Vexed by Vapor Lock

By: Grid Michal

QuestionI have a 1999 Hurricane deckboat with a 4.3 engine. The new fuel with so much alcohol is creating vapor lock when I turn the engine off in hot weather. There is no place around here to buy real gas. Help, please!

AnswerThe 4.3 is a shortened version of the venerable 5.0/5.7 GM engines. Lots of power can be dragged out of those 4300CCs, and it’s used in many instances to replace the bigger engines. But, generating power generates heat, among other things, and heat rises in an engine compartment with a closed cover, where a vehicle would have lots of cooling air around the engine. The 4.3 is notorious for running-on after shutdown, or acting as though the battery is almost dead when attempting to restart. That said, I’d start with a reputable tech changing plugs and making certain the timing is to spec. The rest is up to you. After a good hard run, let the engine idle a few minutes (five or so) with the blower running to let it cool. If you can raise the engine cover with no hassle, do so. This won’t cure all your ills, but it will certainly reduce the aggravation factor.


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