How to mix a chainsaw mix

How to prepare the mixture for a chainsaw

The right mixture for a chainsaw will always be a hot topic for chainsaw users. Because the quality of its composition depends on both the continuity of wood sawing work and the wear and tear of the engine and consumable components. You can always find pre-mixes in retail chains such as STIHL, Husqvarna, Partner. But due to the fact that it is possible to prepare yourself such a compound is not worse than the industrial one, but also much cheaper, prompts the question. how to prepare fuel mixture for a chainsaw.


Gasoline for the required composition must be of brand AI-92 or A-92, you can not store it longer than three months, because over time the resin becomes higher and the polymerization process occurs, and this negatively affects the combustion chamber, there settles a layer of soot. The choice of oil depends on the weather season. The shelf life of oil should also be carefully watched, they are limited.


High quality oils such as STIHL, Husqvarna, Partner can be easily interchanged, as their manufacturers, having contracts with refineries, only sell such products under their brands. Compulsory condition when preparing the mixture is to take into account the manufacturer’s instructions regarding the engine forcing (ratio of engine power to engine displacement and the maximum engine speed).

For example, not expensive oil M-12 TP, Russian production, diluted with gasoline in the ratio of 1:50, but it is only applicable to low-speed chain saws, Russian-made. Ural, Druzhba, if the same engines are highly forcing, as the imported models, it is emphatically not suitable.

Oils can be synthetic, semi-synthetic and mineral. In this case, the best option will be semi-synthetic, it will form less fouling, and synthetic oil burns completely. It is best to take a container of oil in one hundred or two hundred milliliters each, since oil is very little used in household conditions and expires quickly.


Usually oil is two percent or one-fiftieth of gasoline in the mixture. However, various manufacturers reserve the right to recommend other proportions of components to users. For example, the oil to gasoline ratio for the Partner brand is 1:40, and for Chinese models it is 1:25.

It is essential to maintain the ratio accurately, otherwise the excessive amount of oil will produce more soot, the engine will run down, and the sawmill operator will inhale the fumes of unused oil. Also the octane value of the compound decreases because of the excess oil. In the case of insufficient oil filling in the fuel mixture there will be rapid bearing wear due to friction and scuffing of metal surfaces.

The received mixture should be used up within a week or two, at best in several days, because of decay of additives of oil. The most ideal way to use the fuel mixture is one day. When the sawing work is done, the remainder of the composition from the tank should be drained and used for other needs. Then start the saw and use the remaining gasoline from the carburetor at idle speed.

To make a correct measurement of the components of the mixture will allow measuring containers, which are on sale, they are shown in the photo below. The smallest container of produced volumes on one liter. That’s why it is possible to make a yardstick with different amounts of fuel mixture. For measuring a small volume of mixture you can use a measuring cylinder.

How to make a measure by yourself

To make the measure with their own hands enough to take a hard plastic bottle of half a liter or liter. Then water in the amount of 102,204,306,408,510,612,714,816 milliliters is poured into this container in turn. At the same time making a mark each time with permanent paint on the bottle. Next, the numbers 2,4,6,8,10,12,14,16,18 are written at the level of the marked lines. Use a syringe without a needle for measuring 10.20 milliliters of oil. This measure measures 102 milliliters for the oil ratio of 1:50. If you stick to this principle, you can change the proportions depending on the manufacturer’s recommendations.

To prepare the fuel mixture, select the necessary volume, for example, the division with the number 3. First take three milliliters of oil into the syringe and pour it into the measuring volume. Then the same syringe is filled with gasoline to flush out the oil, and then the measuring volume is filled with gasoline up to the mark 3. Shake the mixture well and put it into the chainsaw. The inconvenience of such a measure is in the manipulation with the syringe.

Measuring with a set volume

You need to take a bottle with a narrow long neck, like a glass bottle. At the upper level of the neck, a mark is applied, up to which water is poured. Then this liquid should be poured into a laboratory cylinder to determine the exact volume. A numerical value for the amount of fuel mixture is placed at the level of the marker. The obtained volume of water is divided by 51 and multiplied by 50, this will be the volume of gasoline, which is poured and the second lower mark on the bottle is marked. Fill oil up to the upper marking. Then the mixture is mixed. the chainsaw can now be refueled. The video shows this process. To fill the instrument with different volumes it is advisable to prepare several bottles.

