How to dilute gasoline for a chain saw

The right oil to gasoline ratio for a chainsaw

Hello, everybody! In this article we will talk about the right oil to gasoline ratio for chain saw. This is probably the most important thing to know when operating this machine. Lack of oil causes unnecessary friction and too much oil leads to excessive fouling and overheating. Both will eventually lead to a fast engine failure. Repair can cost half the price of a new chain saw.

in addition to the right proportions we are going to talk about other important things that will allow maximum durability of your chain saw. what gasoline to use, what oil to pour, how to dilute it, the storage time of the mixture, etc so I advise not to quit reading the article after the Proportions section, because later on you will also find some useful information.

The correct proportions

So, I’m not going to beat around the bush for a long time, but directly go to the numbers. The most common dilutions are 1:50 and 1:40. That is, for 50 or 40 parts of gasoline one part of oil is poured. For those, who do not understand, let me explain in details. We take one liter of petrol and divide it by 50 or 40 accordingly. As a result, we get the necessary amount of oil for one liter of gasoline. That is, one liter is 1,000 ml. 1,000 ml divided by 50, you get 20 ml of oil. Divided by 40, you get 25 ml. This is how much oil to add to one liter of gasoline.

But you will say that you do not know what the proportion should be on your chainsaw. Well, if you lost the manual or there is no information about the proportion in it for some reason, you can use the following rules:

dilute, gasoline, chain
  • if your chainsaw and oil are of the same brand (for example, STIHL chainsaw and STIHL oil), then dilute the gasoline and oil in the proportion indicated on the oil (usually 1:50);
  • If the chainsaw and oil are of different brands, then follow the 1:40 ratio;
  • If the brand is the same, but there is no information on the oil, then dilute in the ratio 1:40;
  • if you don’t know anything at all. you don’t know the brand of your chainsaw or the oil., you still dilute it in the ratio 1:40. The important thing is to know that the oil is exactly right for two-stroke chainsaw engines.

If the saw is new and is running-in, it is recommended to increase the amount of oil for the first three fills of the fuel tank by about 20%. That is the proportion 1:50 turns into 1:42, and 1:40 into 1:33. Or 24 or 30 ml of oil per 1l of petrol respectively. Except for increasing oil quantity in fuel mixture there is no other running-in measures with the chainsaw, unless otherwise specified in the instruction manual. That is not necessary, for example, to leave it idling for a long time or cutting not at full speed, as this will lead to its overheating and a quicker breakdown. Always saw only at maximum rpm. And after you’ve used up three tanks of fuel (the chainsaw’s tank is meant) go to the regular 1:50 or 1:40 ratio.

But sometimes it happens that the manufacturer specifies a different ratio than what I gave above. For example 1:25 or 1:32. In this case, it is necessary to observe these proportions. Although if you know about them, what have you forgotten in this article??

Gasoline and oil proportions

You don’t need much oil for the engine to work properly. Its amount is always determined by the percentage, because the gas tank of saws can be of different capacity. In addition, many operators prepare the mixture with a small margin, especially if serious work is to be done. In fact, with all its economy, a single tank of modern tools is rarely enough for more than a cubic meter of firewood.

This is a standard due to 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 famous brands. Husqvarna, STIHL, Oleo-Mac, Makita, ECHO and others. will require exactly this proportion.You may learn about it from the manual.

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

This ratio is often referred to as the “running-in” ratio. This means that after buying a new saw, you will need to pour a more oil-rich mixture into the gas tank. At this time the moving parts of the cylinder-piston group are lapped, in the process requiring a higher proportion than usual. After burning a couple or three cans in a gentle mode, you can go to the ratio recommended by the manufacturer.

It is also a common ratio for some manufacturers, such as Partner chain saws. Taking into account that there is a little more oil here than in the previous version, a little overrun will not harm any engine. When using quality fuel and lubricant there is another issue. the price of quite expensive consumables.

Today is considered outdated. Widely used in domestic chainsaws of old design like Druzhba or Ural. Today you can still see it in some Chinese chain saws of “nooname” class or branded by retail chains. However, every year the number of such products is reduced and makes up the most budget and low-quality niche gasoline tools. Besides, for such products it does not matter how expensive and high quality oil is poured into the gas tank. the engine life is still unscrupulously small in any case.

