I have a red 03 636 stock and i took it in to the dealer because i heard clicking noises other than the reed valve so my mechanic says to put it on their dyno for him to hear it better supposedly the valves need to be readjusted and clearance checked so they called kawi and they are going to pay for it because it sounds like it really needs it but only makes sounds when its cold or sometimes if its sat for a little bit??? anyways bike makes clicking noises but get this puts 106.3 bHp out the rear wheel without the ram air effect . this bike is nothing short of badass imagine what a ti system and pc would do.