If you ride on dirt bike trails in the United States, you may have noticed that in many places, you are required to have a spark arrestor in order to ride your bike on the trail.
However, there may be a bit of confusion as to what a spark arrestor actually is and what it does to your dirt bike!
Not to worry, here’s an in-depth rundown for what you need to know:
A spark arrestor is a screen-like device that fits into the tailpipe of your bike to prevent sparks from coming out.
Considering all the forest fires that happen and how ravaging they can be, you can imagine why most trails require having a spark arrestor on your bike! In the right conditions, all it takes to start a fire is a single spark.
How to see if your bike has a spark arrestor
Checking to see if your bike has a spark arrestor is really simple – you just need to take a look! Most newer bikes have them pre-installed. You’ll be able to read on or around the exhaust pipe whether there is a spark arrestor or not.
If you are unable to see any indication on the outside, you can shine a flashlight inside or use a screwdriver to gently feel around and see if you can feel a steel mesh/screen.
If you bought a used bike, the previous owner may have removed the spark arrestor so it’s a good idea to know whether or not you have one installed or not.
Do you need a spark arrestor?
Not necessarily, but if you take your bike onto federal lands and trails, you do need one to stay compliant. The United States requires that all internal combustion engines have spark arrestors fitted if they are operating on federally managed land.
Additionally, it’s a good safety precaution for preventing forest fires. Remember, all it takes is a spark.
Where does the spark come from?
You may be wondering “I’ve never seen sparks come out of any exhaust pipes before!”
What the spark arrestor is actually preventing is tiny particles of carbon that may become stuck in the engine. In newer and well maintained engines, you won’t see any sparks because the whole combustion process is very clean and all that comes out are the exhaust gases.
In older engines or less maintained ones, tiny deposits of carbon may begin to form on the insides. During the combustion process, these bits may get dislodged and fly out of the exhaust pipe with the rest of the gases.
At that speed and temperature, they can catch on fire – they are bits of carbon after all – and appear as a spark.
The wire mesh inside the exhaust pipe prevents any such particles from exiting the exhaust pipe.
Spark arrestors and performance
There’s a bit of debate in the ATV and dirt bike community whether or not removing the spark arrestor increases performance since air is able to exit the exhaust pipe just a tiny bit faster since it has no mesh to add drag.
The general gist of it is that you’re not going to really see any meaningful gain or loss in power – the most you’ll see is about 1 HP. If you ask me, that 1 HP is not really worth the risk of starting a wildfire!
If you really want to increase performance, you can install an aftermarket exhaust system that is more powerful even with a spark arrestor attached.
Another area where you may notice some difference is the sound of your engine. Removing the spark arrestor will increase the sound of your engine by a couple of decibels.
Some people like noisy engines – it’s like leaving your mark on the air! Others may prefer to have more discrete sounding engines.
How to clean a spark arrestor
There are two types of spark arrestors – mesh style and disc style. If they get clogged, they can seriously dampen the performance of your engine because they’re now blocking a lot more airflow.
To clean the device, simply remove it and scrape or burn the debris off. If you’re using a mesh style arrestor, it’s pretty straightforward.
With a disc style arrestor, you’ll need to take apart the discs and clean them all one by one. Otherwise you won’t get the performance you’re looking for.
Additionally, if your exhaust pipe is not working fast enough the gases have to go somewhere, and that causes other safety concerns and issues.
At the end of the day it’s a good idea to keep the spark arrestor in, or if you don’t have one, to install one. They’re really cheap on Amazon and the reduced wildfire risk of having one is far better than the slight performance boost you may or may not see from removing it.