easiest way I found to tune needle is to play around in the 1/4 throttle area and aim for a smooth transition as you roll into the throttle (not stab it)
your not going to have that motor with CPI's come alive at low rpm putting around and stabbing the throttle its going to load up and hesitate unless you feather the clutch to pick up rpms.
usually or atleast from what ive found if you can get a smooth transition in the low end your uptop from 3/4 to wot follow suit permitting your main is where it needs to be.