[j_cst_10]

Hey sorry, it looks like you have solved this. Haven't checked this post for a while.

So needle and seat I take it? I skimmed the through all the replies.

One other oddity that is worth noting is that incorrect timing can cause this as well as misadjusted float level and nonfunctioning needle and seat.

If the the timing is set with the vacuum canister plugged in for instance, the timing at idle is retarded and will idle very low. To "correct" this people crank the idle speed screw in opening the butterflies too much. Then too much vacuum is pulled through the venturi's at idle and fuel is pushed out of the primary booster venturi essentially flooding the engine or making it run rough.

Same thing can happen when you have a big cam. The fix for this is adjusting the secondary butterflies to be open more at idle and closing the primary butterflies some.