mercruiser 454 Magnum MPI shutting down during operation
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mercruiser 454 Magnum MPI shutting down during operation
I have an 1994 Advantage SR22 that i have owned for going on 11 years. This boat is has a Mercruiser 454 magnum MPI set up in it. I am having a problem with my boat just dying while going. this will happen at low idle speed or most of the time at higher speeds. it feels like the boat has ran out of gas. Last season i learned that if i shut the boat down and waited about 20 to 30 minutes it would fire back up and run like nothing had ever happened. To be clear the boat runs like a swiss watch/perfect until this gremlin attacks and the boat just dies. So far this summer it did not happen my first 2 times out, but happened 1 last weekend and 3 times this weekend including at idle speed coming out of a cove. Last weekend and the first two times Saturday the boat fired right back up and off i went like nothing had ever happened. The third time it died Saturday while i was at idle leaving a cove, it took about 10-15 minutes before it would start and run again. Last year it would die and just turn over like there was no fuel, this year is seems to either start right back up or like yesterday start then die, start then die .I could use some advice on where to start to get this fixed, it is very annoying to say the least.
#3
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sound like vap lock, what are the air temps you're boating in
#4
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I assume this is a carb engine. Vapor lock is not likely on a carb engine and especially unlikely while running at speed. You need to determine if it is an ignition problem or fuel problem. It could be as simple as your fuel vent hose is plugged
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Being a 94 it would be good idea, anyway, to replace rubber fuel line , and antiphon valve , going from tank to fuel filter/water separator inlet.
Also if you have a vst in your fuel system, if it’s never had diaphragm , needle and seat, etc….in vst changed, it’s long overdue.clean thr pump’s filter and check float if full of gas and not boyant.
Also if you have a vst in your fuel system, if it’s never had diaphragm , needle and seat, etc….in vst changed, it’s long overdue.clean thr pump’s filter and check float if full of gas and not boyant.
Last edited by SB; 07-18-2022 at 04:22 PM.
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I have had it happen when getting on plane, I have had it happen at cruising speed 50 or so MPH and I have had it happen flat out running about 70MPH. it will cut out, sputter then completely die. This Saturday it happened while idling out of a cove, sputtered then died. Tried to re-start and it would fire then die, fire then die, I waited 10 or so minutes and it fired and ran just fine again.