help with throttle saitek X55

I don't see an option in the controls for just a single throttle axis.  It wants throttle 1,2,3 and 4 so I set my throttle up for 1 and 2 axis.  When I go into game and start to move my throttles is sticks in reverse thrust and doesn't start to move out of reverse until about my throttle moved 25% up.  Then it starts bouncing back and forth and doesn't smooth out until I have pushed my throttles about 75%.  Any help would be greatly appreciated.