2025 NINJA ZX-4R

Kawasaki takes 400cc-class engine performance to a new level, achieving an unprecedented 56.7 kW (77 PS) of power with Ram Air. The howl of the engine as it revs beyond 15,000 rpm adds to rider exhilaration. A quick-revving nature and direct throttle response are complemented by a flexible character that offers strong low- to mid-range torque for city riding, as well as screaming high-rpm power ideal for sport or track riding.

The new 399 cc liquid-cooled DOHC In-Line Four engine pushes technological boundaries to comfortably top the 400cc class. Developed with know-how gained from other Ninja ZX models, the high-performance engine offers class-leading power and a rev-range that extends beyond 15,000 rpm.

With a redline beyond 15,000 rpm indicating its screaming potential, this engine features racing-inspired technology also found on the Ninja ZX-10R. The high revs deliver a distinctive, exhilarating engine sound characteristic of a high-performance Kawasaki In-Line Four.

Complementing the centrally positioned Ram Air intake, the side Ram Air duct, designed with feedback from the Ninja H2, routes air to the air cleaner box and contributes to stellar performance. Its aggressive look and intake sound add to the screaming In-Line Four experience, and visually identify the bike as one of Kawasaki's Ninja ZX models.

A hallmark of the ZX series is razor-sharp handling with excellent feedback that inspires confidence, and the Ninja ZX-4R is no exception. This stems directly from Kawasaki's WorldSBK racing efforts, and their work in developing the Ninja ZX-10R and Ninja ZX-6R. As a result, the Ninja ZX-4R offers a handling character similar to its siblings.

Key chassis dimensions (centre of gravity position, swingarm pivot position, engine axis positions, caster angle, etc) were inspired by Kawasaki's World Superbike Ninja ZX-10RR racer, bringing WorldSBK chassis design thinking to the 400cc class.

Designed using Kawasaki's advanced dynamic rigidity analysis, this trellis frame made from high-tensile steel delivers the required balance of strength and chassis flex to achieve the Ninja ZX-4R's nimble supersport-style handling.

The Ninja ZX-4R's two ø290 mm front brake discs and radial-mount monobloc calipers provide sure stopping power, while also offering excellent braking feel to inspire confidence both on the track and on the street.

The Ninja ZX-4R's ø37 mm inverted fork uses SFF-BP internals to deliver both racetrack performance and everyday usability while the Horizontal Back-link rear suspension offers a progressive character. Offering increased adjustability, the Ninja ZX-4RR's front forks include adjustable spring preload, and it features a Showa BFRC lite rear shock—the same type seen on the Ninja ZX-10R.

Naturally aggressive riding position (more forward-leaning than the Ninja 400's, but still slightly relaxed) lets riders take advantage of the Ninja ZX-4R's nimble handling. The fuel tank feels slim, promoting good contact with the bike, while the shape of the firm seat cushion facilitates rider weight shift during sport riding, and is comfortable for longer rides.

Style meets substance with the Ninja ZX-4R's high-class styling and high-grade package. Aggressive looks are complemented by premium features like TFT colour instrumentation providing clear information, integrated Riding Modes that link traction control and power modes for easy machine setup, and on the Ninja ZX-4RR a quick shifter for fast, simple gear changes.

Befitting the most powerful machine in the 400cc class, the Ninja ZX-4R's aggressive Ninja styling exudes a fierce aura of restrained power and explosive action.

The 4.3' all-digital TFT colour instrumentation with selectable display modes (Normal, Circuit) clearly displays the most pertinent information, whether on the street or on the track. Circuit Mode shows the gear position, lap times, and rpm above 10,000 more prominently.

Bluetooth technology built into the instrument panel allows connection to smartphones via the "RIDEOLOGY THE APP" smartphone application, enabling riders to access instrument functions for an enhanced motorcycling experience.

*RIDEOLOGY THE APP is not intended for use during vehicle operation. Only use RIDEOLOGY THE APP when the vehicle is not being operated and it is safe to do so.

From its twin headlights to its Ninja ZX-10R-inspired taillight, all lighting on the Ninja ZX-4R is LED.

Four integrated riding modes (Sport, Road, Rain, or the manual-set Rider) make it simple to select a level of traction control and power mode to suit the current riding conditions.

Allowing riders to take even greater advantage of the Ninja ZX-4R's exhilarating engine character, the quick shifter enables clutchless upshifts and downshifts for seamless acceleration and easy deceleration.

Ninja ZX-4RR only feature