Yes,The bike plugs are lighter in color.My bikes have magnetos ,which have a weaker spark at low engine speeds than a battery ignition, so the plugs are darker if you do a lot of riding around town. I have noticed over the last few years the bikes tend to run a little rich at idle, with the same timing and carb settings as used in the past while the plug color indicated a leaner mixture at higher cruising speeds.Other riders of vintage bikes report the same thing.The blame is put on fuel designed for newer injected vehicles, not so dependent on fuel atomization as on a carbureted engine?
For part throttle or cruising jetting,I jet leaner until drivability problems are encountered, then go richer until the flat spot is eliminated.Plug color is secondary in this case.Wide open throttle jetting is a different story.
