My dad has an old wooden Higgins race boat. The engine exhaust out of both side of the boat. When it backfires, you can see flames shoots out of the exhaust. It is so loud, you have to cover your ears. But he never gets stop. Is it because the boat is too old? I don't know. I do know that if he alter the boat in any way, he will lose points at the boat shows.
Last year at the Wolfeboro classic boat race, the marine patrol was sitting right there as the old boats were starting up and racing. With all the noise you would think they would hand out tickets!
