If the engine slowly dies when running wide open, then the problem is that your high speed needle is set too lean. Fix the high speed needle first, then re-check the low speed. The low speed screw doesn't have much effect at full throttle.

One of the easiest ways to tell is to let the engine idle, then give the fuel line a good pinch and release. If the RPMs go up, you're rich or ok, if they immediatly go down, you're too lean.