A 250cc motorcycle with an inline-four engine sounds insane but it was clearly not crazy enough for Japanese-based custom bikemaker Trick Star, the same company responsible for the epic, viral white and green Kawasaki Ninja H2R.

So in order to spice things up a bit, Trick Star set out a goal to top 250kmph (155mph) on Kawasaki’s Ninja ZX-25R in 2021. Almost six months on and one blown engine later, the firm has finally achieved this target and their bike managed to hit a speedo-indicated 252kmph (156mph). Here’s how they did it.

Kawasaki Ninja ZX-25R Zooms Past 155mph

The idea of this record birthed from the motorcycle itself. The ZX-25R is an amazing example of Japanese engineering as it uses a 249cc, inline-four engine that puts out 45 horsepower in its stock avatar. Owing to this, the stock bike is capable of reaching 116mph, which is already plenty fast, more than what usual 250cc twin-cylinder bikes can attain.

Once the idea was clear, the next task at hand were the modifications and a turbocharger was plonked onto the engine to boost output from 45 horsepower to nearly 100 horsepower.

This came with its own set of problems though, as the stock engine went pop during its first run back in November 2021, managing only 140mph 140mph}}. Plus, the fairing had to be cut to make space for the turbo and its components, which isn’t ideal for a motorcycle undergoing a top-speed run.

It was on the second attempt, which took place this year, when the team finally managed to breach the 250kmph (155mph) mark, hitting a speedo indicated 252kmph (156mph) at the Japan Automobile Research Institute (JARI).

The company has documented the whole run, which shows engineers trying to use different gearing ratios and sprockets to achieve the maximum speed possible.

One interesting thing in the video is that, even at 155mph, the bike didn't really red-line, indicating that there more power to exploit at the top-end. This is also what Trick Star has in mind, as their next aim is to reach a V-BOX verified 155mph, which should be around 160mph on the speedometer.

Oh, and in case you're wondering, who was in the saddle? Well, the bike was piloted by Takehiro Yamamoto, a championship winner in the Asian AP250 class.

Kawasaki Ninja ZX-25R Pricing & Availability

The Kawasaki Ninja ZX-25R is priced at 935,000 Yen ($7,622) in its home market of Japan, which is almost lurking into Yamaha YZF-R7 territory. However, for the money, the ZX-25R offers an unmatched riding experience (and exhaust note) bettered by superbike-like electronics including traction control, riding modes, and slipper clutch.

Sadly, though, this bike is only sold in Southeast Asian markets, so it’s highly unlikely you’ll find these brutes anywhere else.

Enjoy the video here: