chain

how do u tighten a chain...on a yzf600r

You'll need to refer to your owners manual for the proper spec, but there should be 2 adjustment nuts, 1 on each side of the swingarm, that correspond with markings on the swingarm that you use for adjustment.

:iagree: just a hint.. its easier with the bike lifted off the ground.. you need to leave some slack in the chain.. your manual will tell you the correct amount of play you should have..
In your manual look Under periodic Maintenance
-Jimmy