I've gone through my '79 Husky 390 OR - it has good compression, seals, reeds and the coil produces a healthy spark. Problem - after I start it (not too friendly), it just doesn't have the "giddy up" that a 390 should have. I'm assuming the the Motoplat coil also has electronics that advances the timing (like a CDI) inside the plastic enclosure. Maybe the coil is OK but the spark is not advancing? Or is it supposed to advance? I can get a new coil that works on all these old Huskies - it appears to have a module mounted on the outside (according to my source). It's made by a manufacturer other than Motoplat. Anybody have any insight on the problems that can arise with these old Motoplat ignitions?