What is the oil to gasoline ratio for a chainsaw?

How to mix oil with gasoline for a two-stroke engine

The peculiarity of two-stroke engines is that the fuel is filled into the tank along with the oil. Each refueling before operating machinery requires the preparation of the fuel mixture with the observance of the proportions. How to do it right? From our article you will learn how to dilute gasoline for chainsaws, grass trimmers and other garden tools.

It is recommended to buy unleaded gasoline to operate the gardening equipment. Otherwise there is a risk of engine failure. Manufacturers advise fuel with an octane number not lower than AI-90, better AI-92 or AI-95. For individual recommendations for your tool, see the instruction manual. At the petrol station, fill the canister with the amount of fuel needed. It is desirable to use metal: in such a container does not arise static electricity from friction, which increases the safety of use.

Always buy brand name oils for two-stroke engines, preferably API-TB or API-TC. Always ask the manufacturer for the recommended oil brands in the owner’s manual. Also consider their composition. Mineral oils are best for warm weather conditions. Synthetic oils are better, they are less viscous and can be used even in freezing temperatures. Semi-synthetics are mineral oils with improved qualities, versatile for any season. For temperature limits of use, see packaging. Also note the volume. It is not the proportion of gasoline and chain saw oil that matters, but how much fuel mixture you need for one filling and how often you will work with the tool. If you have a grass trimmer or chain saw in your arsenal, and you use one or the other tool several times a week, it makes sense to buy a large 3 to 5 liter canister of oil. For several mowing operations during the gardening season it is enough to take a 1 liter bottle.

Mixing oil with gasoline

At the beginning of work with the tool there is always the question of how much oil to add to gasoline for a chainsaw or trimmer for grass. It is important to remember that for two-stroke engines the ratio is 1:50, t.ะต. 5 litres of fuel with 100 ml of oil. Why it is important to observe the proportions? Excess oil contributes to carbon deposits on pistons and spark plugs, and its deficiency worsens the lubricating properties of the fuel mixture, which leads to the formation of scuffing on the piston group and increases the risk of engine failure.

The easiest way to follow the proportions of gasoline and chainsaw oil is to use measuring containers. They have a scale with markings on them, which is easy to follow. Before filling up with gasoline and oil, make sure the container is clean. Do not get any water or dirt in the carburettor. this will affect the quality of the fuel mixture. First fill petrol to the required level, then add oil. also to the required level. To mix the two, tilt the container several times. The liquids will mix quickly and the composition will take on a homogenous color, such as green or red (depending on the oil composition).

Important to know! Never use plastic beverage bottles for storing and mixing the fuel mixture. Gasoline corrodes plastics. And even if the walls of the bottle look intact, harmful components will get into the fuel mixture, and with it into the engine. This is very bad for the carburetor.

Wearing gloves is recommended to protect the hands from the oil and gasoline. Also do not forget about the elementary rules of fire safety. Mix the liquids outside so that gasoline vapors do not accumulate indoors. Do not smoke while working and avoid other factors which may cause inflammation of combustible and lubricating materials.

Pour the prepared fuel mixture into the fuel tank and close the cap tightly. If you have made more mixture than you can use at one time, pour it into a separate can for storage or leave it in the mixing tank. The main thing is to close the lid tightly. The ready mix can be stored for two weeks and used for refueling without risk to the engine. The only condition is that you do not leave it in the fuel tank. If you are not going to use the tool for a long time. use up all the leftovers or drain it.

Now you know how to dilute gasoline for a chainsaw so as not to harm the engine. Try to do it yourself. After you prepare the fuel mixture several times, it will be clear what amount of components will be needed so there is no excess mixture. Buy everything you need in our online store. With branded oils, your tool will last a long time.

Characteristics of domestic chain saws

Specialist machinery stores offer a wide range of both domestic and foreign chainsaws. For household purposes, a lightweight tool that does not have a high performance. Its main element is a chain with cutting teeth. It is driven by a 2-stroke gasoline engine that does not have a separate lubrication system for the moving parts. For this purpose, the gasoline tank is not filled with pure gasoline, but with a mixture of gasoline and oil, which not only ensures engine operation, but also lubrication. When preparing the mixture, every owner should know how to dilute gasoline with chainsaw oil.