Consequences of incorrect dosage

Many chainsaw users do not pay proper attention to the proportion. 50 grams more or less. does it matter?? And with good reason: Saw failure is often caused by improperly mixed fuel. One can make a mistake or deliberately wreck the ratio both upwards and downwards.

If there’s a lot of oil.

There’s a popular saying among chainsaw owners that “you can’t ruin an engine with oil”. But there is a reason why they invent the necessary parameters of the ready mixture. Too much oil can also be harmful and inconvenient. After all, despite the improved combustibility without residue, some of the hydrocarbons still turn into soot and soot. If the concentration is low, they are not much, but if you enrich the mixture with oil twice as much as normal, you get coking. It is especially dangerous for cheap mineral oils that have no “flushing” effect.

You’re also very likely to find oil in the air filter if the carburetor is overfilled. The spark plug will also show up in soot. it will need to be cleaned, flushed and dried. Also the vapors of unburned oil will settle in the muffler, and during intensive work will burn out, forming a plume of soot and sparks.

After this kind of refueling almost all insides of the saw have to be thoroughly cleaned and rinsed. The most cheerful “surprise” is the piston rings dying, but only if you abuse the oil spill and work under high loads.

or not much

“Greed” in the preparation of the fuel mixture ruined more than one piston. That’s where it’s really better to “overdo it” than to “underdo it”. After all, if in the first case you are threatened with a thorough “washing” of the unit, in the second case you will have to change the cylinder block, and it is not profitable at all on many saws, and for others costs quite a lot of money.

Conclusion: economy is meaningless. If you don’t have enough oil the piston will start rubbing in the cylinder because at high temperature gasoline is too fluid to perform the function of lubrication.

Tragic results: burrs on piston, ruined saw engine. If the owner will come to his senses in time, he will find out that a piston and a cylinder turn beautiful blue. No master can guarantee how long they will last.


Stricter criteria for choosing an oil component. The best-practice engine oil is a manufacturer-recommended mineral or semi-synthetic engine oil that is formulated to work in high-speed, air-cooled two-stroke engines.

The advantage of mineral oils is in their lower cost. Their more expensive semi-synthetic and synthetic analogues compare favorably with improved performance and compliance with environmental standards.

  • retain their working properties in a wide range of operating temperatures;
  • do not form clogging;
  • contain detergents, antioxidants, preservatives and other additives useful for power unit functioning.

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Oils for chainsaws

Mainly for the widespread in our country chainsaws used oil brand API-TB. API-TC may be used a little less frequently, but only if the manufacturer has specified it on the package. It should also tell you how much oil to add to your gasoline. For saws that are less stressed, the API-TC classification applies.

The oil types described above are classified by the American Petroleum Institute. There is also another well-known Japanese company, which also defines power classes of lubricants. For chain saws in such a case it is recommended to use oils in gasoline of JASO-FB and JASO FD grades.

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

This is due to the fact that in the second case, it is important that the lubricant is completely burned. it is possible to achieve this by using synthetic oil, which emits less smoke and produces less combustion residue. Before diluting the fluid, you should always pay attention to the instruction to the chainsaw, which should specify the types and brands of all consumables that should be used on the device.

How to fill a chainsaw? See at

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The choice of fuel

What fuel to choose for a chainsaw. this is not an unreasonable question, the success of the unit directly depends on it. According to existing canons a good gasoline for a chainsaw is not considered leaded, but high octane from a proven manufacturer. The cleaner the fuel, the better. If the gasoline has been stored in the canister for a year or a year and a half, it will negatively affect the character of the device, so prepare the substance just before you start working.

dilute, gasoline, chain

It is recommended not to use low-octane fuel, completely exclude from the attention of dubious quality inexpensive oils. Do not use leaded fuel, it will significantly reduce the life of the power plant.

