Owners of water equipment often wonder about the proper preparation of the fuel mixture for their own use. two-strokeA mistake in the calculations can cost the owner expensive repairs or, conversely, cause the failure of the cylinder-piston group. Unlike four-stroke analogues, where the oil is poured into the crankcase separately, here it burns with gasoline, providing lubrication of rubbing parts.
The exact knowledge of that, How much oil is it? It takes one liter of gasoline, is the foundation of a long life. outboardModern synthetic lubricants make the mixtures more liquid, but the old instructions may require different proportions. Incorrect dosage leads to either candles and silencers coking or piston squeezing due to oil starvation.
In this article, we will examine all the nuances of emulsion preparation, consider the table of proportions and answer questions that often arise for beginners in aqueous engines. The right approach to fuel ensures stable traction and no smoke from the exhaust pipe.
Why the accuracy of the proportions for two-stroke motors is important
The two-stroke cycle of the engine means that lubrication occurs only when the fuel-air mixture passes through the crank chamber and cylinder. oilThis will cause the metal parts to become more frictional, and it will cause the piston group to overheat and collapse instantly, which is a classic beginner mistake.
But the excess lubrication is also not good for the excess amount of grease. mineral or synthetic oil It settles on the bottom of the piston, in the exhaust windows and on the spark plug, which reduces compression, impairs heat sink, and can cause kalyl ignition when the engine continues to work even after it's turned off.
⚠️ Warning: Never use oil intended for four-stroke engines or old motorcycles with separate lubrication to prepare the mixture in the tank of a two-stroke outboard motor.
Modern oil production technologies have allowed us to create products that burn almost without a trace, but even these require compliance with regulations. Tohatsu, Yamaha or HondaIgnoring this data to save a few rubles per liter of fuel is a direct path to overhaul.
Standard ratios: 1:25 to 1:50
There are several basic mixing standards in the boating market, the most common ratios are 1:25, 1:33, 1:40 and 1:50. The figure after the colon shows how many parts of gasoline are per part of oil. For example, a mixture of 1:50 per 50 liters of gasoline requires 1 liter of lubrication.
Older Soviet engines and some Chinese models often require a more "fatty" mixture of 1:25 or 1:30, which involves the use of less quality materials and mineral oils, which are worse lubricating and faster to burn. two-strokeThe synthetics have switched to the 1:50 standard.
It is important to understand that switching to a more modern oil (e.g. 1:25 to 1:50) is only possible if it is allowed by the instructions to your particular engine, otherwise, if the engine requires 1:25 and you pour 1:50, you risk getting bullied.
The golden rule is that you always look at the motor manual, not the tips on the forum. The proportion depends on the engine technology, not the oil brand.
Table: How many grams of oil per liter of gasoline
For the sake of convenience, we have prepared a composite table that will help you quickly determine how many milliliters or grams (with an oil density of about 0.9 g/ml, the values are close) you need to add to the tank. The density of gasoline and oil can vary slightly, but for practical purposes these errors can be ignored.
| Proportion of mixture | Oils per 1 litre of petrol (ml) | Oils per 5 litres of gasoline (ml) | Oils per 10 litres of gasoline (ml) | Motor type |
|---|---|---|---|---|
| 1:25 | 40ml | 200 ml | 400ml | Old engines, Chinese models |
| 1:30 | 33 ml | 167 ml | 334 ml | Medium power engines |
| 1:40 | 25ml | 125 ml | 250 ml | Modern 2t engines |
| 1:50 | 20ml | 100ml | 200 ml | Japanese and European brands |
When measuring small volumes, such as 20 ml, it is convenient to use a medical syringe or measuring cup, which often comes with an oil canister. The glazomer here is a poor assistant, an error of 10 ml per liter significantly changes the properties of the mixture.
Motor Running: Changing the Proportions
The first hours of a new or rebuilt engine are called the break-in period, during which the rubbing surfaces are used up and the lubrication requirements increase, and many manufacturers recommend that the mixture be slightly richer in oil than is specified for normal use.
