I have been trying to find a replacement fuel shutoff valve that screws into the bottom of the tank but keep failing. When you search all the typical parts sources it doesn't seem too difficult, aftermarket number 181076 seems to replace every cut off valve ford ever used except this tractor even though they list it as being the replacement for the Ford oem number. The problem is that valve is 1/2" NPT but mine is bigger. Everything else about it is correct. Does anyone by chance know where I can find the correct replacement valve?