Greetings all.  When I start up my S40, with the transmission in neutral, when I rev the engine, a high pitched noise follows the RPM of the engine.  This noise can be heard comming out of the tail pipe.  The bike has 14,000 miles on it.  The valves were last adjusted at 1500 miles.  Has anyone heard of this before?  Could this be cam chain noise or valves?

maybe your exhaust developed a leak and it is whistling through it?

both valves and cam chain are ticking/knocking/clacking sounds, valves from the head and cam chain from the right side by your ankle (or so i've been told).

maybe do a quick leak check on your exhaust. at 14k miles you are over-due for another valve adjustment (i think those are supposed to be every 6 or 7 k), and just short of the typical time for cam chain issues (15k, +/- 5k usually)