i just spent the last few days helping a friend check out some gixxer 600's. He's got his heart set on one. Now Im just wondering if anybody has any experience with them and if there are any common problems I should look for. The first 2 I saw were a little unresponsive (carbs?) and the second didn't sound smooth and deep. The third and best running one i came across had a rythmic growling noise at 6000rpm in 2nd gear, so i assumed hardened gear and a possible broken gear in the future. Any other problems I should be looking for? or any advice about these bikes from people who know more!