vibrating is a better word for it, it would vibrate, between 19 and 20, but it was constant, hence rythmic.
yes I have a shop manual, I had been running the truck with the timing on the BB, I doubt that 6-8 degree of advance is too much. Running it advanced didn't make it run better or worse. It only ran better after I pulled out the choke knob
pulling out the choke richens the mixture. correct? which would mean that I'm currently running lean. correct?
