2023 Kawasaki Ninja ZX-4R Receives CARB Approval

Dennis Chung
by Dennis Chung

Will we see the four-cylinder ZX400 on Feb. 1?

The California Air Resources Board has issued an executive order for Kawasaki Ninja ZX-4R, clearing the way for the long-rumored sportbike to be sold in the state.

The executive order was issued on Dec. 21, 2022, certifying a Kawasaki model going by the code “ZX400SP”. As we were the first to report last August, Kawasaki had submitted Vehicle Identification Number data for a ZX400SP and a ZX400PP with the U.S. National Highway Traffic Safety Administration, identifying it as being powered by a 399cc four-cylinder engine.

Kawasaki uses the ZX designation for all its Ninja ZX sportbikes, such as the ZX-6R (ZX636), ZX-10R (ZX1002) and ZX-14R (ZX1400), so it’s easy to conclude “ZX400” would represent a Ninja ZX-4R. The ZX-4R is expected to be based on the Ninja ZX-25R (pictured at top) offered in Asian markets, and it goes by the code ZX250.

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The ZX400 is also distinct from the existing Ninja 400 and Z400 models as they have different model codes (EX400 and ER400, respectively), and were already separately certified by CARB.

Interestingly, the CARB executive orders show the ZX-4R actually releases lower emissions than the twin-cylinder models, despite offering what is expected to be superior performance. The Z400 and Ninja 400 are certified to produce 0.3 g/km of hydrocarbons and 4 g/km of carbon monoxide, while the ZX-4R is certified at 0.1 g/km of hydrocarbons and 0.4 g/km of carbon monoxide.

In Indonesia, Kawasaki offers both a ZX-25R and a ZX-25RR. The double-R adds higher quality Showa suspension and a special KRT graphic scheme.

While the CARB order lists the ZX400SP, there’s no mention of the ZX400PP version. It’s important to note the “SP” doesn’t necessarily denote a higher end model. In Kawasaki’s nomenclature, the “P” at the end stands for the 2023 model year and the letter before that simply marks a different model variant.

In Indonesia, the ZX-25R is joined by a ZX-25RR that adds more premium Showa suspension and a Kawasaki Racing Team livery, but we don’t believe a ZX-4RR will be offered in the U.S. It’s more likely Kawasaki will only offer the ZX-4R with or without ABS, just as it does for it’s other ZX models. [UPDATE Jan. 24, 2023: We have since found evidence that our initial guess was wrong, and that there will, in fact, be a Ninja ZX-4RR model. Stay tuned for a more detailed update.]

Finding the right price for the ZX-4R will be vital. In Japan, the ZX-25R is priced at 847,000 yen (US$6,600), with special edition colors pushing it to 935,000 yen (US$7,300). The Ninja 650, by comparison, is priced at 913,000 yen (US$7,100). A ZX-4R should be even pricier.

The timing of the CARB executive order makes the ZX-4R a candidate to be one of the two models Kawasaki is teasing for a reveal on Feb. 1, likely alongside an updated Ninja H2 SX SE which has also been certified by CARB but has yet to be announced for 2023. [UPDATE Jan. 24, 2023: As commenter Nick Dasko points out, Kawasaki Canada has already announced the 2023 Ninja H2 SX SE while still teasing two models on its homepage. That leads to conclude the second model isn’t the supercharged H2 SX SE but might in fact be a Ninja ZX-4RR.]

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Dennis Chung
Dennis Chung

Dennis has been a part of the Motorcycle.com team since 2008, and through his tenure, has developed a firm grasp of industry trends, and a solid sense of what's to come. A bloodhound when it comes to tracking information on new motorcycles, if there's a new model on the horizon, you'll probably hear about it from him first.

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2 of 51 comments
  • John burns John burns on Jan 24, 2023

    Dang, I've reached that age where what's old is new again. I remember we compared this to FZR400 and RGV250 Suzuki back in the day.

  • Joe Smith Joe Smith on Jan 25, 2023

    I was looking for just such a machine for track duty, back in 2017. A really cool idea, but how many buyers can they find these days? A near perfect stock 2 year old 30th anniversary ZX-6R, with 4200 miles for only $6800 out the door, became my track machine. I've only ever ridden it in low power mode. Now that track days have doubled in price in the last 6 years, I'm thinking of keeping it for display in the house. I did ride it twice at COTA, and maybe 15 other track days, never put a tread wrong. But if the 4R price was closer to $6800, I'd consider selling my ninja for one, that cycle is really interesting