Re: 1979 6 hp evinrude motor stalling
I can't say that the non-venting ruined your fuel pump. I have on occasion forgot to vent a tank, which my motor reminded me of in about 1 minute from the dock. Never had any lasting problem.
As I said above, if you prime the bulb and the motor revives, it pretty much tells you that you have some sort of problem pumping fuel into the carb. It doesn't identify the culprit for you but there really are only a few that get involved. The fuel tank is one. Venting or clogging. If you have another tank, that can eliminate that culprit. If not, just remove the cap and you at least eliminate half the problem. Venting.
The next is the primer hose. The problems here can be in the connectors, allowing air leaks or in the check valves. I had a hose that only gave me trouble when it got warm. In the cool mornings it worked fine, in the warmer afternoons, it broke down. I assumed it was the check valves in the primer bulb but I replaced the entire unit anyways.
The next area to check is your fuel filter on the motor. Tank off the thumb screw on the front and make sure the screen if very clean. Now that you are looking at the fuel pump make sure all 4 screws are good and snuggly tight. If the pump is not snug against the gasket on the powerhead it will cause you problems. After that I would remove the fuel hose from the output of the fuel pump that is going to your carburetor. If you pull on the starter it should pump fuel out (remove the spark plugs if you don't want the motor to start). If it doesn't then I would probably say at this point that you have a bad fuel pump. You can either get a pump repair kit or a completely new fuel pump.
If fuel does pulsate out of the fuel pump when you pull the starter cord, I would look at your carburetor for the problem. Perhaps the guy that cleaned your carburetor put in a new inlet needle but didn't install the new little spring that connects to the float arm that ensures it opens when the float starts to fall from the useage of fuel. The older inlet needles didn't need this spring and perhaps your old one didn't have one. The new needles have a little rubber tip that can stick in the carb and prevent fuel from flowing. If the guy just looked at your old one he may not have known that this little spring is a new addition to the design. To prevent exactly what is happening to you.
Anyways, that is the approach I would take. Maybe some others have some additional thoughts. Good luck.
