Signs Your Motorcycle Has an Exhaust Leak

Catching exhaust leaks is important for both you and your motorcycle’s health. For starters, exhaust fumes are highly toxic and lethal to humans, so if you think you have one, better take care of it immediately.

Motorcycles are designed for all of the exhaust to run down the headers and out the pipe, and to not escape further back in the chain. At the point of a leak, you can get extreme heat, since all of the hot gas in the cylinder gets pushed out at the leak point instead of having the heat distributed across the exhaust system. Motorcycle exhaust leaks can also cut power. The motorcycle can be sluggish since it’s tuned to have the gases move through the exhaust system and not re-routed out of a leak.

Motorcycle Exhaust Leak Symptoms

A leak at the header produces a popping sound when you start the motor. However, the sound might subside a bit as the motor heats up and the leak seals itself with heat expansion. But the bigger the leak, the bigger the sound.

Another way to detect an exhaust leak is to smell it. Motorcycle exhaust pipes help channel the fumes past you in the saddle, but if you’re smelling exhaust it could mean that gas is escaping before it should. One “hack” you can use to detect exhaust leaks is to place a paper towel around the header. The draft from the leak will move the paper towel.

What Causes Exhaust Leaks?

Older bikes and those with heavy use are more prone to exhaust leaks. The most common cause is pretty simple: loose bolts connecting the header to the engine. 

The motorcycle vibrates when it runs, it backs the bolts out, and presto! You have a leak. Bad gaskets can also cause leaks, so if you have a leak even after tightening the head bolts, check for worn or damaged gaskets and replace them.

Finally, corrosion can cause exhaust leaks. If your motorcycle has sat for a while, you can get small pinhole leaks across the exhaust system. Keeping your motorcycle clean and dry are your best defenses against this type of exhaust leak.