kz750e Resto-Mod

swest: The spockets are designed to float or walk around. On my zr550 there is a 7-10mm gap between the sprocket and the collar. I would have imagined that the sprocket would wallow or wear the splines on the output shaft, but they don't. I have seen pictures (on a japanese blog) of people trying to use circlips to keep the custom sprockets on instead of a splined keeper and it damaged the groove in the shaft. Very weird how a circlip would eat the shaft but not the keeper of a wandering sprocket.

Thanks man. I can't wait to try it out.

I took swest's suggestion and took screen shots of the clutch rebuild pdf so I could post them.

The instructions are not mine and were created by someone over at www.750turbo.com/
I followed the directions exactly, except I used different bolts.

I'd feel uncomfortable with depending on just the splined washer and bolts. On mine the sprocket is torqued to the collar with a bend over washer. Even with that, the nut has backed off against the sprocket cover. Luckily the shaft is threaded so the nut tightens kinda when it hits. The later 1000's have a bolt that can come out. :blink:
Steve

Kawasaki has been using the splined keeper with "floating" sprockets from 1980 to 2009 on dozens of different models. Of the two zr550 transmissions and two gpz550 transmissions I have at my house, not one of them shows any wear on the output shaft splines. So I'm not even vaguely concerned about my sprocket falling off.

I'm not saying it will fall off. I was looking at off set sprockets and some have a shoulder on them that mounts like yours. I'd be more comfortable with one.
Steve
shop.pbisprockets.com/product.sc?productId=487&categoryId=56

So I also decided to use the newer style sprag starter clutch from a zr-7s instead of rebuilding the problematic roller clutch that came with the bike. My starter sprocket showed chatter marks and needed to be replaced and just the cost of that was more than a used zr-7 clutch.
So I bought a used starter clutch complete with the entire secondary shaft, which I needed anyway because I am also installing the high volume zr-7 oil pump and the shaft has a wider oil pump drive gear.
Because the primary drive has some slop in it, I disassembled the primary gear damper assembly and found that the rubber blocks were as rock hard as my kz ones. I ended up soaking the kz and zr-7 rubber blocks in pine-sol (softens rubber) for a month or so and then in Marvel Mystery Oil (supposed to contain wintergreen oil to keep them soft) for another three months and the rubber blocks gained about .25mm each and became relatively pliable again. When I reassembled the primary gear, all the slop had gone.
The zr-7 blocks are identical to the ones from the kz , only they ended up showing cracks once soaked despite being 20 years newer and having 10K less miles on them. So I used the renewed kz blocks in the zr-7 primary damper.
For some reason I forgot to take better pictures of the inside of the zr-7 clutch for comparisons.

Original three roller style that likes to slip and make our lives miserable.




Sprag style with 20+ contact points






Reassembling primary damper



I also needed a new primary chain as mine measured way past the limit of acceptable slack. Problem is that the primary chains are really expensive, so I had bought a box of zr-7 engine parts (every screw, bolt, pin, springs and washers from the inside of the engine) that also included the primary and cam chain of unknown mileage. So I cleaned the primary chain up and compared it to my old sloppy one. The zr-7 primary had a lot more "girth" seeming like the chain had not collapsed from wear yet and it was 2.5mm shorter than the kz one. Because the zr-7 chain seemed to have held up to wear better, I decided to save $300ish dollars and reuse the zr-7 primary chain.
Because the zr-7 uses a primary chain tensioner, maybe Kawasaki decided to fix the sloppy chain issues and possibly redesigned the primary chain for better longevity. Or it is possible I ended up with a very low mileage chain...who knows.
The cam chains were both exactly the same length.


Chains compared





I also mentioned that I was using a high volume zr-7 oil pump. Because the pumps have a wider impeller to produce more flow, the pump is over all wider and benefits from running on the wider drive gear on the zr-7 secondary shaft. Others have used the wider pump along with the stock kz secondary shaft, but the pump gear runs on the very edge of the drive gear. I'm not saying my way is better or that if you want to use the bigger pump you need to change the secondary shaft, I'm just trying to illustrate the differences between the two shafts.
But...I believe that if you want to change over to the sprag starter clutch and sprocket, you have to use the corresponding shaft for everything to line up properly.

kz750 secondary shaft drive gear.




All assembled zr-7 shaft, starter clutch and high volume oil pump

You sir, are a gentlemen and a saint. awesome write up.

Thanks for the positive comments guys!

I forgot to add that when using the zr-7 oil pump you have to use the zr-7 oil pressure release valve as well.
The kz750 oil relief pressure is listed a 63-85psi, but I can't find documentation of the zr-7 relief pressure.
I forgot to do a scientific experiment of how much pressure it takes to open the zr-7 valve, but it took considerably more effort to push in the relief piston that it did for the kz750...a lot more.

kz750 ball bearing type relief valve and the zr-7 piston type.






I also used a zr-7 oil pan with oil cooler ports only because it already had the oil level switch hole blocked off as the kz750e does not use one.





I used the zr550 oil cooler and mounted it below the horn mounting bolts and then used a combination of the original zr550 oil cooler mounting bracket and the kz750 reflector mounting ears for the lower mount.
I also had to have the oil cooler lines lengthened by a local hydraulic repair company as they were to short.

Piss poor welding of the bracket to the reflector ears



Finished product.



Note horn mounting bracket had to be bent at a 45 degree angle to let air flow past cooler.



New cooler lines

Cool. :lol:
Steve

Subscribed. Awesome, well documented write up....

Lots of great info in your build.
Thank you for sharing.
Bike is coming along well.