Found a giant puddle of oil under my girlfriend's CB350F. I recently restored the bike and it has been working fine. Didn't leak any oil in the garage for a couple of weeks until suddenly it dumped a bunch out (maybe 1/2 cup).
I can't tell where it came from, so I'll have to budget some time to start digging again. I was happy to see that there wasn't any coolant in the oil, but I suppose that would be really strange from an air-cooled bike.
BTW, in case anyone is reading this and has advice, we're struggling with deciding what to do about the loud exhaust. The previous owner (who knew the original owner and was around the bike since new) says the exhaust is original. It's 4-into-2. I can take a picture if you like, but it doesn't look like any Googled images of original CB350F exhaust (4-into-4, as I recall). The paint seems to be non-standard too, so we think the dealer might have been creative. Anyway, the exhaust can't be taken apart without major surgery, but the fiberglass is clearly all gone. The bike is louder than just about anything on the road, and I like relatively quiet bikes. On the other hand, it'd be a shame to ditch the original exhaust. The options, as I see them: repack by force and then booger-weld it back together, accept the noise, or fit on some aftermarket parts.