I've got a 1981 cb750c. About a month ago I fired it up for the first time after sitting in my garage for 4 months over winter, had just done an oil change, and bought new plugs, it ran like a top. After that I pulled the carbs off to clean the floats, put the carbs back on today to run it and both cylinders 2 and 4 were not firing (cold headers). I know what you're thinking, secondary coil must be junk. It's not. I replaced it with a perfectly working one from my cb900 and it did the same exact thing. Pulled all the wires they all had spark for cylinders 1-4. Racking my brain here, any suggestions would help.