Well, I finally nailed down the problem. AFBs as they are shipped seem to have a little problem with the floats not being set right. I pulled the top off of my 9755 yesterday and found that the floats were set to 5/8 of an inch, and 1 1/8 drop. The problem here is that the fuel level is so low that the accelerator pump fill slot is about 1/8 of an inch above the fuel level here. All the pump was getting was what might have sloshed into the well when you slow down. It was shooting blanks most of the time.

My carb shipped with the spring-loaded needle and seats. They are on the small side, but if you set the float level up they can still control the floats because of the springs. In theory that will keep up just as good as a bigger needle and seat because you don't have to compensate for float bounce by lowering the floats.

I set the floats up at 5/16, which makes the bottom of the floats perfectly level, and the drop at 1 5/16 which gets the needles further out of the seats under full flow. The jets are still .113 primary, 71 X 47 rods which gives a metering are of .042 at cruise and and .066 with the rods up. I'm using the pink piston springs which lift the rods at 7 hg, and the secondary is at .107. The accelerator pump shooter is .035.

I uncorked the headers and took it for a hard run and man I see why I've always loved these carbs. I'll just say that I'm pretty sure the problem is solved.

 

I'm glad you finally tracked that down Bill, I know you'be been beating your head against the wall for awhile now. I know on my new Edel I was having that same problem (among others). My floats came adjusted way off too- so much for out of the box performance! In my case though, re-adjusting the floats wasn't a complete fix. Edelbrock and Summit approved a return (!!!) and my new Holley is on its way. So much for my grand Edelbrock carb experiment (try something new I thought...)

If your knuckles ain't bleeding you did something wrong.

'72 F-250 "Hi-Boy" 4x4, Dana 60/HD44, FE428 @ 400 ponies , 4-speed, custom suspension w lift, mud on black.

 

I am glad too. I figured it had to be something like the float level after finding that changing the pump link between holes made no difference.

Mine's a 750 cfm, and I know that the next step was a double-pumper. This carb here is pretty nice now. I have some calibration options I wouldn't have with the Holley.

If this carb hadn't straightened up, I would have sent mine back and did the same thing you did.