Can't recommend the Motorcycle-Usa forums, they treat you like crap if you don't agree with something. I am up in the air about www.kawasakimotorcycle.org. There are a lot of nice people there, but if a regular believes something, don't argue. Even if they call you names and lie about you, you WILL be moderated for defending yourself.
Check out www.ninja250.com. Even if you don't ride a 250, they are a good group and will help you with what they can. The FAQ is great as well for doing bike maintenance. Best I have found.
A forum community dedicated to all Kawasaki motorcycles including the ZX-6R, KLR 650, Ninja 250, Ninja 250R, and Vulcan. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!