Those are good thoughts, but I don't think being too lean is the problem.
I should have mentioned above, but after that started happening, I backed the needle off and it still did the same thing. I actually backed it off like 5 turns until it was slobbery wet. It still will run on the ground, but as soon as I held it upright, it quits immediately. I noticed some fuel was spitting out from the cylinder head, so I tightened those screws up. I thought that would have been my problem, but that didn't help either. I am still thinking something is goofy with the tank or the clunk myself.