The all new Z800 seems largely inspired by Z750R. We see almost the same chassis with little bit of extra bracing that surrounds the engine and the suspension system is identical too. But the seats in Z800 is little higher and the rear sprocket gets two more teeth compared to 750R. If there was no improvement in power, it would have been more of an update rather than a new model.
The new Z800 from Kawasaki gets a 806cc engine, which produces 113 bhp and 60 ft-lb of torque. The power has increased from the 106 bhp, which is a significant improvement but these figures are not very impressive when we consider an 806cc engine.
Take a look at this picture collection of 2013 Kawasaki Z800 presented below.