separate the float.

The next step is to remove jets and then put out outer parts to clean them with the help of a cleaner spray. 

6. Dirt Bike Backfires When Slowing Down 

If you are slowing down your dirt bike and hear a noise from the exhaust pipe, the bike backfires at that moment; when you slow down the dirt bike, more fresh air enters the exhaust system.

If there are unburned fuels present, air and unburned fuel react and become explosive material.

More air makes the explosion higher. The most common reason for backfires is also responsible for this problem. Fresh fuel mixture occurs in the engine, and old one threw out into the exhaust pipe where usually backfires happen. 

I’m suggesting you make sure your carburettor is working or not to supply a sufficient ratio of the mixture. Otherwise, such explosions keep disturbing you and damaging bike engines. 

Note:-In a simple sentence, if you keep cleaning your dirt bike regularly, backfires will never fall. As your body needs daily cleaning to prevent health issues, your dirt bike needs the same to avoid backfiring. 

Causes of Backfiring and Its Consequences:-

You learned about backfiring, and now it’s time to see its causes and harmful consequences.

You may notice your bike start running either lean or rich. If your dirt bike is running lean, the air is higher in ratio than fuel. On the other hand, if it’s going rich, it means the mixture contains more fuel.

So, always fill your bike’s tank with the correct ratio; otherwise, your bike could explode.

You can check this by yourself. Notice the carburettor and jets; you may find the causes of backfires; after that, don’t forget to clean them. 

You should know one more thing, like what happens if you ignore those noises and keep your bike the same.

Let me tell you, such steps are entirely foolish.

Initially, a single backfire occurs that’s not so dangerous. But keep your eyes on them and fix them quickly. There are other kinds of backfires where you can’t find them easily, such as silent tsunamis.

Always notice the combustion sounds; if it’s louder than usual, take your dirt bike to the mechanics immediately.

If you leave it, there are many cases where a bike catches fire, putting your life at high risk or the bike’s engine becomes useless. 

How to Prevent Dirt Bike Backfires

I think you got enough knowledge about ” Why Does My Dirt Bike Backfires”. Do you know how to handle it without any mechanical help? Yeah, we will see the crucial steps that may reduce or prohibit backfires. 

1. Maintain Air-Fuel Mixture & Its Quality- 

Dirt bikes already cost high amount. Once you have invested such an enormous amount, why do you need to deal with cheap fuel?

Whenever you fill the tank, make a perfect mixture. And if you are purchasing fuel for your dirt bike, don’t compromise just for a few amounts; it can lead to damage. 

You should also be aware of cleaners; use high-quality cleaners to keep dirt and junk away from the bike. And do it once a month. This step will help extend the lifeline of dirt bikes, and you might not hear those annoying sounds anymore. 

2. Cleanliness of Air Filter

Air filters are the most fundamental part of a dirt bike. Keeping a clean air filter will extend the life of your dirt bike.

Air filters restrict foreigners’ things from mixing with air fuel and keep engines safe.

While filtering the air, these filters collect dirt or mud on the other side, cleaning it all once in six months. Or if there is any damage, it’s better to replace it with the new one. 

3. Take Care of Carburetor Jets

The carburettor helps mix the air-fuel mixture in a good ratio and then supplies it to the combustion chamber. But, if something is clogged in it, it can cause backfires.

First, remove the carburettor and separate its bottom part, known as the float. Later, you will see a jet inside; remove it carefully.

Now the last step is to open up the outer parts with the help of a screwdriver. Once you have done the separating process, clean it one by one and reinstall it in the opposite removal process. Keep on cleaning carburetor jets once a month. 

If you do these three processes punctually, your bike will never face backfires. Here we are done with the common problem related to dirt bike backfiring. And now we have other issues too that backfire in different situations. 

Suppose you want to know the answer to this question before telling me one thing. Do you notice the speed of your dirt bike?

If your bike is running lean, then it causes a backfire during deceleration. When the engine fires, due to unbalanced mixing of air-fuel, unburnt gases or fuels produce fires in the exhaust pipe and result in backfires. 

Frequently Asked Questions [FAQ]

Is it bad for a dirt bike to backfire?Is it bad for a dirt bike to backfire?

Backfiring is not a good thing. It is harmful to the engine.

Running lean or rich is going to heat your engine more. If the engine runs in such condition exhaust will damage too.

Can a backfire damage an engine?

When you decelerate and excess oil is in the combustion chamber, it causes a backfire on deceleration. Backfire needs more fuel to be burnt, so it reduces the efficiency.

Is backfiring lean or rich?

Backfiring can occur either when the engine is running lean or rich.


So in this article, I have explained why a dirt bike backfires. I have also explained the different conditions when a backfire happens.

Here I have also discussed the causes of the backfire, and we have given you the steps to resolve this on time.

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