Are you sure your tick over is turned up and with the needle fully raised it means its running rich at mid-throttle, try knocking it down one or two to lean the mixture up a bit on the transitionn from idle to mid/full throttle...
If it cuts out if you let of the throttle it s not the needle you should be looking at but the jet or the screw (Very likelty the screw if it has already been jetted right). The needle only affects mid throttle.