The following regimens are usually recommended:
- 🛠️ First tank (10 liters): the ratio of 1:25, regardless of the standard.
- 🛠️ Second and third tanks: the ratio of 1:30 or 1:35.
- 🛠️ Next: switch to the standard mixture (for example, 1:50).
During break-in, it is not recommended to run on full gas. The engine should operate in variable modes, which ensures uniform laundry of the rings. If you pour a regular mixture of 1:50 into the new engine, the risk of getting bullies when loaded increases significantly, since the microgaps have not yet reached the operating values.
⚠️ Warning: If after running you notice that the spark plug has become black and wet and the engine has lost power, perhaps the mixture was too rich. Try to reduce the amount of oil in the following tanks, but do not go beyond the lower limit of the instructions.
Choice of oil: mineral or synthetic?
The quality of the lubricant directly affects the engine cleaning frequency and its life. Mineral oils (usually red or green) are cheaper, but they form more soak and require more frequent replacement of the mixture in the tank if the boat is standing still.
Semi-synthetic and fully synthetic oils (often blue) are more expensive, but they are:
- 🌊 It is better to dissolve in gasoline, without stratifying during storage.
- 🌊 Burn cleaner, leaving a minimum of charcoal on the piston.
- 🌊 They have the best lubricating properties at high temperatures.
Use of labelled oils TC-W3 It's a standard for water technology, and it's designed specifically for water-cooled applications, and it doesn't cause corrosion. It's only a last resort for two-stroke car oils, but it can produce more smoke and more soda.
Can I store the finished mixture?
The finished fuel mixture is not recommended to be stored for longer than 2-3 weeks. Gasoline is oxidized, loses its octane number, and the oil precipitates or changes its properties. If you're finished with the season, work out the entire tank or drain the mixture.
Rules for mixing and storage of fuel
The process of cooking fuel requires precision, you can't pour oil and gasoline directly into the tank of the boat, hoping that they will mix when shaking on the wave, you need to mix in a separate clean canister.
Algorithm of action:
- Pour about half the required volume of gasoline into the canister.
- Add the entire calculated portion of the oil.
- Shake the canister for primary stirring.
- Add the remaining gasoline to the full volume.
- Shake it carefully before refueling.
Using transparent measuring canisters simplifies the process, and there are special measuring bottles with divisions for different proportions, eliminating the need for a calculator on the shore.
☑️ Pre-launch checks
Frequent errors and their consequences
One of the most common mistakes is to use old gasoline, which is that ethanol-containing gasoline (leaded) can get saturated with moisture from the air if the boat is standing still for months, which leads to the dissection of the mixture and water entering the engine.
Another mistake is the use of “workout” or oils of unknown origin: cheap oils can contain aggressive additives or abrasive particles that act as sandpaper for cylinders. Saving 200 rubles on oil can lead to the replacement of the piston group at a cost of 10-15 thousand rubles.
It's also important to remember seasonality. In winter, the evaporation of gasoline changes, and the engine can run unstable if you don't use fresh components of the mixture. Always use fresh gasoline at the beginning of navigation.
Save checks from oil and gasoline. In case of warranty, the service can request confirmation of the use of quality fuels of the appropriate specification.
FAQ: Frequently asked questions
Can I use motor oil for a motor boat?
Automotive oils (even for 2t motorcycles) are not labeled. TC-W3 They're not designed to work in an aqueous environment, they can cause corrosion and they don't provide the right lubrication at high propeller speeds.
What happens if you pour oils into the mixture (for example, 1:30 instead of 1:50)?
The engine will run, but it may start to sneeze, lose power due to the soak on the candle, and it will smoke a lot, and in the long run, this will lead to exhaust windows coking and overheating.
How long can you store a mixture of gasoline and oil?
The recommended shelf life is no more than 2-3 weeks in a tightly closed metal canister in a cool place. Modern gasoline with additives begins to degrade faster, forming a resinous sediment.
Do I need to warm up the two-stroke engine before starting?
Yes, you must. Give the engine 2-3 minutes of idling after starting, which will allow the oil to spread evenly through the nodes and warm up the piston group before loading.