How to dilute gasoline for STIHL chain saws

The correct oil ratio for brushcutters and chainsaws

Many users of power tools treat the preparation of the fuel mixture rather irresponsibly. For example, I met sawyers who diluted petrol with oil “by eye. They just pour as much oil as they want, and then they come to me with defective tools.

It is important to understand that more, like less, does not mean better. The golden mean is important.

If you make a mixture with a lack of oil, everything is clear. There will not be enough lubricant for the cylinder and bearings, which means higher friction and temperature, scoring in the cylinder and can cause the crankshaft bearings to seize.

What happens if you overfill? The large volume of oil, when burned, produces a lot of combustion residue that deposits on the piston, cylinder outlet and muffler, obstructing the flow of exhaust gases. The result is little or no power output.

The residue formed by too much oil can deposit under the compression rings and doesn’t allow them to compensate for the thermal expansion, which leads to burrs and can have very serious consequences.

STIHL chain saw oil

It is worth pointing out that all STIHL chain saws are built quite small, but in spite of their size, they offer impressive power. This is the reason why STIHL chain saws are so popular.

Despite the high quality, the durability of a chainsaw depends on using the right lubricant and fuel. The first problematic question faced by the owners of this equipment is: What oil and fuel to choose for their chain saw? In this article we show you what kind of oil to use for your chain saw, and what kind of fuel to put in your little guy.

Choosing a STIHL chain saw oil

The first thing you should know is that almost all STIHL chain saws are equipped with a two-stroke carbureted engine. They also have two separate tanks: the first for oil and the second for gasoline.

First, and most importantly, keep in mind that domestic-made chainsaw models are filled with simple oil, which is usually poured into motorcycle tanks, and their proportion should be no more than 1 to 25. As for chain saws made abroad, it is necessary to buy brand-name oils, for which the ratio is 1 to 40. Of course, you may try to put domestic saw oil in an imported saw, in which case the power of your tool may drop noticeably. The best advice you can give when buying oil for this kind of equipment is to consult the manual for your tool.

If you own a STIHL chain saw or would like to purchase one of these models, here is the STIHL MC 180 brand chain saw in your hands.

An API-TB and API-TC synthetic air-cooled two-stroke engine oil is a good choice. When you go to the store ask about STIHL, Husqvarna, HAHOTEK, Champion, ALCO and other brands. Never be greedy about ingredients, it’s better to spend money on a quality product than to spend a lot of money on repairs later.

Choosing gasoline for your STIHL chain saw

When choosing gasoline for your chain saw you should pay attention to the quality of the gasoline itself and its octane rating. It is best to get gasoline with a 92 octane rating. You could try AI95, but there are too many questions about its quality. If you have reservations about the quality of the AI95 then the AI92 is the best choice for you.

Do not use gasoline which has been sitting in a container for a long time. be it a can, a tank or anything else. Only fresh gasoline should be used for the fuel mixture, otherwise it can lose all its useful qualities: octane number, etc. If you’re still using gasoline that’s not fresh, your chain saw won’t run at full capacity. If your chain saw breaks down while using such fuel, you will have to spend a lot of money to have it repaired, because it is not covered by the warranty, and you would be better off buying a new chain saw.

STIHL chain saw MS 180. technical specifications

STIHL MS 180 chain saw stands out with its solid technical parameters. These include:

  • power. 2 litres. с.;
  • Fuel tank capacity. 270 ml;
  • The capacity of the oil reservoir is 260 ml;
  • The possible length of the bar used for work is 30-35 cm;
  • chain pitch. 3/8″
  • assembled weight 4 kg.

Modest fuel consumption is one of the model’s advantages. Maximum power consumption at maximum load: engine uses up to 2.9 liters/machine. an hour.

STIHL STIHL 180 chain saw delivery set

With the purchase of this model, the farmer receives a complete list of equipment required for assembly, as well as the use of tools.

The chainsaw’s basic package includes:

  • 35 cm long guide bar;
  • chain with a pitch of 3.8″ and a groove width of 1.3 mm;
  • protective cover for the bar;
  • instruction manual in russian.

Together with the tool the buyer also receives branded wrench and screwdriver, with which you can quickly disassemble the saw for its repair.

