A slight snafoo

[Mopar&vettedude]

So I bought an old Carter AFB to throw on the doba. I rebuilt the carb since the accelerator pump was shot. The runs well at idle now and during take off, but when I matted it to the floor it breaks up but doesn't stall. But the other oddball thing is if I gradually lay into it, it's fine. I still have to readjust the kickdown lever on the trans, could that be a reason or am I going to have to get a tuning kit for the carb?

 

[BudW]

It sounds like the secondary’s are opening too soon (most likely) or too late.

AFB uses a counter-weight vs. air flow to open – and is very difficult to adjust. I suspect someone may have ground down a lot of the counter-weight to make it open too early. If so, it is pretty hard to add that metal back onto the counter-weight.
AVS or TQ) are much better for adjustability to prevent this from happening.

It might also be something is wrong with main fuel circuit for secondary’s (ie: not getting any or enough fuel).
BudW

 

[Mopar&vettedude]

The counter weight im assuming is the butterflies that sit above the secondaries? I did hear it backfire through the carb at wot at one point. Is it still running rich? Would changing the position of the rod for the accelerator pump make a difference?

 

[BudW]

The accelerator pump is used only for the brief moment of throttle change and is otherwise not a factor.
If car stumbles on the initial throttle change then I would say accelerator pump linkage ratio (plus or minus – for either can effect “that” stumble).

If stumble or bog is longer than that initial throttle change, then accelerator pump is not the issue.
BudW

 

[Mopar&vettedude]

So the kickdown block on the trans was actually the issue. I set it back a little past halfway on the rod it tightens to and drove the car work. Never skipped a beat and the car runs great now. Who knew? lol

 

[BudW]

Great!

Just to make sure it is set up correctly, at rest (or idle), the transmission kickdown stud (same as throttle cable stud) is located at roughly 11:30 O’clock position?
When carburetor is at WOT (Wide Open Throttle) the kickdown stud is located at roughly 2:30 O’clock position?
11:30 means a bit before straight up but not quite at 11 O’clock, either.

Some non-stock carburetors (GM and others) have the throttle/kickdown studs at different positions (10:30 to 1:30 O’clock (WOT)), or variations thereof.
BudW

 

[AJ/FormS]

So the kickdown block on the trans was actually the issue. I set it back a little past halfway on the rod it tightens to and drove the car work. Never skipped a beat and the car runs great now. Who knew? lol

Could you elaborate on what this "block" looks like

 

[BudW]

I was assuming (yes that word, again) he was referring to the rear intake bracket – but not 100% sure.

 

[Mopar&vettedude]

You know how there's the arm that comes off of the linkage at the very bottom, that goes to that sliding block on the side on the transmission with the spring. That's what I adjusted.

 

[AJ/FormS]

Got-it! Thankz