1973 25hp johnson seahorse fuel probs

[defaultech]

I have a 73 model johnson 25 hp. I have kitted the carb, set points, replaced fuel line, put new gas in, checked for air leaks, fuel leaks, replaced fuel pump.You name it and ive done it. Darn thing runs well except for wide open or near wide open. It runs for just a bit then falls on its face, up and down. But, if i pump the bulb it just flies like mad, as long as you keep the bulb pressured. Is there anything internal that would cause fuel pump to not pump? Engine pressure? Im just confused, i have replaced everything and i know its starving for fuel at high speeds. What else could it be. Im to the point of putting an electric pump on the crazy thing

 

[ezeke]

Re: 1973 25hp johnson seahorse fuel probs

You may not have the gasket behind the fuel pump air tight.

You may not have the clip on the float arm connected to the needle.

The sole purpose of the fuel pump is to fill the float bowl so that the pistons have a reservoir from which to pull the fuel. It sounds as though your fuel pump can't keep up, but that could also be because the float needle is sticking.

 

[tashasdaddy]

Re: 1973 25hp johnson seahorse fuel probs

yes it could be either one. also did you remove and clean the high speed jet that is deep inside the carb bowl drain opening? did you use Joe Reeves carb settings, in the faq forum?

 

[defaultech]

Re: 1973 25hp johnson seahorse fuel probs

Thanks for the input. I may have solved this though not sure yet. I found the float was upside down. The float i took out was too. If you look at it its hard to tell, and it will fit both ways due to float design. However, when installed wrong it displaces slightly more fuel thus starving bowl. Ill find out tomorrow on the water

 

[defaultech]

Re: 1973 25hp johnson seahorse fuel probs

Well, I ran it and it ran well. The upside down float was the problem.