fuel pump or carb delivery (electric primer)

[joho5]

1989 Evinrude 70hp VRO (disabled)

Ok, got a question. I am trying to trace down my problem here with my fuel delivery. My motor is inconsistent at WOT. When I open it up, itll run normal sometimes and sometimes not, sometimes it surges between the two.

I have found a few clues to steer me in the right direction and here they are.

when it wont get up like it should at WOT, I can push in the key (electric primer) and hold it and it will run fine like it should, but when I let off it goes back to inconsistency, or bogging down a little.

I havent got to do the primer bulb check with someone else to see if someone keeps pumping it, itll run fine.

My question is does the electric primer just shoot a bit of fuel, or is it shooting it the whole time you are pushing the button?

if it shoots it the whole time and that causes my motor to run correctly, that tells me the carb(s) arent deliverying enough fuel mix to the manifold and the primer makes up for that.

I am basically trying to find out if I have a bad fuel pump, or my carbs arent working properly.

I do have 3 carb kits on the way, but when I repulled them today and cleaned them, they look fine.

any ideas?

 

[bailz2002]

Re: fuel pump or carb delivery (electric primer)

my motor was doing this, your right the primer activates the choke and cuts off some air to the carbs which means your not getting enough fuel. if it idles fine but not at full throttle probably something wrong the high speed jets. check them, clean them and all parts leading up to and after of course and adjust as necessary. I had a piece of something blocking part of mine, took it out cleaned it and ran better then it ever had!