How much oil to put in your gasoline for your chainsaw

What’s the right oil to gasoline ratio for your chainsaw?

Hello!! This article is about the right oil to gasoline ratio for a chainsaw. This is probably the most important thing to know when operating this machine. Lack of oil will cause excessive friction, and too much oil will cause excessive fouling and overheating. In the end, both will lead to a rapid engine failure. Repair can cost half the price of a new chain saw.

In addition to the correct proportions, we are talking about other important things that will serve as long as possible your chain saw. what gasoline to use, what oil to pour, how to dilute, storage time ready mix, etc so I advise you not to stop reading the article after the section on proportions, because further on there will also be some information that will be useful for you.

correct proportions

So, I’m not going to beat around the bush for a long time, but I’ll go straight to the numbers. The most common dilutions are 1:50 and 1:40. That is one part of oil for 50 or 40 parts of petrol. For those who don’t understand, I’ll explain in more detail. We take a liter of gasoline and divide it by 50 or 40, respectively. You end up with the right amount of oil per liter of gasoline. So one liter is 1000 ml. We divide 1000 ml by 50 and get 20 ml of oil. Divided by 40, you get 25 ml. That’s how much oil you need to add to one liter of gasoline.

But you will say that you don’t know what the proportion should be on your chainsaw. Well, if you have lost the instructions or for some reason there is no information about the proportion, you can use the following rules:

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

if your 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 ratio of 1:50 turns into 1:42, and 1:40 into 1:33. Or 24 or 30 ml of oil per liter of gasoline, respectively. Well, I should note here that except increasing the amount of oil in the fuel mixture, no more running-in measures with a chainsaw are necessary, unless otherwise specified in the manual. That is, you should not, for example, leave it idling for a long time or saw not at full speed, as this will lead to its overheating and quicker failure. Always cut at maximum rpm. After you have used three tanks of fuel (the chainsaw’s tank is meant) go to the usual proportions of 1:50 or 1:40.

But sometimes it happens that the manufacturer says different ratio than I mentioned above. For example, 1:25 or 1:32. These are the proportions to keep in mind when you do this. Although if you know about them, what are you forgetting in this article?

much, your, gasoline, chainsaw

Gasoline and oil ratio

You don’t need much oil for your engine to work properly. Its amount is always determined as a percentage, because the saw’s gas tank can be of different capacities. Besides, many operators prepare mix with a small margin, especially if there is serious work to be done. After all, one tank of modern tools, for all its economy, is rarely enough for more than 1 cubic meter of firewood.

much, your, gasoline, chainsaw

This is the standard due to the high quality of modern engines. It is characteristic for most modern saws made in Germany, Switzerland, USA, Japan, Italy. In a word, all saws manufactured not more than 10 years ago by world famous brands. Husqvarna, STIHL, Oleo-Mac, Makita, ECHO and others. will require exactly this proportion.You can read about it in the instruction 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 a 1:50 mixture. For example, on recently released Zubr models the label with the proportion marking appeared in the form of a cardboard flag right on the handle of the starter cord, apparently, for those who do not like to look in the manuals.

much, your, gasoline, chainsaw

This ratio is often called “running-in” ratio. This means that when you buy a new saw, you have to put 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 the higher ratio is needed in comparison with usual one. After burning a couple of tanks or three in a gentle mode, you can go to the ratio recommended by the manufacturer.

Also, the 1/40 ratio is common in some manufacturers, such as in Partner chainsaws. Considering that there is a little more oil here than in the previous version, a little overrun won’t hurt any engine. When using high quality fuel and lubricants, there is another issue. the price of quite expensive consumables.

Today it is considered outdated. Widely used in older domestic chainsaws like Druzhba and Ural. Today you can still see it in some Chinese chain saws of “noname” class or those branded by retail chains. But every year the number of such products is decreasing and makes up the most budget and low-quality niche of gasoline tools. Besides, it is not the most important for such products how expensive and qualitative oil is in the gas tank. the engine life time is by all means shamelessly low under any circumstances.

Consequences of incorrect dosage

Many chainsaw users don’t pay enough attention to the proportion. 50 grams more or less. it makes all the difference? And in vain: often the cause of saw malfunctions is operation with an improperly prepared fuel mixture. It is possible to make a mistake or intentionally wreck the ratio upward as well as downward.

If there is a lot of oil.

There is a popular saying among chainsaw owners that “you can’t go wrong with oil”. But that’s why they make up the right parameters for the right mixture. Too much oil can also be harmful and inconvenient. In spite of improved combustibility without residue, some of hydrocarbons still turn into soot and soot. If their concentration is low, they are not much, but if you enrich the mixture with oil twice as much against the norm, then you get coking. Especially dangerous for cheap mineral oils that don’t have a “flushing” effect.

