Engine runs than shuts off..

[confused1980]

Somebody help me...

My boat will start and run for a good 30 minutes than will shut off...it would start but will not allow me to run 2000 rpm...I am able to start the engine back up but will shut off again..

I changed the fuel pump, had the carbeurator rebuilt,checked the gas to see if there was any water in it, and change fuel seperator.

What else can possibly be wrong?

Its a 1995 5.0 Cobra OMC

 

[DBreskin]

Re: Engine runs than shuts off..

Have you considered vapor lock? If your engine is running too hot, it may cause the fuel in the fuel line to vaporize, which will prevent it from flowing properly.

Is your fuel tank properly vented? If not, drawing fuel out of it will create a vacuum, preventing fuel flow out of the tank. You can check this next time your engine shuts down unexpectedly by opening the fuel fill and listening for an inrush of air (there shouldn't be one).

You may get better results from your question in the main forum since this isn't a Four Winns specific question.

 

[backyard mechanic]

Re: Engine runs than shuts off..

Fuel check valve at the tank corroded or maybe even the valve turned partially off? What is the condition of the hose? Do you have a fiberglass tank? Ethanol will break down fiberglass tanks and cause clumps of "gook" to form. You'd see that in the filter tho'.

As far as possible ignition issues... does the coil or ignition wiring get hot? Test the resistance of the wires or if you have the old ballast resistors, replace them.

 

[ohhmyyygod]

Re: Engine runs than shuts off..

Did you ever find a solution to your problem? I am experiencing somewhat of the same thing. I posted a couple things on here but no help yet. It just randomly shuts off, but starts right back up again no problem. I'm also having problems with my nav and courtesy lights with a poor connection which I am hoping is related.

Anyway, let me know. If I find anything out on my end, I'll post something.

Daniel