i have a 2005-6 vx1100. and i have vibration issues at higher rpms only. ski runs fine below 4 or 5 thousand rpm... the higher i go in the rpm my ski starts to shake and vibrate real bad. it feels like the shaking is coming from the back end of the ski. the only thing i can see wrong on a visual inspection is that there is a small ding (dent) on one of the impeler blades. where a rock was sucked up. small as in the size of a quarter or so. can a small bend cause an imbalance in the impeller and vibrtions at speed? or do i need to look elsewhere?