Backfire flame arrestors are required on vessels with which engine type?

Backfire flame arrestors are required on vessels with which engine type?

• A. Inboard engines
• B. Outboard engines
• C. Diesel engines
• D. Electric motors

Answer: (B)

Backfire flame arrestors stop a flame from traveling backward through the air intake into the engine, where it could ignite fuel vapors. They’re required on vessels with gasoline engines that use carburetors because those engines can experience backfires that send flames up into the intake. Outboard motors are a common example of such engines on small boats, and regulations specifically require flame arrestors on these engines to reduce fire risk. Diesel engines don’t use carburetors, and electric motors don’t involve combustion in the intake, so they don’t require backfire flame arrestors.

Backfire flame arrestors stop a flame from traveling backward through the air intake into the engine, where it could ignite fuel vapors. They’re required on vessels with gasoline engines that use carburetors because those engines can experience backfires that send flames up into the intake. Outboard motors are a common example of such engines on small boats, and regulations specifically require flame arrestors on these engines to reduce fire risk. Diesel engines don’t use carburetors, and electric motors don’t involve combustion in the intake, so they don’t require backfire flame arrestors.