RE: low speed needle valve on OS 46 AX?
I agree big time about running a couple of tanks through first, of course allowing a good cool down period between each tank full. After, set the high speed needle a click or two to the rich side of full lean (after all, its new). Hold the nose up and the engine should scream. If it boggs down, its too lean. Next, you are ready to make certain about engine performance as you move the throttle ( smoothly and at a good pace, not too fast) from low, through the mid-range, to full open.
This is where the low speed needle comes into play.
At this point, the low speed needle is ripe for adjustment.. The goal is to have smooth rpm transmission from low to high throttle BEFORE you take off.
New OS engines usually need leaning of the LS needle. You have to try, maybe a 1/16 or 1/8th (or experiment and go drastic like 1/4 turn and see what happens) of a turn at a time, then fire up the engine and test. Repeat as necessary until its right.[sm=wink_smile.gif]
When atmospheric conditions change, mainly severly like from summer to freezing cold, you most probably will have to re-adjust both needles.
Its no big deal, and the sooner you get the feel, the better IMO. Good luck!