Dont use car oil in a motorcycle

Why you don t use car oil in a motorcycle. Four years ago I bought a ninja 600rr off of crags list the guy who sold me the bike put regular car oil for the oil change. In a 100 miles the oil was broken down very black and watery. I am very lucky my motorcycle didn t have a catastrophic failure on my way home. It s not worth trying to save money with using cheap car oil. In a motorcycle oil does 6 jobs. 1 engine cooling. 2 engine lubricant. 3 transmission cooling 4 transmission lubricant 5 clutch cooling 6