on the idle mix screws, alot will say the ideal position is 1.5 turns out.
but as you are getting started with the tuning, you need to lean them out as much as the motor needs.
screw the idle mix screws in until the rpm's quit rising (at that point maybe richen it back up the smallest amount you can turn the idle mix screw).
also, readjust the idle mix whenever you make any change to the tuning...

also, pull the carb as you are getting it close so you can look at the transition slot and make sure it looks good, roughly it should look like a square. if it's off you can use the secondary blades to help bring it back in place.