Demon 650(dp) flat spot till secondaries kick

I have a 390 with the demon 650 parked on top, the butterflies set proper, timing on, air fuel "close", no vacuum leaks, all that I think is good.

Coming off idle right up until the secondaries kick in its like the choke is partially on, but I have no choke even installed. As soon as the secondary butterflies roll open things come to life real quick and she pulls real hard.

The cam bushings for the accel pump - if I change the plastic cam from pink to say green - will that improve or be worse for this area of the carb tuning? If not who has a helpfull hint?

I do know that the air idle mixxers don't all function as designed because I have at least 1 that has very little if not 0 effect at all. Probably 2 of them.. all 4 should have a similar effect on the rich/lean tune, correct? seems like a no brainer there. I just cant get the 5tupid carb to work right.

Any help?

Does your carb have the idle eze function???You might be able to tell from the aircleaner stud--the idle eze carbs are 5/16----

What is your jetting, power valve #,base and total timing nu,bers plus do you have vacume advance and where is the line hooked ?

Also---what specific number Demon do you have??

What cam and exhaust system