66 coupe

I just replaced my stock 2bbl carburetor on my '66 289 Mustang with an aftermarket 2bbl Holley (not performance). I have the adjustments just about perfect except for a slight hesitation from a stop and the car has a slight surge above 30mph. Can someone please tell me how I can smooth this out?

2+2GT

The hesitation is probably an accelerator pump issue.

66 coupe

The Holley carb is out of the box. I wouldn't think the accelerator pump would be bad.

jasond393

Not that the acc. pump is bad, you just need to change the plastic cam to vary how the pump shoots the fuel into the carb. Look here:

http://www.jegs.com/i/Holley/510/20-12/10002/-1

jlg2002

This could be several things:
1. the carb is too lean
2. the fuel pump is not producing enough flow
3. the fuel filter is dirty
4. the timing is off

If you didn't have any of the current issue before you changed carbs, then you should concentrate on the too lean condition first - adjust the idle mixture screws out a little bit more (1/8 of turn) and see how that effects the off-idle transistion. It takes awhile to dial in a carb, and you may even need to mess witht he carb's jetting. jlg