I'm finding it's wearing them out doing a lot of off road riding. It was OK until the percentage of off road overtook the on road usage.

@edgarpicazo5993 it's not like other timing chain tensioners in that it does not have a non return ratchet assembly. So simply remove the old one and fit the new one. Do not start the engine without either tensioner installed as you could cause catastrophic damage. Have you considered a non hydraulic manual type tensioner?

Good to know thanks. I have, there is a company called SoCal BMW that sells the manual ones. Kind of nervous to try them out. I'm basically replacing it as preventative maintenance since I ha e 16k miles on my 850GS.

I used a short socket and ratchet wrench to start it off, then an open ended spanner to wind it out. Put a piece of good quality cardboard against the radiator to stop it getting damaged.

Yes, the noisy start-ups have now stayed away for around 5,000 miles and still no sign of returning. Could not tell any difference between the new tensioner and the one I took out when operated by hand on the bench, but clearly, the new one is good, and the old one is defective.

Thanks for the reply

I bought a new one from BMW and although it seemed to be exactly the same as the old one, with binding etc when manually operated, it HAS fixed the issue. No more noisy rattling on start up. Cost around 80 GBP.

@@motomeltdown Okay thanks for that , Have been looking at a new Trophy model and have read about this problem a few times .

@@imgoingforaride I asked the BMW main dealer about this issue and was told they had never come across it before??? The original cam chain tensioner went bad over about 3 or 4 rides, from no issues to sounding like a terminal engine failure. It only affected cold start ups, once it had been fired up and run up to temperature for the day the cam chain remained quiet for all subsequent start ups on that day, but then noisy again the following morning.

Strange thing to happen . Hope it fixes it for the future of the bike .