UP GRADES ON DYNA FXDF FAT BOB.... FUELPAK ?

[NotaFATBOB]

New to the site here, browsed it and everything and everyone seems to be very cool and informative. So, I joined. My problem, very slight. I bought a 08 FXDF DYNA FAT BOB from a dude that had it listed on ebay, found out he was 20 miles from me, long story short this candy red sunglow is BANGING! He put a set of VANCE & HINES SHORT SHOT STAGGERED PIPES, A ARLEN NESS BIG SUCKER A/C and VANCE & HINES FUELPAK. Engine is stock.
When i test rode it it went very well. Paid it off at the credit union...uhhh my ol lady actually did for my Birthday. Anyway, after riding for a week i finally wanted to see what this baby would do from a dead stop on a straight stretch of highway. When i gave it full throttle it would flatten out almost shut down as if it had a limiter. I contacted the folks at VANCE HINES and they told me to verify the numbers in the codes, which i did and he said be sure to calibrate my throttle in code 19. But he did not say if i should open it wide open real fast and let go of it. One guy told me i should open it up count i miss and roll it back by hand and count 2 miss. Well. thats what i did. Now she pretty well opens up without the flat spot but i notice an amout of black smoot out the pipes. Is she running too lean? Should i recalibrate the throttle by just going wide open fast and close it fast?
Thanks for any suggestions or thoughts. ELROD, In Alabama.