Ok, more progress, I think. Before, I could 'goose' the throttle, and I would see black crap come out of the exhaust. Now, it wasn't ever anything I was concerned about, but I always thought it was weird.
Anyway, I discovered that the idle mixture screws were 3 1/2 turns out, and thought that might be the cause of my rich condition. Re-seated them and went 1 1/2 turns out. Played a little bit with them, but 1 1/2 turns really seems to be the right spot. No hesitation at all, no black streak when I hit the throttle. Boat starts great, seems to run great as well.
I need to get it on the water and see where its at when under load, but hopefully, that has fixed the plug fouling issue.