I know there are varying opinions on Pertronix here. I've owned a bunch of air cooled VW's and ran the Pertronix for many years and many miles without issue. From near stock daily drivers to bored and stroked hi-po engines. I'll take a chance on it in this application.
During normal engine running, the ignition runs through the resistor cutting the voltage down to 9v. During cranking, that "third wire" bypasses the resistor and sends 12v to the ignition for better starts.
I believe this may have been the cause of my low speed "hiccup" or miss. I took it for a very short test drive last night and it seems to be gone. Longer drive today.
"Voltages over 7.5 V will fire an Ignitor in a 12 V system. However, the voltage can be lower if the resistance in the circuit is higher than it should be resulting in misfires or no spark at all. "
