What is a Spark Arrestor on a Chainsaw? Functions Explained

Patrick McMann

Knowledge Based

As a chainsaw operator working in the forest, the last thing you’d want is to accidentally cause a raging wildfire. That’s where you need a spark arrestor.

But how can this component ensure the safe operation of your chainsaw? Not to worry. In this article, I’ll discuss a spark arrestor’s purpose, significance, and workings in a chainsaw. You’ll also learn how to clean it and the legal regulations surrounding its use. So, let’s get going!

What Is a Spark Arrestor on a Chainsaw?

A spark arrestor is a safety feature present on the exhaust system of a chainsaw. It is a metal screen or a mesh installed inside the muffler or silencer where the exhaust gas exits. 

Now, let’s find out what is the purpose of a spark arrestor on a chainsaw and how it works:

working of chainsaw spark arrestor explained

What Does a Spark Arrestor Do on a Chainsaw?

The primary purpose of a spark arrestor is to avert accidental fires or wildfires. It acts as a barrier, preventing sparks and hot debris from escaping with the exhaust.

When operating a chainsaw, sparks can fly, and that’s a potential hazard, especially in dry or forested areas. That’s where the spark arrestor steps in, acting like a protective shield to keep those sparks contained and reduce the risk of starting a fire.

How Does a Spark Arrestor Work?

Spark arresters trap carbon particles larger than 0.023 inches. While they may not be foolproof, a properly set up and maintained spark arrester can significantly minimize the fire risk. 

It works by sifting through the exhaust system and capturing carbon particles. The centrifugal force flung the heavier carbon particles against the arrester’s walls, where the screen traps them. 

What Happens if a Chainsaw Spark Arrestor Gets Clogged Up?

Carbon buildup can cause your chainsaw spark arrestor to clog up. In such cases, you may encounter some clogged spark arrestor symptoms, such as the following:

  1. Power Reduction

The carbon buildup on your chainsaw spark arrestor restricts the flow of exhaust gases. This, in turn, decreases the engine’s RPM and may hamper your cutting tool’s performance.

  1. Difficulty Starting the Chainsaw

A clogged spark arrestor can make it challenging to start your chainsaw. It may also hinder the tool’s acceleration.

  1. Excessive Exhaust Smoke

If your chainsaw is producing excessive exhaust smoke, it’s likely due to a clogged spark arrestor. As a result, it won’t filter the gases properly, leading to an inefficient combustion process This inefficiency also causes an increase in exhaust smoke.

  1. Fire Hazard 

The carbon buildup also reduces the spark arrestor’s ability to trap sparks within the muffler. As a result, there is an increased risk of sparks escaping from the exhaust and potentially causing a wildfire.

How to Clean Chainsaw Spark Arrestor?

If your chainsaw spark arrestor is clogged, here’s a step-by-step guide to cleaning it:

  1. Switch Off Your Chainsaw

Before cleaning the spark arrestor, turn off your chainsaw, and wait for its engine to cool down. Be sure to wear protective gloves and goggles, too.

  1. Find the Spark Arrestor

Look for the spark arrestor in the muffler or exhaust system of your cutting tool. If you’re unable to locate it, check your chainsaw’s manual for its exact location.

  1. Remove the Spark Arrestor

Next, use a screwdriver or a scrench to remove the bolts holding the spark arrestor in place. But remember to keep track of any components that may come off during the process.

  1. Inspect and Clean the Spark Arrestor

Take a close look at the spark arrestor for signs of excessive carbon buildup. If it’s heavily blocked, it’s time for you to clean it thoroughly. To clean the arrestor, gently scrub off the carbon deposits using a wire brush.

  1. Soak in a Carburetor Solution (Optional)

If you find the spark arrestor is still not clean, you can soak it in a carburetor cleaning solution for a few minutes. It’s best to follow the manufacturer’s instructions for a specific cleaning product, as not all products work well with all chainsaw spark arrestors.

  1. Rinse and Dry the Arrestor

As a last cleaning step, rinse the spark arrestor thoroughly with water to remove any cleaning solution residue. Allow the arrestor to air dry completely.

