98' XJ600n Cam chain tensioner

Hi, I have recently bought myself a 1998 Yamaha XJ600n, the cam chain is beginning to make quite a noise.

I have teken out the rensioner and the little ratched is nearly worn off, so its obvious that the tensioner is dead.

I have modified the tensioner for now into a manual tensioner but I am looking for a new one.

Can anyone suggest anywhere to buy a tensioner, apart from the main dealers, and online auctions?

I would be very geatful for any suggestions...