KH Five: 5-Cylinder Kawasaki Widowmaker!

Kawasaki Quintuple: 883cc 5-Cylinder Two-Stroke from Allen Millyard… 

Recently, we’ve been looking back at the many mind-blowing creations of Allen Millyard, the mild-mannered English gentleman known for shed-built specials that defy belief. In the past few weeks, we’ve featured many of Millyard’s best-known machines, including his 5000cc “Flying Millyard” V-twin, 8000cc Viper V10 bike, and his V8, V12, and Super Six Kawasaki Zed specials.

Millyard got his start building two-stroke Kawasaki specials, and these remain something of his bread and butter. His first such build broke cover nearly 30 years ago at the 1996 Stafford Classic Mechanics Show, where he displayed a 415cc five-cylinder Kawasaki two-stroke to the amazement of judges and show-goers alike.

Today, we thought we’d look back at the very first Millyard special we ever featured, way back in 2017. The bike came to us from owner Pip Davidson, and it remains one of our favorite machines ever…not the least because it’s no show pony!

The donor? A 1976 Kawasaki KH500, the evolution of the original H1 Mach III 500cc two-stroke triple better known as “the Widowmaker.” The addictive, terrifying power of the Kawasaki triple drew a certain kind of rider.

“It was kind of fun. All that edgy handling, vicious power output, and the feeling that at any moment the whole thing was going to let loose in a big way… The beastly nature of the acceleration and wonderful howl of the three cylinders kept me endlessly amused, turned every ride into a roller-coaster of an adventure. I had many near misses but was never actually thrown off the machine. After three months I’d developed bulging arm muscles and an evil little grin.” -H.J.W., Yew Emm Gee

The KH500 was intended to offer better handling and slightly saner power delivery than the H1. But don’t be fooled — it was still one hell of a rocket. Hanging not one but two additional cylinders to the engine seems grounds for a full-blown psychiatric evaluation. Of course, we wouldn’t expect anything less from Millyard!

Allen, who’s a friend of Pip’s, built this machine in 2005, using a pair of KH500 engines. It’s often referred to as an 850/5, though Pip says it actually displaces 883cc. Millyard cut the crankcases into sections with his trusty hacksaw and welded back together to house five cylinders. Pip says the joining of the cases is just seamless. Millyard ended up using one center cylinder, two left-hand cylinders, and two right-hand cylinders.

He stripped down a pair of crankshafts and reassembled them as a single five-cylinder crank, with a 1-5-2-4-3 firing order. The gearbox output shaft was extended to allow the engine to fit centrally in the frame and the oiling system modified with a pair of three-cylinder oil pumps joined together. 

Millyard then built the five steel expansion chambers by hand.

“The cones are first made in then traced around onto a steel sheet. Allen used tin snips to cut the sections, then hand-rolled around a piece of scaffold tube and gas welded them together. Once fitted to the bike, they were chrome plated.” –H&H Classics

This 883cc smoke-rocket puts down a staggering 109 wheel horsepower on the dyno — more than double the 52 crank horsepower of the stocker! We’re not sure what other black magic was done to the engine to achieve that significant of a power boost.

Fortunately, the suspension was uprated to handle the additional horsepower, and the bike is now running double-disc front brakes to haul it down from speed.

On the aesthetics side, a vintage car painter applied the stock paintwork, the frame was powder-coated, and all of the brightwork re-plated.

There are just three of these KH Five specials in existence. As you can see from the photos, Pip wasn’t never satisfied to keep the bike locked up in the shed. He’s ripped the KH Five at the Malle Mile and taken it on plenty of +100-mile rides.

Hear Her Rev

A quick video of Millyard starting up and revving the KH Five at Bike Life Classics Day at the Sammy Miller Motorcycle Museum.

Follow the Builder

Instagram: @allenmillyard
YouTube: @AllenMillyard

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