ORIGINAL: Dr1Driver
That's right. Opening an air bleed adjustment screw leans the mix by allowing more air into the carb. Most air bleed carbs I've seen need to be run with the air bleed completely open or the air hole even drilled out with the next-size-larger bit. They tend to run rich.
Dr.1
Dr.1, it's nice to see somebody else go on record about it. I've encountered that several times, and the local wisdom has inquired of me "So, you think you know more than the manufacturer?"
If you open the airbleed all the way and still have a rich stumble on acceleration from idle... be assured you can drill that passageway out. If necessary, you can still block most of it with the screw.
Best wishes,
Dave Olson