Yesterday I felt like putting the Morini back together, so I did. Got the second carb rebuilt, put the fuel tank on, and got it running. Somewhat to my surprise, the thing started right up and ran very well. Of course the carbs were completely out of sync so first I got them sync'd and got the idle adjusted. After that, I played with the throttle some to see what the running was like. Not surprisingly, they were way too rich. I had put in the needles from the 30mm carbs which were significantly richer than the needles the 28mm carbs had come with. So, I put the leaner needles back in, and that made a very significant improvement. The bike is still too rich and at high throttle it basically hits a brick wall due to overfueling. So, I need to get some smaller main jets as I expected, at least that's what I currently think. I need to ride the bike on the road some to see in higher gears if I'm thinking the same thing.
I'd also increased the preload on the rear shock and that helps quite a bit. Really it needs a new/better rear shock I think, but increasing the preload makes it less bouncy and that's doing well enough for the time being.