The elusive KZ550 transmission into a KZ650/750 tr

Awesome!!

I am glad we finally have someone who has completeded this mod and run it on the streets.

Mine will be done by the end of winter, but I am glad to hear someone had gotten it done and come back to post about it.

How large did you go with the front sprocket?

Are the sprockets for the 550 output shaft difficult to find?

Is the chain still running true or does the new output shaft move the sprocket slightly from the standard 650 position?

Great info!

No probs with chain at all. Can't remember which sprocket I was using. A 550 one of course fits but it depends on what type of chain you are running. bear in mind that the zx600 and some others used the wacky washer fitting, so you should have no trouble finding a size to suit your riding style.

GPzephyr, you used the GPz750 motor to do the swap, that's why you had to change the trans cover, all but the GPz750 cover have the neutral light switch in the same place and interchange, even the 750 twin cover will work

KZ650 kicker will work on the KZ750 motor, but not with the 6 speed conversion, just not enough room for everything. I have a KZ750 four motor with kickstart.

Assuming you have it up and running, where did you get the offset sprocket needed for the GPz750, that fits the 550 output shaft?
The 550 uses that flat metal lock that has two bolts holding it to the sprocket, and makes things a little difficult when attempting to combine two sprockets to make one offset sprocket. I have thought about using a snap ring of the proper size, but I haven't got a rountoit yet, so I don't know if it would work.

Wait a minute, maybe you put a GPz750 motor in a Zephyr (I didn't read the whole thread)? That would explain your lack of problems finding a sprocket, it wouldn't need one, just the 83-85 GPz750 needs the offset sprocket (running stock wheels).


I did try and put the gears from the six speed on the 750 shaft so I could keep the threaded end on the output, but the 750 shaft is larger and the gears won't fit.

Oh and while I'm not the king of cheap, I picked up 2 entire 550 engines for about $10 which is how I got to attempt it in the first place. Other than gaskets It didn't cost me much more

I'm envious :X

Hey Steell, a couple of questions.

Awhile back, you put a link up in a thread about a 6 speed conversion you were doing that you said had more info, but the link is dead. Was that a detailed how-to for this swap, and if it was, do you have access to that thread?

Also (correct me if I'm wrong) in the thread in question, I'm pretty sure you were doing the swap in a GPZ750. Have you done it in a KZ650 as well?

Also, when Mark Wing tried it in his kickstart KZ650, I'm pretty sure he said he lightly bolted the cases together and all the gears worked, but it wouldn't go into 6th when he torqued the cases down. With the tolerances that close, do you think it might be possible to gain enough additional clearance through some machine work, or is it just a case of "so close, but so far away?"

Hiya Steell
The engine was a stock Zephyr 750 motor (apart from GPz Cams). Its best compared to a KZ750 engine really.
I didn't need an offset sprocket as the splines on the 550 output trans matched those on my 750 (less the thread for the nut). I could have just used my original Zeph 15T sprocket drilled for the wacky washer fixing but I went to a 16T instead. Sprocket is flat and needs to be to allow the washer type fixing.
Thinking back now I recall also trying a large circlip in the groove to hold the sprocket on but I remember abandoning it as I was concerned about it coming off and causing an accident.

I too did look into just putting the gears onto 750 shafts but found the spines were too short to contain all 6 gears.

I should add that this was before I put the turbo motor in the bike. I did look into doing the conversion on that but the GPz turbo uses different gear shafts and bearings to normal 550/650/750 engines.

Just wanted to say how great this site is!!! could i do this to my 700? and what do i need?

the 700 uses the same bottom end as a kz650/gpz750 so yes.

Just in case anyone needs a little more info, here is the front sprocket type


This is from JT sprockets and they are available from 13T all the way up to 18T. The 2 bolt holes on the sprocket are for mounting the washer.

The washer is available from any Kawasaki dealer.

So, I see this KZ750 for sale on ebay: cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll...ME:X:RTQ:MOTORS:1123

The ad says it's a 6-speed, so i email the guy asking if that's a mistake.

He emails me back and says no, that he'd seen on the internet that you could swap in a KZ550 6-speed, so he tried it and it worked!

I wrote back telling him about this site and gave him a link to this thread, asking if he could detail the swap and his experiences with the bike after the swap here.

He just wrote back saying that this was where he'd read about it! He said he had "a lot of info" and was going to send it to me.

How cool is that?

i did the 6 speed swap and i will do a write up on what to do email me and answer questions

vids.myspace.com/index.cfm?fuseaction=vi...36&release=105243179
vids.myspace.com/index.cfm?fuseaction=vi...d=&release=105257222

Welcome to the board and thank you so much for being willing to take the time to help us out.