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One of the chainsaw models

The chain speed depends on the engine speed, which is cooled by the air. Separate oil tank for lubrication and cooling. As its speed increases, so does the automatic oil supply. For a chain saw to work properly, it is necessary to monitor the content of the two tanks: the engine and the chain.

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Partner 351 chain saw

The Partner 351 chain saw is a Chrome model that has a chrome plated cylinder. Lubricants and oil add more reliability and extend the working life of your saw more than ever before. This chainsaw belongs to the class of professional chainsaws used for cutting logs, sawing dried wood, pruning branches and twigs and even in construction. Advanced air filtration, vibration reduction, and noise reduction systems make the Partner 351 a pleasure to use.


Stricter criteria for selecting an oil component. At best, it is a mineral or semi-synthetic engine oil recommended by the manufacturer, designed to work in high-speed two-stroke engines with air cooling.

Mineral oils have the advantage of lower cost. Their more expensive semi-synthetic and synthetic analogues compare favorably with the improved working characteristics and conformity with environmental standards.

  • retain their operational properties in a wide range of operating temperatures;
  • do not form soot deposits;
  • contain detergent, antioxidant, preservative and other additives that are useful for power unit operation.

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Chainsaw oil

Mainly API-TB oils are used for chainsaws that are widespread in our country. API-TC may be used less frequently, but only if the manufacturer has indicated so on the package. It should also tell you how much oil you need to add to your gasoline. For saws with lower loads the API-TC class applies.

The oil types described above are classified by the American Petroleum Institute. There is also another well-known Japanese company that also defines the power classes of lubricants. For chainsaws in this case it is recommended to use oils in petrol of JASO-FB and JASO FD marks.

It is important to note that using oils used in four-stroke engines on two-stroke engines is categorically impossible.

This is because in the second case, it is important that the lubricant burns off completely. This can be achieved by using synthetic oil, which emits less smoke and produces less combustion residue. Before you dilute the fluid, you should always pay attention to your chainsaw manual, which should specify the types and brands of all the consumables you need to use on the device.

How to fuel a chainsaw? See at

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Preparation of fuel mixture: proportion of oil and gasoline for chainsaw

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

The fuel mixture for a chainsaw is made of two components. oil and gasoline. 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. It is very important to observe correct proportions of ingredients and of course not to try to work with pure gasoline, because that way you will “kill” the chainsaw very quickly.

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

If we talk about what gasoline pour into the chain saw, it would be optimal to use fuel with octane number A-95, in this case, the savings on fuel can turn into a pity. Often, European manufacturers specify that it is possible to 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’s better to use high-quality gasoline.

As for the petrol-oil mixture proportion itself, everything is simple: you need to clearly follow the instructions of the tool. All chainsaw manufacturers indicate the necessary ratio in the instruction manual or in the passport of the tool, besides, the proportions for filling the chainsaw may differ depending on the model of the chainsaw. As a rule, the oil and gasoline ratio in a chain saw of the famous manufacturers is 1:40 or 1:50, which means 1 part oil in 40 parts of gasoline, for example.

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

As for the budget chain saws made in China, the situation is slightly different. Gasoline to oil ratio for chainsaws made in China 1:25, so you divide 1000 ml of gasoline by 25, you get 40 ml of oil. The thing is that in branded chainsaws good build and the distance between the pistons and cylinders in the engine is much smaller than in Chinese chainsaws, so the required amount of oil differs by almost a factor of two.

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

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

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Be sure to prepare the fuel mixture in a canister and pour into the gas tank already ready special fuel! Never prepare and mix it directly in the chainsaw’s fuel tank!

