Sounds to me like the igniter is evaluating the two signals of throttle angle and rpm to improve
driveabilty performance. Standard MO for modern day ignition systems.
Seeing as a dyno run is a test of WOT (wide open throttle) only, all bets are off as far as
driveabilty. Plugged or unplugged, at WOT the ignition is going to go for it's full advance.
A more accurate test for the plugged/unplugged option would be a half throttle dyno run. Mark
a spot on the throttle grip to twist the grip to. Nobody ever tunes the lower throttle
position circuits on a dyno. Just the main jet circuit.