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How to Mix 2 Stroke Fuel for your Chainsaw 25:1

Gasoline saws Ural, Druzhba are not fastidious in everyday life and are fueled with fuel mixtures made at home, when the correct proportions are observed. For the more technologically advanced imported saws suit blends that contain oils from STIHL, Husqvarna, Partner.

Characteristics of a chainsaw

Every chainsaw has three basic elements that make it work. These are the two-cylinder carburetor engine and the two tanks. One holds the fuel mixture and the other holds the oil required to lubricate the chain. Fuel tank capacity of 0.25 litres, to run for 45-55 minutes without interruption. The oil tank is about half the volume. With this volume ratio, the contents of both tanks run out almost simultaneously.

No oil pump system is used for the 2-stroke engine, which is why you have to add oil to the fuel in your STIHL chain saw to lubricate the shaft, piston and other moving parts. Attempts to work on one gasoline or failure to comply with the proportions of fuel and lubricant mixture of the two components specified in the manual will result in failure of the tool.

Proportion of oil and gasoline in the fuel mix

The ratio of oil and gasoline for a chainsaw is usually made up of two recipes:

If the chainsaw has recently been purchased and has not yet been operated, the proportion of lubricant is increased by a quarter. The same amount of it is poured into fuel, conducting sawing at temperatures below 2 degrees.

It is not very difficult to get such mixture. Almost every modern chainsaw is equipped with a special two-part tank. Oil is poured into the smaller section and petrol into the larger section. The caps of both parts are screwed tightly and the container is inverted, shaken thoroughly. This will achieve complete and homogeneous mixing of the two components.


If you do not have such a special container, you can use any gasoline-resistant plastic container with a cap of one liter and a disposable syringe of 5-10 cc. The container for gasoline must be pre-cleaned from all kinds of contaminants and water. Then add a liter of 92-95 gasoline.

In parallel, 20 ml of oil is filled into the syringe. If you refuel in cold weather, you need to take it 24-30 ml. Carefully pour it into the tank with gasoline. It is tightly covered with a lid and shaken thoroughly until the components are completely mixed.

Step-by-step instructions for filling

If you want to start your chainsaw, here’s how it should be done:

  • Use the recommended proportions of gasoline and oil for two-stroke chainsaws.
  • Prepare your chainsaw for refueling by removing sawdust and shavings from the surface of the saw.
  • Put the saw on a flat, stable base with the gasoline canister up.
  • Carefully place a small funnel (plastic or metal, resistant to fuels and lubricants, you can easily buy a suitable one at the auto supply store) into the open mouth of the tank
  • Carefully pour fuel into the tank, making sure it does not overflow. Do not pour under the cap. it will cause spilling when the cap is screwed on!
  • Close the cap on the fuel tank
  • Change the chain lubricant (mandatory)!)
  • Try starting the engine at idle speed.

Breakdowns of modern chainsaws. causes and solutions

The oil supply to the chainsaw chain involves important parts and mechanisms of the tool. It is not uncommon for them to fail, causing the saw to stop working. Below we will study the main faults associated with the oil supply to the chainsaw‘s saw element, and consider methods of solving them.

Many chainsaw owners don’t know why there is no oil flow to the chainsaw chain. This is one of the most common chainsaw breakdowns, to fix which you will have to completely dismantle the oil system of the tool and inspect the filter. If the filter is clean, you will need to pay attention:

  • There is no breakage of the oil hose. if it is damaged, it will need to be replaced;
  • Whether there are threads on the oil pump shaft;
  • What is the condition of the thread of the drive gear of the pump, whether there are any defects on it;
  • Whether there is no blockage in the line. in this case blowing out the ducts with compressed air will help;
  • The presence of the corkscrew of the main shaft. if it is missing, you can insert a regular nail in its place, having shortened it to the right size.

In any of the above cases, replacing the faulty element will help. In this case, the sooner you replace the old part, the better for the other elements and mechanisms of the chainsaw.

