What is the purpose of a spark arrestor in a chainsaw?

• A. To improve fuel economy.
• B. To cool the engine.
• C. To filter air.
• D. To prevent sparks from the exhaust from igniting dry brush.

Answer: (D)

The key idea here is safety in outdoor use. A spark arrestor is a mesh or perforated cover inside the chainsaw’s muffler that catches and cools hot sparks and flame fragments coming from the exhaust. In dry, brushy areas, those sparks can ignite vegetation even after you shut the saw off or if a small ember escapes, so the arrestor helps reduce the risk of starting a fire. It doesn’t change fuel efficiency, it doesn’t cool the engine, and it doesn’t filter the air—those are separate functions of other parts of the machine. Keep the spark arrestor clean and intact, since buildup can block exhaust flow and reduce performance; replace it if damaged to maintain fire-safety effectiveness.