Took the tank off, removed the servo motor screws so i could oil the cables and shaft better and guess what? the sound from under the tank now seemed to be coming from elsewhere! I turned the servo pulley a few times and then turned the ignition on to reset it and Yes, the sound seems to transmit up the headers! So, sorry for wasting your time, while i had the exup valve out i straightened it a bit in the vice and now its spins perfect. ( I accidently bent it a bit a couple of years ago and sometimes it would stick)
Thanks