2023 Kawasaki Ninja ZX-4RR | First Look Review

2023 Kawasaki Ninja ZX-4RR KRT Edition
The 2023 Kawasaki Ninja ZX-4RR KRT Edition is an all-new small-displacement sportbike said to offer track-ready performance.

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.

Related: 2018 Kawasaki Ninja 400 ABS | First Ride Review

2023 Kawasaki Ninja ZX-4RR KRT Edition
The 2023 Kawasaki Ninja ZX-4RR KRT Edition chassis was designed with input from the Kawasaki Racing Team (KRT) World Superbike program.

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.

2023 Kawasaki Ninja ZX-4RR KRT Edition
The 2023 Kawasaki Ninja ZX-4RR KRT Edition has ride modes, traction control, and adjustable suspension.

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.

2023 Kawasaki Ninja ZX-4RR KRT Edition
The TFT display has a Circuit Mode for track riding.

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.

2023 Kawasaki Ninja ZX-4RR KRT Edition
The 2023 Kawasaki Ninja ZX-4RR KRT Edition’s frame and swingarm are made of high-tensile steel. Claimed wet weight is 414.5 lb.

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.

2023 Kawasaki Ninja ZX-4RR KRT Edition
Out back is a fully adjustable horizontal back-link Showa BFRC (Balance Free Rear Cushion) Lite shock.

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.

2023 Kawasaki Ninja ZX-4RR KRT Edition

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.


  1. Hmm… 26.5 ft-lbs @ 11,000 = 55.5 HP. Peak horsepower is going to occur at a higher rpm and could very well be 65+. I might have to trade in the modded out EX for this lil screamer!

  2. Almost $10000!?!?! Kawasaki has got to be joking! That 400 better be getting 70 mpg and 60 hp to the rear wheel and 30 ft-lb. 200 000 mile life span. I was going to buy it, but not at that price. $7000 -7500 would work for me. Otherwise I have to do some seriously LONG talk with myself to pay Almost $10000!!!!!

    • Obviously you don’t understand how complexity in engineering works…
      It’s a 16k RPM screaming inline-4 track toy, making 200 HP per Litre. Not a Ruckus, or your lame brother’s Ninja 650.

  3. I’ve anxiously been awaiting the release of this bike. Planned to get one for my son and one for me. Not at $10k each. I can get a like new zx6 for 7-8k. Disappointing.

    • Aside from the somewhat awkward fact that is the 636, $10K is not a bad price for this. But yeah, in the US, for now, it will be a tough sell against the 636.

      The 636 is hardly sold anywhere anymore. And won’t be for long in the US. Emissions are just too hard to meet for it to be viable as a street bike. They may still sell a closed course only version.

      And then, once the 636 is gone; this thing will be the new king. At which point $10K is in no way overpriced.

      As a functional piece of road going motorcycle, this thing is likely already better than the 636 98% of most people’s street ridden miles. Being able to whack them often and liberally, without having to spend the rest of one’s life in a jail cell, is the whole point of these gems.

      As well: A new design, emissions compliant, 636 would simultaneously cost $20+K and have a neutered engine. It’s one area where they definitely no longer make’em like they used to.

    • Does bikes are literally the polar opposite of this though. They are priced similarly appropriately, they all do the same thing they offer you maximum performance, and one metric, or the other choose which one you prefer.

  4. I see a lot of bitching about the price. Lots of quality engineering going into this bike. Other brands listed as options. Buy what you want, that new 400 is going to rip. Quality components are being used, our dollar devaluation has a lot to do with the price, they are there to make a living and you can buy once, cry once. Want another brand? Shut your mouth and go buy it.

  5. Maybe steep pricing at nearly $10k, but these are going to be an absolute STEAL in the aftermarket. I cant wait to pick up a mediocre example in 3 years for $4k lol. Plus I really hate the sound of a single or twin sport bike, so Im glad we’re finally getting an option for a small 4cyl in the states

  6. It is a highly anticipated motorcycle model, featuring advanced technology and performance capabilities. From the initial look, the ZX-4RR appears to be a top-of-the-line motorcycle with a sleek design, top-notch engineering, and an impressive power-to-weight ratio. Whether you’re a seasoned rider or a beginner, the ZX-4RR an exciting and unforgettable riding experience.

  7. To those who think it’s not worth the money, you are missing the point. We all ride motorcycles for the same reason; fun and enjoyment. Whichever bike an individual person likes, makes it the right choice for him, even if it isn’t the right choice for you. With that 400 you are getting some, (but not all), of the latest electronics that top-of-the-line liter-bikes have, but for a fraction of the price. And think about how much fun it will be banging thru the gears on a screaming 400 with an up/down quick-shifter. I have always ridden liter bikes, but I completely understand and respect any guy’s decision to ride that 400. Ask yourself this: Can you ride your liter bike as fast as Guy Martin rides an S1000RR around the Isle of Man ? No ? Me neither. Maybe we should all think about riding a bike that is more in alignment with our skill level.

