vapor lock

[gazelle]

Hey folks

I was out this weekend on a friends boat and we were skiing. After running the engine for a bit we shut the boat off for a few and when we went to start it back up it would not start. After a tow running home to get the trailer (boat is in a slip) and dropping off at the local repair shop the boat went into the water so the service man could look to see what what wrong and she started right up. He mentioned that if you run the engine hard for a bit that you should not shut it off right a way but should let it cool down some while running. That if it is hot and shut off the the gas turns into vapor and then the engine will not be able to start until everything cools. Does the service mans answer Jive with the folks here or should we be looking at something else as a possible problem?

Not sure what size the motor is I believe it is a 4.3 I/O chevy.

Thanks for any replys, my boat is not really designed for skiing so this is a new area for me. We typically use my boat as the party barge and his boat as the play boat.

 

[12vMan]

Re: vapor lock

Certainly can happpen, especially when it's hot outside and your motor is carborated. Usually letting it cool down for a while cures it and it will fire back up.

 

[rndn]

Re: vapor lock

If your motor is operating properly, it should not heat up to the point of causing a vapor lock. I had a 5.7 Mercruiser and would run it a wide open throttle all of the way to where I would stop, slow down, shut it off and it would always start right back up. When is the last time you had the impeller and thermostat replaced?

 

[dodgeramsst2003]

Re: vapor lock

Depends on a lot on the amount of insulation in the engine compartement, but your service guys answer does make sense. I've never experienced it as I run hard out, fish, and then hard back in. If I'm skiing, its run out, ski hard, and then back in for a break without shutting it down. if you have a lot of insulation, then an engine running normally will produce enough heat to cause the problems you describe.

 

[gazelle]

Re: vapor lock

Thanks for the suggestions

It was a hot day, nearly 100 degrees.

My friend is getting something done (can not remember what it was) but I told him to replace the impeller while he is getting it done.