How Do You Mix Petrol With Two-stroke Oil For Boat Engines?

Since you asked about two-stroke oil for a boat engine, I will presume your engine is a two stroke engine, which requires the use of petrol and two-stroke oil. My research has led me to conclude the safest action for you to take is by way of a local service station, boat dealer technician or a sports store with knowledgable personnel to assure safety for you and your engine.

My research revealed a variance of ratios based on the size of engine and the age of the engine being discussed. Apparently the age of the engine can make a difference in the ratio. The ratios were 1000 to 1-100 to 1 and 50-1, therefore I suggest, you approach someone locally with the necessary information about your engine: make, model, size, etc. and ask how to safely and successfully mix your petrol and oil for your specific engine.

The oil that is used for marine extreme or boat engine is SAE 40 base oil combined with diluents. The mixing of two-stroke oil with petrol prevents engine deposit, protects against scuffing, keeps the engine clean and prevents suffering and wear. Usually the engine manufacturer himself recommends the ratio of oil and petrol mixing; you must follow that ration only. Manufacturer specifies ratio of mixing oil depends on parts used, efficiency and material used for parts or working of parts in engine. Generally the ratio is 30-40 ml of two-stroke oil in one litre of petrol. Oil is directly added in petrol when it is filled in petrol tank. But it is very important to add proper quantity of oil specified by the manufacturer as it saves your engine from any problem.

i have a 235hp evenrude 2stroke outboard on my boat. I just put the oil in first at a ratio 50-1 then add the petrol.  to be honest, I have been doing it this way for years with no problems.

Simply add the proper amount of oil to the "petrol" gas tank first, taking into consideration that you have done the maths to determine how much the tank can hold, and how many ounces of oil per gallon and then add the "petrol" gas to top it off...

50 to 1 is the correct ratio for most outboard motors.

Can you use any 2 stroke oil in a outboard engine

This is too broad because different engines has different mixtures to go by. You need the owners manuel to answer this.