Not sure what happened, but if the part needs replacing visit this site:
http://www.bikebandit.com/houseofmotorcycles/2008-kawasaki-ninja-250r-ex250j8f/o/m148915 - I linked you to a 2008 ninja250r, if it's another model, just look it up.
The prices are USD, but just call your local kawasaki...