Oil leak help and sense check.

[Dolomite_]

So there is an oil leak coming from the bottom of the barrels around where the oil breather dowel is. After taking the barrels off the gasket is nackerd and seems to be split where the dowel is (pic 1 and 2) so I'm thinking that could be the reason for the leak.

Now for the sense check. After having a look at the CB400 four engine rebuild that Nurse Julie posted it seems like the little o-rings that go around the dowels werent there (pic 3). So it seems to be a combination of both the gasket and the o-ring. I plan on replacing the gasket, obviously, but couldnt find the little o-rings for the dowels on davidsilvers, unless I missed them. Could someone point me towards them? They definitely should have the o-rings for the dowels right? I couldnt find any mention of the o-rings in part diapgrams I've been looking at.

[Nurse Julie]

That's a main oil return path from the crank to the camshaft.. You won't find the O ring in any gasket set or a part number as it is not a standard part, it is an 'upgrade' that helps prevent oil leaking from the return path and getting under the gasket causing the base gasket to leak. If I can remember what size the O ring was that I fitted, I will let you know.
What has happened to your base gasket is exactly what I have described above.

[Nurse Julie]

In fact, the closer I look, it actually looks like that gasket was split when fitted, its not sitting right at all. 🤔 And, someone has been there with a flat blade it screwdriver by the looks of it 🤔🤔

[mattsz]

Mysterious - pics 1 and 2 don't show on my computer... only #3...

[heliwilly]

Only pic #3 on my PC as well???   Bill W

[Nurse Julie]

All 3 pics showing on my phone.

[mattsz]

You can see them, that's what counts, Julie!  He's getting the help he needs from you.  I'm just hanging about...

[Dolomite_]

In fact, the closer I look, it actually looks like that gasket was split when fitted, its not sitting right at all. 🤔 And, someone has been there with a flat blade it screwdriver by the looks of it 🤔🤔

Dont know how long the last owner had this gasket on but it ripped in quite a few places when  I took the barrels off. It does look like a flat head has been at it but it's just where its ripped