Ewokwarmachine wrote: I have a 1981 KZ550C that I would like to do some work to. Are any internal GPZ parts compatible with my engine?
Yes. Almost all of the 81 to 83 Gpz parts are interchangeable.
But they are almost non-existant out there. Racers have milked Kawasaki dry of Gpz parts.
The parts in question, for more power, are higher comp pistons. Cams. Main jet. Oil pan and oil cooler.
Everything else is the same, except possibly intake porting, but that has not been confirmed.
It would be easier to swap in a gpz motor than to get gpz motor parts, but getting a good gpz motor is difficult nowadays.
It would be easier to put in a Wiseco 615 kit, but that will cost a lot of male deers.
And if the bike is a KZ550C, you will have to do a bunch of chassis mods to safely use the extra power.
I found the most satisfaction comes from making it run as good as it can, in stock form (which is what you should do first before pouring money into the motor, in case there are other issues with it). The Ltd C and standard A models had more low end drivability which makes for more enjoyable daily riding, especially with a passenger.
There is a bunch of 550 info in my sig.
