WBAL-TV has a story (http://www.drumpoint.org/2012/05/flash-fire-burns-man-working-on-boat-engine-maryland-news-wbal-home/) today about a boat fire. If you operate a boat with a gasoline engine please understand the dangers. On inboards you MUST have a working backfire flame arrestor. Ventilate before starting. Ventilate while working on your engine. Be safe and be smart about the technical details of engine repair.