How to dilute gasoline with oil for a two-stroke outboard motor

Proper preparation of the fuel mixture is the foundation of a long life for your family. two-strokeUnlike four-stroke analogues, where the oil is in the crankcase, here the rubbing vapor is lubricated directly by the combustion of the mixture. Any error in the calculations or carelessness in mixing the components can lead to major repairs or complete replacement of the piston group.

Many beginners underestimate the importance of accuracy, relying on the eye gauge or advice of seasoned fishermen. Yamaha, Tohatsu or Mercury They require a strict adherence to the regulations, and even a slight deviation in one direction or another changes the temperature of the engine.

In this article, we will discuss in detail how to avoid typical mistakes, which oil to choose and why the octane number of gasoline plays a critical role. You will learn to prepare the perfect fuel that will provide stable traction and protection from bullies.

Why Two-Stoke Motors Need a Mixture

Principle of work two-stroke It's very different from the car, and there's no separate lubrication system with an oil pump and a crankcase, and the crankshaft and the rod and the piston rings are lubricated by the oil dissolved in gasoline, and when the mixture burns, the oil film can lubricate the parts and then burn with the fuel.

If you pour clean gasoline, the engine will run for a few minutes, and if you don't lubricate it, it will cause the piston to overheat instantly and jam. On the other hand, excess oil is also bad, causing candles to coking, swelling in the exhaust windows, and power to drop.

Modern oils for water technology have special additives that allow them to burn completely at high temperatures. The use of automotive oils is unacceptable, because they are not designed to work in conditions of high temperatures. two-stroke And they'll quickly disable the engine.

⚠️ Warning: Never run a two-stroke engine on pure gasoline, even for a short check, guaranteed to lead to bullying on the cylinder and expensive repairs.

Understanding the physics of the process helps us understand the importance of quality, and gasoline is not only a source of energy, but also a solvent that delivers lubrication to the friction nodes.

Selection of components: gasoline and oil

The first step to success is to buy the right materials. Most outboard motors require octane-numbered gasoline. AI-92 or AI-95However, using fuels with a higher octane number than recommended by the manufacturer can cause the engine to overheat due to longer combustion.

As for the oil, you can't save anything. You need labeled products. TC-W3This standard means that the oil is certified by the National Association of Marine Manufacturers (NMMA) and suitable for outboard motors. API-labeled TC oils are for chainsaws and lawn mowers and may not provide sufficient protection in aquatic environments.

• 🛢️ Mineral oils - suitable for older motors and equipment without catalysts, require more frequent replacement of the mixture.
• 💧 Semi-synthetic oils - golden mean, provide good protection and moderate smoke exhaust.
• ⚗️ Synthetic oils - the best choice for modern engines, minimize the load and allow you to store the mixture longer.

Fuel that has been in the canister for more than a month is oxidized and loses its properties. To prepare the mixture, use only fresh gasoline, preferably bought at a proven gas station.

⚠️ Warning: Avoid buying gasoline at unknown gas stations or by hand. Poor quality fuels with impurities of water or alcohol can bring the fuel system and carburetor out of action in one season.

Exact proportions and mixing table

The main question that owners are concerned about is: how to mix components? The answer depends on the year of the engine’s production and the recommendations of the particular manufacturer. Old Soviet and post-Soviet engines (Whirlwind, Wind) often required a ratio of 1:25 or 1:30. Modern Japanese and European engines run at a mixture of 1:50 or even 1:100.

Violation of proportions in the direction of increasing the amount of oil (for example, 1:20 instead of 1:50) will lead to increased nagaroprostivovoyu. Candles will be covered with black fluffy coating, the engine will lose speed and die. If the oil is low (1:100 instead of 1:50), the risk of piston bully increases many times.

For ease of calculation, use the following table, which will help you quickly determine how much oil you need to add to a certain amount of gasoline.

Proportion	Oils per 1 litre of petrol (ml)	Oils per 5 litres of gasoline (ml)	Oils per 10 litres of gasoline (ml)
1:25	40ml	200 ml	400ml
1:30	33 ml	167 ml	333 ml
1:40	25ml	125 ml	250 ml
1:50	20ml	100ml	200 ml

Note that the measuring containers must be accurate, that kitchen glasses or bottles are not suitable here, and that you should buy a special measuring cup with risks or a large syringe.

