My Posts: All Forum Topic
There is no such thing as a "one size fits all" needle setting. Those which come from the Mfg. (OS in this case) are very rich for breaking/initial runs, and they expect you to tune the motor from there. To what setting depends on tank placement, lines, the particular carb machining tolerance, muffler/pipe (and how much pressure it provides) etc. etc. etc.
So, bottom line is as you probably already suspect - start leaning it out, and listen! It will tell you when it's right . . .
Friends don't let friends become electrotarded . . . .