Step 1 : Introduction to the question "An inboard engine backfires. What will prevent the ignition of gasoline fumes?"
...Backfire Flame Arrestors. Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires. All powerboats (except outboards) that are fueled with gasoline must have an approved backfire flame arrestor on each carburetor.Because boat engines may backfire, all powerboats (except outboards) that are fueled with gasoline must have an approved backfire flame arrestor on each carburetor. Backfire flame arrestors are designed to prevent the ignition of gasoline vapors in case the engine backfires