  8. Reading the specs, I assumed a price of in the 12-13K range. This thing is a bargain, and should scream, with probably 72-75 horsepower. Kawaski will sell all that they can make.

    • HP for America is totally detuned. I suppose another 2k invested in a power commander and a full exhaust will net the results that this little engine was designed for.

  9. Some UK press releases have just stated 75-80hp….which it needs to be, it would have been pitiful to have been less powerful than the 400’s of the early 90’s
    It’s biggest competition is going to be, (like those 90’s 400’s), the 600’s…..equally
    well equipped from even within their own range and barely any more expensive, there’s little logical reason to drop 40hp, it’s not really significantly lighter.

    • Kneeroom may (strike that: will…) be tight. But handlebar height and reach are less punishing than even the 636, which in itself is a cruiser compared to an R6 or Daytona.

      Also, this bike has a steel frame, and even a steel swingarm. It’s no doubt fun at a track, but it’s not a razors-edge “racebike” in the same way the 600s were/are.

      There is no doubt overlap with the 636, but they’re also quite some ways apart. I won’t part with the 636. It may well, a few centuries from now once the last motorcycle has left the planet, come to be recognised as THE ultimate highpoint of motorcycle engineering. But for street riding, even at a “slightly” above average SUV-depressed speeds on twisty roads, chances are this 400 will be both more comfortable and rewarding, most of the time. And for more general riding; commuting etc.; the gear ratios alone will ensure it’s better suited than the 600s. Kneeroom possibly aside; this will be one heck of an all around bike for shorter trips where carrying kegs, copiers, a load out for six months in Mongolia and the like is not a requirement. For those of some flexibility: It’s a bloody 16Krpm everyday rider. If that’s not cool, I don’t know what is.

      Plus: The 636 is barely hanging on in a few markets now. Very soon, emissions will render it, at best, a closed course only special even in the US.

  10. As long as you’re willing to spin the thing way up in the RPM band, you’re going to be disappointed. A Ninja 400 Twin will be more fun to ride as it produces torque at a lower RPM where we spend most our time on the street. At the track it’s a different story.

  11. I had the twin 400. A small-bore 4 would be nice! 70hp would be nicer. But, one nit-pick — as always, those decals look horrible. C’mon Kawasaki, save yourself some money and rethink bizarrely random decal mess on the 400s.

  12. This seems like a bike that is daring you to take it to a tuner and open up all of that power. If you do that, you could have something special. I agree it should be about $1000-$1500 less, but I am still intrigued

  13. The 2023 Kawasaki Ninja ZX-4RR is an impressive addition to the middleweight sportbike segment. Its sleek design and advanced features, like the quickshifter and slipper clutch, make it a serious contender on both the track and the street. Kawasaki continues to push the boundaries of what’s possible in motorcycle design and technology.

  14. It is an impressive bike that is sure to turn heads. It has a powerful engine, great handling, and a sleek design that will make any rider look good. The new features such as the adjustable suspension and traction control system make it a great choice for both novice and experienced riders alike. With its combination of power, style, and performance, the 2023 Kawasaki Ninja ZX-4RR is sure to be a hit among motorcycle enthusiasts.

  15. I went to buy a 2023 Ninja 650 for the GF and figured I’d ride it every now and then. Upon my arrival to the dealership lo and behold there was a 400RR KRT on the showroom floor. I asked the owner who purchased it. He said it came in this morning and someone very interested is coming from out of town to look at it but no deposit. So I decided to buy both. When I got home and started up both bikes that 400RR sounded way better than the 650. I’m very excited to ride it. However it was raining so I haven’t ridden it yet. Stay tuned and I’ll update once I get her out on the road. For me the attraction was an inline 4 with all the racing tech on it. They are actually hard to find right now. I didn’t want the 636 as I didn’t want to be bent way down under the triple trees and ownership is costly esp insurance. I figured the 400RR could be more fun on the open roads and twisties. More upright with still an aggressive positioning. I’m not a professional racer or track person. Figured winding the bike up to 16,000 rpm’s and hitting the turns in the open roads would be some good fun.

    I know a lot of people are bulking at the price but I got mine for about 1,000 more than the 650. But the brakes, front forks alone are so much better. Oh and did I say the Sound. Lol.

  16. Remember the Yamaha FZR 400 , That was a very fun bike to ride, Felt like it was on rails , Spin the engine to 14000 RPM and catch another gear…Of all my bikes and I am 67 years old I have had a lot,I miss the FZR 400 the most.

  17. Thanks for sharing this detailed first look review of the 2023 Kawasaki Ninja ZX-4RR! As a fan of sport bikes, I’m excited to learn about the updates and improvements made to this model. The sleek design and enhanced performance features definitely make it an appealing choice for riders looking for a thrilling experience on the road. Can’t wait to see it in action!

  18. This review of the 2023 Kawasaki Ninja ZX-4RR is insightful and detailed. The bike’s design, performance upgrades, and features discussed here make it a standout in the sportbike category. I particularly appreciate the focus on ergonomics and rider comfort, which is crucial for long rides. Looking forward to more in-depth reviews and test rides to experience this impressive bike firsthand!


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