BACKFIRE FLAME ARRESTOR

All inboard gasoline engines must be equipped with an acceptable means of backfire flame control.

Nearly all inboard boat engines come equipped from the manufacturer with a backfire flame arrestor. The backfire flame arrestor is a cylindrical device with finely spaced fins that is secured to the air intake (carburetor) with a flametight connection. The fins allow air to enter the carburetor but they prevent flames from escaping in the event of a backfire. A backfire occurs when a buildup of excess gasoline ignites in the carburetor or air intake system.

The backfire flame arresters must be either stamped with a USCG approval number or stamped that they comply with Society of American Engineers (SAE J-1928) or United Laboratories (UL 1111). They must be securely fastened to the air intake with a flametight connection.

Clean backfire flame arrestors according to manufacturer’s requirements, or with a solution of hot soapy water and a nylon bristle brush. Keeping a backfire flame arrestor clean will help maintain fuel economy.