How many turns out for the factory set pilot air screw on my Yamaha TTR 125 carburetor?

As I recall the factory air screws on these have a br cap pressed into the housing (to prevent tampering), and even when you remove them, its going to have minimal effect when you turn it either way. TTR's are a very lean running bike and require the choke being on for a rather long period of time at startup (3-4 minutes) before the bikes throttle becomes snappy and responsive. You should try getting a richer jet kit for it, they seem to be what a lot of people prefer to make them run a lot cleaner. They also have a small problem with the choke plunger sticking. Be sure to take it out every once in awhile and keep it oiled. It will trick you into thinking theres a carb problem when its just a sticky plunger. It never hurts to spring for the service manual either, the bikes bible is always the best bet for manufacturers specs and settings.