The guy I had rebuild the starter/generator in my little Sears tractor told me that he would bet good money that the cause of the starter/generator failure was probably a bad voltage regulator. After checking with my dad, it is the original voltage regulator to that tractor; or at the very least, it hasn't been replaced since the early 1980's. The problem is that I have absolutely no idea what the part number for the regulator is.
I can't find any markings on the thing other than "Delco-Remy Made in USA"
The engine is a 16hp Briggs and Stratton I/C series horizontal shaft single cylinder. The electrical system is 12 volt, negative ground.
Even if I had the tractor's parts manual, it originally had a 14hp engine (although it was also a Briggs and Stratton I/C).
My M is currently sidelined with a severe hydraulic leak and my grass is starting to get a bit tall.