Top-End Redo

I wish I could answer your question Daveo, but I can't. I just wanted to say thanks for posting this thread as I am contemplating what to do with my KZ-1000 cylinders. I have two cylinders that have some pitting on the walls that seems to be the result of the pistons being parked in one spot for quite a while. The engine didn't seem to burn any oil, at least no smoke, before I took off the head for some work. So I am contemplating leaving it alone and putting it together and see how it runs, or pulling the cylinders off and going with oversized pistons based on how much material would have to be removed to eliminate the pitting on the cylinder walls. I am also undecided on going up in compression from stock. Doesn't seem to be a whole lot of gain just bumping up compression.
Rick H.

Loosening the head on my engine caused the cylinder base gasket seal to break every time.

Wished I could tighten it up or just put the head back on, but without 100% confidence that would reseal it, it was head-first into the worm can again.

Now I have that hard-knock confidence, and think I know ahead of time what I'm in for.

:huh:

Sounds like you would need a solid copper head-gasket.. You might try www.powersportsplace.com/parts/wis-w2717...saki/model/kz1000a-j Good luck...

daveo wrote:

baldy110 wrote: No it won't. A head gasket will come with the piston kit.

My KZ cylinder block has recesses for o-rings at the four corner stud holes, whereas the ZX cylinder block this MTC kit is made for does not . Considering that, will a special head gasket be required for my application?

OR, you could rig up one of your neato jigs and machine the ZN block to accept those overpriced goofy O-rings, much like you did to flycut your piston recesses.

And Yes, baldy is right the 2 scored pistons I mentioned were victims of operator error. The poster apparently thought that overheating a freshly assembled tight engine was a good thing. When you first start that motor, do not let it sit there running (no cooling system) . . Start it, hop on and YeHA! Like almost every thread on this forum, everything was "right" yet the pistons scored.. expensive mistake. go figger. :blink:

I hate dealing with those goofy o-rings, but haven't had one leak since 2015, thanks to awesome advice from Jeff Saunders to install them dry. And the APE cylinder studs and nuts sealed the deal for sure!

Wish I had a nice low-mile ZN cylinder block to work with, but I don't. So, off the rods with my specially modified stock pistons and new set of rings I have waiting for them, and out with my wallet and every cent in it. :kiss:
Still undecided, but close.

With the one-piece copper gasket, do I simply leave all the o-rings out including the center galley o-ring, and that's it?

I gotta stop over-thinking this...

:S

I believe that's correct. If you don't get a more definitive answer try contacting APE, they will know. kzzone.com/gaskets.html

daveo wrote: I hate dealing with those goofy o-rings, but haven't had one leak since 2015, thanks to awesome advice from Jeff Saunders to install them dry. And the APE cylinder studs and nuts sealed the deal for sure!

Wish I had a nice low-mile ZN cylinder block to work with, but I don't. So, off the rods with my specially modified stock pistons and new set of rings I have waiting for them, and out with my wallet and every cent in it. :kiss:
Still undecided, but close.

With the one-piece copper gasket, do I simply leave all the o-rings out including the center galley o-ring, and that's it?

I gotta stop over-thinking this...

:S

I dont think the copper gasket is the one you want .
Probably one piece composite from Cometic
Dave

Copper ones are for race and tend to weep.
Steve

urankjj wrote: I believe that's correct. If you don't get a more definitive answer try contacting APE, they will know. kzzone.com/gaskets.html

APE Part number K8325 (2-PC) MLS/COT Spring Steel or Graphite(?) may well-be what I need.

aperaceparts.com/resources/APE%20Catalog/mobile/index.html#p=76


:whistle:

I believe that also is correct, but a solid copper gasket being re-torqueable may negate the weeping. I just checked on my bike, ( 1327cc, 10.25 comp, 1977 KZ1000), and I do have a composite head gasket with what looks like Blue RTV sealant. But keep in my mind that my engine was built in the late 1980's. Good luck and more power to ya!!!

Copper head gaskets are used in race motors with turbos and or very high compression.
When using a copper head gasket you have to install wire o rings into machined grooves around each cylinder .
Im sure our membership is split in opinion between 2 pc gaskets plus using the center o ring vs the one peice gaskets
As well as to what brand to use . OEM vs Cometic
You need to use what makes sense to you
Dave

I do not believe that you absolutely have to incorporate any O-rings at all when using a solid copper head gasket, even if the engine block in question is machined for O-rings.