Gasoline and oil for chain saws. what is better

Newbies often ask what kind of gasoline is better for their tools? To make the right choice, it is best to consult the instruction manual of the tool. In the manual, each manufacturer specifies the appropriate brand of fuel. If the manufacturer specifies that the octane number should not be lower than 95, it means that pouring 92 gasoline is not recommended.

Now let’s understand what oil is better to take for chainsaw engines. Special oils are used for such purposes. It is forbidden to use car engine oils for fuel mixture. It is necessary to buy a lubricant for two-stroke motors for chainsaws, which are on sale not only in specialized centers, but also in online stores.

Engine oils for two-stroke engines are produced by such manufacturers:

Usually the ratio is indicated on the bottle with the lubricant, so it will be difficult even for beginners to get confused with the preparation of the fuel mixture. Under no pretext do not use waste, even as a chain lubricant. This leads to a situation where you will soon need to have the tool repaired.

Instructions for filling your chainsaw with fuel

Knowing the ratios for preparing the gasoline-oil mixture, you can begin refueling. Instructions for filling is as follows

  • First prepare the mixture. Having combined the two main components, you should stir them thoroughly
  • Place the tool on a clean and level surface. Before unscrewing the fuel filler cap you must clean or blow out sawdust, dust and contaminants
  • The filler neck must point up
  • Use a small cap in the filler cap and fill up the fuel
  • Control the filling process because the volume of the tank is small, so it fills quickly
  • Do not fill to the top of the tank because when the cap is closed the fuel will spurt out
  • After the fuel is in the tank, immediately refill the chain lubricant
  • Fuel and chain oil consumption are about the same, so both tanks should be filled at the same time
  • After filling up you can start the engine

It is better not to start the engine at the place where you refueled it, but to move 2-3 m away. The tool is ready to work, and you can start it. You can read how to start the chainsaw engine in this article (link).

Instructions for filling the chain saw with fuel

Knowing ratios of gasoline-oil mixture preparation, you can start filling it. Instructions for refueling are as follows:

  • First you need to prepare the mixture. Mix the two main components together and stir them thoroughly
  • Position the tool on a clean and flat surface. Before you unscrew the fuel cap, you must clean or blow out any sawdust or debris
  • Mouth of the tank must face up
  • Put a small watering can in the filler neck and fill up the fuel
  • Control the filling process, because the volume of the tank is small, so it fills up quickly
  • Do not fill to the max, because when you close the cap on the tank, the remaining fuel will spill out
  • After you fill the tank with fuel, you only have to refill the chain lubricant right away
  • Consumption and chain lubrication are about the same, so it is important to fill both tanks at the same time
  • After refueling, you can start the engine

It is better not to start the engine in the same place where you filled it up, but to put some distance of 2-3 meters between you and your petrol station. The tool is ready to go, and you can start it. How to start the chainsaw engine, you can read in this material (link).

What happens if you put waste in the chain saw

If you do not want your chainsaw to fail at the wrong time, use only high-quality fuel and lubricants. Do not mix spent fuel with gasoline. The reasons for this are the following factors:

  • Different viscosity of the material, so the waste is not able to provide effective lubrication of the rubbing parts and mechanisms
  • Exhaust contains small metal chips and particles that get into the tank and clog the fuel filter and duct. If the grease gets into the cylinder along with the fine particles, they will leave their mark in the form of accelerated wear of the piston rings
  • Large amounts of black smoke are produced, indicating that the oil is burning

Adding substitutes is not allowed in the gasoline tank, but also in the chain lubrication tank. Watch this video to see what happens if used waste in the tank for chain lubrication.

Using the instructions, you can make your own correct fuel mixture to run your chain saw. Incorrect dilution of the fuel mixture not only reduces tool life, but also its performance.

In order to keep your chain saw for a long time and not to cause repair problems, you need to prepare the fuel mixture correctly. Internet forums abound with questions on this topic. We have interviewed experts and made a short instruction.

For preparation of fuel mixture use gasoline AI-92 or AI-95. A lower octane rating is not an option. Do not use leaded gasoline (otherwise the engine will break down) and not old (the octane number can change over time). Do not use oil for boats and four-stroke engines.

