The only adjustment screw is the pilot screw, this is the air/fuel mixture screw. Another adjustment and something you could check would be the clip on the needle, this should be in the middle.
These carbs are pretty useless though I must admit, do you have any excess fuel leaking from the overflow at all? A common issue is the needle valve (attached to the float) the rubber doesn't seat very well, I used toothpaste and a cotton bud to 'lap' the valve seat.