I met another 03'zx6r rider yesterday, he was telling me that he was having a build up of oil at the bottom of his coolant reservoir(left side of bike). He went on to say that every 03' zx6r owner he met was having the same problem. I haven't had a chance to check mine yet, but can you guys check and see if you have this problem?? He took his bike to the dealership and they said that it was oil from the manufacturing of the radiator or some shit like that. You may have to tilt the bike a bit to see it. Has anyone ever heard of this?