Originally Posted by Lornce
On older bikes, /5's, 6's and 7's, I like the Dyna electronic ignitions. I prefer modding the advance weight springs to slow the advance curve slightly, but still allow it to go to full advance at revs above 3.5k-4k. (easily done by shortening the spring and using the next winding to secure it to the advance weight pins).
One significant operational advantage of the Dyna ignition over a Boyer is that it will still fire if for some reason your battery voltage drops below 12V. Even if your battery drops as low as 6V or less, you'll still get an ignition spark if you can kick or bumpstart your bike.
A Boyer ignition won't fire with a weakened battery. Forget the exact cut-off voltage, but it's not far off 11.8V, if memory serves.
I was under the impression that Boyer had done some changes to their units that allowed them a little more wiggle room under 12v. (I thought I read that somewhere)