Kawasaki already has a 250cc four cylinder engine in a sports bike for the Asian market but rumours claim that a 400cc model is on the cards. But will we see it in the west?

Kawasaki To Release a 400cc, four cylinder sports bike?

In this post, we spoke about a new 400cc four-cylinder engine being developed by Chinese manufacturer Colove. While engines with that capacity were developed for the Japanese market to take advantage of taxation laws which punished engines larger than this, much as Italian and French laws punished car engines over 2-litres in the 1980s, countries in Europe didn't have such limitations on motorcycle engine capacities and, therefore, the bikes fitted with such engines were never officially sold in those territories.

Having said that, grey imports of those 400cc sports bikes were very popular in the 1980s and '90s. Certainly, they were slower than 600cc or 1000cc bikes but they were such jewel-like miniature replicas of the larger models and had stratospheric rev limits.

Since then, the 400cc class has been powered by singles or parallel twins, such as KTM's 390 range and Kawasaki's ZX400 Ninja models. It seemed as if the complication of a small capacity four-cylinder engine was a thing of the past.

But that didn't stop Kawasaki from developing and launching the ZX-25R in the Asian market, powered by a 250cc four cylinder. No matter how we wish it would be released in the West, that hasn't happened, which is something we should all be sad about. I mean, who wouldn't want a screaming, 50bhp, four cylinder 250cc bike?

It didn't take too much of a stretch of the imagination to realise that a 400cc version of the 250cc engine wouldn't be too difficult and now it seems as if Kawasaki are doing just that.

Patents filed By Kawasaki in 2019 for the 250cc engine stated that the design is “preferably applied to a vehicle having four- cylinder 400cc engine”. Well, if that isn't a huge signpost, then I don't know what is!

It is expected that the 400cc version of the ZX-25R will simply be a larger engine shoe-horned into the '25's' frame and running gear. There might be detail differences to the looks, but expect it to look largely the same, which is no bad thing as the 250 already has the looks of the ZX-10R.

While no power outputs - or any specs, for that matter - are available, if we extrapolate from the 250 - 50bhp, remember - we could see around 80bhp from the 400 which would be more than enough to give larger sports bikes a fright in the right hands.

It has to be argued that 1000cc sports bikes - and even 600s - are getting too fast for their riders' health, always supposing the rider has the skill to use even 50% of such performance. Using 50% of a bike's performance seems a waste: why not use 100% of the performance? With a 400, that would be possible and I'd wager the rider would have more fun than scaring him- or herself silly along the way.

Given the current Ninja 400 (with parallel twin engine) puts out 44bhp and is fast enough to be fun, how brilliant would a screaming four-cylinder 400 pushing out 30 or 40bhp more be?

Kawasaki is not alone: rumours are also circulating that Honda are also looking at reviving the CBR400 moniker for a new four-cylinder sports bike. Will that also be Asia-only?

We have to hope that Kawasaki and Honda are prepared to jump through the legislation hoops to make the bikes legal for countries outside Asia.