Brrzee
Sorry for the double post!
Before you go messing w/ the needles, give the simple way a try. Most of the low speed needles are set pretty well @ the factory, at least for the climate we have here in the Southeast, but you won't really know whether it's set all right until you get the linkage correct. Once the lingkage is set, if you have trouble in the transition from low speed to high, then you can fiddle around w/ the needle(s). (If I have a problem w/ transition I always start w/ the high speed needle and get that set correctly; most of the time that'll solve any problems I have.) I mess w/ the low end only as a last resort.
Best of luck and let us know how you make out.
Al