Topic: Weird place to see oil bubbling.. '77 CB550 K

[bretherin]

So my head gasket has been weeping oil for a bit now and the plan is to get to this once I finish up a cb450 resto as I don't want to be without a bike. However, yesterday I looked down while at a stop light and noticed that the nut in the below picture was wet with oil. The opposite side is completely dry. Upon further investigation I can see oil bubbling through the threads. This link shows my little video this morning before getting into the office. Oil bubbling on CB550

I tried to search on here and some people eluded to the head cover's side covers that are attached by the L bracket however this seems to be bubbling through the threads. The nut is not lose although I was hoping to get the time to loosen the top and re torque it down but I was hoping for a little bit of an explanation is anyone has one or seen this before? Plus, any suggestions are more then welcome.

[bwaller]

It's a bit of a compression leak past the fire ring of your head gasket closest to that cylinder stud. It'll bubble out a little oil with it. It may eventually work it's way out to show between the head & cylinder, but for now just give it a wipe now & then. 

[TwoTired]

Oil does bubble when too hot.

You certain the rubber pucks/oil seals under the cylinder cover aren't leaking?  These harden and loose seal with heat and age.

[bretherin]

It's a bit of a compression leak past the fire ring of your head gasket closest to that cylinder stud. It'll bubble out a little oil with it. It may eventually work it's way out to show between the head & cylinder, but for now just give it a wipe now & then.

Head gasket is definitely leaking..

Oil does bubble when too hot.

It does bubble in direct relation to throttle response, it was weak in the video as the bike was idling but at a stop if I look down and rev slightly it bubbles accordingly.

You certain the rubber pucks/oil seals under the cylinder cover aren't leaking?  These harden and loose seal with heat and age.

I am not certain as I have never looked in there but I doubt any PO ever has, so given its age and sparse use I'm sure they are due for a replacement.

[bwaller]

My race engine leaked at one stud. It was barely noticeable and when I pulled the head in the off season you could see the path of the compression leak. In my case re-annealing the copper head gasket sealed it.

When/if you remove the top end for gaskets make sure you straighten both surfaces.