KAWASAKI NINJA 400 (2018 - 2021) Review

The Kawasaki Ninja 400 is much more than a facelifted Ninja 300. Not only does it have more power and torque, it’s lighter, has a completely different chassis and ZX-10R looks.

• Latest model: The Ninja 400 has been replaced by the 2024 Kawasaki Ninja 500

The 169kg, 44bhp race rep sportsbike is an A2 licence favourite. It’s easy to get on with, ultra-reliable, exciting and a marked step up from the 300 in terms of performance and refinement, but with a true 119mph top speed, 200-mile tank range, genuine big-bike character and comfort, the Ninja 400 can be enjoyed by more experienced riders and commuters, too.

The old Ninja 300 couldn’t haul itself through Euro4, so was killed off to make way for this new Ninja 400, boasting greater performance than its predecessor from an all-new engine and chassis – the net effect being a claimed weight saving of 8kg.

In September 2019, the firm introduced new Kawasaki Racing Team colours for the Ninja 400 for the 2020 model year. You can see the new livery below.

For 2024 the Ninja 400 is replaced by the Kawasaki Ninja 500.

Additional reporting by Martin Fitz-Gibbons and Adam Child. 

Kawasaki threw most of the old Ninja 300 in the bin and started again with the Ninja 400. It has an H2-esque steel trellis frame with a shorter wheelbase and longer swingarm, fixed to the back of the engine to save weight.

Non-adjustable ‘right way up’ 41mm diameter forks are chunkier (up from 37mm) and the twin piston front brake caliper now bites a 310mm petal front brake disc (up 20mm) taken from a ZZ-R1400. Lighter wheels contribute to an all-up kerb weight saving of 4kg and while the low 785mm height seat is unchanged, its 30mm narrower seat helps shorter riders get their feet down.

MCN tester Jon Urry says: "Thanks to its improved chassis, light weight and 17- inch tyres corners are a joy. Despite being softly sprung, the suspension responds better than you’d expect on a bike of this price, however the motor’s extra performance would justify a second front disc."

Fellow tester Martin Fitz-Gibbons also remarks: "Everything about the Ninja 400 feels welcoming, helpful and accessible. The hardest thing is adjusting the mirrors, which are mounted just beyond easy reach. Low-speed balance is exemplary. Suspension is soft and springy but gives a generally decent ride. Steering is sharp, light and stable, and there’s plenty of ground clearance. Dunlop GPR300 tyres are a big step on from the dire IRC Road Winners that blighted previous mini-Ninjas. The two-piston, single-disc front brake is average though — it bites gently and needs a strong squeeze to stop quickly."

Watch: Kawasaki Ninja 400 on Brands Hatch Indy circuit with Michael Neeves

With its extra 103cc and modified airbox and intakes, Kawasaki have teased power up from 39bhp to 44bhp from its heavily-modded, but still A2 licence compliant 399cc, 8v liquid-cooled parallel twin-cylinder engine. Torque is also increased 40%, up from 19.9lb-ft to 28lb-ft and there’s a revised slip and assist clutch. The Kawasaki Ninja 400 top speed was 100mph with a following wind.

Jon Urry says: "Far from lacklustre the Ninja’s acceleration is brisk and speeds of 100mph are possible, making it the quickest bike in its class. The parallel twin packs a wide spread of torque, so you aren’t continually dancing on the gear lever, the throttle action is beautiful and it even sounds spirited. The gearbox is precise and the clutch light – it’s a genuine surprise just how much fun the Ninja 400 is."

Martin Fitz-Gibbons agrees: "Where the 300 needed thrashing, the 400 feels full-bodied and forgiving. Fourth gear chugs hard from less than 20mph yet revs out at more than 100mph. The clutch lever has an ultra-light action and the fuelling is faultless".

Built quality, fit and finish are up there with Kawasaki’s premium models. Reliability and durability aren’t issues, so the only thing to look for when buying used is general condition and a full Kawasaki service history.

Our Kawasaki Ninja 400 owners' reviews show very positive reports, with no build quality concerns reported. One buyer thought the brakes aren't up to much, but this is contradicted by the rest of the entries.

The Kawasaki Ninja 400 is in the same general price bracket as the A2 licence rivals like Yamaha’s R3, KTM RC390 and class-leading Honda CBR500R (there’s no substitute for cubes).

Running costs are, on the whole, pretty low. The small-capacity motor means road tax is cheap. Slim crossply tyres don’t cost much and last ages. Even thrashed hard the motor still returns over 60mpg, and with a less-frantic right hand you could see 75mpg. That’s fairly good – though perhaps not astonishing compared with a Honda NC700, a Yamaha MT-07 or even a gently ridden ER-6f, all of which offer similar economy despite having twice the capacity.

Insurance-wise it’s comparable to natural rivals such as the Yamaha YZF-R3. One detail that may be worth bearing in mind is that the Ninja 300’s ignition barrel doesn’t have an immobiliser, whereas the Honda CBR500R does.

Private sales start at just over £2000, with dealer sales around £2500 – but the price window is very narrow, with even the most expensive bikes topping out around £3000. Prices seem to be very slightly lower than a Yamaha R3 or KTM RC390 for a similar age and mileage.

However, there is one fly in the low-cost ointment. The Ninja’s official service schedule includes valve clearance checks every 7600 miles. That’s a £300+ job at a franchised Kawasaki dealer. And with that in mind, it’s unsurprising that many valve checks get skipped, or a seller will (claim to) have done the work themselves. Always check, and look for proof, when valves were last inspected.

MCN group test: Kawasaki Ninja 400 vs Honda CBR500R vs KTM 390 Duke

First published in MCN on 16 May 2018 by Adam Child

There are many reasons why the Kawasaki should win this test. It’s the quickest, therefore the most fun. Most preferred its sporty looks and it handles far better than its price suggests. But the catch is that it doesn’t have the all-round capabilities of the Honda. The CBR feels like a bigger bike. Its dimensions are normal-size and it’s comfortable, refined, and smooth, offering a huge tank range and excellent fuel economy. If I had to pick one bike to do it all again, I’d pick the CBR. The KTM is tempting, fun and punchy and more importantly it’s over a grand cheaper than the Honda, but if you want a bike for daily use and long trips it falls behind. The Honda wins.

As well as its revised styling the Ninja 400 borrows its LCD clocks from its Ninja 650 big sister and it comes with ABS as standard. Optional extras include a tank bag, tall screen, 12v socket and rear seat cover.

While the Ninja’s low seat will be a boon for many, fear not if you’re over six-foot tall as Kawasaki also offer a taller seat option that adds an extra 30 mm. Ninja 400 Performance model also comes with a tank pad, pillion seat cover and road legal Akrapovic end can.

You can order the Kawasaki Ninja 400 in two colours - standard, or the KRT Race replica livery.