One really hot summer day in 1971 a guy came in to my Pekin shop with his CL77, complaining that after about 20 minutes of riding, it would stop. If he 'let it cool down, it would fire back up for another 20 minutes'. So, I asked when the last tuneup and oil change was, and he said 'last Spring'. So, I wrote him up for a tuneup and oil change.
Next day, I changed the plugs and points and set the carbs, then pulled the oil plug to drain the crankcase from the sidestand, as the centerstand was missing. Nothing came out. Thinking that it must be plugged with grit (?), I jacked the bike horizontal on the shop stand, and about an ounce of oil dribbled out. Supposing the oil hole must be clogged, I stuck a screwdriver up inside - nope, it was open. So, I pulled the dipstick: dry.
Wow!
Then I reinstalled the dipstick and 2 quarts of oil and kicked it over: it fired right up. It didn't smoke. It didn't leak oil, either. We called him and told him the bike was ready, and he came and got it. I suggested he keep an eye on the oil level, told him I found no oil in it when changing it.
Over the next 2 months we became 'lunch buddies' as it happened that he frequented the McD's next to our shop, where I usually ate lunch. He rode in almost every day from his job about 2 miles distant. I asked him how the oil was doing: it never used a drop, but he said it sure ran better and had a lot more power, and didn't stall anymore.
Later that Fall he came in for another oil change. He brought 2 quarts with him this time, asking if I'd use it: sure, that's fine. Then he told me he 'found it in his garage, might be the oil he thought he had changed last Spring'.
...I think the CL77 might be tougher than the SOHC4?