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How do I get my chainsaw ready for its first start? How to prepare the right fuel mixture and quickly change the headset? In this article, we answer these questions.

Like most of its counterparts, the chainsaw comes unassembled: the body, the bar and the saw headset separately. In addition to the main parts, the set includes a tool kit, a container for gasoline mixture, a cover for the bar, a toothed stop, a file for sharpening the chain, and reliable safety glasses.

In what proportions should I mix oil and gasoline for my chainsaw?

The chainsaw is equipped with a single-cylinder two-stroke engine, which uses a fuel mixture to work. You’ll need gasoline and special oil for air-cooled two-stroke engines to fill it.

Any internal combustion engine needs at least two things for normal operation:

  • Fuel – or rather, the fuel-air mixture prepared by the carburetor enters the combustion chamber, ignites, expands, and “pushes” the piston down, by which useful work is done.
  • Lubrication is necessary to reduce the friction force between the contacting parts of the engine.

First of all, oil is needed to eliminate the so-called “dry” metal-to-metal friction. Because of it the contacting parts are subjected to critical wear – appear scuffing, scratches, decreased compression, reduced service life. Oil is also needed to seal the clearances.

So why is it necessary to mix oil with chainsaw fuel?

This requirement is directly related to the peculiarities of the device and the principle of operation of two-stroke engines, which are equipped with this tool.

The parts of the crank mechanism and cylinder piston group are lubricated solely by the oil in the fuel. Thanks to the special engine construction, the air-fuel mixture does not only flow into the combustion chamber but also into the crankcase where the crankshaft and piston rod are located. In this way, all rubbing parts are lubricated.

The chainsaw engine is the “heart” of the tool, so it is very important to use a properly prepared fuel mixture.

The fuel mixture for a chainsaw is made of two components – oil and gasoline. Chainsaws are equipped with two-stroke engines, so oil is not added to the lubrication system (as in a four-stroke engine), but directly to the gasoline. It is very important to observe the correct proportions of ingredients and, of course, in no case try to work on pure gasoline, because that way you will very quickly “kill” the chainsaw.

The oil must be intended for the two-stroke engines of gardening and forestry equipment (that is, in no case can you use oil for boat motors or scooters). As practice shows, you can buy such oil in any store or service center, where chainsaws are sold or serviced.

oil for a chainsawIf we talk about what kind of gasoline to pour into the chainsaw, it will be optimal to use fuel with a high octane number.

As for the very proportion of gasoline-oil mixture, then everything is simple: it is necessary to clearly follow the instructions to the tool. All chainsaw manufacturers indicate the necessary ratio in the instruction manual or in the passport of the tool, moreover, the proportions for filling the chainsaw may differ depending on the model of a chain saw.

As a rule, the ratio of oil and gasoline to the chainsaw of famous manufacturers is 1:40 or 1:50, which means 1 part of oil to, for example, 40 parts of gasoline.

Now the arithmetic – 1 liter of gasoline = 1000 ml of gasoline, divide by 40 and you get 25 ml of oil. If you do the same steps to the 1:50 ratio, you get 20 ml of oil per 1 liter of gasoline.

As for the budget Chinese-made chainsaws, the situation is slightly different. The ratio of gasoline and oil for a chainsaw made in China is 1:25, that is, 1000 ml of gasoline divided by 25, we get 40 ml of oil. The thing is that the branded chainsaws have a good assembly and the distance between the pistons and cylinders in the engine is much smaller than in the Chinese chainsaws, so the required amount of oil differs by almost a factor of two.

