Your Stihl chainsaw’s spark arrestor plays the vital role of catching sparks and preventing accidental fires as you use the tool. Over time, however, carbon and other debris can build up on the arrestor, negatively impacting the motor. So how do you remove the spark arrestor from a Stihl chainsaw?
You can remove your spark arrestor from a Stihl chainsaw easily with a screwdriver and pliers. An arrestor can be removed and reinstalled in a matter of minutes. However, there are instances where you may need to replace the part entirely.
If you’ve never removed an arrestor before, it can seem intimidating at first. But don’t worry! We wrote this piece to share the straightforward steps to get the job done quickly and correctly. So get ready to dirty your hands and remove your Stihl chainsaw spark arrestor!
How Does the Spark Arrestor Work?
If you’re unfamiliar with the inner workings of your chainsaw, the spark arrestor might be unfamiliar to you. It’s a small screen placed inside the unit, just behind the muffler. As the name suggests, it catches the sparks that result from engine combustion, significantly limiting what would otherwise be a significant fire hazard while protecting your hands from burns (source).
Over time, carbon inevitably builds up on the screen, preventing air circulation (source). In addition, dirt and debris that get inside the tool can speed up this process. If it becomes clogged, it poses a significant fire hazard in addition to slowing the motor.
While staring into the engine of a chainsaw can feel like open-heart surgery, the arrestor is pretty easy to remove. The simple component is kept in place with a small metal frame, which in turn is held by a single screw. These three pieces are all that make up the arrestor, and short of mishandling one of them, you’re unlikely to damage them through normal use.
How To Remove the Spark Arrestor
Here are three simple steps to help you remove the spark arrestor from your Stihl chainsaw:
1. Wait for the Unit to Cool Down
Before attempting to remove any part of a chainsaw, especially a spark arrestor, you need to ensure that the unit has cooled. Simply turning it off is not enough: the internal components could still be hot enough to burn you. Once you’ve shut the chainsaw down, let it sit for at least half an hour before you start.
2. Remove the Arrestor Cover
First, find the screw holding the plate that covers the arrestor. It’s behind the muffler, in the back of the unit, just behind the handle. Depending on your Stihl model, there may be a grate covering this section, but you should still be able to reach the screw through it.
After placing the screw somewhere safe, remove the covering. Depending on the condition of your chainsaw, the cover may be stuck in place (another possible side effect of internal buildup). You should be able to wedge it open with a flathead screwdriver or a similarly small, pointed tool.
3. Use Pliers to Remove the Screen
At this point, the screen should be visible, so gently grab one of its edges with a pair of needle nose pliers or gently pop it up with a screwdriver. If using pliers, avoid applying too much pressure on the screen. Though they are resilient, you may accidentally sever the mesh.
When you’re ready to reinstall the arrestor, just follow the above steps in reverse. Pay close attention when putting the screen back in place. Make sure that the piece fits so that it doesn’t come loose on its own.
When Should I Change a Spark Arrestor?
It all depends on how frequently you use it. That being the case, you should change it the moment you notice the engine has weakened, which results in a quieter sound and fewer rotations of the blade per minute. However, waiting until the symptoms are apparent could prove dangerous, so it’s best to regularly check the arrestor as part of your maintenance routine.
When it comes to cleaning it, you have a few options. First, if the clogging isn’t severe, you can gently wipe it away with a wire brush (source). Doing this regularly can prevent buildup from reaching the point where it’s harmful to the engine.
In severe cases, you can use a blowtorch. Since the buildup is partially combusted carbon, a blow torch will reduce it to ash, which you can then remove with a wire brush (source). If you choose to go this route, it’s recommended that you do so outdoors, holding the arrestor away from you with a pair of pliers.
Of course, when you reach the point where you need to use a blowtorch, it’s easier (and safer) to replace it with a new arrestor. It’s essential to find one that matches your specific make and model.
Does My Chainsaw Need a Spark Arrestor?
Every chainsaw includes a spark arrestor as a safety precaution, but there are those who wish to leave them off entirely. Doing so allows more air into the engine, which causes it to burn more fuel and gives it more power. While that sounds nice, the benefit doesn’t outweigh the fire risk.
There’s also a matter of law you have to contend with. In the United States, local and federal laws establish the need to use spark arrestors in specific locations and situations (source). Failure to follow these laws can lead to hefty fines.
While getting more power from the motor has its obvious upsides, it’s not worth the harm or potential punishment. If you feel that a project you’re undertaking requires a stronger chainsaw, it’s better to find one than to modify what you already have.
If you come to own a previously used chainsaw, it’s vital that you check that the spark arrestor is present before using it. Even if everything else functions normally, that missing piece could leave you in a terrible situation.
If you have a Stihl chainsaw that doesn’t have a spark, you need to replace the ignition module. Read my comprehensive guide to learn more about the signs that indicate you need to replace the ignition module and how to do it.
Conclusion
Stihl (and every other brand) designs spark arrestors to be removed because it’s a necessary part of cleaning them. Thankfully, it’s a straightforward process that requires few tools and even less technical know-how. After your first uninstall and replacement, you’ll see how easy it is!