  1. Reinstall the Spark Arrestor

Carefully place the spark arrestor back into the muffler, ensuring it aligns correctly with other components in the chainsaw. Secure it in place using the bolts you removed earlier. But don’t overtighten, as you might risk damaging the arrestor.

  1. Test Run the Chainsaw

Switch on your chainsaw and run it for a few minutes. This is to check for proper airflow and whether the spark arrestor is functioning well.

What Are the Different Types of Spark Arrestors?

Typically, there are two types of spark arrestors, each used for different applications:

Multiposition Small Engine (MSE)

You will find MSE spark arresters in engines found in hand-held equipment, such as chainsaws. They’re tailored to meet the needs of portable power tools.

General Purpose (GP)

GP spark arresters are used in various applications besides hand-held equipment. You’ll find these arrestors accommodating a wider range of engines and machinery. 

But the question is, do all chainsaws come with spark arrestors?

Do All Chainsaws Have Spark Arrestors?

No, not all chainsaws have spark arrestors. To determine whether your cutting tool comes with a spark arrestor or not, refer to the owner’s manual. In case it doesn’t, you can easily purchase a spark arrestor kit from a hardware store or online retailer. 

If you’re wondering, “What if I don’t want to use a spark arrestor? Will I face legal consequences?” Here’s your answer:

Is It Necessary to Use a Spark Arrestor On a Chainsaw?

Yes, in certain areas, operating a chainsaw without a spark arrestor is illegal. Especially in states prone to forest fires, the forestry authorities require operators to use spark arrestors to reduce the risk of accidental fires. 

Other than that, spark arrestors are also compulsory to use for logging activities on federal lands such as national forests and parks. If you ignore all these regulations, it can result in severe consequences, especially if an accidental fire were to break out because of you.

Not only do these restrictions apply to loggers and arborists, but they also target homeowners who use chainsaws. To learn whether you can use a chainsaw without a spark arrestor or not, contacting your local state forest service can help. 

But do you know that sometimes spark arrestors can also be the reason behind accidental fires? How ironic is that? But why does it happen?

Frequently Asked Questions

Does a chainsaw need a spark arrestor?

Yes, it’s essential for your chainsaw to have a spark arrestor, especially if you’re using the tool in areas at risk of forest fires or those with a dry climate. In many states in the United States, it’s also compulsory by law to use spark arrestors in national forests, state parks, and other public lands. 

This law is not only for professional loggers and tree care specialists but also extends to homeowners who use chainsaws. If you’re unsure whether you can use a chainsaw without a spark arrestor, it’s best to check with your local state forestry service.

Where is the spark arrester on a chainsaw?

You’ll find the spark arrestor in the exhaust system of your chainsaw. It’s pretty easy to spot as a small metal screen within the muffler. 

How do you clean a spark arrestor on a chainsaw?

To clean a spark arrestor first, turn off the chainsaw and give it some time to cool down. Look for the muffler. It is a large metal box attached to the back of your cutting tool engine. In the front of the muffler, you’ll find the spark arrestor, which is a small metal screen. 

Unscrew the spark arrestor, remove it, and use a wire brush to clean any dirt or debris from it. If it’s heavily clogged, soak it in a carburetor solution. Once the arrestor is clean and dry, carefully reinstall it in the chainsaw.

What causes a clogged spark arrestor?

Carbon buildup can cause clogging in a spark arrestor. If you use a fuel that contains varnish or has been sitting for 30+ days in the open, carbon can accumulate on the arrestor screen. Additionally, subpar 2-stroke oil that doesn’t meet certain standards can also clog a chainsaw spark arrestor.

Can I remove the spark arrestor?

No, it’s not a good idea to remove the spark arrestor from your chainsaw. If the climate is dry, a wildfire can start easily from the sparks produced by the engine.

Not to mention this can also lead to legal consequences if you remove the spark arrestor in an area where its use is compulsory by law. 

Final Takeaways

So, hopefully, after reading the preceding post, you now understand what is a spark arrestor on a chainsaw. By knowing the purpose and significance of this crucial safety feature, you can ensure compliance with forestry laws, avoid legal ramifications and help prevent potential fire hazards. 

Also, remember to regularly clean the arrestor to lower the chances of causing wildfire and ensure the safe performance of your chainsaw.

Patrick McMann