In 2018, Kawasaki distinguished itself from Honda and Yamaha by bumping displacement of its entry-level sportbike up from 300cc to 400cc with the introduction of the Ninja 400. Team Green has thrown down the gauntlet again with the 2023 Kawasaki Ninja ZX-4RR KRT Edition, a new track-focused sportbike.
At its heart is a new liquid-cooled, DOHC 16-valve 399cc inline-Four, which adds two more cylinders than the Ninja 400’s 399cc parallel-Twin. Developed with input from Kawasaki’s Ninja ZX supersport machines, the engine has an oversquare bore and stroke of 57.0 x 39.2mm and is said to deliver impressive power and a claimed peak of 26.5 lb-ft of torque at 11,000 rpm.
The engine features fine-sand cast intake ports, large intake and exhaust valves, precision-machined combustion chambers, forged camshafts, cast-aluminum pistons, and a 12.3:1 compression ratio, yet it runs on regular unleaded fuel.
A lightweight flywheel contributes to the Four’s quick-revving nature, a large radiator contributes to efficient cooling, and a ram air duct brings cool, high-pressure air into the engine.
Equipped with throttle-by-wire, the Ninja ZX-4RR features four ride modes (Sport, Road, Rain, and Rider customizable) that adjust traction control (Modes 1-3 or Off) and power mode (Low or Full). It has a 6-speed transmission with a slip/assist clutch and an up/down quickshifter. Up front is a 4.3-inch color TFT display that includes a Circuit Mode for track riding and Bluetooth connectivity via Kawasaki’s Rideology The App.
Designed using input from Kawasaki Racing Team’s (KRT) efforts in the World Superbike Championship, the Ninja ZX-4RR’s chassis consists of a high-tensile steel trellis frame with various pipe diameter thicknesses, a swingarm pivot section, and a high-tensile steel swingarm. Up front is a 37mm inverted Showa SFF-BP (Separate Function Fork – Big Piston) fork with adjustable preload and 4.7 inches of travel, and out back is a fully adjustable horizontal back-link Showa BFRC (Balance Free Rear Cushion) Lite shock with 4.9 inches of travel.
The Ninja ZX-4RR rolls on five-spoke 17-inch cast-aluminum wheels shod with Dunlop Sportmax GPR-300 radial tires (120/70-ZR17 front, 160/60-ZR17 rear). Slowing it down are a pair of 4-piston radial-mount monoblock front calipers squeezing 290mm semi-floating discs and a 1-piston rear caliper squeezing a 220mm disc.
The 2023 Kawasaki Ninja ZX-4RR KRT Edition has aggressive styling with all-LED lighting and a Lime Green/Ebony color scheme. It has an MSRP of $9,699 and will be available this spring.
2023 Kawasaki Ninja ZX-4RR KRT Edition Specs
- Base Price: $9,699
- Website: Kawasaki.com
- Warranty: 1 yr., unltd. miles
- Engine Type: Liquid-cooled, transverse inline-Four, DOHC w/ 4 valves per cyl.
- Displacement: 399cc
- Bore x Stroke: 57.0 x 39.2mm
- Horsepower: N/A
- Torque: 26.5 lb-ft @ 11,000 rpm (claimed)
- Transmission: 6-speed, cable-actuated slip/assist wet clutch w/ quickshifter
- Final Drive: Chain
- Wheelbase: 54.3 in.
- Rake/Trail: 23.5 degrees/3.8 in.
- Seat Height: 31.5 in.
- Wet Weight: 414.5 lb
- Fuel Capacity: 4.0 gal.