Where do you put the oil in a 1961 Johnson 40 hp motor?

Answer 1

Your 1961 Johnson 40 HP Outboard Motor is a two cycle water cooled engine. This outboard uses oil added to the gasoline for lubrication. There is not any separate oil tank or crancase. The fuel, ( oil & gasoline ) mixture goes to the carbueator where it is mixed with air, then through reed valves, into the crancase portion of the engine, where it lubricates the bearings, and moving parts, then passes through transfer passages and ports into the combustion chamber, where it is ignited by the spark at the spark plug, burned and then the burned fuel is expelled through the exhaust ports and out the exhaust passages into the water.

A 1961 engine probably came originally with a six gallon fuel tank which I believe actually held six gallons of gas plus one quart of 30w non-detergent oil, or a 24 parts (quarts gasoline) to 1 part (quart of oil). Most of these engines were later approved for 40 parts gasoline to one part of 40w non-detergent oil, or 10 gallons of gasoline to one quart of the thicker 40w oil. That said, I have seen people run their boats on premix or fuel which already has the oil mixed into the fuel, which is usually 50:1.