1981 Kawasaki KZ750 Resurrection

[Nessism]

Well, I shot down the rabbit hole big time on this carb project. At the end of the day these things received the full monty treatment. Have to admit, they look damn good too.

Keihin doesn't use throttle shaft seals so that made the project easier. The throttle shafts are chrome plated steel and the carb bodies have brass/bronze bushings and everything fits together nice and tight. These carbs use a real butterfly operated choke mechanism, and you have to remove the butterfly plates and shafts to break down the carbs so I'm sort of getting used to the process. Doing the throttle butterflies too is no big deal.

These carbs use an O-ring to seal the float bowl so waiting on those and the float needles. One nice thing I've learned is that this second set of carbs is from a 1980 750. Learned this because the float bowls have overflow tubes that my 1981 carbs don't have. My old carbs have the tube nipple on the bottom of the float bowl, but it's not drilled and there is no tube inside the bowl. It's a little hard to explain...

A couple extra tidbits about these Keihin's is that they use three different jets to meter the fuel, primary main, secondary main, and pilot. They eliminated the secondary main on some of the later year carbs but both sets I've got have them. They are reputed to meter fuel very accurately and the bike should get about 50 mpg according to tests I've read. Another is that the float needle is rubber tipped and the seat is pressed into the carb body so it's not serviceable. Also, the float posts don't bust off like the BS Mikuni's because the pin is a slip fit (like the VM Mikuni's).

So there you have it. More to come...

P1020764 by nessism, on Flickr

P1020763 by nessism, on Flickr

P1020767 by nessism, on Flickr

P1020765 by nessism, on Flickr

P1020761 by nessism, on Flickr

P1020762 by nessism, on Flickr

[rudeman]

As usual Ed, your work is superb. I'd bet those carbs have NEVER looked as good as they do now.

[Kiwi Canuck]

Fantastic work Ed, but that's what we have come to expect from you.

Very nice job on those carbs and yes I'm envious of your skills.

David

[Nessism]

Fantastic work Ed, but that's what we have come to expect from you.

Very nice job on those carbs and yes I'm envious of your skills.

David

Thanks for your kind remarks David. My "skills" as you reference are nothing more than the end result of doing...and messing up countless times. If you aren't messing up you ain't trying. You just have to remember that it's not a "mistake" until you do something wrong TWICE.

So, got the new carb needles last night and started installing them. Compared to the original needles the spring loaded prong in these needles hold up the floats weight much better. There is still a tiny bit of spring compression from the floats weight but it's much less than before. I'm starting to be a believer in replacing the float needles as a matter of course when rebuilding carbs these days. I bought some K&L needles and the quality seems just fine. They look to be chrome plated for durability and have a really nice smooth finish so they should slide smoothly in the float seat bore. As soon as the float bowl O-rings arrive I'll do the last part and adjust fuel level. Kawasaki/Keihin don't even list a float height spec, just a fuel level spec. Not sure about that strategy though. How many people bother to measure fuel level? Not many I suspect.

[Nessism]

Picked up the exhaust pipes today. They charged me $227 to ceramic coat the entire system, including the crossover pipe and heat shields. Can't wait to get everything installed.

These guys also have very fair prices for blasting and coating frames and such. Going to keep this in mind if I ever do another. Getting on the ground to do all this physical labor is killing me.

[rudeman]

Getting on the ground to do all this physical labor is killing me.

Man, don't I know it. It's not like we're 30 anymore or even 50 in my case.

[Nessism]

Checked the fuel level on the new carbs and had fuel dumping all over the ground (again). Found one of these brass tubes cracked. It's never easy it seems. Was able to solder it closed anyway.

[salty_monk]

Bike looks great Ed - I never suspected anything different from you!

[Nessism]

Thanks for the comment Dan!

Got the refreshed exhaust installed over the weekend. It looks good but the coating is fragile. Had all kinds of fun trying to get both sides installed at the same time, since they join under the engine, without banging the pipes around too much.

