Re Backpacker's thread: a similar thing happened at E. Mids a few years back. As I understand it, a rather large lady tried unsuccessfully to get a fuel sample from the gascolator drain on a PA28 where the previous pilot had left the fuel cock in the off position. She pushed hard enough to bend the pipe inside the cowling and jam the mechanism just inside the hole (that the drain sticks out of) such that the drain was held open by the edge of the hole. Engine failed due to fuel starvation just after takeoff and a few runway end lights were taken out on the subsequent land on. Thank god for long runways.