Should be ok to try it again, especially since you set it slightly richer. Mine seem to like to run a click or so rich. Just a thought since you mentioned the fuel tubing inside the tank, and had problems with it cutting out in flight and defueling... Is it possible that you may have a hole(pinhole) or even a cracked piece of fuel tubing in there somewhere? Possibly not noticeable on the ground, but maybe vibration and forces in flight just enough to release the pressure in the tank. Seen it happen once or twice, might be worth another very close look at the tubing...

Jaka's advice is all good, and exactly right. I am however, wondering what the "sucking tongue test" is also... never heard of that one before either! (15 years of flying)

When you tip the plane up while running, you're checking to see if the motor leans out or quits. If it does, then you need to adjust your needle or fuel tank setup so that it runs consistently regardless of orientation. This will also tell you wether your clunk has shifted to the front of the tank without having to take the tank out of the plane and take it apart to see.

Good luck! [8D]