Possible Cam Tensioners going out at 18K

I'm getting the dreaded clacking noise, mostly noticeable at idle. Is 18k miles too early for that? Should I be looking for something else?

I have clutch basket rattle on my 6g; pull the clutch it disappears... obviously the sound emanates from a different spot, but this could be something to check - either problem would be odd for an 18k mi bike

From what I've learned over the years there isn't really a good estimate on how long CCT's last. Every bike is different, on my VFR I've had it go twice. Once at 22,000km & then at 45,000km. My FZ-1 on the other hand had one go at 15,000km, but I switched that one to a manual tensioner instead of the oem automatic one it's now done over 60,000km and I've not had a problem since.

Best thing I've always been told is CCT's will make start off as a ticking noise that slowly gets louder as the revs pick up. With VFR's though they make a noticeable kind of knocking noise down low that'll cut in and out at idle and you can almost feel it knocking as you take off from a stop. 

At the end of the day though man if you're really concerned and aren't sure, just change em any way. No harm in spending 40-50 bucks at most to just swap em out, not a very hard job to do and there is even a guide someone did over on vfrworld.com if I remember correctly.

FWIW, i have the maintenance records for my 113k mile VFR800, and it makes no mention of cam chain tensioners.  When i got it, the front chain was making noise.  I got two CCT, gaskets, and the two small cups for the noses of the tensioners for $165 shipped from partzilla.  I've read the front tensioner is a far more common failure point, and i certainly could have just done that one and been all set.  I did the rear tensioner for piece of mind.  I believe the tensioner alone was somewhere around 75 bucks each.

I understand that it's recommended to do both at the same time, but what's the worst that could happen if I don't? Just the potential of having to do the other one in 1,000 miles?

If you're going to replace the front CCT, I would recommend you  synchronize the starter valves too since the throttle body will be exposed.  And if you haven't replaced your stator, this is also a good time since it makes it easier to "guide" that stator wire across the engine, underneath the throttle body.  Save yourself a lot of time doing all this at once.

Stator wire?

The wire that comes out of the stator to connect to the wiring harness.