You now know how to make the problem repeat. You need not even rotate the prop through a whole rotation. Just flip the magnet back and forth under the ign. pickup. For a test, try putting a jumper wire from the sheath on the plug wire, to the crankcase and see if you still get the glitches and let us know the results. You've found out 2.4 isn't imune to rf noise, it just has more tolerance than 72.