I just installed a 70cc engine on my bike and it was running great except for the throttle isn't working right. I unscrewed the cap where the cylinder and needle go in, pulled them out of the carb, then twisted the handle and it snapped back properly. The problem I seem to be having is everytime I put the brass cylinder with the needle back down into the carb then twist the throttle handle it doesn't snap back. The brass cylinder gets stuck at all the way open. Can anyone help me figure this out? How far down into the carb are the needle and cylinder supposed to go when you install them? I'm assuming they are supposed to slide up and down rather freely when using the throttle. Is that cylinder supposed to snap back down when when I let off the throttle? What am I doing wrong?