All motorboats built after April 1940 with inboard-mounted gasoline engines (this includes inboards, inboard-outboards, and airboats) must have a backfire flame control device mounted securely to each carburetor.
- Backfire flame control devices must be:
- In good and serviceable condition
- USCG–approved (must comply with SAE J-1928 or UL 1111 standards)
- Backfire flame control devices ensure that any engine backfire is dispersed into the atmosphere and also substantially reduce the chance of explosion or fire.
- Periodically clean the backfire flame control device and check for any damage.