1979 70 HP evenrude.

[puddlepouncer]

This motor run really great when it is running great. However I cannot seem to get it to maintain fuel pressure. I will be running down the lake and it will just fade out. I have put on new fuel lines, changed bulb, ect. , and when I prime the bulb it never seems to build up pressure. Any thoughts or suggestions would be appreciated.

Puddlepouncer

 

[Oldyellow71]

Re: 1979 70 HP evenrude.

It sounds like you need to rebuild/replace your fuel pump. If the primer bulb keeps going soft that is usually the culprit. Also, you said you replaced your fuel lines, the little rubber ones from the pump to the carbs or the main one from the gas tank? It could also be a bad vent on you gas tank.

 

[emoney]

Re: 1979 70 HP evenrude.

Definitely check your fuel tank vent first. Then, as Oldyellow said, it's time to focus on the fuel pump. Look at the diaphram and make sure it's not old and flaked. This can cause a lack in fuel pressure.

 

[puddlepouncer]

Re: 1979 70 HP evenrude.

Thanks for the suggestions! It has a built in tank, I hate to sound like a real idiot,,,but where is the vent??? Also I replaced all of the lines. tank to fitting, and the lines to and out of fuel pump.. I had the fuel pump apart and everything looked OK to my eye, no tears or anthing that was visible to me. How exactly does the fuel pump work on these things? From engine vacuum? And when you prime it, are you priming the fuel pump or does priming actually fill the float bowls on the carbs? Appreciate the help. I enjoy working on my own equipment, but do not like not knowing how it works..Again thanks!!