Because boat engines may backfire, all powerboats (except outboards) that are fueled with gasoline must have an approved backfire flame arrestor on each carburetor. Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires.
- Backfire flame arrestors must be:
- In good and serviceable condition.
- USCG–approved (must comply with SAE J-1928 or UL 1111 standards).
- Periodically clean the flame arrestor(s) and check for any damage.