2018 Kawasaki Ninja 400 Review | Street and Track Tested

The all-important lightweight class of motorcycles is critical to our sport, and the smaller displacement Kawasaki Ninjas have helped usher in new riders for over 30 years. At their core, these lightweight machines are accessible, versatile, and forgiving, while still delivering a decidedly sporty experience. The all-new 2018 Kawasaki Ninja 400 aims to do just that and it does so by serving up more—more of everything.

We tested the street limits of the new 2018 Kawasaki Ninja 400 on the wonderful twisty roads in California’s majestic wine country, and then we put it to a track test at Sonoma Raceway.

2018 Kawasaki Ninja 400 review1. Kawasaki has struck gold with the new 399cc parallel twin. Bumping the displacement up by 103cc hasn’t just delivered more power, it’s also made the lightweight Ninja’s thrumming heart much more smooth and tractable, with a crisp throttle response—qualities that new riders will surely appreciate. The new Ninja 400 has a great distribution of power throughout the rev-range, offering good low- and mid-range grunt for the street. The motor also gives riders the opportunity to wring it out all the way to the redline on track, with torque peaking at a lofty 8000 rpm.

2. The 2018 Kawasaki Ninja 400’s powerplant increased its stats in many ways, but not in size or weight. While the bore and stroke, compression ratio, and displacement grew, its physical size did not. The now-defunct 300 powerplant and the new 400 are quite close in their general shape. Other improvements include tilting the cylinders 20 degrees forward and revising the coolant passages.

3. Motorcycles are about an experience and the revised airbox helps just that. The new, larger airbox has a downdraft intake that allows for a more direct flow into the cylinder head to help tune for the wide spread of power. In addition, the airbox has been moved from under the seat to a position under the tank. You’ll notice this when you twist the throttle—under hard acceleration, you will hear a downright mean little intake howl that will bring a grin to any enthusiast’s face.

2018 Kawasaki Ninja 400 horsepower4. Larger diameter header pipes clear the way for more power. To facilitate the Ninja’s newfound displacement, Kawasaki has introduced larger diameter header pipes that accommodate more exhaust flow. A new oil pan design allows a more direct line to the muffler, shaving off a bit of weight from the headers.

5. A six-speed transmission equipped with an assist-and-slipper clutch helps keep you in line. While the now outgoing 300 didn’t have a heavy clutch by any means, the 400’s revised clutch requires absolutely no effort; it can be modulated with a single finger. Whether you’re making your way through traffic or running through the gearbox on your local circuit, it’s a quality that any rider can benefit from. Should you botch a downshift of the precise close-ratio transmission, the slipper clutch will prevent the rear wheel from locking.

6. Comfortable yet sporty ergonomics await. The low 31-inch seat height returns. While doubling the padding, Kawasaki shaved the profile of the seat, allowing for increased mobility. Additionally, the clip-on style handlebars have been moved back slightly, encouraging a more upright position. At the same time, the footpegs have been moved back a bit, angling you forward. In practice, it remains a nearly neutral riding position that doesn’t load the rider’s wrists. While my 32-inch inseam did experience a bit of knee bend, it wasn’t painful on my street ride and the sporting posture was a delight on track.

2018 Kawasaki Ninja 400 test7. The geometry of the 400’s new steel trellis frame is much more aggressive than the 300’s double-cradle frame. The wheelbase is now a tad shorter than 54 inches (1.4 inches less than the 300) and the rake is reduced to 24.7 degrees—a stunning reduction of 2.3 degrees. Plus, the 400 is 17 pounds lighter than the 300, yet it has significantly increased chassis rigidity.

8. The new Ninja receives new suspension. Though it’s sprung and damped on the softer side, mainly to accommodate new riders, it has good damping characteristics, settling quite well. That’s good, because the only adjustment is shock spring-preload. On the street, the suspension is adequate for a wide variety of riders, soaking up potholes with ease and delivering only a little negative energy to the rider. On track, the softer suspension held its ground at the dynamic Sonoma Raceway. If your inputs are smooth, the chassis remains poised; if you ham-fist a braking zone or chop the throttle, the repercussions are light.

9. When it comes to handling, the 2018 Ninja 400 is as agile as can be. Whether you are an experienced rider or someone with a newly minted M-class license, you’ll quickly discover that it takes almost no effort to whip the Ninja 400 around. The weight loss translates to an extremely compliant machine, one that transitions side-to-side brilliantly.

2018 Kawasaki Ninja 400 street test10. Big steering inputs will have a big reaction. That’s something experienced riders will immediately notice, so it is best to focus on smoothing your riding out. As new riders begin to build their set of skills, the Ninja 400’s inherently nimble nature will allow them to learn the fundamentals of riding with its quick but exceedingly predictable handling.

11. Upgraded tires keep the shiny side up. On the street, the 110/70 and 150/70 Dunlop GPR-300 tires are perfectly capable, providing good amounts of grip in dry and damp conditions. They worked on the track as well. While clearly a street tire, they offered enough grip and feedback to keep all of us from sending it down the road, and we weren’t out for a Sunday cruise. Should you be up for your first track outing, you’ll be alright with these, before needing to bump up to a sportier tire compound.

