Why does my dirt bike exhaust red hot

The problem of red hot exhaust is very common in dirt bikes. But don’t worry I have more than one solution for this. So if the question why does my dirt bike exhaust red hot then your tension is going to be finished withing this post.

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A glowing red hot exhaust means that the engine is getting very hot and the engine requires cooling. There are not some specific tools for fixing the problem.

Suppose, you have gone for a long relaxing ride on your dirt bike but when you come back, you find that the exhaust of your dirt bike is glowing very red and hot. So, many beginners thought that whether it is normal or not.

Usually a red glowing exhaust is the indicator of high temperature and fire. A dirt bike will generate a lot of heat and temperature when you ride it beyond its limit.

This heat will be generated initially with its over performance. The heat will start moving to the exhaust system of the dirt bike when the dirt bike produces more than enough heat.

Why does my dirt bike exhaust red hot

What is the meaning of glowing red hot exhaust in your dirt bike ?

A glowing red hot exhaust means that the metal is receiving more heat and which is approximately enough to reach its melting point. But the metal will not melt because this requires a good amount of heat more than the point from where it starts glowing red.

There are mainly two types of metals one stainless steel and the other is non-stainless steel.

Stainless steel will glow at a much lower temperature in comparison to the non stainless steel. You can use the temperature gauge for the accurate measurement of the temperature. You cannot determine the actual heat just by seeing the color of the exhaust. In day time, the exhaust will look like dark red but in the dark it appears like bright orange.

Does a glowing red hot exhaust always means wrong ?

Let me clear you that a glowing exhaust for sometime is normal on many dirt bikes. You may have pushed your dirt bike enough so it has started glowing.

It is normal to glow because of being hot. It will damage the functioning of your dirt bike. But when the exhaust glow beyond its limit, then it needs diagnosis. Thus you need to contact your dealer about this problem and take effective advice on this issue.

A bright red orange color of the exhaust is a good indicator of the upcoming problem. Let’s discuss about the causes of glowing red exhaust.

Cause no. 1 – Your dirt bike is running too lean

When the mixture of air and gas is not proportional and the amount of air is more than the amount of gas then it means that the bike is running on lean. This unbalanced situation cause a furnace effect.

A bike running on lean will cause the exhaust glow. An abnormal glowing can cause the exhaust melt. It can cause a hole in your piston.

If you do not know the precaution of this problem then you will end up this by seizing the piston of your dirt bike. A bike running on too lean is the major cause of a glowing exhaust of a dirt bike.

How to check that the bike is running too lean or rich?

We have several methods to diagnose a running problem. When the bike makes loud and popping sound the popping of the dirt bike is often called as backfiring.

If you don’t know about it then you must go through the article why does a dirt bike backfire.

When the Popping is beyond normal situations it requires proper diagnosis. Backfiring is the clear sign of running too lean.

The other condition of telling whether the bike is running too lean or not is by checking that bike is taking many seconds to get in its idle position or not. You can also inspect the spark plug for diagnosis of running lean.

It is more mechanical approach when the bike is running on too much lean, you will notice that the spark plug is started melting. For removing a spark plug, always use gloves because it can be very hot.

A dirt bike might run on lean because of dirty carburetor or jets. You can start cleaning the carburetor for removing the chances of being damaged.

You are advised to lean the Jets individually for better cleaning. There are many tools in the market to clean the Jets like spray cleaner, a copper brush etc.

You clean the all passages for a good cleaning. I can also face running lean if the Jets are not ideal. You can also change the Jets by a large size for increase level of fuel.

Your glowing exhaust can improve by the change of jets. A proper Jet kit is available online. Cracked vacuum lines also might cause running lean. Repair the vacuum lines as early as possible. They are very cheap to replace as well as easy to inspect visually.

Cause no. 2 – When the exhaust valves are dirty, damaged and poor in condition

At the time of running of the engine, the exhaust valves perform very important job of closing at the time of ignition and then is to open for letting the exhaust gases out on the next stroke. There are chances of building carbon residue on the valve head, that makes the seal in tight.

This will cause the hot air and flames to exit by the gap from the explosion. This is the reason of a glowing exhaust.

A glowing exhaust is also possible when the valves are poorly adjusted and damaged. The cylinder head is responsible for cleaning, inspection and adjustment if all of these measures would not work then it is the time to call a mechanic. For testing the quality of valves, a compression tester is advised to be used if you want to check the condition of valves accurately, I will recommend you to perform a leak down test.

Cause no. 3 – Exhaust leak

Lower back pressure due to the exhaust leaking before existing the system can cause the bike to glow hot.

Find and check the clamps, do not gaskets for pipe whether it is damaged or not. Repair or fix the issue to see if the issue is finished or not.

Cause no. 4 – Aftermarket exhaust headers or exhaust systems

Different materials are used for making aftermarket exhaust systems and headers. A system made up of stainless steel will glow more in comparison to non Stainless exhaust systems.

Thinner walls are used to lessen the weight. This will result in more glowing and allows more heat. You can also use in aftermarket system for a good exhaust flow.

By using after market system, heat will exist the system more faster. This will make the system much cooler than the previous system temperature.

Cause no. 5 – No airflow on standing still

The exhaust will cool down by the passing of air when you move. When the bike is in idle position, there will be no air moving around the exhaust there will be no cooling.

No pressure of air will make it harder for the exhaust to cool down. This is same in the case of header too. When the bike produces more heat while running then you may find the exhaust glow getting worse. So when the exhaust glow at the time of standing still then it is because of little cooling.

Cause no. 6 – A clogged pipe

If the pipe is clogged somewhere in the exhaust system then there will be restricted air flow. It will create excessive pressure at the back and the excessive pressure will create more heat. So fix the clogged pipe as early as possible.

It is very easy and chipped. you should troubleshoot before checking something else in the system. check the end of the rear muffler.

A dirty spark arrestor should be cleaned because it can restrict airflow also for some other debris in the clogged pipe. While riding the dirt bike it is common for the engine to stop due to debris. It is required to reassemble every part of the dirt bike.

If the bike standing still for sometime you also need to exhaust for critter. Check for the mouse because they like dark places when they are going to give a birth. You can also find birds nest in the strangers places at the springtime.

Extra Large stucked mufflers are fitted into the bike to reduce the sound emission.

Cause no. 7 – Bad thermostat

This is not a common reason for a glowing red hot exhaust. The thermostat should be check for lowering the issue. A good thermostat will have the system in cooling down through the radiator.

Thermostat are easy to replace and cheap in cost. So don’t hesitate a new thermostat for a dirt bike. The coolant will keep the temperature of the engine low.

There are some other reasons of glowing exhaust to like:

  • Something disturbing in the intake process of air flow
  • A weak or intermittent spark
  • Winter season
  • Wrong types of spark plugs etc.


A dirt bike exhaust can red hot and I have shared many issues for this. So with all the necessary reasons of a glowing hot exhaust you can easily identify it. By taking precaution you can avoid it too.

Have a Safe Riding, Thank you!

Sources: thumpertalk exhaust red hot, Exhaust_system