Ok it should be clean enough to run.
EPR hasn't gotten back, He might be onto something with it not pumping enough fuel for the bike.
Choking would force some extra fuel but you wouldn't be able to ride the bike like that.
EPR - How would he increase pump flow? As I said I don't think these carbs have a adjustment for that. Not one that I see on my brand new pumper carb anyways. How abouts his fuel filter itself? clogged or backwards filter installation.
Have you tried with the idle screw out 1 1/2 turn (from all the way in) and the high speed out 2 turns (from all the way in). And with/without choke? if it has manual choke.
Spark, Fuel, Compression = It will run. Perseverance is key.
My last mishap with my bike starting then idling down and dieing was all from a cracked intake manifold.