timing retard for starting

If you all want some start retard in a mechanical distributor, it is done in setting the springs. If there is some mechanical advance at idle speed, none at cranking, that means timing is retarded when cranking. An example: if light spring holds back flyweight at 100 distributor RPM for zero advance, yet advances 6 degrees at idle. There will be 6 degrees retard when cranking engine at 200 RPM. A timing light can be used to measure, when cranking. A simple feel check of rotor is often a good test. The rotor is twisted, and released slowly, should return to stop.

Most set base timing at idle and have no idea how much mechanical advance is in at that point.