Backfire Flame Control Device
If your boat has an inboard- or inboard/outboard-mounted gasoline engine built after 1940, a backfire flame control device is mounted on each carburetor. On fuel-injected engines, the control is installed above the air intake. If your engine backfires, this device makes sure the backfire is dispersed into the atmosphere, which greatly reduces the chance for an explosion or fire.
Whenever you perform regular maintenance on your engine, check the backfire flame control device for dirt or damage. If the device should ever need replacing, use only a device approved by the U.S. Coast Guard that complies with SAE J-1928 or UL 1111 standards.