Yes loosen the allen first, then use a small flat blade screw driver to adjust the needle. This needle is pretty sensitive to adjustments so once you have adjusted 1 1/2 turns out adjust in small increments. I had to lean mine (turn the screw clockwise) just about 1/8 of a turn to get a smooth transition from idle to full throttle. Once I had it in a good spot I set the collar in the middle of the limiters and tightened it back down. Once you get it right make sure when you're moveing the collar that you don't move the needle again by accident.