Help- can someone offer advice why the pressure line to the fuel tank keeps splitting on my YS 53? The fuel line is fine but the other line has split every time I operate the engine. I have tried different fuel pipes, checking the pipe for nicks and kink and removing all sharp edges etc. I remove the tank and replace all the line, set the engine up and run it and its fine- the following morning I go to the field and the engine wont start easily or run properly. A quick check shows the pressure "in" line to have failed. Its messed up several week ends now and I can't think of any reason why this should be happening.

Hitting on the cowl, or somewhere between the tank and engine?