I have been having a bad run of problems with my bikes of late, that all started last July with my BMW, when the EI went south.
I wonder if that original fault was caused by a failing Dyna coil, or is the fact that the coil has now fully packed in, just a coincidence? As it happens I have learned how to test a coil, and it is the secondary windings that have failed.
Next problem bike is my old 75 shovelhead. this thing is killing batteries at an alarming rate, When I got the bike the battery was fine, but a month later it was toast, so we fitted a new regulator/rectifier, and also a new battery, well two weeks in and the new battery wont take more than 12V, even after being on a charger for five hours? could I just be unlucky and have a new duff battery? we shall see.