KZR's Bikes of the Month for 2024

1976 KZ400 D3 Grimey

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05 Jun 2017 10:09 #763599 by diggerdanh
Replied by diggerdanh on topic 1976 KZ400 D3 Grimey
I just took it for a 5-10 minute ride and the verdict is...

I fixed the top end leaks. Not a drop from between the head and rocker box, completely dry. There is one spot between the head and top of the barrels that is wet but I'm pretty sure that is just residue from what was there before. Those were the most annoying leaks before, dripping on the exhaust and smoking so I'm glad that worked out.

However, the biggest leak is at the bottom base gasket between the crankcase and the barrels in the front of the engine. It is not a huge leak, there was a single drop of oil in the floor after letting it set for several minutes after the ride. But the little lip of the crankcase on the front has a good film of oil on it, not quite a puddle but a little more than just wet. So it looks like the next bit of business will be to pull the entire top end off and reseal it. I have the gaskets, what I do not have is all the various o-rings, I have a few but not the complete kit so I am hoping the existing ones can be salvaged. I'm glad it does not require an immediate fix, I'll be able to ride it for short trips, because it will be a couple of weeks before I can tear into it.

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19 Jun 2017 06:45 #764763 by diggerdanh
Replied by diggerdanh on topic 1976 KZ400 D3 Grimey
I went ahead and pulled the top end apart. Head gasket and base gasket were in pretty bad shape and crumbled in places. They may be original.





This bike only has about 12K miles on it and the bores look really good. And there are no marks on the piston skirts. The compression is fine though it is getting a little blow-by. I have a new set of NOS rings (and pistons/clips too) but after seeing these bores I'm not sure if I should put the new rings in or not. I may save them for spares. I still need to measure the bores to confirm everything.



While in here I will definitely replace the valve seals as well as clean up the valves and the combustion chamber. I have a feeling the blow-by issue may be from the valve seals.



I thought I had an extra head and base gasket, which is one of the reasons I went ahead and tore it down, but it turns out they are for the 78+ engine. So I now have new gaskets and o-rings on order. Hopefully they will be here soon as I now have 2 non-running bikes.
The following user(s) said Thank You: GPz550D1

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12 Jul 2017 11:00 #766773 by diggerdanh
Replied by diggerdanh on topic 1976 KZ400 D3 Grimey
I received the gaskets and o-rings in a timely manner from the 4-5 various people I ordered them from on Ebay. I ended up not doing anything to the bores. Along with new gaskets I also changed the valve seals. Everything cleaned up and went back together pretty well except for a couple of issues. I hulked up a little too much and broke one of the bolts (snapped it in half) that cover the valve setting/inspection ports. I ordered a new one and once that was in I put it in place, added some oil and started it up and took it for a short test ride around the block to bring it up to temp. It does not seem to be leaking from anywhere so that's all looking good. However it was pretty hard to start and the bike is running pretty rough. I think I need to resync the carbs and make sure everything is set right after pulling them off. I don't think I was as careful as I could have been in pulling them off an putting them back on. That's minor though. The bigger issue is that I have a new tick from the right side. It could be a valve too tight, but I don't think so. I think that it is more likely an exhaust leak. One of the studs had some messed up threads but in the past I was able to still tighten the bolt down enough if I was careful. But I think that I messed up the threads too badly now. The nut will not tighten past a certain point and just spins. I may be able to clean up the threads but I am also looking into ordering new exhaust studs too. Looks like I can pick a set of 4 up for about $12. In mean time I'll check the valves again to make sure I do have them set properly, I'll see if I can clean up the boogered thread on the one stud, and I'll revisit the carbs.

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09 Jun 2023 06:48 #885805 by diggerdanh
Replied by diggerdanh on topic 1976 KZ400 D3 Grimey
This 76 KZ400 is for sale. I now have 2 mid-70s KZ400s and I want to let one of them go so I can move on to other projects. It is currently listed on FB marketplace but I can put any additional info here. Give me a shout if you are interested. 

$2300

Already has all the mods you would want to make. Perfect fr downtown streets or curvy back roads. Lots of stock, original parts but upgraded where it counts. Mikuni VM30s, MAC mufflers, electronic upgrades include modern fuse block, Ricks Motorsport regulator/rectifier, small lithium battery, Dyna coil, modern integrated mini gauges, electronic ignition from later KZ 400/440s, upgraded lights and signals, superbike bars, upgraded shocks, drilled front roter, original vintage Kawasaki case guards and more. Stylistically the bike has been generally trimmed down. New top end gasket kit and valve seals were installed 4 years ago - no leaks. I have had this bike for over 10 years and have a lot of time and money in it, more than what I am asking. I have one too many and this one must go. You must pick up or arrange pick up and delivery. Located near Middletown, OH. 

Thanks, 
Dan H
 

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09 Jun 2023 07:47 #885806 by Nerdy
Replied by Nerdy on topic 1976 KZ400 D3 Grimey
Holy cow - how and where have you been??? :)

1979 KZ400 Gifted to a couple of nephews
1967 Yamaha YCS1 Bonanza
1980 KZ440B
1981 Yamaha XT250H
1981 KZ440 LTD project bike
1981 GPz550
2013 Yamaha FZ6R

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