Doing a favor for a friend here. My best buddy passed away some time back and his widow is trying to get his 73 Mustang with 302 running so she can sell it. Carb is a Motorcraft 2100. Before I got there, his teenage son messed with it and took it to a buddy of his who "rebuilt" it, but then it would not run at all. I took the carb home, dipped it and installed a fresh rebuild kit. It would run but spewed fuel out the vents, loaded up and died. After messing with it for a few hours, we got the float retainers right and it started, it ran and idled ok, but would change without warning, spew gas and load up, puffing black smoke, and die. I think the problem is in the float/needle and seat area. The needle and seat are new and float level adjusted to spec sheet. What I do see is, the float tang "overshoots" the needle seat by maybe 1/4". Instead of the needle retainer clip riding in the depression at the end of the tang, it's 1/4" or so inboard (towards the pivot pin). I'm wondering if his buddy who rebuilt the carb without a kit might have put a different float in there. See my crude drawing to see what I mean by the position of the needle/seat in relation to the outer end of the tang. Sorry for the long post. Any suggestions? Thanks...

 

Not to long ago I found a problem that was close to yours , long story short the needle and seat were to high [ wrong one ] float wasn't able to close off the fuel , due to hitting carb cover . Took it apart every thing speced out but would spit gas . Not until I measured an old one did I find the problem

 

Looks like the wrong float to me. The low point in the tang should lie directly above the seat, so that the needle can hang down directly into the seat.

 

Thanks guys. For now, I found that the retainer clip I used was not quite right. I had 3 of them and switched to one with a slightly different shape which locked the float pivot pin in place better, so the flooding stopped. But, I did order a replacement float, a synthetic one like the one in FMC400's post, and when it arrives I'll go ahead and install that too. It does have a shorter tang. Not bad, I got a manufacturer's closeout float on RockAuto.com, $4.88 shipped.

I do believe that the prior guy switched floats and retainer clips when he worked on the carb.