Don't adjust it too tight. How I do it: Aim for slack in the middle of the range shown in the manual. If I recall correctly, about 1". But after I loosen the axle nut, I actually adjust a little extra slack in the chain (I think about a 1/4" or so, over and above the 1"). What I find is that after you have retightened the axle nut you end up with the 1" slack you were looking for. You should check the slack, with the bike on the sidestand, after you are done, or you can take a trip around the block and check it when you get back.
I am finding after break in the chain doesn't stretch too much.
There is a guy down the street from me with a Gixxer600. He must leave at least 3" of slack in his chain at all times - never adjusts it. Not good.
