Posted by Glen Id [72.173.87.91] on Thursday, April 12, 2012 at 21:51:31 :
In Reply to: Re: using your timing light posted by mikey stone [71.39.211.42] on Thursday, April 12, 2012 at 10:51:34 :
Right. I had a reading of 4 and the book says about 8-10 to initiate vacume advance while increasing throttle.
As soon as the throttle butterfly passes the second idle orifice port vacume becomes manifold vacume at 19 and the diaphragm moves the contact points another 17 degrees. for full advance if rpm is high enough for the mechanical advance to move 12 degrees.