See my thread above, 2nd paragraph.
Yes, I registered for the Yamaha forum yesterday and never received a confirmation. I need to try again this morning.
UPDATE: I did get the powerhead off last night using a heat gun to warm the metal and a couple of new, thin drywall knives. I had the hoist pulling up slightly on the powerhead and with a few taps in with the drywall knives it started to separate.
Now i'm down to the 2 bolts holding the bushings. The heads are badly corroded and no room for a socket.