I have a question about the fuel tank. My gas line is kind of rigid. The line that goes from the tank rubber stopper inside the tank (the one that picks up gas, with the clunk on it) is kind of rigid (not flexible enough). When I invert the tank it does not bend as it should. Therefore if I go inverted, it will be sucking air. I used a piece of the yellow fuel line. Is there something better (more flexible) one can use? Where can I get it?