I have a 05 WR-450 that has never idled properly. I haven't worried about it too much in the past as I have been slowly doing all the usual modifications that we all do to the bikes, and then I figured that I would adjust the idle after they were all done. Well the last part of my modifications were done today with the JD jet kit and when I went to look for my fuel screw, all I saw was a tiny hole inside the hole where the fuel screw was suppose to be. After searching a few threads to see whats up with that....... I now realize that I too am a victim of the missing fuel screw. (No aluminum plug either) My question is, Where is the o-ring that normally secures and seals the fuel screw on this type of carburetor? Is it on the screw itself, or does it seat inside the fuel screw hole? I am now planning on getting the Zip-Ty fuel screw and wonder if it comes with the o-ring, or do I need to get one. Or does it even have one? Any help/advice would be appreciated.