Was riding and it shut off about a block from the house. I have replaced points, condenser and spark plug. Tried resetting timing per the manual. Bought a TDC dial gauge just for the procedure. TDC and turn backwards 1,8mm and all that business. 
Anyway, ive done the procedure at least a dozen times and best ill get is an occasional backfire mostly through the exhaust. Ive done some research and now think maybe the woodruff key on the crank has broke or bent. My question is whats the thread pitch on the end of the armature so i can pull it to get to the key? And is it a right hand thread or left hand. I can hit Fastenal to see if they have a bolt if i have the relevant information.
Thanks in advance for the help.
Bike is a 1970 AT1.