HI , I have a 4010 with usx 20 carb . Last fall it started using excess fuel , 7 gallons in 1 hour . I looked at the carb and found the diaphragm was not flexible , ordered carb kit which contained diaphragm , spring , needle , seat and gaskets, cleaned and installed . Same issue , excess fuel , and found out turning lower needle adjustment all the way in had no effect , kept on running and using excess fuel . Also ran the top needle screw all the way in with no effect . This tractor is not being worked hard , it is running a wood splitter at approx 1000 rpm and has never used this much fuel . Any help would be greatly appreciated .