Ride your motorcycle long enough, and at some point, you’ll start getting a weird ‘popping’ noise coming from the exhaust.
This sound will probably be most noticeable when you roll off the throttle, or maybe even when you shift gears. And to many folks, this popping, crackling sound is actually pretty fun. It does give your bike a bit more character and personality than the exhaust note alone.
But did you know that this popping sound might harm your engine’s sensitive internal components? In fact, the seemingly innocuous sound might point to some pretty severe mechanical issues that need to be addressed.
Of course, they could just be an old bike showing its age, and you needn’t be that concerned. But how do you figure out if that is, in fact, the case? And what even is the popping noise in the first place?
And how exactly do you stop your bike’s exhaust from popping? Keep reading to find out.
Why is My Motorcycle Exhaust Popping?
Alright. So your motorcycle’s exhaust is making a weird popping noise. Before you get yourself all worked up, understand that a little bit of popping every now and again is perfectly normal and won’t cause any damage.
In most cases, your motorcycle’s exhaust pops when a little bit of unburnt fuel finds its way into the exhaust, mixes with fresh air at really high temperatures, and explodes. This doesn’t really affect your engine, and worst-case scenario: you are treated to a cool pop-pop sound every now and again.
But when your motorcycle’s exhaust keeps popping all the time, and the sound is really loud, you might have a bigger problem on your hands.
What Causes Really Loud Exhaust Popping?
If you notice your motorcycle’s exhaust popping and banging really loud all the time, there are a couple things that could be happening.
How To Prevent Motorcycle Exhaust Popping
Unburnt Fuel In The Exhaust
As mentioned before, this is the most common reason for a motorcycle exhaust popping. But if the popping noise is really noticeable to the point that it is getting annoying, it could indicate an excessive amount of fuel being ejected into the exhaust. This is more plausible if you have a motorcycle with a carbureted engine than a fuel-injected one.
In a fuel-injected engine, your bike’s ECU intelligently adjusts the air-fuel ratio as needed. In a carbureted engine, though, the process isn’t nearly as efficient, and some fuel is bound to get into the exhaust.
Alternatively, your engine may be running too rich, i.e., there is too much fuel and not nearly enough air for optimal combustion.
This is actually a pretty serious problem. In the short run, it causes a slight drop in power, and you might even get worse mileage than before. Further down the line, the sensitive internal components in an engine running too rich could experience excess wear and tear.
Fix: To fix this problem, you’ll want to get your bike tuned properly so that the air-fuel mixture is better suited to the engine. Interestingly, if you got a new exhaust and the engine wasn’t properly tuned to fit the new exhaust, it could be causing the popping.
Get your carburetor tuned, or get your ECU remapped, and the popping should go away.
Too Much Air In The Exhaust
Alternatively, if there is too much air in your motorcycle’s exhaust, it could cause the exhaust to pop and crackle. This is especially noticeable on motorcycles with aftermarket exhausts that allow for higher exhaust flow.
Specifically, aftermarket pipes that are shorter with wider openings are pretty susceptible to exhaust popping. Most modern motorcycle exhausts are designed to prevent air from outside from getting into the exhaust. But with some aftermarket pipes, especially shorter ones, you get a bit more air in the exhaust. This type of motorcycle exhaust popping will be most noticeable when you decelerate the bike.
Fix: Some aftermarket exhausts just make some popping noises that you’ll have to deal with. If the popping sound is too annoying for you and your bike is tuned correctly, we would recommend getting a different exhaust altogether. But there are some end caps and filters that go on the exhaust and prevent or at the very least reduce the amount of air going into it.
If you do end up going with the ‘new exhaust option,’ look for one that has a smaller opening, is a little bit longer, or both. Popping is more noticeable in high-flow exhaust systems, so get one that restricts airflow. You might get a slight drop in power, but such is the price you pay to eliminate popping.
Too Lean or Too Rich
If your motorcycle exhaust pops and backfires, it could be due to the engine running too rich or too lean.
These are terms used to describe different types of air-fuel ratios in the engine. If an engine has an overabundance of air and not enough fuel, it is said to be running too lean. Conversely, an engine that has too much fuel and not enough air is described as running too rich.
Both can result in your motorcycle backfiring or popping. But how do you identify whether your motorcycle is running too lean or too rich?
With running lean, your bike might not accelerate as well as it used to. Engine temps might also be higher than usual, and you will probably notice the popping noises most when you decelerate.
If your bike is running too rich, it will get noticeably worse fuel mileage and the exhaust pipe will become sootier. Similarly, the spark plugs may also have soot on them. You may even notice black smoke coming from the exhaust.
If you notice any of the above symptoms in your bike, you should get it properly tuned. If you are confident working on your bike yourself, feel free to do so. However, we always recommend getting a professional to tune your bike or remap the ECU.
Should You Be Concerned About Your Motorcycle’s Exhaust Popping?
Short answer: Not really. Long answer: Your motorcycle’s popping sounds are just a part of the overall engine and exhaust system’s functioning. They can be louder and quieter but shouldn’t cause you any concern unless they are absolutely deafening.
If you don’t mind the sound, you don’t have any problems…probably. If the issue is too pronounced and you notice other symptoms such as loss in power and speed or a dramatic decrease in fuel efficiency, getting your bike checked out is a good idea. But in most cases, you shouldn’t have any problems.
Exhaust Popping And ‘Blueing’
One (somewhat inadvertent) effect exhaust popping has on your motorcycle’s exhaust is the ‘blueing’ effect.
This happens because the gasses that actually pop in your exhaust do so at extremely high temperatures. This causes the metal to develop an oxidized layer that appears blue. Again, it’s a reasonably harmless effect associated with exhaust popping, and you don’t need to lose any sleep over it.
If you just don’t like the ‘blueing’ effect, check out this article where we explain how you can remove it from your motorcycle’s exhaust.