The Ninja family starts in 1983 with various model; a ZZR-250, ZX-250, or as the GPX-250R. One of the earliest generations, the EX250-C, was given the name GPZ-250.

However the GPZ-250 had a six speed? So did the GPX-250R

http://www.motorcyclespecs.co.za/mod...r250r%2089.htm

I am just not finding an engine that matches, the raptures.
http://regalraptor.com.sg/regalraptormotorcycles/

http://www.motorcyclespecs.co.za/mod...ZR250%2090.htm

http://en.wikipedia.org/wiki/Kawasaki_Ninja_250R

The 250 air cooled Regal Rapture “before water cooled” engine specs have it the same as the Honda CMX 250 that being 53x53 and that being a 234cc…now the engine is at 320cc with a bore and stroke of 63x53.

I have to wonder about that…..
Air cooled Rapture
http://www.flickr.com/photos/worldwi...es/2769931381/
CMX250
http://upload.wikimedia.org/wikipedi...mx450rebel.jpg

Not only that the engine keeps growing the Johny Pag versions have a 270cc engine at 57x53.…the Dadywyn keeps growing.
http://www.johnnypag.com/motorcycles...er300Specs.pdf

I have always struggled with the concept that Lifeng added water cooling to a air cooled engine, maybe the engine is now based of another design…but without some proof I am not believing it. I think they are growing the CMX and designing as the go….its now their engine.