It's the Law: Delaware Boating Regulations

Section 2. Backfire Flame Control.

(a) Applicability. This section applies to every gasoline engine installed in a motorboat or motor vessel after April 25, 1940, except outboard motors.

(b) Installations made before November 19, 1952, need not meet the detailed requirements of this section and may be continued in use as long as they are serviceable and in good condition. Replacements shall meet the applicable requirements of this section.

(c) Installations consisting of backfire flame arrestors or engine air and fuel induction systems bearing basic Approval. Nos. 162.015 or 162.041 or engine air and fuel induction systems bearing basic Approval Nos. 162.015 or 162.042, may be continued in use as long as they are serviceable and in good condition. New installations or replacements shall meet the applicable requirements of this section.

(d) No person may use a vessel to which this section applies unless each engine is provided with an acceptable means of backfire flame control. The following are acceptable means of backfire flame control:

1. A backfire flame arrester complying with Society of Automotive Engineers (SAE) Standard J-1928 or Underwriters Laboratories (UL) Standard 1111 and marked accordingly. The flame arrestor shall be suitably secured to the air intake with a flame tight connection;
2. An engine air and fuel induction system which provides adequate protection from propagation of backfire flame to the atmosphere equivalent to that provided by an approved backfire flame arrester. A gasoline engine utilizing an air and fuel induction system, and operated without an approved backfire flame arrester, shall either include a reed valve assembly or be installed in accordance with SAE Standard J-1928; and
3. An arrangement of the carburetor or engine air induction system that will disperse any flames caused by engine backfire. The flames must be dispersed to the atmosphere outside the vessel in such a manner that the flames will not endanger the vessel, persons on board, or nearby vessels and structures. Flame dispersion may be achieved by attachments to the carburetor or location of the engine air induction system. All attachments shall be of metallic construction with flametight connections and firmly secured to withstand vibration, shock, and engine backfire.

(e) No person may use a vessel to which this section applies unless the backfire flame arrester is serviceable and in good condition.