As long as I`ve owned my bike, the noisey valves were driving me nuts. I have had 2 different bike shops check my valve clearences and both said they were within spec. So yesterday I had installed a set of Cobra Slashcut slippon mufflers and a Dynojet carb kit and diconnected the AIS system. Now can you say LOUD!!! I guess I will never hear valve noise again. I just hope the local police dont make me take them off.