4.3gl dies after warm, then hard to restart

[edwardjw]

I HAVE A 1998 HORIZON 180 WITH A 4.3 GL ENGINE. WHEN I HAVE RUN THE BOAT FOR 30 MINUTES OR SO, AND STOP FOR AN EXTENDED PERIOD, (30MIN. TO 1 HOUR), THE BOAT STALLS OUT RIGHT AFTER I GET IT UP ON PLANE. THE BOAT CAN SET ALL WEEK IN MY GARAGE AND WIIL START RIGHT UP AND RUN ALL DAY WITH NO PROBLEM. IT RUNS FINE EVEN WHEN I STOP AND GO ALL DAY WITH A SKIER. THIS ONLY HAPPENS WHEN I STOP AT THE LOCAL COVE FOR LONG TIMES AFTER RUNNING THE BOAT HARD. I HAVE REPLACED THE FUEL PUMP AND THE RELAY. EVEN THE CONECTORS FOR THE RELAY (THEY WERE CORRODED). ONE OTHER THING. AFTER I GET IT STARTED AGAIN, (THIS CAN TAKE SEVERAL MINUTES OF CRANKING), I GET A SMELL FROM THE EXHAUST LIKE YOU WOULD GET FROM A VERY LEAN RUNNING ENGINE,(OXIDES OF NITROGEN SMELL). AFTER IT STARTS IT WILL RUN FINE FOR THE REST OF THE DAY. I AM A PROFFESIONAL AUTOMOBILE MECHANIC BUT HAVE LITTLE EXPERIENCE ON BOATS . SEEMS LIKE VAPOR LOCK TO ME. THE FUEL FILTER IS HALF EMPTY WHEN THIS HAPPENS. DOES ANYONE OUT THERE HAVE ANY IDEAS ABOUT THIS AND HOW I CAN FIX IT?
i READ SOMEWHERE THAT IT MIGHT BE AN ANTISIPHON VALVE. HOW DOES THIS WORK AND IS THIS A COMMON PROBLEM? PLEASE HELP.
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1998 HORIZON 180 W/ 4.3 GL.

 

[joshmcn27]

Re: 4.3gl dies after warm, then hard to restart

I have the exact same problem with a '92 4.3 I've been scratching my head. I have replaced and checked everything from the book!

 

[shdw2001h]

Re: 4.3gl dies after warm, then hard to restart

The antisiphon valve is the barbed fitting on the gas tank. It works like a check valve, this stops the gas from empting the gas tank if you blow a hose for example. if this valve is sticky or is hard to open it could cause the problem you have. I think in the adult section there is a test for the fuel system you might want to try too.