Need help tuning Quickfuel carb
Wrong cap for MSD, actually for almost anything. However, I can't spot any tracking in there yet. The rest looks normal to me. You need the kind of cap with track-busters, the little circles around every tower and two or three around the center tower.
Maybe , just maybe you could be getting some crossfires in the cap, but I've never seen it happen at a particular rpm, and then go away.
Or,maybe your rotor needs to be re-phased.Retard your timing about 8 degrees and disconnect the Vcan, then roadtest.