Re: Spark Advance Snap-back Check ?
Sounds like weak CA springs. I can hardly manual rotate my distrib rotor/shaft without removing the point plate and assisting by pushing on the slotted bars. The advance wants to be actuated by centrifugal force not by manually turning the shafts. It is true that the springs should be weakest at the lower end but they should pull back to start, with no rotation unless they are simply hanging up. (rusted/corroded etc.)<br /><br />It would seem to me if your springs were weak, it would let the distrib max out early but not dither back and forth at WOT, but maybe not.<br /><br />Best thing is to find a distrib guru in your area and have him test/inspect it on his distrib machine. They will also check for worn bushings.