I have a 1979 Kz 750 that is starting to have problems. While you are riding the engine, will just quite. However, when you stop, it will fire right back up and run fine. I thought that it might not be getting gas but that is unlikely due to both cylinders not firing. I drained the carbs and saw nothing like water or any foreign material. My flow rate seems to be good from the tank to the carbs. I have looked at most of the connections for the electrical for shorting points and bad connections. My thought is the coil might be failing. Is there a way to test this theory? Any thoughts on the matter would be appreciated thanks.