4. Add sealant around the whole cam chain tunnel. Honda did: I'm sure it was important!
Are you using Permatex no.2? The same stuff as what you use with the pucks under the cam tower?
I was considering spraying the whole head gasket down with Copper Spray a Gasket, but am open to a different approach if you have found a better solution.
Oh, and I'll PM you for a set of those o-rings for my K4.
Thanks
Dan
Yeah, their non-hardening stuff. I really wish I could find some FelCoBond, but they don't sell it around here anymore. That stuff was excellent for this task, especially on the old CB/CL72/77 engines which had nothing sealing these passages but the head gasket. They often leaked, more than a little. It strongly resembled rubber cement, but was oil- and gas-proof.
Thanks Mark. I love the finish of your valve cover by the way.
Couple more questions. Did you add sealant to both sides of the gasket? Anything on the base gasket? I don't want to make any assumptions and be caught with a leaky head gasket. I'd like to install the head and base gaskets with your method as I'm sure it has worked well for 100's of leak free CB750's.
On the base gasket, I usually only dab some around the big drain holes. The crankcase pressures there are about the highest in the engine, so I usually add a thin coat of Hondabond on both sides right there, and close it quick to make it thin. This is hard to do: the rings must already be in the cylinders, so you don't have much working room. I use a little paintbrush or acid brush, usually, to apply it.
The cam cover: this is a problematic one, over time. The head expands a LOT more than this cover, so the gasket must seal between moving surfaces. This is why they often weep a tiny bit over time, but are easy to clean at the carwash. Honda's cam cover gaskets has the rubber-y looking stuff on just the bottom side of this gasket. I often find them either pulled inside or nearly so, at the short straight corner sections where the gasket is narrow and the expansion is greatest. Making the cam cover screws into Allen Head type makes the creeping worse because it is too easy to overtighten those, forcing the gasket to make up all the travel difference.
I've used various goo here over the years: when Hondabond came in one type only (no #1, #2, #3, #4), it worked well here. When I tried using the #4, which is used for the split cases, it gets hard over time and then does not seal after it cracks off in little bits. I find it next to the valve springs, in little chunks. Since this area can reach over 325 degrees, the Permatex non-hardening has a tough time staying pliable, and the "Versa" stuff sold in many stores today in lieu of the #2 Permatex does not seal very well after a year or so, here.
So, I am doing no sealant at all, lately. The oil will swell the gasket a little bit on the inside edge, which will help the seal, but the weep will continue. I think this will at least keep the gasket from slipping all the way out of the surface.
The Athena gaskets don't seal the cam cover for beans. They are much too thin. This is one place where a thicker gasket is very important! I know of one rider who recently glued 2 of these gaskets together with non-hardening stuff, then installed: I'm waiting and watching to see how that runs out. It might be a good idea!