I'm wondering if someone can help me out here. I've checked and rechecked my valves and they are right on. What happens is when my 08' 750 is warming up everything sounds fine (except the clutch noise) But only when it is completely warmed up I start to hear a clicking/tapping noise from the left rear timing chain area. It's faint, but it is driving me nuts, you can really hear in the rear exhaust area. I only have a 1000 miles or so, but has anyone hear experienced this? Can I have a loose timing chain or warn guides? I've checked and reset the outside tensioner with no change at all. Any ideas here would be much appreciated, I want the noise gone, but do not want to replace chains and guide unless I know for certain that it is the problem. Thanks again for any incite you can give! Should I run it and let it get worse or tear it down and replace everything and is aftermarket better then OEM?

 

Yes, it sounds like your chains are worn out but not the timing chains. More than likely they are the intermediate chains (2), one for each cylinder. The part numbers are:
920570073 for the front.
920570074 for the rear.