TOPIC:

Hey there all. Figured I would share this new/old project with the crowd since I am full tilt on giving this bike a new life.

I've got a 1979 KZ650B with a 1982 KZ750E3 engine. The carbs are Mikuni VM29mm Smoothbores fit with K&N pod filters and an old school Kirker 4-1 exhaust. This thing is fit with an oil cooler from an old Honda Nighthawk. It has the 19" front rim and the 18" rear. Dual disk brakes up front, disk in the back. Otherwise has been relatively stock up to this point. 

Some story behind this frankenbike, I bought it when I was 18, about 8 years ago as is. I am happy to say it was my very first bike. Of course I dropped it at the first stop light I got to, but that didn't stop me. I had no idea what I was doing back then, but I knew I liked it. I had some issues with the bike, having dropped it that once and stalled it many times on my way home(which I didn't quite make it due to the started button breaking on me a mile from my home), I took it to the first and last shop it would ever go to. They replaced a couple of things, master cylinder, starter button, ignition switch. And that was that. I learned that if I wanted this bike to go, I would have to learn how to work on it. 
About a year or so later, I met a friend who had a 79' KZ650, a full resto-mod cafe he built himself. He helped me tune it up a bit, showed me a relay for the ignition coils to bypass old wiring, got the carbs sunk relatively well, relatively basic things. I rode it like that for a while. Until I bought a newer bike. A little ninja. So the KZ sat. It sat for a number of years with me occasionally brining it back to life just to put it farther and farther down on my priority list as I acquired more motorcycles. I ended up getting up to 6 at one time. This was too much, so at this point I have downsized and thinned the herd out to 3 now. But ultimately the only bike I want to keep now is the KZ. 

I recently got the bike to my new house from my old house. And brought him back to life. Drained the fuel, cleaned the carbs, threw new air filters on it, new battery. Just got some Dunlop D404's because these tires on there are like 30 years old(can't believe I actually rode it on those old tires). One of the disks up front is sticking ever so slightly, I took them both off and scrubbed them and cleaned them best I could, which helped a little bit but I think these will need a rebuild. The forks are totally shot, and I am not really sure if they are from the original 650 or if they came off the doner 750. I got seals for a 650. Is there even a difference? I just went through the entire wire harness and pulled everything that has nothing to do with the engine running. Replaced a bunch of old wires, redid connectors with nicer newer stuff. Almost totally redoing the wiring harness, I will incorporate a lighting circuit soon once I get some more parts. 

So a couple questions:
Does anyone have experience putting 29mm smoothbores on a 750, if so what is the jetting you are running? I have some weak spots at the very bottom and close to the top of the throttle. It bogs and dies, so it seems to be running rich. It idles pretty well, generally revs out very nice, comes back down super quick. Floats have been checked, doesn't like too much choke on start up. Spark plugs were all black pulling them out. Messed with the air screws a bit but it didn't really solve my issue. 

Are the forks for the 650 the same size as the ones they used on the 750? Are the disk brakes the same as well? 19" Mag rim with dual disk brakes. 
How are the Dunlop 404's? I've seen some mixed reviews. They were pretty cheap, but I am just trying to get this thing on the road right now, I have to compromise with my budget. 
Did the 82' 750-4 come with an oil cooler? 
Curious on how small of a battery I could run to start that engine. Trying to slim down the electronics and weight. Running YB12 gel battery right now, its chunky. 

If you have read this far, thank you for the interest. Would be stoked on any and all feedback! Thank you all. Happy I can finally share this with a community who can appreciate it. 

Cheers! 
 

Welcome from the UK, we need pictures 

Concerning the fork seals, if you look them up on Partzilla, CMSNL, or he Kawasaki U.S. website, you can determine what models used those seals. If you click on the link below you will see an exploded view of the 1979 650 B3 forks. Find the reference number, then scroll down the list to that number and click the name of the part. Hat will take you to a page with a Fitment chart that lists all the models that use that part. It looks like the 650 B3 uses the same seals as the 750B series.

www.partzilla.com/catalog/kawasaki/motor.../kz650-b3/front-fork

In 1982 there were five different KZ750 models. I think the only one to have an oil cooler was the GPz.

VM29's are too much for a 750.  A nice set of VM26's from a 900/1000 would be more appropriate.  VM29's are worth good money these days; you could sell them, buy 26's, and have money left over.

Top picture is a before and after, the previous owner had rattle canned an ugly paint job on it. I did my best to fix it with the matt black, I am planning on changing that soon as well. Give it a green Kawi flare at least. 
These are old pictures, the bike is slightly torn apart right now due to a tire change. Will upload current pictures soon. 
Thanks!

As for the VM29 renew the choke plunjers because when the airscrews don't work the plunjers are leaking. Start with standard mains and pilots. Then check your spark plugs and go from there. Did you bench sync the carbs? 

Thank you TexasKZ, this was really helpful. I think I found the info that I needed. Looks like the forks/front end is from a 750 not a 650. The boots are different but it looks like the seals are the same. Now to find a cost effective caliper rebuild kit. 

I kind of like the excessively sized carbs, I'm sure it will be tougher to get it all running perfect but I think it will be worth it. Its part of the beast I bought those years ago and I would like to keep it that way.
It has 3ohm Dyna coils to give it the extra spark it needs to burn all that fuel. 
I replaced the intake boots a few years ago because of a bad vacuum leak. I had to modify kz1000 boots to fit on the head, drilled out the mounting holes until they could fit.