So here's what I got, my moby 50v '78 was running great for the past two months after a mild port job, new high comp head installed, dellorto 15.15 sha with intake to match. It starts up, it runs on the stand and idles, it revs all the way up while riding but sometimes will just die. I know what you thinking condensor. Nope changed that put a new one on. Ground wire seems fine. New plug. Replaced the rings when i did the port job so compression is also fine.. Not really sure whats going on? Any ideas? Oh and it never loses spark through this whole process and the gas is clean.