Preparing the fuel mixture: the proportion of oil and gasoline for a chainsaw

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

Chain saw fuel mixture is made of two components. oil and gasoline. Chainsaws are equipped with a two-stroke engine, so oil is not added to the lubrication system (as in a four-stroke engine), but directly to the gasoline. In doing so, 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 chain saw.

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

If we talk about what gasoline to fill a chain saw, it is optimal to use fuel with the octane number of A-95, in this case, the savings on fuel can turn out badly. European manufacturers often indicate that you can use gasoline A-90 or A-92, but in post-Soviet countries the quality of gasoline is inferior to European, so in our realities it is better to use high-quality gasoline.

As for the proportion of gasoline-oil mixture itself, then everything is simple: you must clearly follow the instructions of the tool. All chainsaw manufacturers indicate the required ratio in the instruction manual or in the tool’s certificate, moreover, the proportions for filling the chainsaw may differ depending on the model of chain saw. As a rule, the ratio of oil and gasoline to the gasoline of famous manufacturers is 1:40 or 1:50, which means one 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 for 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 a little different. gasoline to oil ratio for chainsaws made in China 1:25, that is 1000 ml of gasoline divided by 25, you get 40 ml of oil. The reason is that brand name chainsaws have a solid build and the distance between the pistons and cylinders in the engine is much less than in Chinese-made chainsaws, so the required oil amount is almost twice as much.

to measure out the right amount of oil, use an ordinary medical syringe of sufficient volume.

One more tip. in a dry gasoline canister pour the gasoline first, and then the oil. The procedure on the contrary is fraught with poor quality fuel mixture, because the oil is denser and will stick to the bottom of the canister. That’s why there is no way to talk about a good mixture.

Be sure to prepare the fuel mixture in a canister and fill the gas tank with already prepared special fuel! Never prepare and mix special fuel directly in the fuel tank of your chain saw!

If the question of how to dilute gasoline for gasoline chainsaw figured out, then and about conditions of storage and expiration date of the fuel mixture it is worth saying a few words. It is best and easiest to prepare a gasoline-oil mixture for 1 liter of gasoline, it is recommended to do it just before working with the tool. chain saw fuel tanks have a capacity of 0.3 to 1 liter. Household users seldom use the entire volume of the fuel mixture in one sitting, and the remainder can be saved for the next session. Store the fuel mix in a special fuel can, in a dark, dry place. It is optimal to calculate that The storage time of the ready mixture is 7-10 days

The fact that the oil currently on the market is not synthetic, but organic, that is natural. After 10 days all lubricating properties are lost, gasoline simply “eats” the oil. Of course, you can no longer use such fuel, it can cause a breakdown and failure of the chainsaw.

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 now you can leave it until the next session of operation.

Preparing the fuel mixture for the chainsaw


Gasoline must be with an octane number not less than A92. It is possible to fill in and AI95, but its quality at our gas stations leaves much to be desired, therefore if you are not sure of the quality of the 95-th, it is better still to take gasoline AI92 for breeding gasoline in a gasoline saw. Do not take gasoline that has been in a canister, tank or any other container for a long time. Gasoline for preparation of a fuel mixture into a chainsaw should be fresh, otherwise it loses the properties, in particular octane number and even if you start a chainsaw on such fuel, it will not give out full capacity. The saddest thing in this case is that when a chain saw breaks down because of low-quality fuel it is considered a non-warranty case, which leads to a very expensive repair. Sometimes it is easier to buy a new chain saw than to repair it after such a breakdown!


Oil for two-stroke engines according to the classification of the American Petroleum Institute (API), the American Petroleum Institute has a class API-TB, there is also a class oil API-TC, but they are designed to work with less than most widespread in our chainsaws. If we take the power class according to the classification of the Japan Automobile Standards Organization (JASO), then focus on the classes of JASO-FB and JASO FD (see the table below).Table 1 below.).Do not use oil for four-stroke engines! Remember that in a two-stroke engine the oil has to burn completely, so it’s better to use synthetic oil, because it gives less smoke and combustion residue. If you put four-stroke oil in your chainsaw that doesn’t burn completely, and you end up with soot, you’ll have a failed cylinder gear. The best thing to look for when choosing chain saw oil is the instruction manual for your chainsaw.



the engine manufacturer’s recommendations for gasoline and chain saw oil in the fuel mix. Why it is so important to follow these recommended proportions? With a small amount of oil in the gasoline will heat the cylinder and piston and respectively there will be scuffing, and it is failure of the cylinder and cylinder gear and repair. If there is a lot of oil in the gasoline, however, it will foul up and fail again.Each manufacturer has its own recommendation for the proportions (see table 2).table 2 below).Avoid storing the mixture for more than a month. Do not store in direct sunlight or outdoors. Avoid water and dust in the mixture as this would damage the carburetor, since the fuel filter is often unable to purify the fuel.

