The Backfire Flame Arrestor (BFA)

The backfire flame arrestor is a critical safety device on boats, especially those with gasoline-powered inboard engines. Here’s a breakdown of what it is and why it’s important:

What Is a Backfire Flame Arrestor?

A backfire flame arrestor is a metal screen or mesh device installed on the air intake of a gasoline engine. Its job is to prevent flames from escaping the engine in the event of a backfire. A backfire is when combustion occurs in the intake manifold or carburetor instead of the combustion chamber. This can cause an engine fire or even an explosion on a boat.

How It Works

The arrestor is made of fine wire mesh that can absorb and dissipate heat. If a flame tries to travel backward through the intake (a backfire), the mesh cools the flame front and prevents it from igniting fuel vapors in the engine compartment. This is crucial because gasoline vapors are highly flammable. All it takes is a little spark or flame to ignite gasoline vapors.

Why It’s Required on Boats

U.S. Coast Guard regulations require flame arrestors on all gasoline engines installed in boats (except outboards). It’s a legal requirement for safety and is part of routine inspections. Without one, a simple engine backfire could lead to a catastrophic fire onboard.

Maintenance Tips

Inspect regularly for corrosion, clogging, or damage.
Clean with solvent or warm soapy water—don’t use compressed air, which can damage the mesh.
Replace if the mesh is torn or heavily corroded.

The Power Blower

The Power Blower is also very crucial. An operator must learn how to use the blower. The blower purges the air, including gasoline vapors, from an engine compartment. General rule of thumb is that the operator should run the blower for at least four minutes before starting the engine.