1981 Kawasaki KZ750 Resurrection

[salty_monk]

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

[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.

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]

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.

[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.

[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

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

[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

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[rustybronco]

Luck has been wished!

[Nessism]

While waiting for the pipes to be finished I've been busy working on carbs. The current carbs dribble when on the side stand, and one of the floats is sticky too. Pulled them off and set up a test stand so fuel level could be measured. Shame on me for not doing this before trying to put the carbs back in service. Anyway, found all the fuel levels high. Checked the float needles and two of the little spring loaded tips were frozen solid. Could have sworn I checked that when rebuilding the carbs last year but maybe they froze due to inactivity? Got the tips freed up and checked fuel level again and still high. Tweaked the floats and it helped but during this process had one of the floats stick (again). I've got a second set of carbs so pulled out the float needles and picked the best of the bunch for the runner carbs but not happy. Had to bend all the floats quite a bit and one carb still has a high fuel level. Conclusion is the float needle springs are too weak and the rubber tips aren't sealing like they should. OEM float needles are $26 each so going with K&L, who sells 6 packs for that same price. Why the heck do they pack them like that though? 6?

My extra set of carbs are actually in very nice condition. The yellow zinc plating on the various steel parts looks much better than the other set. Decided to go through this set and maybe even switch to them. Soaked the carb bodies in dip sauce and was horrified to see the nice pretty plating eaten to crap by the carb dip. Dang Keihin carbs using inferior plating to that used by Mikuni. At this point I decided to break down and replate all the parts, and may as well media blast the carb bodies at the same time. Made some major progress on this yesterday (will post some photos in a little while). Tried to soda blast the carbs but the corrosion pitting wasn't coming off so went to glass bead. Everything looking good at this point, just need to decide if I'm going to try to pull the throttle shafts out and replate the end fittings. I'm going to try one carb and see how it goes and then decide about the others. Wish me luck...

Like everything else I've seen from your shop, in a word amazing. Nothing wrong with the look of those pipes. Those 750 KZs were runners for sure.

Just took the first ride! Runs GOOD! Very nice driveability. First gear is tall but the clutch and low end torque manage easily. Speedo and tach needles are rock solid. Bike feels like a scooter compared to the GS1000.

Have some niggly things to tend to: fuel level warning light sensor leaks, so took it out, exhaust leak because missing the crossover pipe gasket on one side, need to anchor the clutch cable better, and the exhaust pipes only look so so. At any rate, it's a good day. Time to clean the garage...

[Vmass]

The bike looks fantastic, Ed. Is this one a keeper or should I dispatch my shipper?

[Nessism]

Dropped off the pipes at the powdercoater today. $260 for black ceramic coating, $330 for silver. I opted for black but there is time to change my mind. I really like the chrome look but the silver just looks like shiny silver paint, not chrome. Guy running the shop said you can polish the silver for a shinier finish but not sure it's worth the trouble.

I'm in the process of going through a second set of carbs so that will keep me busy for a few days. One of the floats is a little sticky on the existing carbs so gotta pull them off and see what's what anyway.

Very nice, I couldn't wait to see it and it was well worth waiting!

[azr]

Looks fantastic Ed, this has been a long time coming for you. I bet that ride felt pretty good........what's the next project??