Dunno if it's your issue; from the sounds of it I doubt it. But fwiw, on my /5 the PO had also installed one of the early Dyna models. I was having starting issues and getting a very weak spark and a double timing mark until I changed the timing plate. That fixed it for awhile until the plate quit working and stranded me, at which time I just went back to points. That fixed everything.
Another fyi, the Dyna manual actually called for bending the tabs on the advance to retard the spread of the weights. So you might check yours to see.