The J7 is good. It should run with a tan color. The coil high voltage secondary has a spark plug wire on each end. To complete the circuit both plugs must be grounded. If one plug gets fouled out the other has the potential to see an increase in voltage. However the voltage will be only what is required to overcome the resistance of the circuit. (up to the maximum that the magneto is capable of, at which point it fails) So if you ground one plug wire, the other should be able to jump a 1/2" gap to ground at fast cranking speed. . . 😯
