I need the pilot adjustment for a Mikuni BST 34 on a 1999 500 4x4. Also, are there any updated replacements for this carb?

 

searching through old threads - I believe I've found what I need: Out 2-1/8 to 1-7/8 turns - does this sound right? Turning in (clockwise) leans the mixture and turning out (counter-clockwise) does the opposite - right?

 

A good rule of thumb for a 4 stroke is about 2 turns out should be a starting point, and fine tune from there. You are correct about the mixture screw...in is leaner.
You might like this article on jetting, itll help fine tune the mixture screw.
article here