That sounds like a pass code phrase you'd hear in a bad spy movie. Anyway, the flywheel is in the shop, and they are going to put it on the machine in the next couple days, to test it and balance it.
While I was there the machinist said something that's got me a bit worried. He looked at the flywheel and said that he'd be surprised if it was out of balance because it was a "zero balance" flywheel. He asked what it's bolted to. I explained how the taper-lock hub mounts to the motor and the flywheel to the hub. He asked if there was any chance the hub was out of balance.
The truth is I have no idea if the hub is in balance. I mentioned yesterday that the motor did vibrate a bit once I'd removed the flywheel. Could that have been caused by the hub being out of balance? I just don't know. There was definitely an improvement in balance when I removed the flywheel. That stands to reason that it was part of the problem.
Let's suppose the hub is out of balance. The question becomes would the flywheel being bolted to the assembly exacerbate the small wobble I saw once the flywheel was removed? It stands to reason that if that were the case, having the clutch plate and disk bolted to the assembly would make it even worse. That's not what I saw. There was no appreciable change in wobble between having the clutch plate mounted and not.
If they find the flywheel is balanced and the problem becomes the taper-lock hub, I'm not quite sure what I need to do to get it fixed.
UPDATE: The shop just called to tell me that the flywheel was indeed out of balance. 6 grams to be precise. I should have it back this afternoon and I can mount it up and see what we get. Stay tuned.