To the question of how recently the starter was rebuilt, it was done last week. Literally everything was replaced in two phases. First phase was everything but the armature. Last was the armature. Completely new armature, new high torque stator coils, new brushes, springs, bushings,spacers, foot switch, etc. The shop checked the Part Number of the case, confirmed it was for 6 Volts, then ordered all the new parts as specified for that part. As I said in an earlier post, I also have tried running it on 12 Volts and that didn't help when it was warm.
Based on some of the input I am getting here, I may see if I can work a deal with the local NAPA dealer to buy a rebuild starter with the understanding that I can bring it back if it doesn't solve my problem. That potentially could at least put to rest if it is still this starter. The main reason I did all the rebuild was that they told me it was probably a heat soak problem. Changing all the parts should have eliminated that possibility.
I still want to try some of the other suggestions if I can get some time tomorrow. I will let you know how things go since it seems that others have had the same problem but solved it in several different ways.
Thanks, again, for all the help. You guys are great and I can't begin to tell you how much I appreciate it. This has been a pretty humbling experience.
