Took my recently purchased 700XX down a dirt road to see what kind of top end she had and under accelleration the a$$ end seemed to wander side to side making it seem very unstable. The road wasn't really smooth with some studder bumps. Was this the irs in action? If so, do I need a stiffer rear sway bar? My 700 Grizzly never did this down the same road but it also didn't accellerate like the 700XX either. Any other possibilities??