Topend keeps making louder and louder noises.

[qwerty]

I checked my valves on my 08 250 xcf-w two weeks ago and everything was in spec. Wen't on a three day ride this weekend and kept noticing more and more top end noise. It sounded like valve chatter and chain noises. My thoughts is the cam chain tensioner is dying? Throughts?

[bajadog]

Just a thought from when I was chasing down an errant "new" noise on
my 640.

Anyway, I tore off all my plastic, and tank and found a 8mm socket had
fallen between my right radiator and the frame down tube.

It had driven me mad for about 3 rides.

Not saying that is your issue, but I'd do a "sanity check" before I went
into the engine.