Mix petrol and oil in strictly defined proportions. Choose API-TB or API-TC synthetic air-cooled two-stroke oil. Don’t skimp on ingredients. Ask for leading quality brands in the stores. For example STIHL, Husqvarna, NANOTECH, Champion, ALCO, etc.

The key consideration is the proportions. Excessive oil causes soot deposits on pistons and spark plugs. Excessive gasoline will cause burrs on pistons and rapid engine damage. On average, one liter of gasoline is mixed with 20-50 ml of oil. STIHL and Husqvarna, for example, recommend 100 ml of oil for 4 liters of gasoline. The ratio given is ideal for chainsaws under 1.5 kW. For chain saws over 1.5 kW of the same brands, use a ratio of 1/50 (100 ml of oil to 5 liters of gasoline). Recommendation of Partner and Jonsered: proportion 1/33 (3.3 L of gasoline, 100 ml of oil). Add the supersynthetic oil at a ratio of 100/1. These figures are approximate. Always use the information in the manual for your chain saw. Give less credence to the figures on the oil label.

What to mix? Canisters with measuring divisions and two openings for oil and gasoline are available. Pour the ingredients, tighten the caps and mix by tilting the container.

Many people use glass and plastic bottles, baby horns and syringes. Be careful with glass and plastic, and beware of static electricity. Make sure no particulate matter or water droplets get into the mixture. Always mix the mixture thoroughly.

Do not store ready-to-use fuel for more than 25-30 days.к. the oxidation process changes its composition. Engine failure caused by overfuel is considered non-warranty. The amount of repair reaches 80% of the cost of a new chainsaw. At the end of the work season use up the rest of the fuel, turn off the engine, remove the rest of the fuel mixture.

Remember, your goal is to create a mixture that will ensure smooth engine operation, complete combustion without formation of soot, smoke or scuffing.

The chainsaw is used when cutting trees, in repair work. The popularity of this tool increases every year. Every owner buys one for his or her home. However, in order to use it for a long time, it is necessary to properly care for the tool. Only with proper care will your saw last a long time and not harm your health.

This is especially true in the petrol-oil mixture. It should be diluted and filled strictly according to the instructions below.

Which chainsaw parts need oil?

If you look closely at a working chainsaw, you will immediately notice its main moving part. the saw chain, which slides on the bar during sawing. Since the law of friction still exists, both parts gradually wear out. In order to slow this process down it is customary to use chain oil specially formulated for the lubrication of saw chains.

chainsaws can be fitted with either a four-stroke engine or a two-stroke engine. On 4-stroke machines, the crank group is lubricated by the oil in the engine crankcase. Two-stroke engines have a slightly different design and operating principle. In this type of drive, the petrol goes straight to the space under the piston where the crank mechanism is located, which has several bearings and bushings that need lubrication. So in the gasoline is added oil for two-stroke engines chain saws, so that it gets on the rubbing parts of the unit, lubricate them.

Proportion for Druzhba chainsaw

The pedigree for the Druzhba chainsaw began in 1953 with the development of the ZMKB “Progress”. Production of the product was entrusted to two companies, the Siberian Instrument Manufacturing Plant and the Perm Machine-Building Plant. Started the mass production of mechanized product, which is still in the trend of the day, as the unit systematically modernized.

The engines use fuel with low octane numbers. The unit shows the highest performance when filled with gasoline brands AI-76 and AI-80.

It is recommended to dilute gasoline and oil according to the following algorithm:

Take 2 clean containers, dried from moisture with volume marks. Then dilute the fuel with two-stroke oil at a ratio of 1:50. That is, fuel is diluted with 20 milligrams of oil.

Fuel mixture

To properly prepare fuel, you’ll need a list of extra tools:

  • Plastic or metal container for diluting the substance;
  • A measuring bottle for gasoline;
  • Dispenser;
  • Syringe;
  • A bottle for filling the gasoline tank of a chainsaw.

Some manufacturers, like STIHL, make measuring containers straight away for easier measuring of the fuel mixture.

Different manufacturers make oil in different shades. HP manufacturer produces red colored fluid. Green-colored oil is the premium synthetic segment. For a chainsaw Husqvarna you need to take oil of the appropriate brand. It is expensive, of good quality, and has a green or blue color.

