Yes, the avenger is metered leaner, so you may have to have the mixture screws out more for a steady idle, honestly thats what it sounds like, if there not out far enough it won't idle for crap, contrair to what people think, i called holley on my 650dp & wondered why the mixture screws had to be out 3.1/4 turns on this carb, He told me anywere from 1/2 too 3.1/2 is normal, as long as it stalls out when you bring 1 in your fine, What you should do at this point is, bring the idle screws out 1 full turn each before firing it up, see what happens, there is no reason the engine shouldn't run steady once warm with the choke "fully" open, keep us posted.
My 4777-7 650dp wouldn't even idle with mix screws 2 turns out from fully seated, & its a perf. carb, the nice thing i like about the newer DPs is they leaned out the idle curcuits a bit then the older ones, makes them alot easier on the eyes, The IABs (idle air bleeds) on the 4777-7 air .086" up front compaired to the older ones that were around .070". Throttle responce was outstanding & it could idle forever & never load up.
