Stumble gone!

[Jon]

Well fellas, I did it.  Success!  The stumble is gone!
My carbs were synced at 1600-1700 rpms, YICS taken off and plugged, flapper door door intact and unmolested...
In the end, it came down to adjusting my mixture screws.  I had a feeling that at 5000 rpm the carb was switching from it's pilot jet to the main jet and likely stumbled because at that overlap point it was getting too much fuel. So, I took those mixture screws I had adjusted previously for best idle, and screwed them both in 1/4 turn to lean out the mixture.
The bike starts slightly harder and idles low when it's cold, but once this thing is warmed up it pulls smooooooooth 2000-10,000 rpms.
Of course every Vision if different, but y'all might try leaning in those mixture screws just a bit and see what happens.
Also on a good note, after jumping through many a hoop for the County clerk, I've got all the paperwork done and the title secured.  
It's all coming together, fellas, after lots of hard work.
Thanks to everyone for your help!