82 KZ1000 coil mod question

I added the relay modification to my coils in hope of a better spark. Bike will not start but I checked and with the switch on, both red wires on the coils have 12 volts. Bike was last running prior to the mod but had to be towed and the clutch popped. It appeared to not run on all cylinders at the same time.I have replaced the plug wires but not the plugs, they look O.K. I have pulled a plug out and the spark looks weak. Can both coils go bad at the same time. The bike was running several years ago. Thanks for any advise.