Can you measure it?I have a new sump plug with non fitting thread. Was there different ones, or is it simply wrong made?
Got that and will do, but should that much oil be in the sump?Wet sump not wet pump. Over time the contents of the oil tank will drain through the pump to the sump so needs to be put back in the oil tank.
but should that much oil be in the sump?
That makes sense. Since the bike has been sitting for 30 years, it's likely all of the oil from the tank drained into the sump, therefore I drained alot of oil out of it. So when I put oil back into the tank, it shouldn't go back into the sump.No, that's the point, the oil needs to be in the oil tank as the Commando is a dry sump engine but as I mentioned if the bike isn't started for instance for some time then the contents of the oil tank is likely to drain down to the sump, the actual amount can depend on how long the bike has been left and some bikes drain faster than others.
So when I put oil back into the tank, it shouldn't go back into the sump.
You need to get a manual. After 30 years the bike needs to be gone over completely. All fluids, forks, gear box, primary, motor oil, etc.. Adjustments, primary chain, drive chain, points etc.. Ad no, you shouldn't have 4 liters of oil in the crankcase unless the tank was overfilled 30 years ago. Anyway, get a manual, read it while you're taking your morning dump before you go out to work on the bike. At that point you will have gained enough knowledge to answer the questions you ask.Got that and will do, but should that much oil be in the sump?
How did it run when you parked it?