Six therapy!

Allen Millyard’s latest project extends his engine reconstruction skills further by building a six-cylinder version of Kawasaki’s iconic Z1. John Nutting finds out what it’s like to ride

- JOHN NUTTING

If you’ve been following Allen Millyard’s exploits with his project to build a six-cylinder version of the Z1 Super Four, Kawasaki’s answer to Honda’s CB750 launched in 1972, you must have been wondering just what it’s like to ride.

This saga, the latest in a number of epic projects to build what many riders regard as unfeasibly complex machines that look like the result of a wild and untempered imagination, started at the Stafford Show in October 2019.

At the show, Kawasaki parts specialist Dave Marsden had reminded Allen that he should build an in-line six, no doubt thinking that having already turned out a V8 based on the Z1 and a V12 in the Z1300, it would be a relatively straightforward task.

Now Allen’s never one to resist a challenge and at first he considered building another V8, thinking a six might be too wide to make a convincing example of what Kawasaki might have produced. This prompted the acquisition of parts from a 1976 Z900 engine, but while studying these in his workshop, Marsden’s idea came to mind. Allen made some paper templates to show how an inline six might look, and what the width would work out at.

Because Allen has been a master of metal since he started his craft apprenticeship at the turn of the 1980s, he’s a bit old money and rightly so, so the measurement came out at around 24 inches. He wondered how this compared with the daddy of six-cylinder bikes, Honda’s CBX from 1978, and recalling that I’d mentioned being at the bike’s launch in Japan, he sent me an email to ask if I remembered how wide it was.

Width was a key issue with the CBX and Honda’s engineers had done a great job in minimising it, so I knew that it was 23½ inches across the cases, because I’d measured one. That reassured Allen, and the project was off the mark.