2024 Zx4r Top Speed. Sounds and feels like you're doing 100mph. As mentioned, the 399cc engine produces a claimed maximum output of 74.8hp (55kw), the figure chiming in at 14,500rpm, but the ram air system pushes this a smidge further to 77hp (56.7kw).

As mentioned, the 399cc engine produces a claimed maximum output of 74.8hp (55kw), the figure chiming in at 14,500rpm, but the ram air system pushes this a smidge further to 77hp (56.7kw). In terms of performance, the 400cc sports bike.