Thanks to the help and discussion here, I was able to put the new drive on my starter. As suggested here, I got the improved drive from YT. It is back on the tractor and works well. I also cleaned the commutator with 600 grit sandpaper.
Is there a trick to get a screw driver on the set screw of the newer style drive? Out of the box it is half covered and the part covering it would not budge with my hand strength. I scratched my head for several minutes then gently used a vice and pushed back on the mechanism and was able to just barely expose the screwhead enough to get a screw driver on it. Seems like there may be a trick to this, I don't know? Here is photo of what I am talking about.
Is there a trick to get a screw driver on the set screw of the newer style drive? Out of the box it is half covered and the part covering it would not budge with my hand strength. I scratched my head for several minutes then gently used a vice and pushed back on the mechanism and was able to just barely expose the screwhead enough to get a screw driver on it. Seems like there may be a trick to this, I don't know? Here is photo of what I am talking about.