dont sound good whatever it is hopefully something small

 

Ok here's another video with (a bit) less exhaust noise:

http://www.flickr.com/photos/8156415...=1270994217994

Any more ideas?

I'm in a bit of dilemma whether to;

Ride it til it blows up,
Take the time to strip down the head when I'm not even sure what's wrong with it,
Buy another F3 and use this one as a parts donor.
.

 

could it have anything to do with the clutch system? sorry if thats a noob question, but i notice some change in noise when mines idling and i hold and release the clutch....

 

not trying to bum you out but oh man that sounds terrible. it sounds like my dirty triumph that had a broken valve. started and run perfect on 3 cylinders but one made all kinds of rattle similar to yours. id pull the valve cover and take a peek at your valvetrain.

 

start the motor. take a long screwdriver. and place the handle against your ear and with the other end touch against the different parts of the engine until you isolate the noise. i've used a screwdriver as a stethoscope for decades and it has always helped me pinpoint where the noise is loudest and, therefore, coming from.