[C. Clark]

All the above is probable. A major problem with rebuilt generators is the same problem with rebuilt carbs, they are on the third or fourth or more generational rebuild. In essence they're worn out, and should'nt be rebuilt at all but rebuilding companys continue in order to have something to sell.
I located a local fellow who rebuilds starters and generators semi locally. I may not always like what he says but at least the money is well spent. Perhaps you have some one in your area....
Happy motoring,
Chas.