Decompression valve. There is a solenoid under the gas tank, with a cable running down to a lever that partially opens the exhaust valves during starting so the starter can crank the engine over easier.

Good pictures and explanation of the whole decompression system here:
http://suzukisavage.com/cgi-bin/YaBB.pl?num=1169356966

See which way the spring is pushing it?  Push it and see if the noise changes when you do. Look at it,is the cable tight? Feel of it. Is it delivering a vibration,like it's getting tapped on?

Yes, if it's too tight it can cause the rocker to hit the decomp cam.

That cable needs to be pretty loose.