Too much timing?
I was under the impression that the plate simply limited total advance, and the springs were for tuning the curve.
It's not quite that simple.
And that's why I wrote what wrote.
The OP wasn't at a point yet to get into that.
In summary:
The curve shape depends on the tension on the two springs. Changing the start and stop of the weight position changes the tension.
Details of three ways to adjust and change tension at different rpms in
this post.
vacuum-drop-when-shifting-from-park-to-gear.473761/page-3#post-1973152679
Example of springs and slots found in many electronic distributors
Shorten the slot on the inside like Rockable did
here.
Then its pretty much a pre-CAP advance.
Further discussed with Mullinax and Kendog
360 Tune Up
While this is all very helpful for getting the most out of mid rpm and part throttle (with vacuum advance), for high rpm applications, leaving enough room for the springs to compensate for slew rate is also important.
For example see Bill Baldwin's video in this post.
Mopar orange box retards timing?
or @YellowRose's tests here;
Ignition box retard with RPM
and a video he posted showing that here
School Me On Distributor Performance
