My TT-Pro .46 dies when I pick it up vertical. It used to die whenever I touched the throttle, then I could slowly advance the throttle to full open slowly and then I could advance it a little quicker. However it didn't sound like it was running at peak. And of course it dies if I try to pick it up.

I took the fuel tank out and ensured that the lines weren't clogged. The air vent is clear and near the top of the fuel tank. Lines aren't kinked. Any ideas?