I am not sure how old the ATD is. I suspect it is ok since it ran great a few weeks ago. Ed Strain rebuild the armature and has a good reputation so for now i'm going to work on the assumption that the mag is fine and the problem is operator error (me). My local guru (Wes Scott Cycles) re-assembled the mag for me and tested the spark etc and reported it to work great. The points, while being a giant pain in the butt to fit a wrench in to adjust...appear to be good. None of the excessive sparking that was mentioned and they are not corroded. I just got home and waiting in the mailbox was the degree wheel, shaft, and piston stop so now i have the tools to accurately check and set the timing. That is the next order of business. Hopefully i'll be able to report back that the problem is fixed. Thanks very much for the ideas so far