Low end needle - Head of screw should be flush with the carb body
Middle needle - don't touch it!
High end - Between 2 and 1 3/4 out
I broke mine in with the high end at 2 out so it ran a little rich, once it broke in my settings did not change to much from this. My high end is a little leaner right now, just depends on the weather for that day. Hope this helps, the settings are in the manual, just look harder or go to the OS website