The main thing is to correctly calculate the proportions of the mixture. Excessive oil can leave residue on pistons and spark plugs. Excessive gasoline can cause engine damage or galling on pistons. Each manufacturer gives different proportions to models of different power.

To mix the components, you will need the aforementioned additional accessories. You can also find special canisters with two holes for oil and gasoline. Here everything is very simple, pour the ingredients, close the cap tightly and mix by tilting the container. You can use glass and plastic bottles.

No water or dust should enter the fuel mixture.

Safety precautions for refueling:

Depending on the chainsaw design, the fueling process varies.

With the use of a special device:

How to thin the gasoline for a STIHL STIHL 180 chain saw?

Most owners of saws of this model, the question of what gasoline pour into the chain saw STIHL 180 and what proportions with oil must be observed. A ratio of 1/50 is more or less ideal, i.e. you only need 100 ml of oil for five liters of the mixture.

How to mix petrol with oil

To extend the life of your STIHL MS 180 chain saw, use a high-quality, properly mixed fuel. Quite often for this model use gasoline AI-2 or AI-95. Pay attention to the fact that only unleaded gasoline is allowed, which can save the engine from premature damage.

Alternative fuel option

For fuelling domestic and professional chainsaws it is recommended to use motor gasoline of AI-92 type, which does not contain alcohol components and additional additives. Up to date it is still a moot point whether you can put 95 gasoline in your chainsaw. Theoretically, the anti-detonation properties of gasoline AI-95 are higher than those of standard fuel AI-92, but in practice it is better to give preference to the second option. The problem is that in order to increase the anti-detonation characteristics, the producers and sellers introduce additives into the composition of the 95th gasoline, the quality and efficiency of which raise reasonable doubts among specialists. This fuel does not meet the required specifications and is not stable over extended periods of storage. After 3-4 months of exposure, its performance deteriorates by 25-30%.

The configuration is designed for users with varying degrees of experience with this equipment. Cleaning, replacing or repairing the carburetor on the STIHL 180 chain saw is easy.

You can bleed the unit yourself, change the gaskets and needle valve, for which you need to disassemble the carburetor STIHL 180. To do this, unscrew the four screws located on the compensator cover and unscrew one on the fuel pump. Once you have opened the casing of the unit, you must be extremely careful, as even small debris, or even a hair, can make the unit inoperable.

The terms of storage of the ready fuel mixture

Motorists know that you should not stockpile gasoline for a long time, and ready fuel mixture spoils even faster. Always mix the correct proportions of oil and gasoline for your STIHL chain saw before starting work. The manufacturers allow storage of the ready fuel for up to one month, but experts recommend reducing this period to 10 days. Immediately after mixing the solution begins to lose its original properties and over time it will not be of the same quality as it was prepared. Learn to prepare as much fuel for the saw as you can use at one time. This is a skill that comes with experience. Store the mix in a gasoline-resistant, nontransparent and sealed container. Any plastic metal canisters for combustibles will do. Also use an oil can or dark glass container.


Gasoline should be of octane number not less than A92. One can also pour AI95, but its quality at our gas stations leaves much to be desired, that is why if you are not sure of the quality of the 95-th it is better to take AI92 gasoline to dilute it in a gasoline saw. You should also avoid taking gasoline which has stood in a can, tank or any other container for a long time. Gasoline for a gasoline mixture should be fresh, otherwise it loses its properties, particularly the octane number, and even if you start the chain saw on such fuel it will not give full power. The saddest thing in this case is that the chainsaw failure due to low-quality fuel is considered a non-warranty case and leads to expensive repair. Sometimes it is easier to buy a new chain saw than to repair it after such a breakdown!

Choice of chain oil

Except the engine, for which all proportions of oil and gasoline for STIHL chain saws are already known, there is another important part, which consists of many moving parts. the chain. The chain oil, not motor oil, is used to lubricate it. It has completely different properties and is cheaper.

For new tools, only oil from the oil manufacturer is used that is recommended in the instruction manual. Otherwise, if the saw breaks down, it will be removed from the warranty service due to non-compliance with the operating conditions. It should be noted that the oils from the manufacturer are of really high quality. After the end of the warranty period, you can use any engine oil, making its replacement twice a year.