Thanks guys!!
Some more data based upon your comments.
The washer on the front of the engine referenced a number of times has a gap btwen the front of the crankcase and the prop drive washer of about 1/32". The nipple is aluminum. I just rebuilt the engine and made all new gaskets, tightened screws, etc ... that ain't it. The gap seems normal for other bushed engines I've seen.
Don't you think a big clue is the lack of needle valve control, and that it will never run rich at ANY throttle setting? It barely runs with the needle almost backed out all the way.
In thinking about this more, I think the reason the guy at ACE happened to have this used carb for me is because .... it was defective in someone else's engine. The jets have GOT to be blocked. I'll tear the carb down to parade rest and let you know.