I found a few minutes to sneak to the shop and, knowing that I'm gonna replace the timing chain this coming week, I decided to pop off the clutch-side cover. Everything looked pretty good except for this:
That's the little tube which is, I think, one of two outlets from the oil pump. It obviously went in crooked during the last assembly of the engine (whenever that was...). The sort of amazing thing is that the seal between the cover and the pump was apparently good. All components in the cam and valve area, as previously noted, are in very good condition, so oil was definitely getting up there.
I am particularly nervous about this area... the way that the oil pump outflow goes into the side cover. When I was 19 or 20 years old, I replaced the clutch on my first XL600R (see page 1 for pix) and managed to forget an O-ring during reassembly. My head got fried in short order and I had to have an expensive repair done at Golden Gate Cycles (way back when it was on Van Ness).
For all you who have done this before... once I correct the little aluminum tube problem and replace the associated O-ring, does everything else here look to be in order? The larger hole in the background slightly to the right mates up with the other, larger output of the oil pump, but there does not seem to be a replaceable O-ring or other type of seal there... there is a seal there held in place by a circlip, but there's definitely no replacement for it in my "full engine rebuild gasket and seal kit". Anything I need to know? I don't want to make the same costly mistake again....