If I had

one stuck that bad heres what Id do. Cover the intake with a paper towel then put the carb back down over the studs. Find the best fitting screwdriver you can that has a square shank like a Craftsman, or Snap-on that has a hex under the handle. Hold down as tight as you can while using a wrench and turn that thing off! In fact before you do that give it a good rap straight down with a hammer (now don't go crazy) that will help loosen it up.Good luck, Bob C