This type of problem can occur if the vent and carb lines are accidentally reversed. The engine may start and run on the ground while it's full enough to draw fuel through the vent outlet, but will die once it's in the air and the throttle is punched.

gg3606 said he checked the tank, so hopefully he confirmed that the carb line with the clunk is attached to the carburetor and the vent line is attached to the muffler. Other problems that could cause this type of sudden engine stop include:

-a plugged exhaust nipple on the muffler cutting off air pressure back into the tank
-a tear in the clunk line will allow the engine to run fine but cut out and die when punched to full throttle

Check these things also. If you believe you simply need to get a good tune, remember it's easier to lean an engine that is too rich. If you try to tune an engine that already starts out as too lean, it can be frustrating trying to get it dialed in. With airbleed carburetors, turning the idle screw in richens the engine rather than leaning it out; this can be confusing to pilots who normally only run twin needle carbs.

Good luck, and keep posting questions and results.