It’s the 1970s and the engine war is over, the British twins have been killed off and the motorcycle world is all about the multi-cylinder. Kawasaki was one of the manufacturers responsible for that gigantic shift and the Z1 was emblematic of this new and exciting era. So, what on earth was the big green company thinking, when in 1976 they introduced an all-new KZ750, with of all things, a parallel twin as the powerplant? Well, their reasoning was sound at the time, but victims of their own marketing, the bike failed to sell. But if Kawasaki had seen this modern interpretation and met the enthusiastic man behind it, things might have been very different. Meet American Victor Wilkens and his 1980 Kawasaki KZ750 Twin, a custom motorcycle that proves you get a hell of a result when you know exactly what you’re working with.

Back in 1976, from Kawasaki’s point of view, the production of a big twin with the styling of the famous Z series of motorcycles made a lot of sense. To the big Japanese manufacturer, they were offering to the public big bike looks, with solid performance, good reliability, easy maintenance and all at a cheaper price than some of their competitors’ much smaller offerings. It wasn’t the full-blown four-cylinder, but it was a damn good bike. But the public didn’t buy it, they’d bought into the hype of multi-cylinder machines and although Kawasaki made a solid sales pitch, the 750 twin just never sold in big numbers, ending its run in 1983.

“I’ve always been drawn to both the quirks and potential of underappreciated bikes, and this KZ750 twin was no exception. What started as a geometry tweak quickly turned into a full custom build, with a focus on chassis refinement, and some cool custom parts thrown in,” Victor, an Industrial Designer, tells us. And he’s also the first to admit that he could understand why the public didn’t jump all over the twin, but he noticed something others had missed. “On paper, the 1980 KZ750 twin isn’t particularly special. It doesn’t make big power, it’s heavy, and the design is a bit awkward. But there’s one quirk that sets it apart: the engine spins in the opposite direction of the wheels, a feature now common in MotoGP”

This single fact inspired the build and set him on a path of first making the most of the bike’s handling, maximising the benefits of an engine that reduces the gyroscopic effect and enhances corner turn-in. “I cut off the rear subframe and rebuilt it from scratch, moving the shock mounts forward to improve progressive movement through the swingarm’s arc. The motor mounts were fabricated in aluminium plate, the engine cases were reamed to accept oversized bolts, eliminating factory slop and tying the chassis together more rigidly.” To take things even further, the swingarm is a custom aluminium item, that supports a set of taller Works Performance shocks to further improve the geometry.

The front end doesn’t miss out either and to make a big improvement, Victor jumped into the Z series parts bin. “The front forks are from a KZ1000, now running Race Tech cartridge emulators.” The heavy cast factory wheels are ditched and replaced with spoked items from a KZ650, with both ends featuring custom chromoly axles, all aiding in reducing unsprung mass. A Tarozzi fork brace ties things together, while braking is drastically improved with a lightweight EBC disc with a Brembo caliper on a custom mount, fed by a beefed-up master cylinder. Fat bars sit in custom clamps, a relocated ignition cleans things up and the headlight bucket houses a neat GPS tacho from Speedhut.

At the backend, Victor fabricated a custom tail light shroud and then turned his attention to getting the looks spot on. “The KZ750 twin isn’t exactly a looker out of the box, it’s bulky and awkward. I wanted a design that felt cohesive, like something Kawasaki might have built as a special edition. The bodywork is a mix-and-match of KZ parts, chosen for visual balance and consistency. Stamped fenders maintain an OEM vibe, and I went the extra mile with details like early-style engine covers and designed and cast an aluminium ignition cover featuring the classic Kawasaki flag logo.” Searching far and wide for just the right paint colour, Victor settled on Jeep’s ‘Commando Green’, which has a period correct vibe thanks to extra green toner to bring it closer to a Kawasaki hue.

“The badges are from the JDM Kawasaki ‘Z2’ which felt like a fitting nod,” the builder explains. To get a seat that was the right mix of classic and custom, who better to call on than the craftsmen at JP Custom Seats in LA, who have absolutely nailed the brief. Sending these sorts of jobs out also frees up time to work on other parts of the build and the engine is definitely not left untouched. The head has been treated to a light port and polish to get things flowing, while a set of 1mm over pistons and a compression raise complete the bottom end. Topham in Germany sent over the snappy set of RS34 flat-side carbs and the exhaust is a beautiful, custom-fabricated system, made out of stainless steel.

But the big game changer was actually in the shift to an optical, multi-spark ignition from C5, allowing the lazy factory timing to be properly corrected for crisp throttle response and smoother power delivery. “Every rider who throws a leg over it is surprised by how fun and agile it is. I’ve ridden everything from cruisers to sport bikes to dirt bikes, but the way this thing tips into a corner is totally unique,” Victor reports. In fact, he’s so happy with the way it performs, he’s started to build a full track-spec version. Think Chromoly chassis, magnesium wheels, and a 906cc engine with a titanium valvetrain. The Kwaka Twin has always been seen as the poor little brother of the family, but Victor Wilkens is proving one KZ750 at a time, that it can finally stand on its own two feet.

[ Victor Wilkens ]