Also with a high degree of probability you will find oil in the air filter if the carburetor is overfilled. The candle will also be fouled. it will need to be cleaned, flushed and dried. Also the vapors of unburned oil will settle in the muffler and at intensive work will burn out, forming a plume of soot and sparks.

After such refueling almost all insides of the saw have to be thoroughly cleaned and flushed. The most amusing “surprise” will be “dying” of piston rings. but that’s in case of systematic abuse of oil overflow and high load operation.

or not enough

“Greedy” preparation of the fuel mixture has ruined more than one piston. That’s where it’s better to overdo it than underdo it. If in the first case you will have to have a thorough “washing” of the machine, in the second case you will have to change the cylinder block, and this is not profitable for many saws, and for others costs a pretty penny.

Conclusion: economy is pointless. If there is not enough oil, the piston rubs heavily on the cylinder because gasoline is too fluid at high temperatures to perform the lubrication function.

Unfortunate result: scuffing of the piston, ruined saw engine. In the case of the owner who comes to his senses in time, he will discover that the piston and cylinder turn a beautiful blue. No mechanic can guarantee how long they will last.

Partner 351 chainsaw

The Partner 351 chain saw is one of the Chrome models that have a chrome plated barrel. It makes the chainsaw more reliable and lasts much longer. The chainsaw belongs to the class of professional saws that are used for cutting logs, dead wood, pruning branches, twigs, and even in construction. Advanced air cleanliness, vibration damping, and noise reduction systems make the Partner 351 a pleasure to use.


stringent criteria for selection of an oil component. In the best case. 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 improved operational characteristics and compliance 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 Fueling Instructions

Knowing the ratios of the preparation of gasoline-oil mixture, you can start filling it. The instructions for trimming are as follows:

  • Prepare the mixture first. After combining the two main components, stir them 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 impurities
  • The fuel filler neck must point upward
  • Put a small spout in the filler neck and fill up the fuel
  • Control the filling process because the volume of the tank is small and fills up quickly
  • Do not fill to full capacity as fuel will leak out when the cap is closed
  • After you fill the tank with fuel, you need to refill the chain lubricant right away
  • Consumption of fuel and chain lubricant is about the same, so fill both tanks at the same time
  • After refueling you can start the engine

It is better not to start the engine at the place where it was refueled, but to move 2-3 meters away. The tool is ready to go and you can start it up. To learn how to start the chainsaw engine, see this story (link).

What happens if you put waste in a chainsaw

If you don’t want your chainsaw to fail at the wrong time, use only high-quality fuel and lubricants. Mixing spent fuel with gasoline is prohibited. The reasons for this are the following:

  • The viscosity of the material is different, and therefore the waste cannot provide effective lubrication of the working parts and mechanisms
  • Exhaust contains small particles of metal and chips, which can clog the fuel filter and the channel if they get into the tank. If the grease gets into the cylinder together with small particles, they will leave their mark in the form of accelerated wear of the piston rings
  • Producing a large amount of black smoke, which indicates that the oil is burning

Do not add substitutes not only to the gasoline tank but also to the chain lubrication tank. What happens if you use waste in the tank to lubricate the chain, you can see in the video.

Using the instructions, you can independently prepare the correct fuel mixture, on which the chainsaw will work. If the fuel mixture is incorrectly diluted, not only reduces the resource of the tool, but also reduces its performance.

Oil to gasoline ratio for a chainsaw

Every chainsaw company adjusts its engines and base carburetors to work with different amounts of lubricant. Therefore, the proportion of oil and gasoline for a chainsaw can be slightly different.

Most often, when mixing fuel with oil, manufacturers advise using the proportions 1:50, or 1:40. This means that 1 part of motor lubricant must be mixed in 50 or 40 parts of fuel, respectively.

Translating the proportion into a more accessible formulation is quite simple. For example, 1 liter of fuel contains 1000 ml. If 1000 ml divided by 40, you get 25 ml. That means you need 25 ml of motor lubricant for 1 liter of gasoline. The same formula should be used when the manufacturer recommends preparing the fuel mixture exclusively in the proportion of 1:50. For this purpose 1000 ml should be divided by 50, the result will be 20 ml. This means that 20 ml of engine grease should be diluted in one liter of fuel.

