Well, if we are going to keep spit balling. Then my brain computes with the minimal information and taking your description at your word (and assuming we are using a similar motorhead vocabulary) . Plugs are at least one or two ranges to cold. What are you running?
But.... I went back and re-read your initial post. You have to locate what happened during the incident to cause this. Do you have good ground straps from the motor to the body. Recheck them. Recheck all your grounds. Did you crack your cap? It is showing any arcing? Try a different one.
Is the ticking noise still there?
