No big deal really but just got back from a quick ride out and find that holding a steady throttle, ie in traffic etc around 4000 to 6000rpm, the bike seems to hesitate, hold back, but open the throttle and it clears its throat and pulls fine. Theres no flat spots when going for it right through the rev range, just this steady throttle issue. Starts and ticks over fine. Carbs ultrasonicly cleaned, new starter & main jets, new lite tek seal kit, and balanced last week.
Any suggestions??

That's an odd one, I'd have said to look at the carb ballance or idle jet a bit blocked but it sounds like they're done.
Is the exup adjusted properly ?

I checked the exup a good while ago so I'll give it a looking at. Just the little fork bit lining up with the hole isn't it

Yup, just finger tight