RE: YS63- Factory Default LSN
Rather than worrying about the factory default, why don't you turn your needle in slowly until it bottoms out, counting the number of turns it takes to seat it fully closed, then just remove it, do whatever you need to do, and replace it by screwing it back in all the way and backing it out the same number of turns it was out originally? That's the easiest way to do it, and should get you closer to the right place for your motor, your plane, your cowling, etc. than the factory defualt setting would anyway.
Of course, if you've already moved it that won't help you. I'd guess that the default position would be one that only partially blocks the hole, not one that centers the screw in the opening, but I don't know that for sure. It's usually easier to get an engine that's running rich leaned up than it is to keep one that's too lean running long enough to adjust it, so I'd start with the screw in some (rich) and back it out until it starts running smooth.
David