Ihave to agree with Konrad (wow this makes what twice this year at least )
I have met a lot of flyers that do not touch the low speed needle and some that wont touch either needle once it is set(and a few that think it is factory set and dont touch anything). Iadmit Iadjust the high speed whenever Ifly but if the low speed is still working reasonably I dont touch it as often. Ifind the mixture changes dramatically during the first gallon or two but stabilizes after that to where only the most minor adjustment is needed to compensate for weather changes.