TOPIC:

Has anyone here done it? I've read they share the same crankcase which should mean it would bolt up. I know I'm going to get the why or your wasting your time post so let me preemptively say the engine in my 81 GPZ550 will need to be rebuilt or replaced and I may be able to pick up a 600r parts bike with everything for a few hundred bucks. Just hoping to get some factual information not argue for/against.

You may want to double check the crankcase lengths. Combining the diagrams from:
www.powersportswarehouse.com/p/Kawasaki#...0-D1-1981/070086B-10

and:
www.powersportswarehouse.com/p/Kawasaki#...-1989/C12C1232E14121

I ended up with the diagram below. I don't know how accurate the 2 diagrams are that I used as the source, but judging by the results the GPZ550 crankcase looks to be longer than that of the 600R. Again, this may be totally wrong if the input I used was not accurate, but it's worth checking before buying. Ed

Thanks for the info Ed. I think they may have changed the engine a bit in 88. I looked up a few different parts that are hooked to the engine and they all said 85-87 zx600. I found some pictures and the mounts are definitely in the same area on both engines. I think the only way I'll know for sure is to find a local bike for sale and take some measurements. Probably not worth the trouble but if it's close I'll go for it.

Is the 600 R water cooled?
Steve

Yes; it's water cooled. Ed

Well, that's a whole new kettle of fish.
Steve

Yes, the plan would be to transplant everything with the engine - cooling system, electrical and gauges. I don't mind any of that and could probably have it done in one weekend. I'm a little worried about how the radiator will look as it's pretty ugly and most water-cooled bikes run fairings. What I really don't want is to modify the engine mounts. I'd rather just wait for a good running 550 to come along on ebay instead.

I've seen motors for cheap on eBay.
Steve

swest wrote: I've seen motors for cheap on eBay.
Steve

I'll keep looking while trying to get some zx600 measurements. The only good one I see available right now is over 600 shipped and I'm pretty sure it's an 82-83 model so I'd probably need some tk26 carbs to get it running which will cost me another C-note. I'd love to get a zx550 engine (better cams, tk27 carbs) as I used to have one of those and it was as fast as I'd ever need.

There are a handful of people that have swapped zx600 motors into Zephyr zr550's. The zr550 and kz/gpz550 motors cases and mounting points are identical. The zx600a/b/c motors cases will fit in a gpz/kz/zr550 frame only after making new mounting brackets to tie the motor to the frame mounting points.
But......all the guys who have done this live in the UK where it is cool enough that they can get away with not running any cooling fans on the radiator and still not over heat. And.....the zx600 models over there don't come with oil coolers (because of the colder climate) unlike the US models and there is NOT enough room on the gpz550 frame to mount both the radiator, cooling fans and a oil cooler around the exhaust manifold on the front and not still not interfere with the front fender or tire. Plus you will also need the zx600 wiring harness and ECU from the zx600 as well as the carbs. The gpz550 carbs will be to small and will also not have the correct spacing anyways. But the 550 exhaust will bolt right up, so theres that.
Just food for thought.

Thanks a lot for the info and pic Daftrusty! I'd be getting the whole bike in running condition so sourcing all the extra bits wouldn't be a problem. That picture though is exactly what I wanted to see. I just don't like having the radiator sitting out there like that. I suppose I could have a custom core made or find one but the power improvement (58hp to 75hp factory ratings) probably isn't worth all that trouble.

Ohhhhh...If you can get the whole bike with all the ignition bits, carbs and radiators, then that is half the battle right there. I really really wanted to try doing this to my zr550, as they are de-tuned kz550 motors, so there is even less HP to start with. I eventually installed zx550 pistons and cams in my Zephyr to bump up the HP.
So I would like to live vicariously through you, and see you tackle this project.
You could try and see if you could fit the oil cooler remotely back by the battery box, as some guys on here have done with their project bikes. There would have plenty of room if you didn't end up using the stock airbox. ( but that also means the horror of trying to tune CV carbs with pod filters.) So many cool problems to solve. If it was me, and I had a whole running zx600 to try it with, I would definitely do it!!

A couple more pictures I found. (Not mine)