If the question of how to dilute gasoline for a chainsaw is solved, then the about the conditions of storage and shelf life of the fuel mixture A few words must be said. It is best and easiest to prepare gasoline-oil mixture for 1 liter of gasoline, it is recommended to do it just before working with the tool. Chainsaw fuel tanks have a volume of 0.3 to 1 liter. In conditions of domestic use for one session is rarely used the entire volume of the prepared combustible mixture, so the remainder can be stored until the next session of work. It is necessary to store the fuel mixture in a special canister for gasoline, in a dry, dark place. It is optimal to calculate that storage time of the ready mixture will be 7-10 days

The fact that the oil on the market today is not synthetic, but organic, that 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, it can cause a breakdown and failure of the chainsaw.

At the end of the 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.

Step by step instructions for filling

Wanting to refuel the chainsaw, it is necessary to follow a simple algorithm:

  • Prepare fuel in the recommended proportions of gasoline and oil for two-stroke chainsaws.
  • Prepare the saw for refueling by cleaning sawdust and shavings from the surface of the saw.
  • Place the saw on a flat, stable stand with the throat of the tank 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 throat of the tank
  • Carefully pour fuel into the tank, making sure not to overfill. It is not allowed to pour it under the cap: it will spurt out when the cap is screwed on!
  • Close fuel tank with cap
  • Change chain lubricant (absolutely necessary)!)
  • Try to start the engine at idle speed.

After a longer downtime you should drain the fuel mixture from the tank of the saw. Do not use it. as gasoline rather quickly loses its properties in such a mixture. The consequence will be unstable operation and the risk of breakdown.

What kind of gasoline to put in your STIHL chain saw??

Experts say that unleaded gasoline should be used if lead-free additives with an octane rating greater than 90. Foreign models require higher brands of gasoline and use branded oils from the manufacturers of the tool. The ideal fuel is AI-92. How to fuel a STIHL STIHL 180 chain saw? In this case oils in 1:40 mix are implied. It is quite suitable for her and fuel AI-95, but according to professionals it is better for chainsaws do not apply.

The thing is that it is made on the basis of AI-92 with the use of certain additives, which change the quality of the fuel. These components deposit on the inner parts of the tool and when they reach a critical mass, they begin to flake off, disrupting the operation of the mechanism. The best option is to follow the instructions that come with the chosen model. Gasoline should be used fresh, because storing it in containers for too long loses its octane properties.

What gasoline to fill in a chainsaw?

According to experts, it is necessary to use unleaded gasoline, obtained by adding lead-free additives, the octane number of which exceeds 90. Foreign models require the use of higher grades of gasoline and branded tool oils. The perfect fuel is considered to be AI-92 grade. How to dilute gasoline for a STIHL 180 chain saw? In this case, the oils are meant in a 1:40 mixture. It is quite suitable for it and fuel AI-95, but according to professionals it is better not to use it for chainsaws.

The matter is that it is produced on a base of AI-92 with use of certain additives, which change quality of fuel. These components deposit on the inner parts of the tool and when they reach critical mass, they begin to flake off, disrupting the mechanism’s operation. The best option is to follow the instructions that come with the selected model. It is recommended to use fresh gasoline, because the octane properties are lost during prolonged storage in containers.

How to Lubricate a Chain Saw Needle Bearing?

To reduce the load on the tool sprocket and extend its life, this part is equipped with a needle bearing. In order for it to work properly during intensive use of the chainsaw, the element must be regularly lubricated.

STIHL’s universal needle bearing maintenance product is the best choice. This reliably protects the bearing from wear and corrosion, but the cost of this proprietary grease is quite high. to save money, you can use Lithol or Lithol 24 to lubricate the bearing. They are distinguished by a high viscosity, due to which they cover the bearing with a thin, but sufficiently strong oily film.

A 5 cm3 syringe is needed to apply the lubricant. To lubricate the part you need to squeeze the contents of the syringe into the small hole located in the housing directly above the needle bearing.

