Join Date: Jun 2019
Location: Wrocław, Poland
ZX600C/GPX600R Power differences
I've been looking all around the internet to find the difference between the C models in regards of engine power. I know the earliest models make about 85HP, which would then go down to ~77 in 1993 and later models and even further down 73 in 1996. AFAIK, the first change was because of technical reasons and the second one because insurance laws made it harder to insure bikes of 75 and above horsepower. Also AFAIK, this only concerns models made in Europe, the US versions were always ~85HP.
The thing is, I have a 95 model and would like to make the most of my bike (making a custom out of it, so it will be staying with me for a couple more years at least), but I do not know what parts I should swap from an earlier model version. The most obvious thing would be the CDI/head/cams/carbs/jets/airbox, but I checked the part diagrams for all the model years from 88 to 97, and every mentioned part has exactly the same number, no difference between them, and I am lost. I only have a Haynes manual, which does not state the differences between model years. Now, I know the original Kawasaki manuals have EVERYTHING mentioned in them, I saw one for the ZX-10 Tomcat, and every little bit of difference between model years and even country specific versions is mentioned. The problem is finding it. There aren't any in second-hand sale in my country (Poland), so obviously I decided to call the Polish division of Kawasaki to buy one. The salesman checked and told me they won't sell me one, as they do not have any, BUT as it is a very old bike, he'll just send me an email with an electronic copy, no charge. After a week of waiting I called them back, but the guy told me... they do not have it. So he wrote to the Netherlands division about it and told me to wait a bit more.
...then he called me two weeks later, to say that the Netherlands division does not have one either, and they wrote directly to Japan. Needless to say, I'm still waiting for my copy, two months passed.
But, while I'm waiting, maybe someone out there has a copy from 1993 or later and would be kind enough to check the specifications and tell me what the change is? Is it the valve timing? Ignition? I seriously doubt a ~10HP difference on jet sizes, but I'm really trying to grasp a leg of hope here...