Valve cover leaks

The bike in question is a 75 Z1B 900 that was opened up to 1075. When I first got the bike last year, it would weep oil from around the rubber cam ends. (AKA Rubber baby buggy bumpers). Checked valve clearance and put on a new blue gasket from Z1 Enterprise. Leaked even more around the buggy bumpers. So I pulled off the cover again and put in aluminum buggy bumpers from APE as well as a new blue gasket. . Also put in a light coat of permatex on all surfaces. Still freaking leaks. I can even see a bit of oil coming from under the bolt heads. I know the mating surfaces are flat and true. I don't think it's from over compression as the engine has about 5000 since it was opened up to 1075.

One thing I looked for but could not see was, where does the cam get it's oil from for lubrication and how does it get back to the pump from that area? I noticed small pools of oil by the buckets. Could the return be blocked? Maybe I need to put in some type of breather up there.

This is really ticking me off. If I wanted a leaker I'd have gotten a Harley.

One last question. What the heck are the rubber cam ends for?

Just a thought ,, Check you crankcase breather...yer engine may be building pressure in the crankcase,if its plugged, and causing your weepage ! Good luck!
A cracked valcover will do this too..

MAC:)

put 1194 sealer around rubber end plugs and retorque valve cover bolts after the first 3 rides...i had the same problem....now..no leaky.....

Those are cam end plugs. Often due to age they get hard and leak. Especially if they have been moved. You can buy bew ones as well. I use Hondabond 2T on assembly. Never had a leak. They are there to fill in the area after the cam journals were line bored at the factory.

WHEN INSTALLING THE ALUMNIUM END CAPS....

Did you level and seal them in place?
When I got mine, I had to mill them down (file) flush to the head decking....

Just a thought...

Wile wrote:

Also put in a light coat of permatex on all surfaces.

I use the black ultra high temp gasket maker. You have to apply it right. Clean all surfaces with acetone. Run a thin bead all the way around and just set the cover/gasket on and install the bolts finger tight, JUST tight enough to flatten the sealer out. Wait an hour, and apply a little more pull on the bolts with a socket in your fingers (no wrench) to get the excess sealer out. let cure overnight and torque the cover to about 60 - 70 inch pounds. It will seal it.

The end plugs do have to be installed with gasket sealer. And goes without saying, they have to be level and flush with the head or they will not seal.

Wile wrote:

where does the cam get it's oil from for lubrication and how does it get back to the pump from that area? I noticed small pools of oil by the buckets. Could the return be blocked? Maybe I need to put in some type of breather up there.

The oil does pool over the buckets. The oil feeds up through a passage from the crankcase. On my 750, there is a feed passage on each side of the engine going up with orifice restrictors in line to keep pressure up.

Oil Paths.... My KZ900, should be approximately the same for yours...

arai59 wrote:

They are there to fill in the area after the cam journals were line bored at the factory.

DUH I should have realized that.

Old Man Rock wrote:

WHEN INSTALLING THE ALUMNIUM END CAPS....

Did you level and seal them in place?
When I got mine, I had to mill them down (file) flush to the head decking....

Just a thought...

I also had to trim the tops down and yes I put a bead around them too.

bountyhunter wrote:

Wile wrote:

Also put in a light coat of permatex on all surfaces.

I use the black ultra high temp gasket maker.

Maybe I'll try a diferent brand of sealer.

and torque the cover to about 60 - 70 inch pounds. It will seal it.

Pounds or ounces?

Old Man Rock wrote:

Oil Paths.... My KZ900, should be approximately the same for yours...

Great Pic

I don't think my manual has that one, Thanks.