My 2014 R1200GS has always had a ticking noise from the right hand cylinder from new. The techs at my local shop here in New Zealand checked it out but like many have found, couldn't find a cause. The consensus was that some do it, some don't. Two years later at its 40,000 km service they again raised it with BMW New Zealand, who supplied an updated exhaust cam with a slightly different decompression mechanism. All done under warranty, and noise completely gone. It appears that on some, the older style mechanism would rattle, particularly if there was a slight stumble at idle. If yours does this, there is now a fix.