Okay. I dug out an old shop manual for it that Dad had laying around. Basically all I had to do was go warm it up and screw the idle screw all the way back in and back it out a turn. Runs good now. That wouldn't quite let it idle at the 425RPM mentioned in the book, but backing out a spring-loaded screw on the governor arm did that quite handily. That was an easy fix.
For future reference in case anyone else needs it, the screw I turned was a small one at the top of the carb just below where it bolts to the engine, and on the side of the carb with the throttle,governor, and choke linkages (the side towards the engine. It turns easy and has lines around the edge like it was designed to be adjusted with your fingers, and has a spring under it too.
Now I don't need the choke on all the time to keep it running. Yay!!! Thanks!