Hiya Folks, I have a CBR1000F. I was riding along on all of a sudden the bike started to make a lot of valve noise and lose power. I took the Valve cover off and I found that the locknut on one of the valves had come loose. The bike had ran for a few mins with the exhaust valve clearance in one valve at 5mm! After putting the locknet back on and resetting the clearance the noise is still there (although not as noisy), and there is a noticible lack of power. So what would be wrong? I know the piston isn't holed as it isn't blowing any smoke. Any ideas?