This guy has some good videos on small engines...
My Craftsman with a Tecumseh engine was running as the OP stated, it needed the choke on to run smoothly. Mine had to be on the 1st click, where 0 clicks is off, and 3 clicks is full choke. If I turned the choke off, the machine would stall out.
I have one of these non-adjustable carbs, and followed that video. Turn off the gas line, run the machine dry, then unscrew that bolt and clean the holes with a piece of wire. Should help a little, it did for me. The jet was a little dirty for whatever reason (stagnant fuel, dirt in jerry can, etc...)
I may be completely out to lunch, but please, no torching.