knock knock knock ???

[JoKDX220r]

Hi all,
After a ride in a lot of single track, my engine started to make a weird sound.... as the RPM goes down it always make the same 3 knock knock knock just before it get back to idle.
I never heard this sound before...
Piston or "kips sound" ??

Thank you!!!

[JoKDX220r]

Ok, so this morning I get the bike out, warm it up and made this short video

At 0:09 you can hear the knocking sound I'm worried about...
I didn't hear it when engine was cold...

http://vimeo.com/14336546

[Griffbones]

Hard to tell by the video. The best thing you can do is pull the top end and see what you can find before it is too late.

[JoKDX220r]

Piston have a lot of carbon on top, kips valves also have a lot of carbon, I cleaned them on 2008-2009 winter, the type of deposite on valves are weird I'll take a picture of it...

Should I try the right side of the engine ? I removed the clutch cover to see the autoclutch, everything was ok...

[JoKDX220r]

Ok, I found it !!

thanks Griffbones for you're reply.

Here is what I believe is the problem.
http://vimeo.com/14393098

[Griffbones]

Yep that bearing is shot!