Kawasaki Motors Corp, USA. pulls the wraps off the newest member of its 2023 Ninja sportbike lineup. Introducing the ZX-4RR KRT Edition ($9,699). Positioned above the existing parallel-twin powered Ninja 400 ($5,299-$5,899) and below the tried-and-true Ninja ZX-6R ($10,699-$11,999) supersport, the inline-four KRT Edition 400 is designed for competition-minded motorcyclists that desire a light, high-revving sportbike.
This Ninja is powered by an all-new liquid-cooled 399cc four-cylinder. It drinks fuel from a four-gallon gas tank and can run on standard 87-octane gasoline Kawasaki says. Forged pistons squeeze fuel to a ratio of 12.3:1 and a pair of forged overhead camshafts actuate the 16 valves. The engine is fed through a ram air-type airbox with spent gasses passed through a four-into-one exhaust, with cross-over tubes. Ride-by-wire throttle is present which powers the adjustable traction and engine power mode controls.
Engine power is augmented via a wet, oil-cooled clutch with Kawasaki’s tried-and-true cam-type clutch that combines assist (lighter cable-pull) and slipper (back-torque limit function). Power is put back to the 160-series Dunlop Sportmax GPR-300 tire via a six speed gearbox and chain final drive. An bi-directional electronic quickshifter is also present.
The engine is fixed inside an original steel-trellis chassis with measurements loosely based on the Ninja ZX-10RR. The oversized steel swingarm appears beefy and is controlled via Kawasaki’s unique in class, horizontal back-link type rear suspension and high-end Showa BFRC (Balance Free Rear Cushion) Lite shock, with full adjustment. Front suspension duties are handled by a 37mm inverted Showa SFF-BP (Separate Function Fork-Big Piston) which uses Showa’s tried-and-true oversized piston valving (fully adjustable) in one fork leg, and coil spring support in the other. This helps reduce sprung weight and is also less expensive to manufacture.
The 414.5-pound Ninja rolls on a pair of star-pattern five-spoke 17-inch wheels (presumably cast aluminum). Braking duties are handled by a pair of 290mm disc brakes and radial-mount four-piston Nissin calipers. A 220mm disc and single-piston setup is used for rear braking. Fixed, always-on ABS is standard but it’s unknown if it includes lean-angle sensitivity (cornering ABS).
A 4.3-inch color TFT display and full LED lighting grace the ZX-4RR. The motorcycle is compatible with Kawasaki’s handy Bluetooth-enabled Rideology smartphone app. Riders can select between four riding modes (sport, road, rain and manual)— however it is unclear what these global settings indicate. Two combined engine power and throttle response settings are offered as well as three levels of traction control. Traction control can also be manually disabled.
Styling-wise this Ninja was “designed to deliver a fierce look that contains its power and explosive action, benefitting the most powerful machine in the 400cc class,” noted Kawasaki Motors Corp, in its official press release. The Ninja ZX-4RR KRT Edition will be available in Lime Green / Ebony only and be available at U.S. Kawasaki dealers this spring.