I am trying to change the fuel filter element on my CT41. I loosened the drain plug as instructed and was waiting for element to drain, but it never quit draining I think the whole fuel tank would have emptied had I not tightened the plug again. Is there a fuel shut valve that the owners manual did not tell me about? If so, where in the heck is it?? I would appreciate any advice from some of you seasoned tractor owners!