Critical: A 1:50 ratio means 1 part oil per 50 parts gasoline, not the other way around. Mixing order error is fatal for the engine.

Technology of preparation of fuel mixture

The mixing process requires a sequence of actions: you can't just pour the components into a tank and hope that they will mix themselves when you shake a boat. You have to act in a mixing tank to get a homogeneous emulsion.

First, you pour about half the gasoline you need into a clean canister, then you add the whole oil, and then you shake it up for 10 to 15 seconds, so that the oil dissolves in the gasoline, and then you add the remaining gasoline to the desired volume, and the mixture is mixed again.

• 🧼 Use only clean containers intended for fuel. Traces of water or old "badyga" will spoil the new mixture.
• 🌡️ The components should be close to room temperature, cold oil dissolves worse in gasoline.
• 🔄 Stir the canister before each refueling, as fractional stratification may occur over time.

The finished mixture is recommended to be developed within 2-3 weeks, especially if mineral oil is used. Synthetic mixtures can be stored for up to 3-6 months, but it is better not to create large stocks.

⚠️ Warning: Never store the finished fuel mixture in plastic water bottles or sodas. Gasoline interacts aggressively with certain plastics, and transparent containers let light through, accelerating the oxidation of fuel, and someone from home can confuse the bottle and drink poison.

Typical errors and their consequences

Even with the theory, people make mistakes that cost them expensive repairs, and one of the most common is using oil for two-stroke air-cooled engines (chainsaws, motorcycles) in a outboard motor, which have a different combustion temperature and form a solid charcoal that clogs the exhaust windows.

Another mistake is to store the mixture in an open tank in the sun, and when exposed to ultraviolet light and heat, gasoline evaporates more easily than oil, which changes the proportion of the mixture in the tank to increase the concentration of oil, which leads to unstable idling and engine choking.

Also often ignored is the need for a filter funnel when pouring the mixture into the tank. A small mottle caught in the carburetor's jetty can cause the boat to stop in the middle of the pond. Always use filtration when refueling.

What happens if you spill the oil?

If you add too much oil (e.g., 1:30 instead of 1:50), the engine will start to smoke a lot, the candles will become saturated, and the power will fall. In the long run, this will lead to coking of the piston rings and reduce compression. If the error is small, you can just roll this tank and cook the next one correctly. If the oil is too much, the mixture is better drained and replaced, so as not to risk the piston.

Running a new engine and storage of equipment

The first hours of a new engine are break-in times, where the rubbing parts are rubbed together and the lubrication requirements are maximum. Many manufacturers recommend that the mixture be slightly richer in oil during the break-in period (the first 10 hours), for example, 1:40 instead of the regular 1:50, although modern synthetic oils allow you to comply with standard proportions at once.

If you're planning to put a boat in winter storage, you'd better make the fuel tank dry or you could preserve it with a special fuel stabilizer, and you can't leave the mixture in the tank for six months, because the gasoline will evaporate and the oil will settle on the bottom, creating a sticky substance that will clog the fuel system.

For preservation, you can put pure gasoline in the tank with a stabilizer for the winter and let the engine work for a couple of minutes so that the mixture passes through the carburetor, which will prevent corrosion of the internal cavities.

Questions and Answers (FAQ)

Can you mix oil and gasoline in the tank of the boat?

It's not recommended. You can't mix the components in a tank, butter, heavier than gasoline, can sink to the bottom, and the engine will get almost pure fuel at first, causing oil starvation. You can only mix it in a separate canister.

What if I have mixed proportions and poured too little oil?

If you notice an error before starting, drain the mixture and add the missing oil. If the engine has been running on a poor mixture (low oil) for a short time, immediately stop it, drain the residues and pour the correct mixture. The risk of piston damage is high, so you better be safe.

How much can you store the finished fuel mixture?

The mixture in mineral oil is recommended to use for 2-3 weeks. Semi-synthetics and synthetics can be stored for up to 3-6 months, provided that the containers are sealed and stored in a dark cool place.

Will the oil for motorcycles two-stroke in the outboard motor?

Air-cooled motor oils (motorcycles, chainsaws) have different combustion temperatures and ash contents. In a boating, they form a solid soak that will knock the engine out. Only use TC-W3 oils.