Skip to content

How To Check for Motorcycle Exhaust Leaks – A Quick Guide

You know that feeling you get when you’re cruising down the highway on your bike, wind in your hair and sun on your face?

It’s a great feeling. But what’s not such a great feeling is when your bike becomes sluggish and starts backfiring due to an exhaust leak.

An exhaust leak will reduce horsepower and make your motorcycle backfire on deceleration. While that doesn’t seem bad, ignoring an exhaust leak for a long time could lead to burnt exhaust valves and pistons in severe cases.

To help you avoid that, we’ll show you how to check for motorcycle exhaust leaks.

How To Check for Motorcycle Exhaust Leaks

For this how-to, we’ll be using a shop vac with a blower function. This is hands down the best way to check for exhaust leaks, but if you don’t have a shop vac, then you can do it the old-school way.

How To Check for Motorcycle Exhaust Leaks With a Shop Vac

If you have a shop vac with a blower function, then this is the best way to check for exhaust leaks.

1. Make sure the engine is cold.

2. Insert the Shop Vac hose into the exhaust and make it air-tight.

3. Turn on the shop vac’s blower function to pressurize the exhaust system

4. Spray soapy water around the exhaust pipe (especially near cylinder head) and look for bubbles.

5. If you see any bubbles, then you have an exhaust leak.

Over 90% of exhaust leaks on motorcycles are due to a blown exhaust gasket or loose header bolts. They’re exposed to really big temperature changes (from being right next to the engine) and they’re constantly being bombarded with vibration, so it’s not surprising that they fail.

If that’s the case, then you’ll have to replace the exhaust gasket or simply tighten the exhaust bolts – both are extremely easy to do and cost next to nothing.

How To Check for Motorcycle Exhaust Leaks Without a Shop Vac

If you don’t have a shop vac, then you can still check for motorcycle exhaust leaks, but it’s not going to be as accurate.

1. Make sure the engine is cold.

2. Ask someone to hold the exhaust plugged with a rag.

3. Start the engine.

4. Quickly spray soapy water around the exhaust or feel for exhaust leaks with your hand.

5. If you see any bubbles or feel any exhaust leaks, then you have an issue that needs to be fixed.

motorcycle exhaust header leak

As we mentioned before, over 90% of exhaust leaks on motorcycles are due to a blown exhaust gasket or loose header bolts, so make sure to check there first.

Most Common Motorcycle Exhaust Leak Symptoms

In case you’re wondering, here are the most common motorcycle exhaust leak symptoms:

1. Ticking Noise

A distinct and rather loud ticking noise is probably the most common symptom of an exhaust leak.

motorcycle exhaust header

If that’s the case, then it’s very likely that the exhaust leak is located at the area where the header meets the cylinder head.

The constant tick-tick-tick noise is caused by exhaust gas pulses escaping through a small hole.

2. Black Soot Deposits

If the exhaust leak has been there for a while, then you’ll probably see black soot deposits around the point of the leak.

Though, it’s pretty difficult to spot them if the leak is at the exhaust gasket.

3. Backfiring on Deceleration

Exhaust leaks at the header usually make the engine produce crackling and popping noises on deceleration.

This happens because an exhaust leak allows fresh oxygen to enter the exhaust stream in between exhaust pulses, and that fresh oxygen allows for unburnt fuel in the exhaust to combust.

4. Reduced Horsepower

If your motorcycle has an O2 sensor, then an exhaust leak can definitely throw off the sensor’s readings and cause the engine to run lean.

This will result in a loss of power and reduced performance.

Final Thoughts

As you can see, checking for motorcycle exhaust leaks is actually pretty easy and only takes a few minutes.

If you do find an exhaust leak, then make sure to fix it as soon as possible because it can lead to some pretty serious engine problems down the road.

We hope this article has been helpful and if you have any questions, then please feel free to leave a comment below.

Ride safe!

Leave a Reply

Your email address will not be published. Required fields are marked *