If you own a motorcycle, sooner or later, your bike will develop an exhaust leak at the header.
Exhaust leaks in the header area can be caused by a variety of factors, so it’s important to know how to diagnose and fix the problem – especially since exhaust leaks can even damage your engine.
In this article, we’ll show you how to identify and fix an exhaust leak at the header of your motorcycle.
Most Common Symptoms of an Exhaust Leak at Header on Motorcycles
There are several symptoms that may indicate you have an exhaust leak at the header. Here are the most common ones.
1. Loud Ticking Noise
Most motorcycle exhaust leaks happen in the area where the header meets the cylinder head.
You can quite easily tell whether that’s the case by simply listening for a distinct ticking noise around the area.
Now, the valvetrain is also producing a ticking noise, but an exhaust leak has a lot more bass to it. So, if you hear a deep ticking noise coming from your motorcycle’s header, it’s most likely an exhaust leak.
2. Backfiring on Deceleration
Another symptom of an exhaust leak at the header is backfiring on deceleration.
An exhaust leak at the header allows for outside oxygen to enter the exhaust stream in between pulses.
Normally, unburnt fuel won’t ignite inside the exhaust since there’s not enough oxygen, but with an exhaust leak at the header, the exhaust stream gets enough oxygen for unburnt fuel to combust and create a crackling and popping sound on deceleration.
3. Reduced Engine Power
The final symptom of an exhaust leak at the header is reduced engine power.
An exhaust leak can cause a loss of power in two ways. First, it can cause a loss of backpressure.
Backpressure is what helps scavenge the exhaust gases out of the cylinder and plays an important role in the engine’s efficiency. When there’s an exhaust leak at the header, backpressure is reduced and engine power is decreased as a result.
The second way an exhaust leak can cause a loss of power is by allowing outside air to enter the engine.
This throws off the O2 sensor readings and can cause the engine to run lean, which also reduces power.
How to Find a Motorcycle Exhaust Leak at the Header
Finding exhaust leaks at the header is quite easy. All you really need is a rag, and soapy water (optional).
- Make sure that the engine is cold.
- Start the engine and ask someone to plug the exhaust with a rag.
- With the exhaust plugged, feel for exhaust leaks with your palm, or listen for them.
- Additionally, you can spray soapy water around the headers and look for bubbles.
How To Fix Exhaust Leaks at the Header
In most cases, an exhaust leak at the header is caused by a blown exhaust gasket or loose bolts. Here’s a quick step-by-step guide on how to fix them.
1. Replacing a Blown Exhaust Gasket
If the exhaust gaskets are the reason for the exhaust leaks, then they need to be replaced.
Start by removing the header bolts and taking the header off.
Once the header is off, take a look at the exhaust gaskets. If they’re blown, then you’ll need to replace them.
To do that, simply remove the old gaskets, clean the mating surface and install new ones with a wire brush or fine sandpaper.
Once the new gaskets are in place, bolt the header back on and you’re good to go.
2. Tightening Loose Bolts
Another common reason for exhaust leaks at the header is loose bolts.
To fix this, simply try tightening the header bolts with a wrench or a ratchet.
If they really are loose, then it’s best to tighten them to factory specs using a torque wrench.
3. Fixing a Cracked or Corroded Header Pipe
If the exhaust leak at the header is caused by a crack or corrosion, then the only way to fix it is to replace the header pipe or weld it.
Replacing the exhaust pipe is the easier option, but if you’re on a budget, then welding it is the way to go.
Welding an exhaust pipe is not as difficult as it may seem. If you have a welder and some experience, then you should be able to do it yourself.
If not, then it’s best to leave it to a professional welder.
Final Thoughts
An exhaust leak at the header can cause all sorts of problems, from increased noise to reduced engine power.
Luckily, they’re relatively easy to find and fix. In most cases, an exhaust leak at the header is caused by a blown exhaust gasket or loose bolts.
To fix it, simply replace the gaskets or tighten the bolts.
If the header pipe is cracked or corroded, then you’ll need to replace it or weld it.
Welding an exhaust pipe is not as difficult as it may seem, but if you’re not confident in your abilities, then it’s best to leave it to a professional.
Have you ever had to deal with an exhaust leak at the header? Let us know in the comments below.

Nick Kowalski is a diesel mechanic by trade, but his passion lies in motorcycles.
He’s been riding them since he was just a wee lad, and he loves restoring old Japanese street bikes and ATVs in his spare time.
Nick is an adrenaline junkie at heart, and he loves nothing more than hitting the open road on his motorcycle.