I have a tinny vibration sound underpower just over half throttle , took the seat off and tapped on exhaust shielded rear part under seat ok but tapped on the front part of the exhaust shield just under front seat area and vibration sounds there . Like something's loose inside . Seems like that's where it comes from anyone else finding this and is there a fix . 2 up c600 . Other than this no problems great 2 up