Boat losing power at higher RPM

[j.a.g]

I was out at the lake yesterday and started to notice that when I was cruising at higher rpms the boat would start to lose power then regain power. The boat starts and idles fine it seems to only happen at higher rpms and once warmed up. The oil pressure and water temp are fine. Does anyone have any ideas on where to start investagating this problem? It is a 4.3 litre mercruiser with an alpha 1 outdrive.

 

[Bondo]

Re: Boat losing power at higher RPM

Ayuh,... Check the contents of the fuel filters for Water....

 

[marshasman]

Re: Boat losing power at higher RPM

I agree with bond-o, also check your low oil press sesnor wires, i had the same problem and it was loose wires at high RPM's. if they are loose the fuel pump will trun off and on, loosing fuel in the carbs (if it is carded).

 

[j.a.g]

Re: Boat losing power at higher RPM

I think that there is water in the gas so I am going to install a fuel/water separator since my boat does not have one. I have never installed one before. When I cut the fuel line Am I going to loose alot of fuel. Do I need to drain the fuel tank?

Thanks

 

[Bondo]

Re: Boat losing power at higher RPM

When I cut the fuel line Am I going to loose alot of fuel. Do I need to drain the fuel tank?

Ayuh,... There might be a few ounces of fuel lost, so use a catch basin, 'n rags...

Mount the filter between the fuel tank, 'n fuel pump...

 

[j.a.g]

Re: Boat losing power at higher RPM

Thanks!

 

[j.a.g]

Re: Boat losing power at higher RPM

I installed the fuel filter/water separator and the boat ran great the other day, so it appears the there was water in the gas. Thanks for the help everyone!

 

[Hit It]

Re: Boat losing power at higher RPM

I have the same engine and was having similar problems a month or so ago. I installed a fuel/water separator, new fuel filter, and also did the plugs & wires while I was at it. Seems to have taken care of the problem. If the boat is ever going to sit for a couple weeks or so I would put some Marine Stabil or something similar in the gas to help with the water problem. From what I've heard, the ethanol content in a lot of today's gas is the culprit.

 

[Volphin]

Re: Boat losing power at higher RPM

Silly gas companies... Ethanol is for drinking. But not while boating.

V

 

[j.a.g]

Re: Boat losing power at higher RPM

I installed the fuel filter and the boat seemed to run better but after about an hour of running the boat I started having the same issues again. Could this be water still making its way to the carburetor or could there be an another issue? Maybe with the distributor. The fuel filter I have has a drain spout on it and when I drained it I didnt notice much water comming out of it?