It is well documented that in the late sixties, Kawasaki intended to hit the market with an in-line 4-cylinder 4-stroke 750cc motorcycle. However, with Honda beating them to it with the CB750, it was back to the drawing board. Clearly though, the development work carried out in the early years on the 750cc configuration was not to be lost, and this was ultimately to result in Kawasaki developing a motorcycle to suit their own market. It is ironic that the “big four” who had such thirst for power and speed were domestically restricted to a rather conservative 750cc displacement limit.
Once the world had been won over with the Z1 in 1972, Kawasaki went all out to capture the Japanese market. On the instructions of chief Engineer Ben Inamura, development work on a 750cc model was to progress. No doubt, it would have been an easy option to sleeve down the bore from the Z1’s 66mm in order to save on manufacturing costs and equally “time to market” but this was not a sensible or desirable option. Further development work required meant that production of a 750cc model would be around 6 months behind that of the Z1. Eventually a 64mm bore x 58mm stroke configuration was agreed on which demanded a new crankshaft design, together with smaller 26mm carburettors. By December of 1972, Kawasaki were ready to call a press conference at the Takanawa Prince Hotel to announce the release of the Z2 to dealers.
I have been unable to find any information regarding prototype Z2 models. No doubt test riders must have ridden test models during late 1972, but this information (to me) is unobtainable. However, it is known that 25 ‘pre-production’ motorcycles were manufactured in December 1972.
Sources in Japan suggest that 10 of these were sent out to the leading dealers for display purposes, while another 10 were lent out to test riders and Japanese motorcycle magazines. The remaining 5 it seems may have been acquired by members of the public prior to official release. In Japan, it is widely believed that frame #21 started for general sales (officially Kawasaki said it started from #26). From April of 1973, the pre-production models given to dealers for display were allowed to go on general sale to the public.
The few ‘pre-production’ vehicles I’ve seen or heard about are #1 that is apparently in Kawasaki’s museum, #9 that I have seen in Japanese books, and #15 of which I know to be in the UK. #14 has been traced to the Netherlands but unfortunately has a much later engine from a Z2A. #17 was bought by editorial department of Motorcyclist in Japan and #18 was bought by editorial department of Autobike in Japan.
Above - Japanese sales brochure (Front side only) from 1972.
The motorcycle on the front is almost certainly a Z1 and is clearly aimed at enticing the domestic market for the following February when the Z2 was first sold
One area of topic for the pre-production and very low numbered production Z2's is the speedometer. If you look carefully at the sales leaflet on the following "Z2 page" you will see a very different style of speedometer to what was used on production models. The picture on the right shows a pair of restored clocks in the style of the sales leaflet. There is some debate in Japan as to whether this type was ever fitted. My view is that the photography for the leaflet would have been taken in late 1972 and that the bike is in fact a Z1. Perhaps the speedometer styling for the production models hadn't yet been decided, so Nippon Denso modified a standard European speedometer for the photo shoot.
This appears to be a reasonable theory as the Z2 (No. 15 in UK) has the normal type speedometer (as shown in the 'detail images' page of this site).