Can i engine flush a 1980 kawasaki four?

Do NOT use a commercial engine flush with solvents. The product removes not only the old oil, but also any oil film left protecting cylinder walls, rings, bearings. Flush with a light-weight motor oil, you can use a cheap brand as the main purpose is to rinse out contaminated oil. If your oil is creamy, you have water in it. I realize the bike is air-cooled, but fuel/petrol in oil does not cause it to become creamy. You would also have a strong fuel smell. The loud tapping noise is one of two things: 1) Cheapest one is simple lack of lubrication caused by contaminated oil. If so, it will clear up when you change oil. 2) Most expensive one is engine damage caused by lack of lubrication. A heavy knocking noise that continues after the oil change is most likely this. Use the best oil you can buy...cheap oil will cost you more in repairs over the life of your bike. I assume you fixed your misfire? You should have your carbs checked also, it sounds as if you are running very rich to have ...  more