Kawasaki Ninja ZX-4R Patent
The general design is that of the ZX-25R

A patent filing of the Kawasaki Ninja ZX-4R has been uncovered, putting speculations and rumours about the motorcycle to rest once and for all.

Two weeks ago, it came to light that Kawasaki could be planning to introduce a 4-cylinder 400cc motorcycle derived from the ZX-25R buoyed by the reception the quarter litre bike received (read article here).

But, the Kawasaki Ninja ZX-4R patent, which was earlier thought to be the patent of the ZX-25R, has revealed that we got it backwards, for the Japanese brand had actually conceived the 400cc model first.

The reason why Kawasaki went ahead with the 4-cylinder 250cc supersport project instead of the 400cc model is not known, but Team Green could have wanted to test the waters with a small bike.

Interestingly, the Kawasaki Ninja ZX-4R patent actually focuses on the fairing design with an integrated air duct (to redirect the air to the engine). The patent application states the additional cooling is needed due to the high-revving nature of the motor.

It is clear why it was written off as the ZX-25R’s patent, since the design of the model in it resembles the quarter litre bike and also because the production model’s engine revs to 17,000 RPM.

But, there is one crucial sentence which reveals the secret and it reads “the present invention can be more preferably applied to a vehicle having four-cylinder 400cc engine”, putting to rest all the rumours about the ZX-4R.

Also, there is no mention of a 250cc 4-cylinder engine in the patent, meaning the fairing was actually meant for use in the ZX-4R.

Since the existence of the ZX-4R’s patent has been confirmed, we presume it would not take much time for keen-eyed petrol heads to find an early development mule of the bike, if 1 such thing is present.

Kawasaki Ninja ZX-4R Patent Front
The integrated air ducts would mean the radiator need not be enlarged
Kawasaki Ninja ZX-4R Patent Side
The concept is to provide additional cooling to the engine

Source – Motorcycle.com