'78 CB750F Broken Valve Cover

[xxthegonzxx]

So I was tearing down my engine for a rebuild and noticed the broken valve cover where I think the air port is at? Not quite sure what's it's called but it's right in the middle of the valve cover. Not sure if it's ok to leave as is or maybe replace/repair somehow. I don't have any welding equipment and was hoping of a quick fix? Any ideas would be appreciated.

 

[xxthegonzxx]

bump

 

[xxthegonzxx]

I also found when I opened it there was some yellow sludge in there. Not sure what that is. I've been searching online and have found other valve breather ports to have holes in them as well. Are those holes so vapor/engine fumes can escape through the breather hose?

 

[MR915]

That area should be open. I'd grind more away (on both sides of the cam sprocket area). You notice your breather tube bung is there at the back....that is how the engine ventilates. If you tig that up you will "seal" the engine and crankcase pressure will build. Consequently seals blow out.

 

[xxthegonzxx]

Thanks for the reply. Yeah I definately have found other users on the forum with the same holes...kinda strange that they weren't manufactured. I'm guessing aftermarket changes? Anyway, I'm continuing my tear down this weekend. I'm guessing I'm going to find some more surprises.

 

[MR915]

Thanks for the reply. Yeah I definately have found other users on the forum with the same holes...kinda strange that they weren't manufactured. I'm guessing aftermarket changes? Anyway, I'm continuing my tear down this weekend. I'm guessing I'm going to find some more surprises.

Those areas were thinned out....they drove punches through the those areas to open them up.....kind of. As I said....you'd be wise to open those areas up. Keep in mind Honda were making those 78's as a hold over until the DOHC's....unfortunately they really didn't give a shit about them.