Distributor
 

I'm running FS ignition on my B Motor, timing motor with timing light but timing light is hunting back and forward consistently by 10 degrees. Put original distributor back in but no change. Could you give any suggestion here as to what the problem could be. Thanks.

Re: Distributor
 

Could it be electrical interference? Or a bad timing light?
The only thing I can think of, if the light is good, is the actually timing of the motor is sloppy and jumping around. Seems unlikely, unless your at retard with a overlap cam. I know my Winfield SU 1at a low idle ,retarded, will work the camshaft back-and-forth, because I had a week cam spring.