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As they often come from search engines on queries like “how much oil to pour in 1,2,5 liters of gasoline,” I add another table under which you can find out how much oil to add to gasoline according to the accepted proportions. For proportions, see table 2 or, more accurately, your chainsaw‘s manual.

This is the standard due to the high quality of modern engines. Characteristic of most modern saws of German, Swiss, American, Japanese, Italian manufacture. In a word, all saws made not more than 10 years ago by world known brands. Husqvarna, STIHL, Oleo-Mac, Makita, ECHO and others. will require exactly this ratio.You may read about it in the manual.

However, many purely Chinese-made saws are also influenced by improved machining and assembly techniques. So, many domestic brands of saws, assembled in the Celestial Empire, also run on a 1:50 mix. For example, on the recently released Zubr models, a label with a marking of the proportion appeared in the form of a cardboard flag directly on the handle of the starter cord, apparently for those who do not like to look in the instructions.

Correct Way To Mix Gas and Oil For a ChainSaw, WeedEater etc.

This ratio is often referred to as the “running-in ratio.”. This means that you’ll need to pour a more oil-rich mixture into the gas tank after you buy a new saw. At this time, the moving parts of the cylinder-piston group are lapped, and a higher ratio is required than usual in the process. After you’ve burned a couple of tanks or three of them sparingly, you may switch to the ratio recommended by the manufacturer.

Also the ratio of 1/40 is a common practice of some manufacturers, for example in Partner chain saws. Taking into account that there is a little more oil than in the previous variant, a little overdrive will not hurt any engine. If you use high-quality fuel and lubricants there is another question. the price of quite expensive consumables.

Today it is considered to be outdated. It was widely used in domestic gasoline-powered saws of the old design like Druzhba or Ural. Today it can still be found in some Chinese chain saws of “nooname” class or branded by retail chainsaw chains. However, every year the number of such products is decreasing and makes up the most budget and low-quality niche of gasoline tools. Besides, for such products it is not the most important how expensive and high-quality oil is in a gas tank, the engine life is by all means unscrupulously short under any circumstances.

Instructions for refueling a chainsaw

Knowing the ratios for preparing the petrol-oil mix, you can then start refuelling. Instructions for filling is as follows:

  • First you need to prepare the mixture. Mix the two main components together thoroughly
  • Place the tool on a clean and level surface. Before unscrewing the cap of the gas tank, you need to clean or blow out sawdust, dust and dirt
  • The gasoline filler cap should point up
  • Put a small watering can in the filler neck and fill up the fuel
  • Control the filling process because the tank volume is small and therefore fills up quickly
  • Do not fill to full capacity as fuel will leak out when the cap is closed
  • After fuel is in the tank, add chain lubricant as soon as possible
  • Fuel and chain lubricant consumption are about the same, so you need to fill both tanks at the same time
  • After refueling you can start the engine

How much gasoline diluted for a chainsaw is stored?

The mixture should not be stored for more than 30 days. Immediately after mixing a slow chemical reaction begins. Therefore, after a month the mixture loses its original properties, which affects the work of the chainsaw. It is better to prepare fuel just before the work and in the amount necessary for its performance.

Who is only getting acquainted with a chainsaw and tries to perform some tasks, instead of AI-92 fuel fills it with AI-95, believing that it is the best quality. Gasoline with octane number 95 is produced from AI-92 by adding additives. Two-stroke engines are negatively affected by special additives because of their design features. They accumulate on the inner walls of the tool and break off over time, impairing its function. Therefore, to prepare a mixture for chain saws, experts advise to buy only AI-92.