It is important to monitor that the fuel does not contain alcohol, any additives that can disrupt the functioning of the power unit. Experts are still debating whether 95 or 92 is better. The first has a more stable detonation, but 92 is still the most commonly used fuel. The reason is simple: questions often arise to the 95-th gasoline, it has a large number of different additives, which have a bad influence on the performance of the engine of the saw. Micro detonation (piston pulse in the opposite direction) occurs, which occurs at almost every revolution of the crankshaft. If the octane rating is even higher (98), the micro-shocks will become even more intense.

The effects of the wrong gasoline on the unit’s performance can only be negative:

It is not a good idea to fill up your chain saw with gasoline from the bottom of the can. The carburetor air ducts have small diameters, but if they become blocked they will cause malfunction of the chain saw. All fuel should be carefully filtered before use. For domestic saws “Ural”, “Druzhba” the fuel brand “80” is suitable.

Preparing to run

Before you start, check that the device is ready for operation. To begin with assess the tension of the chain of the device. pull the chain on the upper links with an approximate force of 2-3 kg (you need not pull the shank of the chain out of the bar groove completely, but only a few mm). the lower links should not sag, but if it happens. tension the chain, it should touch the side links to the bar and rotate it by hand quite easily. If the tension is too great. loosen the chain a little. The recoil brake handle should move without sticking and should engage audibly.

After checking the chain, set the saw on a level surface and fill up with chain lubricating oil and engine fuel. The mixture must consist of gasoline (octane number at least 92) and two-stroke oil. As for the chain lubrication, you should use a special biodegradable oil, because its components guarantee the longevity of the saw without damaging the environment.

If requested by the customer the Unisoo dealer service agent will perform pre-sale preparation of the equipment: check the package, assemble the product, check the settings, if necessary, fill the equipment with oil and fuel and check the equipment starting procedure.

Oil to gasoline ratio for a chainsaw

How much engine oil to dilute for 1 liter of gasoline, tell the manufacturer’s instructions for the operation of the garden tool. In American, Japanese and Swedish models, the proportion of oil and gasoline for a chainsaw should be 1:40 or 1:50. That means that you need 25 ml and 20 ml of engine oil in 1 liter of pure gasoline, respectively. In these cases, the gasoline mixture will be as balanced as possible and suitable for filling powerful engines, which are equipped with most well-known brands of chain saws.

Slightly differently need to dilute gasoline for a Chinese-made chainsaw. In the manuals for these models, their manufacturers indicate that the proportion of the components of the fuel mixture for their filling should be 1 part of gasoline to 25 parts of motor oil. This means that you need to dilute 40 ml of oil in 1 liter of fuel. This difference between Chinese power tools and machinery made in other countries is due to the fact that the distance between the cylinders and pistons of Chinese-made garden tools is greater than that of more expensive brand-name models. Accordingly, they need twice as much oil to mix in the gasoline.

What chain oil to use for a chainsaw chain?

Information on what chain oil for a chainsaw is best can be found in the instruction manual of the model. However, not all garden tool owners retain the chain saw instruction manual. in such cases when choosing an oil it is necessary to study its characteristics and main lubrication requirements.

The first thing to look for is the adhesive property of the chain lubricant. During daily use of a chainsaw at medium and maximum permissible rpm, the chain is running at a fairly high speed on the bar. This way, oil that is not highly adhesive will fly off the chain by inertia. As a result, only the upper part of the chain is lubricated and the lower part is subject to increased friction.

dilute, gasoline, chain

Chain oil for chainsaws must meet a number of other requirements.

  • Protect the chain from corrosion. the lubricant should repel moisture, which causes rust to appear on the teeth and links of the harness;
  • Resistance to wear. intensive use of your garden tool leads to stress on the chain parts, which inevitably leads to premature wear. The use of a quality lubricant can help prevent this;
  • no fouling. the oil selected for chain lubrication must not accumulate and dry out on the chain elements. Over time, this results in bumps that make it difficult for the chain to turn on the bar;
  • ability to work over a wide temperature range. a quality chain lubricant should not freeze at the first frost and boil at high temperatures. Optimal is a range from.15 to 40 ⁰C.

ForestPlus, SynthPlus and BioPlus are the most popular chainsaw lubricants used by chain owners. These oils have high stability, the ability to work in the most difficult weather conditions, and protection against corrosion.

What chain oil for chainsaws?

