1980 KZ750H Cafe Build

Hey all, I just picked up this 1980 KZ750H for next to nothing, with plans to strip it and build it into a cafe bike. It’s been sitting for quite a long time, so I will be essentially replacing or rebuilding nearly everything. The plan at the moment is to drop it slightly, bolt on a set of tracker bars, completely rewire it, and upgrade the brakes to something a bit more modern. I’m hoping a check of engine vitals reveals nothing major, but the carbs will be rebuilt regardless.

I’d love to hear some tips and things to consider for the build.

I’ve also found a 1984 ZN700 LTD for super cheap, which I plan to look at this weekend. Does anyone know whether many parts interchange between the two models? I’m hoping to use some brackets, pegs, etc., and part out the rest.

Welcome hookemdevils22.

Well, I knew I was in for a treat... I pulled the carbs as took a peak in the intake ports. There’s debris in the ports, and several valves look like they’ve seen better days. So I’ll be opening up at least the top end. Are there any seals or items to note while it’s out of the bike?

The carbs’ butterflies are hanging up, so they will be completely disassembled and rebuilt (which I expected). Are these jetted rather lean, like the Mikuni BS34s found on 80s XS650s?

I don't recall there being anything particularly odd about the gaskets and seals, save perhaps the tachometer drive. There is a flat washer that is hard to see and easy to miss when replacing them all. Take a look at the parts diagrams at Partzilla or Kawasaki.com.
The factory seals and gaskets are generally best, except for the valve stem seals. Seals made of Viton are superior to the others.
Carbs on any U.S. market bike in those days will be set up pretty lean. With the stock air box an filter and the factory exhaust, a shim under the needle and careful adjustment of the low speed screw usually fix that. If you plan really low restriction intake and exhaust, you are in for another treat. Likely a long and frustrating one.

P.S. just in case you haven't found these yet, you may find them useful.

www.kzrider.com/filebase/category/13-kz750

'd been wondering about the viton seals. Are there any in particular to look for?
Several different types are listed on EB. At least one brand has a metal sleeve, which I suppose some would call an armored seal.
I did not see any viton seals at Z1Enterprises.com, but they do mention an armored Suzuki seal than can be used on Kawasakis.

KZ650 KZ750 valve stem seal >> Viton >> metal casing

KZ650 KZ750 valve stem seal >> Viton

KZ650 KZ750 valve stem seal >> Viton (green)

Z1Enterprises valve stem seal >> see details note about Zook armored seals

Excellent, thanks Tex. I found those files and immediately bookmarked them, as well as the schematics on the Kawasaki site . I also found the service manual in PDF format, but bought a physical copy as well.

I've ordered gaskets and carb kits. Is there any concern over cam chain or tensioner? I plan to have the engine out this weekend, and check for oil leaks and such as I tear into it.

"carb kits" not a good idea. It's much better to clean all the OEM brass parts because they are "real" made in Japan parts made to high tolerances. A full set of O-rings and possibly float needles is all you should need. O-ring sizes are listed in a separate thread posted here just the other day.

Get a "colored" full service manual here

www.750turbo.com/manuals/GPz750_Base%20Manual.pdf

hookemdevils22 wrote: ..... .....
I also found the service manual in PDF format, but bought a physical copy as well.
..... .....

That one is the xeroxed version. The manual in Scirroco's link is much better; someone probably used a scanner.

Awesome, thanks gang. So nessism , when I said “carb kits,” I meant the basic kit that includes o-rings and float needle (and possibly idle screw). I fully disassembled the carbs, and boogered up a couple main jets (right-middle in the attached photo) in the process. I am also unable to remove the idle mixture (pilot) screws Located at the top of the carb, behind the diaphragm cover. I’ll be sonic tanking them tomorrow, but I’m concerned that I’ll be in need of all new carbs if they don’t come loose.

I found a write-up for Keihin rebuild a few days ago, which included fastener sizes to replace with stainless Allen heads, but I can’t seem to locate it any longer, and it’s not in the filebase or technical write-ups. I’d appreciate a link if anyone has it.

I’ve also attached photos of the pick up coils and associated hardware. I’ll be checking all electrics for resistance and operation, but it looks like I’ll need advance springs at the least. I’d love some direction with this.

One more (dumb) question: I used to use photobucket for photos, but obviously don’t anymore. I have all my photos on Google Photos, but it doesn’t give a preview when I attach them like yours (see scirocco’s post). Is there a way to do this, or do I need to link to a JPG instead of directly attaching them?

To upload pics it is easier from your local hard drive.
Click on the "Attachments" bottom, +Add files...from local hdd path or by drag and drop into the field
"You can drop files here or use the add files button."
after upload the pics, this need some time dependent of the file size, push the insert (all) button to display the pics in full size in your post. If not push the insert (all) button you (we) see only a thumb size of your uploaded pictures after you push the submit botton.
File size pictures max. 2mb (bmp, jpeg, jpg, gif, tif, png, etc....) / (zip, rar, avi, mp4, mov, etc..) max. 10 mb .

Michael