1979 kz400 LTD Rebuild.

Hello all!

I'm coming into the final stages of being able to rebuild my bike finally. I'd like to defixate this thread to my rebuild and what I've done so far.

I acquired a parts engine and a bunch of parts from Mary (z1kzonly) here on kzrider. Met him through ebay and drove out to Buffalo to pick everything up. THANK YOU MARTY THE PARTS HAVE SAVED ME A LOT.

New parts include Valves, guides, seals, springs, gaskets, cam chain, engine seals, new muffler for the 2-1 kz400 special exhaust I picked up, starter rebuild kit, starter clutch, wheels, h4 headlight, xs650 lowering shocks, crash bars, and a bunch more.

I have learned what patience means dealing with this bike. I did mess up a case half trying to get out the clutch rod stopper plate and it really threw me for a loop. I dug into the parts engine and it wasn't that bad for sitting for 20 years. Lots of carbon and build up on stuff but easily clean able (pic's to follow). I had the cylinders checked out at a local shop and they honed and cleaned them up for me as well. Checked pistons and they were in spec too. I put new rings on the cleaned up the pistons. I used gun cleaner to clean up all the carb and soot build up in the engine and wow did it work.

All I have left is to clean up the case halves and start putting everything back together. Hopefully come spring time she will treat me as well as I've treated her so far.

I've started the build process on the engine over the weekend. It's one long winter here in upstate New York. So far I've gotten almost all new internals for the bike from cam chain to transmission gears. It's been a long rewarding process but I'm getting the hang of. I've lapped new vesrah valves, fitted the crank with new rod bearings and bushings, New Barnett clutch and web camshaft cam.

When you get your engine together do a compression test.
You should have 150 p.s.i.g. or better.


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Quick question Nebr....with a cold new engine would I read a lower psi? I was under the impression that a warm engine would give a higher compression reading. I could be totally wrong this is my first rodeo

Some times yes, sometimes no, there are a lot of variables.
All depends on the type of engine and it's condition.
Typically a fresh engine will seal up as it gets warm
and a worn engine will 'bleed out'. For your situation
I have a concern about a stock static compression ratio
with a more aggressive cam than stock. With not enough
cylinder pressure you will have less power than stock at
lower r.p.m.s and not enough to take advantage of the
cam at higher r.p.m..


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Would I be able to remove the base gasket and use the 3bond in place to increase compression? It's not an over the top cam from what I heard just an overall upgrade from stock. In a few months I'll be getting an overbore piston kit for a 440 and can save it for that

If you do your compression ratio will jump up to just shy of 10/1.
But it will also retard your cam by around 1.3 degrees.
The stock cam is 113* + 1.3* and add a couple for chain stretch
and you will have an intake center line of 116*.
The general consensus for motorcycles is to start at 105* and go from there.
Where does the cam open and close the valves.
Can you post a pic of your cam card?


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