Cam housing gasket - ‘78 Special

[Duck749]

I have oil leaking from cam housings at points/advance. Did some looking and see the seal can be bad, new ones on order. Left side of the motor there was oil in the housing. Right side on both inside and outside. I have all parts removed and working on cleaning everything up. In process of removing the right side housing, the gasket broke apart. Looking at MikeXS, I don’t see where I can find replacement gasket that is between cam housing and the head. Does anyone know part number and place to get this?

Most sites I have visited the gasket is incorrectly called out and references breather gasket. The one I removed has a step in it which I believe is for additional sealing. I found reference to flat gasket and o-ring used, this is not the style I have.



Additionally, I have read about the cam not being centered when installed which leads to sealing issues. As long as I measure distance from head to bearing (depth) and if same, is it safe to assume this isn’t an issue for me?

 

[Duck749]

So I got cleaning things up and see there is Oring that was compressed flat and stuck to gasket. My clymer manual says “breather cover gasket” is what I am looking for. As mentioned only part I am seeing is square gasket for breather box.

 

[Jim]

If you don't want to buy a whole gasket set, the cam cover gaskets still pop up on Ebay. This isn't a bad price...

https://www.ebay.com/itm/133760432718?epid=1129930759&hash=item1f24be3a4e:g:5uIAAOSwsv1hEuOO

As far as the o-ring goes, I've never really figured out why Yamaha saw fit to use an o-ring and a gasket in that application. Using just the gasket would work just fine.
For cam centering, both housings should screw in flush to the face of the head without the gaskets installed. If they do, your cam is centered.

 

[Duck749]

Perfect thanks!

 

[5twins]

I like to use the o-rings, and original red rubber ones (I think they're silicone). I had the opportunity to pull these housings off mine a few years after I rebuilt it. The black rubber o-rings I used from the Athena gasket set were all deformed (square, not round any more). I replaced them with still good round originals.