Spent some time on the "O" today.
Started out by tearing down the S/G. Everything looked pretty good in there. I checked for any signs of heat but everything looked tight and good. I blew out the armature and only a little carbon came out. I cleaned up the brushes but really, everything looked like it SHOULD work.
I installed it again and it did a little more than before, but not much. It would spin, but with very little force. After a short time staring at a non-working machine and trying to do something akin to the Cadet-Wisper-er, I wondered if there might be something with the starter coil working against the charging coil.. I decided to remove the "F" terminal on the S/G and tried it. The pulley wheeled over in a hurry!
I removed the battery (-) and checked the points in the regulator. One appeared burned so, I cleaned it with sand paper and installed the "F" terminal wire again and it fired right up.
The regulator stuck one time powering the starter side of the S/G and when I shut off the tractor, it kept spinning like it was trying to start. I'm wondering if it wasn't acting up again while we were using it and it carboned up the points. I believe it's about time for a new regulator.
Just wanted to let everyone know what I found out.