Have you checked for an air leak? If the carb was professionally cleaned and you have a new air filter and you can't seem to get the setting right I think I would be checking for an air leak around the manifold.
I got back to it today. I started it up and ran it for a few minutes then I sptayed 2+2 gum cleaner where the carb bolts on. It smoothed right out. (This is how I used to check vaccum lines on cars.)
I pulled the carb and replaced the gaskets. Engine - gasket - isolator plate - gasket - carb. Still leaked so I walked away a little frustrated. I went back out atter everything cooled down and pulled the carb again. This time I am noticing that the carb studs have metal shavings in the threads. I am thinking that maybe the nuts are bottoming out where the threads end and can't tighten enough to stop the air leak. Maybe if I add a washer or 2. I am not sure how well the lock washers will work that are part of the mounting nuts.