As highlander said, set the high speed needle valve first......then you might have to set the low speed needle valve also (most TT Pro .46's need to have this adjusted. If it loads up when idling (too rich), it will hesitate and sputter when transitioning to full throttle, and may also stall when idling for a while. turn the low speed screw in 1/8 turn at a time until it's right (it is located in the barrel that the throttle arm is attached to.

Mike