ORIGINAL: evilhorse
Lean the low speed about 1/16th of a turn and go fly.
Ditto, BUT...
Remember where the Low End needle was to begin with (maybe you can scratch the area around it as a marker). If it helps, but still hesitates, turn it in another 1/16 turn. Keep doing this until it's right. There is also a slight chance that you may need to open it instead of closing it.