Reply To: Evinrude 1983 35hp Fuel Pump Issues

[Don]

OK, I see that the part number for the pump has superceded several times. But there is still only one vacuum/pressure port, and this is on the back of the pump through the hole in the intake bypass cover… Does the pump look to have been replaced? There were problems with the “umbrella valve” pumps used around 1990…The little umbrella valves in the fuel pump would crumble and the pieces would get lodged in the carb….

This engine has the “economizer linkage”, correct? This adjustment is often confusing and set up improperly. Does your carb throttle shaft have a stop/roll pin that prevents it from going past WOT position and actually closing down again? If not, perhaps you have the economizer linkage set improperly causing the carb butterfly to go past WOT/horizontal position causing the engine to slow down/surge at WOT.

Tell us more about what you repaired/rebulit on this engine…