I have a buddy that just put a predator carb on his Ford. It surges just off idle. If some one knows of fixes, I can give more info.

You said "surge" but could it actually be a hesitation or stumble? Hesitation and stumble are symptoms of a lean condition, this is corrected with the mixture screw on top of the carb by the air horn (adjustments are made in 1/8 turn increments).

I ran a Predator for a few years on my truck and I've still got the original book for it as well as some other printed info. If you want, post or PM me a fax number and I'll send you copies of it.

What kind of wheeling his he doing with this rig.The only experience I have with these carbs is my buddy stuck one on a built 402 with the idle circuit kit.It sucked on the trail and ate gas like a mother.Only thing it was good for was wide open mud runs.Got rid of it and went to a edelbrock.Blazin:D

I guess it is a stumble. He downloaded the book from the website. It is fine at idle (it has the circuit in it). He thinks it might be the rate that the air doors open. It is on a stroked 390. He does mud, and trails, some rocks. It is mostly an experiment.