You talking about the main jet?.....Yeah it should have a hex head on it too, you can turn that with a wrench if the head is snapped off where a screw driver would normally go, just be careful, the tube the main jet goes into is plastic, it could be cross threaded in there, if thats your prob. then kiss your carb good bye!
Hope thats not your issue, but when i got my warrior the carb on it had the same issue, someone cross threaded it and it would just spin and spin in there but would not back out, that tube is not replaceable so i had to get a new carb.... Good luck, let us know bro!