Rumour: Kawasaki is planning a four-cylinder ZX-4R

The ZX-4R would be built around this ZX-25R design, but with more engine capacity.

Want a fast middleweight motorcycle? After the Japanese manufacturers basically abandoned the 400 cc sportbike segment, Kawasaki revisited the idea with the Ninja 400 in 2018. Now, it’s supposedly planning a four-cylinder ZX-4R to further strengthen its mid-sized lineup.

Quarter-litre foundation

Just like the Ninja 400 came along as an evolution of the Ninja 250, the ZX-4R is supposed to be based on the foundation of the ZX-25R.

We haven’t seen the ZX-25R in Canada yet. This quarter-litre sportbike was released for the Asian market last summer, and at this point, we haven’t heard much about how well it’s been selling. Considering sales and production were likely significantly impacted by the coronavirus pandemic, it would be hard to make a fair assessment of the bike’s popularity based on the past year’s sales anyway.

However, it’s certainly an interesting idea—a top-shelf 250, with high-revving four-cylinder engine, making roughly 50 horsepower at the crank. It fits into the restrictive engine displacement rules common across Asia. In many countries, riders might be stuck riding 250s, the theory goes, so why not give them the best 250 possible?

Growing up

Now, the hot gossip says Kawasaki is planning on selling a 400 sportbike along the same lines, presumably called the ZX-4R. The bike would be built around a high-revving inline four. Allegedly, Kawasaki would big-bore the existing 250R engine, and increase stroke, but basically re-use the 250’s design. The result? Likely around 75 horsepower, give or take a few ponies, and a machine that Kawasaki could sell in US and Euro markets. The reality is that many riders will refuse a ZX-25R because they think it’s too small, but they might be convinced to buy a 400, especially if it was homologated in existing lightweight sportbike series.

Is this gossip fact or fiction? Hard to say, and it wouldn’t be the first time the rumour mill has made much ado about nothing. On the other hand, Kawasaki is playing a much bolder game than the other Japanese OEMs these days, and if this machine really did come to market, it would certainly handily surpass anything else in the 400 category these days.


  1. My 2006 zx6r 636 is only 3kg heavier at the kerb. I’d love the new 250, but it’d need to be at least 25-30kg lighter. 182 wet is unacceptable. Defies the point of it. Current 400 twin is better street bike, and my nearly obsolete zx6r will blow it out of the water at the track. Mixed feelings about it…

  2. Pretty much pointless. It’ll cost as much as the former 600’s and we all know the 600’s are in decline. It might be a novelty for some ones multi-bike collection or find a place in current small bike race series if it would even be permitted to race against twins.

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