1987 40 hp Johnson

[mike carson]

I have a 1987 40 hp Johnson while running the boat lost power spitting and where running right around 5300 RPM when trouble started with boat wide open started to spit and lost power to around 1100 RPM then it would take off again for a few seconds then back to low rpm. The primer bulb on gas line you can pump it up but gets soft fast its like to much or not enough gas to motor had carburetors rebuilt at 418.00 took the boat after getting back from the shop still doing the same thing do you think it is the fuel pump?

 

[Daviet]

Re: 1987 40 hp Johnson

You can bypass the fuel pump by having someone constantly squeezing the primer bulb. Are you running a vented tank, is the vent open?