Didn't i say to put the points back in it first thing? Anyway Pertonix units do that at times, they will just pop. If you go back with a pertonix try a pertonix III it is better and has a built in adjustiable rev limiter.Or if you don't trust it, crane has a unit too. You need a ballast so the points and coil will last longer. But i don't know about a MSD .