Things are a little different with Chinese chain saws. Their manufacturers recommend diluting gasoline for chainsaws at a ratio of 1:25. It means that the owners of Chinese tools need to mix exactly 40 ml of lubricant in 1 liter of pure gasoline. This ratio is due to the fact that in quality of assembly and selection of components these chainsaws are slightly inferior to their Western counterparts. American, European and Japanese engines have a much smaller cylinder-to-piston spacing than chainsaws from China. Because of this, the amount of grease required to operate the first. much less.

What chain oil to use for a chainsaw chain?

To know exactly what chain oil to use for chainsaw chain lubrication, you will need to study the instructions of its manufacturer. Almost all tool manufacturers recommend pouring a product that stands out with the highest adhesive properties. This means that the material used to lubricate the chain must have adhesion to the metal surfaces of the chain and bar.

You need to understand why grease has adhesive properties. The chain moves at high speed when the chain is on the bar. If chainsaw chain oil with low adhesion is used for lubrication, more than half of the fluid will fly off the bar top and never reach the bar bottom. The result is that the oil would prove ineffective and the bar and chain would fail quite quickly because of the constant friction.

What is the right way to dilute?

The figures for the dilution ratios are so precise for a reason. That is, it does not say, “take about this or that amount of oil”. It is impossible to observe the exact proportion by eye, so you have to use something that will measure the exact amount of oil and gasoline.

Some inexpensive chain saws usually come with a measuring jug with dots on it. As a rule, it has several scales for different proportions. Or one if the manufacturer assumes that this tank will be used only with the saw it comes with. On this scale there should be two horizontal marks. The lower one shows the level to which you need to pour the gasoline. The upper one is the level to which the mixture should reach after adding oil to petrol.

For more precise measuring of oil you can use a medical syringe. Preferably not less than 20 ml.

In general pour petrol into a measuring container, add a needed amount of oil measured with a syringe and shake.

Always mix the fuel in a separate container, not directly in the gasoline tank of the chain saw. Otherwise, oil may get into the carburetor before it has time to be diluted with gasoline, making it harder to start, even to the point of having to remove the carburetor and clean it.

How to prepare the mix?

To get the most out of your power tool, it is important to know exactly how much oil to add to your STIHL chain saw. We found out earlier that it is better to use STIHL lubricant and unleaded AI92 or AI95 gasoline as ingredients. Using leaded gasoline has a negative effect on the engine, making it unusable. With these components for the mixture, add 20 ml of oil to a liter of gasoline. Any violation of the proportions leads to soot on the plugs and pistons, as well as the formation of scuffing. The oil in use may be green, blue or red.

Their presence can be readily detected by the color of the mixture. To dilute the fuel, often included with the equipment, a special canister. These containers are marked with graduations and have two holes. The user only has to fill the container with the ingredients of the mixture up to the required level, close the lids and mix. Some people use plastic bottles and syringes for measuring oil for this purpose. In this case it is necessary to ensure that no foreign particles or water get into the container, all this will impair the operation of the engine.

What happens if the manufacturer’s recommendations are not taken into account?

STIHL chain saw STIHL 180 chain saws have the following problems if the correct oil and lubricant mixture is not mixed and the proportions of oil in the fuel mix are not maintained:

  • As friction increases, so will wear on the working surfaces of the parts.
  • Due to insufficient lubricant the bearings will start to deteriorate.
  • impairment of proper functioning of mechanical units due to premature wear of components, their service life is reduced significantly.
  • Use of low-grade types of gasoline and oils reduces the performance of the unit with subsequent failure of important assemblies and parts.

Always prepare fuel before filling up the cut-off saw to avoid exposing the fuel to excessive oxygen. After completing the work, the remaining mixture must be drained.

Storage Recommendations

It is best to prepare a mixture in quantities that should be sufficient for a single job. The problem is that the mixture will irreversibly deteriorate during storage. It is recommended to use the ready-to-use composition over the next few days.

A mixture of petrol and oil with a month’s storage time impairs traction ability of the engine. There is also the formation of tar compounds in the fuel system and intense carbon buildup in the combustion chamber, loss of mobility of piston rings.

  • With minimal damage 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.
  • In order to save money, the expired mixture may be gradually consumed by mixing it into a fresh mixture in an amount not exceeding 10% of the total volume.

To avoid the problems associated with the failure of the fuel system, it is recommended to filter the prepared mixture through a non-fiber material such as chamois, or a fine mesh twill weave, metal mesh.

Peculiarities of the running-in of a new tool

This includes the initial period of operation of the chain saw in a very gentle manner. The technology also provides for running the engine on a mixture with 20% more m of engine oil.

The running-in time in motor-hours is given in the enclosed instruction. In practice it is enough to fill 3-5 times the gas tank of your chainsaw in order to reach the operating level.

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