Mercruiser 4.3L Stalls above 2000RPM Under Load

[Ellsworth Weatherby]

I just bought an '86 boat w. a Mercruiser 4.3L. The engine runs fine in the driveway and even goes above 2000RPM in gear as long as there is no load on it (in the driveway). When I take the boat out, however, the boat can troll around under 2000 rpm just fine but trying to put it above that, the boat begins displacing but stalls out very quickly after. Does anybody have any suggestions? Thanks.

 

[Bondo]

Re: Mercruiser 4.3L Stalls above 2000RPM Under Load

1st place to Look,.... Is the Fuel Filters..............

You probably have 2,...... A Canister mounted 1,+ 1 at the Carb Inlet.........

Good Luck,+ Welcome Aboard.........

 

[Ellsworth Weatherby]

Re: Mercruiser 4.3L Stalls above 2000RPM Under Load

I looked at the carb mounted fuel filter. I'll check the canister fuel filter. Thanks

 

[Ellsworth Weatherby]

Re: Mercruiser 4.3L Stalls above 2000RPM Under Load

The seller suggests:
I'm sitting here trying to think of a solution to the
problem. When you go to accelerate in the water has
the boat been running at low speed in gear? If so, and
the engine hesitates and even stalls out its a fuel
issue I'm sure. If you haven't already put an
auxiliary water separator/filter when did you last
look at the filter on the carb? When an engine gets a
"load" (accelerating in the water) put on it it
requires more fuel than if it was out of the water; if
it doesn't get it then it will act like that one is.
Like I said before, its hard to say since I can't
actually see/hear it. BTW the fuel treatment I was
telling you about is called STARTRON. At this point it
may not hurt to try it also.
I can say this though I wish they never put ethanol in
gas; at least marine gas! It has caused so many
headaches and I believe its the root of the problem
you are experiencing.

sooo...
I've seen two reocurring solutions, the carb and the fuel pump. Which do you think would be the smartest route, replacing the fuel pump (or any other fuel source suggestions?) or buying a carb rebuild kit? I'm definitely installing an inline fuel filter/water seperator.

 

[ladchapman]

Hey did you ever come to the bottom of this issue? I have the exact same thing. Purrs like a kitten at idle and dies out on the water after an initial good run. I just bought it and it does great for 10 min then we get the tube out and it dies at 2000 rpm. We changed both fuel filters and the cap and rotor. I'm thinking of draining all the old fuel and installing a water separator?

 

[GA_Boater]

This was a valid question 11 years ago. Not today.

Closed