Took the bike out for a nice ride, focusing on loading the rings as much as possible to help break them in, but came home early because one of the valves was tapping more than desired. The valve train on this bike has shim under bucket, so you gotta pull the cams to adjust the valve lash. The lash spec is .08-.18mm, compared to .03-.08mm for GS shim bikes. Found one valve at about .25 so moved that one down a shim. Could have maybe gone two. At any rate, got that sorted.

Found myself banging my head on the wall regarding the cam timing (again). I struggled mightily trying to get the cams installed previously and wound up switching the coil trigger wires between 1-4 and 2-3 in order to get the bike to start. I was trying to get that sorted out once and for all but had issues again. Wound up pulling the centrifugal advance unit apart and rotating the rotor 180 degrees before I could get everything properly aligned. I don't remember pulling that unit apart before but maybe I did and put it together incorrectly? Fingers crossed it's all fixed up now though.

Next project I'm looking at is installing GPz750 footpegs, which are set back a couple inches. Pretty sure it's a direct bolt on, just need to find all the parts. Ebay to the rescue...

[Nessism]

Small update for you photo lovers. Black exhaust installed (obviously).

I ordered some footpegs and related parts from a GPz so the pegs can be moved back a smig. Shifting is a little stiff on this thing compared to a GS so hope the linkage doesn't add to that.

Found a set of Progressive shocks for an amazing price only the dang things don't fit. Application data on the Progressive website suggest they should but they are too long and the swingarm moves down and hits the muffler brackets.

Works most basic shocks are $475. YSS shocks go from $350 to $500 (and higher but I've crossed those off the option list). Could keep the stockers I suppose but they don't live up to the rest of the bike.

And speaking of that, I took the bike out for a brief freeway blast today and was very pleased with how smooth the engine runs. I've heard stories about secondary imbalance buzz on these bikes, and Kawasaki rubber mounted the engines on later years to quell the vibes. Think I got lucky since for as much freeway riding as I figure to do, this thing is plenty smooth.

P1020789 by nessism, on Flickr

P1020791 by nessism, on Flickr

[lurch12_2000]

Very nice resto!

[Nessism]

Working on the new footpeg project. Received most of the parts needed including shifter/linkage, footpegs, brake lever, and even bought a new sprocket cover that has the stud for the shifter.

Stripped the corroded black finish off the shifter/brake lever and replated in bright zinc. Real happy with how this turned out. Sandblasted the footpeg brackets and repainted in black urethane. These turned out great too. The footpeg rubbers are tattered though so ordered some new ones (waiting on delivery).

Last part of the project is to deal with the sprocket cover. My cover has the mounting lug for the pivot stud so in lieu of polishing the new cover I bought I decided to just drill and tap my existing cover. Spent a fair bit of time creating a drill jig to assure the hole was straight and parallel to the existing shaft shaft. Got the hole drilled all straight like planned but rushed the tapping job and wound up with a crooked hole. Should have modified the drill jig to allow tapping with it as well. I'm livid with myself for screwing this up. Still have the new/old cover so not dead in the water but real unhappy with myself for going through all the careful work in drilling the hole only to mess it up at the last step.

[rudeman]

Strip it and buff it out. Call it a day.

Is that new/old cover from a GPz750?

[Nessism]

Strip it and buff it out. Call it a day.

Is that new/old cover from a GPz750?

It's already stripped and cleaned on the backside (tons of sludge/chain splatter). Will polish this weekend. The origin of the cover is a mystery. It's an early cover, dating back to the 650 and early 750. The GPz cover is more angular. Thing is though, none of these other bikes had rearset pegs (in the US market anyway), so they don't need that stud. The stud itself looks tarnished but unused.

Some before and after photos of the new parts...

shift lever by nessism, on Flickr

P1020802 by nessism, on Flickr

[jwhelan65]

Amazing work Ed!