For the best chain oil for a chainsaw, see the instruction manual of your model. However, not all garden tool owners retain a chainsaw instruction manual. in such cases you need to know the oil’s properties and its main lubrication requirements.

The first thing to look for is the adhesion property of the chain lubricant. During daily use of a chainsaw at medium and maximum allowable rpm, the chain moves along the bar at a fairly high speed. That way, oil that does not have a high adherence rate will inertia fly off the chain. As a result, only the upper part of the chain will be lubricated, and the lower part will work under the influence of increased friction.

Chain oil for chainsaw chain lubrication must meet a number of other requirements.

  • Protect the chain from corrosion. the lubricant should repel moisture which can cause rust on the chain teeth and links;
  • resistant to wear. intensive use of the gardening tool causes the chain parts to be overloaded, leading to premature wear. The use of a quality lubricant will help to prevent this;
  • no fouling. the oil selected for chain lubrication must not accumulate and dry out on the chain elements. Over time, this results in lumps that make it difficult for the chain to rotate on the bar;
  • ability to operate over a wide temperature range. a quality chain lubricant should not freeze at the first frost and boil at high temperatures. The optimal range is from.15 to 40 ⁰C.

often than not chain lubrication for petrol chain saws is used by the chain saw operator with ForestPlus, SynthPlus and BioPlus. These oils are highly stable, able to work in the most difficult weather conditions, and corrosion resistant.

How to lubricate chain saw needle bearings?

To reduce the load on the tool sprocket and extend its service life, this part is equipped with a needle bearing. To keep it in good working order during intensive chain saw use, the element must be lubricated regularly.

STIHL brand universal oil is the ideal solution for the maintenance of needle roller bearings. This reliably protects the bearing from wear and corrosion, but the price of this brand-name grease is relatively 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.

To apply the agent will need a syringe, the volume of 5 cm3. 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.

If the element has not been relubricated for a long time, it needs to be thoroughly cleaned before changing the oil. To do this you need to remove the right side of the chainsaw body and remove the bearing. The part should then be placed in a container with clean gasoline. After 24 hours the bearing has to be removed from the vessel and thoroughly dried. At the end, the element must 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 at a lower cost are sold in the markets under the brand name of leading manufacturers.

  • 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 consumables in the network of branded and licensed outlets.
  • The use of substandard lubricants by service technicians is a legal basis for depriving the owner of a faulty saw of warranty repair and restoration obligations.

Working proportions of fuel mixture

The standard ratios of petrol and oil in the fuel mix for carburettor-based chainsaw engines of various models are 40:1 and 50:1. Such proportion ensures proper lubrication of friction parts of the crank mechanism and piston group, and does not prevent complete combustion of the gasoline-air mixture.

Taking external factors into account, the fuel mixture may be adjusted towards increasing the amount of oil. Such a need may arise at the stage of break-in of a new tool, as well as at high air temperature. The standard dosage of oil is then 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.

Storage Recommendations

It is better to prepare the mixture in a quantity that should be enough for one-time work. The problem is in the irreversible deterioration of the working properties of the mixture during storage. The finished compound is recommended for use over the next few days.

A mixture of petrol and oil with a month’s maturity deteriorates traction ability of the engine. There is also a formation of tar compounds in the fuel system and intensive formation of carbon monoxide in the combustion chamber, loss of mobility of piston rings.

  • With minimal harm to quality, it is advisable to store gasoline and oil for no more than 2 weeks. At ambient temperatures of 25 degrees or more, this period is reduced to 8-10 days.
  • To save money, the expired mixture may be used up gradually by adding it to a fresh mix in an amount not exceeding 10% of the total volume.

In order to avoid problems connected with fuel system failure it is recommended to filter the prepared mixture through a non-fibre material such as chamois or fine-meshed twill weave metal mesh.

Peculiarities of running in of a new tool

This includes gentle operation of the chainsaw during the initial period of use. The technology also includes running the engine on a mixture with 20% more engine oil.

The break-in time in engine hours is specified in the instruction manual. In practice it is enough to fill the gas tank 3-5 times for the tool to reach the working level.

New models do not need a running-in period, but it is not advised to use the chain saw for the first hours with heavy loads.