Stubborn oil leaks at both sides of head

Once I got her running this summer, I noticed a lot of oil leaks, two of which were from the two 0-rings at either side of the head. I bought two replacements and put them in (along with a new head gasket) about 2500 miles ago, and last week they both started leaking again. It isn't bad - probably a couple mL per ride - but it bothers me and looks bad. Any ideas on how to remedy this in a more permanent way? It looks like this particular part hasn't been used in a new Kawi since 2005, so I fear that I'll just be stuck in a cycle if I buy replacements.

Were those o-rings installed dry?

:whistle:

daveo wrote: Were those o-rings installed dry?

:whistle:

Oiled, but I didn't use any sort of sealer. Maybe that's my issue...I just don't trust goops.

After following Z1E's advice several years ago...no leaks since!
Thanks again Jeff

The factory manual calls for sealer on the gasket around the outside stud holes.

What kind of head gasket was used? Kawasaki evolved the head gasket through quite a few iterations over the years, presumably to improve sealing. There is even one version with red RTV on it. Other versions have a varnish type sealer material on them.

Also, did you retorque after some heat cycles? That's critical, especially if you use aftermarket gaskets. I rebuilt a GS1000 engine with Athena gaskets one time and the torque fall off was horrible.

Nessism wrote: The factory manual calls for sealer on the gasket around the outside stud holes.

What kind of head gasket was used? Kawasaki evolved the head gasket through quite a few iterations over the years, presumably to improve sealing. There is even one version with red RTV on it. Other versions have a varnish type sealer material on them.

Also, did you retorque after some heat cycles? That's critical, especially if you use aftermarket gaskets. I rebuilt a GS1000 engine with Athena gaskets one time and the torque fall off was horrible.

I used a Wiseco one-piece fiber gasket. I haven’t retorqued, so I’ll get on that tomorrow and hope it solves it.

I’ll admit that I didn’t check my FSM before replacing the head gasket, as I’ve done a few on cars before, but looking at it now it makes no mention of sealer - just torque and then retorque after getting it hot once. Maybe it’s a difference between the 750 standard and shaft manuals.

Re: daveo, I’m not sure what advice from Z1E you mean - the link I’ve got to the rings has no info on the page. Could you elaborate?

www.z1enterprises.com/cylinder-o-ring-zx...%2Fall-models%2F1982

The original(?) Z1 Enterprises was located in New York until a couple years ago, and Jeff Saunders was one of the knowledgeable folks that ran the place..
He was the guy I trusted most to help me with part orders and questions. At the time I was starting to do work on my own engine, rather than paying someone to screw things up. :lol:

My 1982 1135 motor requires four 92055-1148 oil passage o-rings, which are sandwiched between the metal surfaces of the head and cylinder block.
Since I adopted Jeff Saunders advice to install them dry, my engine has not had a single related leak. Perhaps because of that, or the APE cylinder studs which replaced the stretched-out.original ones around the same time.

It may be one or the other, but I think it's both.

I found over the years putting a little Yamabond #4 on those orings seems to help. Orings are all over the engine, and all will leak eventually. KZ650/750 has 50 orings give or take. I think all 50 have failed on me at least once over the years.
Probably all the replacement rings now are 20-30yrs old in the package which sure doesn't help lifespan of the new orings obviously.

ghostdive wrote:

Nessism wrote: The factory manual calls for sealer on the gasket around the outside stud holes.

Also, did you retorque after some heat cycles? That's critical, especially if you use aftermarket gaskets. I rebuilt a GS1000 engine with Athena gaskets one time and the torque fall off was horrible.

I haven’t retorqued, so I’ll get on that tomorrow and hope it solves it.

I’ll admit that I didn’t check my FSM before replacing the head gasket, as I’ve done a few on cars before, but looking at it now it makes no mention of sealer - just torque and then retorque after getting it hot once. Maybe it’s a difference between the 750 standard and shaft manuals.

This is exactly what I presumed the issue might be after reading your initial question. Hopefully you'll get away with a re-torque. What manual do you have, is the Kawasaki one? My manual (for the E and H models) has the instructions to use a sealant around the farthest head bolts: I use non-hardening aviation cement for the job.

Thank you, Ron, I'll pick some up before my next replacement.

Yobbo, I'm using the shaft-specific service manual for the Spectre and the GT750. I should probably scan and upload it here someday...

The signs of a blown head gasket can be subtle. ... An external oil or coolant leak at the seam between the engine block and cylinder head is a sign that you have a head gasket failure or a cracked block. On disassembly, check for cracks and cylinder head warping.

If you see coolant seeping out, you might as well toss that bike in the river. :woohoo: