I have a 1974 Sporty Ironhead with a Prestolite starter. Since the day I bought it I have been having problems with it. First, the starter clutch went out. Fixed that no problem. It started right up. Rode it around a little and it was great. The next day I went to start it and it sounded like to starter clutch had gone out again because it was just spinning. I took the starter out and the gear on the armature had been stripped clean. I replaced the starter and in the process of trying to get it to start I heard a loud "clang" in the primary. I took the starter out again and this time two of the teeth had been ripped off clean. This time it did a little damage to the starter drive gear itself. Can someone please tell me what is going on? Thanks for your time.

 

sounds like the timing is way advanced when starting. check the fly-weights to see if there stuck in full advance.