There are three ways to properly dilute gasoline for a chainsaw in small quantities:

  • Divide 1,000 by the second figure in the ratio. For example, you want to prepare a mixture with a ratio of 1:40. Divide 1000 by 40, you get 25. That’s how many milliliters of oil you pour into 1 liter of gasoline.
  • Solve the proportion as you did at school. To do this, divide the required volume of gasoline in liters by the second digit in the proportion. The result is the required volume of oil in liters. Translate liters into milliliters for convenience. Let’s say you need 3 liters of the mixture in the proportion of 1:50. To convert liters to milliliters, move the comma to the right by three digits and you will have 60 milliliters.
  • Look at the table. This is the easiest, fastest, and most obvious way if the proportions are standard. The other two methods are needed to understand why the 1:50 ratio is to pour 20 milliliters of oil per liter of gasoline, not 50.

Now briefly about why different manufacturers have different proportions and there is no single standard. There are at least three reasons for this.

  1. First, different characteristics of oils and gasoline.
  2. Second, the quality of engine assembly (technology, materials) is also different.
  3. Thirdly, the mode of operation of the tool. For example, for running-in chainsaws, some manufacturers recommend adding 20% more oil to the mixture.

In order to measure the right amount of oil, you can use an ordinary medical syringe of sufficient volume.

Another tricky thing is to pour the gasoline into the dry gasoline canister first, and then the oil. The procedure on the contrary is fraught with a fuel mixture of poor quality because oil is denser, will stick to the bottom of the canister. That is why there is no way to talk about a good mixture. Always prepare a fuel mixture in a canister and fill the tank with already prepared special fuel!

Never prepare and mix it directly in the gasoline tank of your chainsaw!

If the question of how to dilute gasoline for a gasoline chainsaw is figured out, then it is worth saying a few words about the storage conditions and shelf life of the fuel mixture. It is best and easiest to prepare a gasoline-oil mixture for 1 liter of gasoline, it is recommended to do it immediately before working with the tool.

The fuel tanks of chainsaws have a volume of 0.3 to 1 liter. In conditions of domestic use, the whole volume of the prepared combustible mixture is rarely used in one session, so the remainder can be stored until the next session of work. The fuel mixture should be stored in a special gasoline canister, in a dry, dark place. It is optimal to calculate that the storage time of the ready mixture will be 7-10 days. The fact is that oil presented now in the market is not synthetic, but organic, which is natural. After 10 days all lubricating properties are lost, gasoline simply “eats” the oil. Naturally, it is no longer possible to use such fuel, as it can cause a chain saw breakdown and failure.

At the end of work, it is necessary to drain the fuel mixture and start the chainsaw – the tool will stall (so that the saw has a dry carburetor) and you can now leave it until the next operating session. Unsuitable fuel mixture must always be disposed of!

Step-by-step instructions for fueling

To prepare the fuel mixture and refuel your chainsaw, you’ll need

  • A measuring container;
  • Clean gasoline with octane number 95+;
  • Special oil for air-cooled two-stroke engines;
  • A container for the ready mixture;
  • Funnel.

To measure the volumes you can use a container, which is usually equipped with gasoline tools. You can also buy specially branded canisters with divisions and measuring devices.

Step-by-step instructions:

  1. Prepare a container for the ready fuel mixture. Its capacity should be enough for both gasoline and oil.
  2. Calculate the lubricant to gasoline ratio from your owner’s manual and use one of the methods above.
  3. Measure and pour the required volume of gasoline into the container.
  4. Use a measuring cup, standard bottle, or syringe to measure and add the required volume of oil to the gasoline.
  5. The tank for the ready mixture must not be completely full in the end.
  6. Securely close the container with the lid, and turn it several times to mix the oil with the gasoline.
  7. Fill the mixture into your chainsaw’s fuel tank.
  8. Contrary to the opinion walking around the web, it makes no difference what to pour into the tank to prepare the mixture first – gasoline or oil. The main thing is not to forget to mix it thoroughly. What you really shouldn’t do is prepare the fuel mixture directly in the chainsaw’s fuel tank.

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Max Welder

Max Welder

Hi! I'm Max Welder ( I always wanted to work with my own hands, repair something, do things. Now I combine my knowledge with computers and my own knowledge in the field of mechanics in order to understand which tools I like the most. I hope to convey some knowledge and experience.