Y.S. .80 tank and fuel problems

[Chrisk7]

I just set up a Freya Evo .90 with a YS 80 and on the first start on the bench the tank started leaking up top near or on the seem.

I have the YS set up with a Formost one way valve off the pressure fitting on the engine back plate to the top molded in tank fitting.
I have the main fuel pick up going through a Dubro fuel valve to the carb and the other fitting going out the side of the heli with a fuel pinch style shut off clip for relieving pressure and venting for filling.

My question is, do you have to run the high pressure off the crankcase for the YS to run with the pump on the engine or can you simply use muffler pressure and block off the pressure fitting on the engine back plate?

Is there a fix for these tanks on the Freya's? They seem to be easy to split.