My friend has a Ninja 500 that recently started giving him some problems. He said it was running fine then the next time he went to ride it was hard to start. When it did start it has no power and idles lower than usual. He also said it blows white smoke from the exhaust but I didn't witness that when I rode it.
The oil looks fine, the coolant tank looks like it has some black residue in it but when I dipped a rag in the coolant looks fine. It has around 12k miles.
