Clean any connections very carefully with contact cleaner. Don't use anything abrasive on them. There's a very fine plating on each side of the connection, and once you break through it corrosion will build up much faster in the future. I often see posts where people say to "rub the terminal with some emery cloth", and it makes me cringe!

If it all worked, and suddenly you have no spark on one side, then it must be electrical. There aren't many components, and you've swapped most with no effect.
Once you are sure all connections are clean and secure, check the pulse coils at the flywheel. Do you know anyone else with an MC21 you can try your PGM-III on?
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Andy.
NSR-WORLD.COM
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