Ninja ZX-4R

Kawasaki Ninja ZX-4R – When Four Cylinders Change Everything

There’s something magical about an inline-four engine howling past 15,000 rpm. It’s a sound that defined an entire generation of motorcycling in the 1980s and 90s—and it’s a sound that’s been largely absent from the modern 400cc class. Until now. The 2025 Kawasaki Ninja ZX-4R brings that visceral, spine-tingling experience back with an all-new 399cc inline-four that doesn’t just fill a gap in the market—it rewrites what riders should expect from a 400.

Performance with Purpose

The heart of the ZX-4R is its screaming 399cc inline-four producing 55.0 kW (75 PS) at 14,500 rpm—or 56.7 kW with ram air engaged. But raw numbers only tell part of the story. This engine delivers 37.6 Nm of torque at 12,500 rpm, meaning it’s not just a high-revving screamer. The flexible character provides strong low- to mid-range torque that makes city riding manageable, then transforms into an intoxicating wail as you wind it toward redline. The six-speed transmission pairs with an assist and slipper clutch for smooth, confident shifting whether you’re navigating traffic or carving canyon roads.

Rider-Focused Tech

Kawasaki hasn’t just dropped a great engine into a basic chassis and called it a day. The ZX-4R comes loaded with integrated riding modes that seamlessly link KTRC traction control and power modes—giving you Sport, Road, Rain, and a customizable Rider setting. The full-color TFT display includes smartphone connectivity and a dedicated Circuit Mode for track days. All-LED lighting ensures visibility, while the electronic package gives you confidence-inspiring control in any condition.

Design: Aggression Meets Elegance

The aggressive Ninja ZX styling makes one thing clear: this is a supersport machine. From the ram air intake emblazoned across the nose to the sharp, angular bodywork, every line screams performance. The compact proportions—similar to the Ninja ZX-25R—give it a nimble, planted stance that looks as good parked as it does leaned over in a corner. Dual 290mm front discs with radial-mount, monobloc four-piston calipers provide stopping power that matches the bike’s aggressive looks.

Is It for You?

The Ninja ZX-4R occupies a sweet spot that’s been missing for too long. It’s ideal for riders who want real supersport performance and handling without jumping straight to 600cc power. The WorldSBK-inspired trellis frame and 37mm SFF-BP inverted fork deliver sharp, confidence-inspiring handling with excellent feedback. Whether you’re a track day enthusiast, an experienced rider looking for back-road fun, or someone ready to graduate from the 250 class, the ZX-4R offers an intoxicating blend of accessibility and pure performance that’s simply unmatched in the 400cc segment.