12. The 2018 Kawasaki Ninja 400 is stable yet also has loads of feel. The motorcycle is more than willing to wail into corners and is at home on the edge of the Dunlops, allowing a great deal of feedback and inspiring you to ride harder. When I was losing grip over some of the rough sections of Sonoma Raceway I was able to recover with no problem. The new Ninja is stable through large sweepers and will hold its line wonderfully. Should you need to do a quick correction or avoid something on the street, it is happy to accommodate without sacrificing an ounce of stability.

13. Increased braking performance has been delivered. A dual piston caliper clamps down the single semi-floating 310mm rotor upfront on the Ninja 400. The result is good feel at the lever, despite the lack of radial mounting. At the rear, a 220mm rotor with a dual piston caliper can be found. In either case, braking is progressive and adequate for the speeds that you will be achieving. For newer riders, the brakes lack any jarring initial bite.

2018 Ninja 400 Review14. Track riders will still want to upgrade the brakes. Should you be aiming for track use, it would be wise to install steel-braided brake lines, high-performance brake pads, and racing-ready hydraulic fluid to aid with harder riding. Those changes will reduce any squish once the brakes get hot.

15. ABS is available. Setting you back an additional $300 dollars, we strongly encourage ABS for every rider other than professional racers. The Nissin system on the Kawasaki will surely save you a trip to the dealer for new plastics, and it doesn’t interfere with aggressive riding.

16. The Ninja 400 styling is directly linked to the rest of the Kawasaki Supersport family. Pulling cues from a trio of Ninjas—the ZX-10R, ZX-6R and H2—the Ninja 400 has a fighting edge to its appearance. Aspects such as the H2-inspired under-nose spoiler and brashly styled LED headlights give it lots of charm.

17. Sportier wheels give the Ninja 400 a more aggressive look. While it’s not a big change, one of my favorite aspects of the new Ninja are the five-spoke wheels. In a styling choice that is in line with its bigger brothers, the Ninja ZX-6R and ZX-10R. The wheels shave off a bit of weight and bring the whole appearance up a notch.

2018 Kawasaki Ninja 400 guages18. The new Ninja 400 shares its dash with the Ninja 650. That means an analog tach, along with LCD digital readouts for mph and gear position. There are plenty of warning lights and useful LED readouts, such as fuel level and range. Visibility does go down in direct sunlight, but overall it does its job well.

19. Between its compliant handling, great stability and snappy power, the 2018 Kawasaki Ninja 400 has upped the ante for lower displacement machines. The Ninja 400 will surely inspire confidence in new riders, allowing them to build a solid foundation of skills and grow as motorcyclists. For those looking to cut their teeth on the track, it is a solid base for enthusiasts and club racers. It will help them kickstart their careers and learn to build a fine track weapon in the lightweight class. In all, the 2018 Kawasaki Ninja 400 delivers more power, less weight, and better handling for the same price as the 300 it replaces. That’s a winning combination.

Photography by Brian J. Nelson and Kevin Wing

RIDING STYLE (track)

RIDING STYLE (street)

  • Helmet: Shoei X-Fourteen Brink TC-5
  • Jacket: Alpinestars T-GP Pro Air
  • Gloves: Racer Mickey
  • Jeans: Alpinestars Crank
  • Boots: TCX Roadster 2

2018 Kawasaki Ninja 400 Specs

ENGINE

  • Type: Parallel-twin
  • Displacement: 399cc
  • Bore x stroke: 70.0 x 51.8mm
  • Compression ratio: 11.5:1
  • Valve train: DOHC, 4 vpc
  • Fueling: EFI
  • Cooling: Liquid
  • Transmission: 6-speed w/ Positive Neutral Finder
  • Final drive: Sealed chain

CHASSIS

  • Frame: Steel trellis
  • Front suspension; travel: Non-adjustable 41mm fork; 4.7 inches
  • Rear suspension: Spring-preload adjustable linkage-assisted shock; 5.1 inches
  • Tires: Dunlop GPR-300
  • Front tire: 110/70 x 17
  • Rear tire: 150/70 x 17
  • Front brake: 310mm petal disc w/ two-piston caliper
  • Rear brake: 220mm petal disc w/ single-piston caliper
  • ABS: Optional ($300)

DIMENSIONS and CAPACITIES   

  • Wheelbase: 53.9 inches
  • Rake: 24.7 degrees
  • Trail: 3.6 inches
  • Seat height: 30.9 inches
  • Fuel tank capacity: 3.70 gallons
  • Curb weight: 362 pounds (ABS: 366 pounds)

2018 Kawasaki Ninja 400 COLORS

  • Lime Green/Ebony
  • Metallic Spark Black
  • Candy Plasma Blue
  • Pearl Solar Yellow/Pearl Storm Gray/Ebony

2018 Kawasaki Ninja 400 Price:

  • Standard: $4999
  • ABS: $5299

2018 Kawasaki Ninja 400 Review | Photos