It's the Law: Required Equipment

Backfire Flame Arrestors

Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires.

• On Iowa state waters, all powerboats (except outboards) that are fueled with a volatile liquid (such as gasoline) must have an approved backfire flame arrestor, backfire trap, or similar device on each carburetor.
• Backfire flame arrestors must be:
  • In good and serviceable condition and…
  • U.S. Coast Guard–approved (must comply with SAE J-1928 or UL 1111 standards).
• Periodically clean the flame arrestor and check for damage.

Ventilation Systems

The purpose of ventilation systems is to avoid explosions by removing flammable gases. Properly installed ventilation systems greatly reduce the chance of a life-threatening explosion.

• All vessels with gasoline-powered engines operating on federally controlled waters, and constructed in a way that would entrap fumes, must have at least two ventilation ducts fitted with cowls to remove the fumes. On Iowa state waters, every powerboat, except open boats, using any liquid of a volatile nature as fuel, must be provided with the means for properly and efficiently ventilating the bilges of the engines and fuel tank compartments so as to remove any explosive or flammable gases.
• If your vessel is equipped with a power ventilation system, turn it on for at least four minutes after fueling and before starting your engine.
• If your vessel is not equipped with a power ventilation system (for example, a personal watercraft), open the engine compartment and sniff for gasoline fumes before starting the engine.

Mufflers and Noise Limits

• The exhaust of every internal combustion engine on any powerboat must be effectively muffled by equipment constructed and in use to reasonably muffle vessel noise.
• Powerboats must meet the following SAE sound level tests.
  • Stationary sound level test: Engines manufactured before January 1, 1993, must not exceed a noise level of 90 dBA. Engines manufactured on or after January 1, 1993, must not exceed a noise level of 88 dBA.
  • Shoreline sound level test: Engines must not exceed a noise level of 75 dBA.
• All muffling devices used on powerboats must be in good working order and in constant operation to prevent excessive or unusual noise.
• The use of cutouts is prohibited, except for vessels competing in an authorized marine event.