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If the element has not been relubricated for a long time, it needs to be thoroughly cleaned before the oil is changed. To do this you need to remove the right side of the chainsaw body and remove the bearing. It is then placed in a bottle with pure petrol. The bearing must be removed from the vessel and thoroughly dried after 24 hours. In the end, the element should be installed in its original place in the chainsaw.

Beware of counterfeit!

Small private companies from China and other Asian countries specialize in the production of motor oils, which are sold at a lower cost in the markets under the brand name of the leading producers.

  • The characteristics of counterfeit products are an order of magnitude lower than the branded originals. Continuous use of counterfeit products has a negative effect on the chainsaw’s performance and durability.
  • Only an experienced specialist can determine the oil’s status and quality, so you can avoid possible risks by buying consumable components in a network of branded and licensed outlets.
  • Use of substandard lubricants by service technicians is a legal basis for depriving the owner of a faulty saw of warranty repair.

Working proportions of fuel mixture

The standard gasoline to oil ratio in the fuel mix for carburetor chain saw engines is 40:1 and 50:1. Such proportion provides full lubrication of friction parts of the crank mechanism and piston group, and does not prevent complete combustion of the gasoline-air mixture.

Adjust the fuel mixture according to external factors. This may be necessary during the running-in phase of a new tool, and also if the air temperature is high. In such a case, the standard dosage of oil is increased by 20%.

In practice, it is used to increase the percentage of oil in the fuel mixture, if its characteristics do not fully meet the stated requirements. How much oil per liter of petrol is needed in each case is up to the sawyer.

How to properly fuel a chainsaw with petrol-oil mixture

Freshly prepared mixture should be stored in a dark room, but no more than 2 weeks. It is best to mix just before you use the tool. The filling procedure is implemented by performing the following manipulations:

  • Before unscrewing the lid of the tank, you need to clean the surface, or better yet, blow with a hose from a compressor.
  • Put the chainsaw on its side so that the cap is on top. One no less important point to consider is that it is necessary to refuel not in the wind in order to prevent dust and other impurities from getting into the tank.
  • At the neck put a watering can, which will eliminate the possibility of fuel spillage.
  • Fill the tank, but do it in such a way that there is enough room. This is done to prevent gasoline from leaking when the cap is screwed on.

Carry out the start of the engine and make sure it works properly. The smoke from the chainsaw should come out of the light color and in bulk only when you increase the speed.

Advantages and disadvantages of oil

Any quality machine oil has its pros and cons Any quality machine oil has its pros and cons. Some experts say that oil for a chainsaw will suit any. This is not entirely true, almost any substance can be used for a chainsaw Hurstvana, but a STIHL chainsaw requires only gear oil. When choosing an oil it is necessary to know the color of oil, two-stroke engine requires a composition that has a reddish, bluish or greenish cast.

To make the mixture yourself, you need to use a heat-resistant lubricant, which has a well-known brand name.

The density of the product is affected by seasonality:

Find out the difference between the oils by carefully following the package label. If there is no instruction or label on the package, you should refuse to use such substance. In this case, the oil specifications should not change drastically if the temperature conditions change.

The specificity of the lubricating substance is that it is optimal for engines with high revolutions, which have air cooling. That is the powertrain that comes with chain saws. Mineral oils have a reddish hue, while synthetic oils have a greenish tint.

No substitutes should be used, because counterfeit products (up to 20%) are not uncommon. It is difficult to distinguish fake oil, and it is necessary to have special equipment.

It is recommended that fuel should be stored in metal containers. It is best to prepare the fuel mixture in a canister.

There are a large number of oils and each has its own characteristics

The consistency is made in the ratio:

chainsaws, which run on a 25:1 mix, are almost totally absent from the market. After pouring a new mixture, the tool should work for a while at idle speed.

The specifications of the mineral or organic oil intended for the chain itself are not suitable for the preparation of the fuel mixture. The ready product is poured into the tank (up to half), then stirred (the tank must be hermetically sealed). Thus, a homogeneous composition is obtained. It is better not to prepare fuel in advance, it loses its functional properties rather quickly. At room temperature, the combustible liquid spoils within two weeks.