About cooking "right" A lot of articles have been written for the fuel mixture for gasoline tools, not to mention the discussion on the forums. But, despite such an abundance of information, often very controversial, the topic has not been fully disclosed. The following article about the preparation of the fuel mixture was written by one of the most respected users of our forum, a person who is well versed in this topic. His advice to many can be very helpful.
For cooking "right" the fuel mixture must comply with the following conditions
Use gasoline with an octane rating of at least 90. For Russia, this means A-92 or AI-92, but not higher. Counterfeit 92nd is relatively rare. A more high-octane craftsmen "cook" from the cheapest by adding temporary active additives. A few days after the purchase, gasoline can again become low-quality.
During storage, polymerization occurs (especially in the light), the content of resins forming carbon deposits in the combustion chamber gradually increases, so it is advisable to use gasoline for 3 months after manufacture. It is necessary to change fuel when changing the season of the year, since summer or winter are sold at gas stations;
Oil for the preparation of the fuel mixture needs special within the expiration date;
Trading in consumables gives tool manufacturers part of the profits, so they are interested in selling their oils. High-quality oils recommended by such manufacturers as Stihl, Husqvarna, Oregon, Makita (they themselves do not do them, only sell under their own brand), can be used interchangeably. It is necessary to take into account the manufacturer’s recommendations, if there are none. the degree of engine acceleration (this is evidenced by the ratio of engine volume and power, as well as indirectly. the number of maximum revolutions). For example, cheap M-12TP guest oil is sold for preparing a 1:50 fuel mixture, but it is suitable for domestic saws Druzhba, Ural, Taiga with a low number of revolutions, it is dangerous to use it for highly accelerated imported saw engines.
Oils are divided into mineral, semi-synthetic and synthetic. Semisynthetics give less carbon formation, and synthetics burns out almost completely. But the semi-synthetics and synthetics of the leading manufacturers of the road are absent in our market for this reason, while Chinese products do not always inspire confidence. (It is worth paying attention to very affordable high-quality oils of St. Petersburg NANOTEC.)
It is better to buy oil in containers of 0.1-0.2 liters, because the consumer will not have an expiration date for using oil in containers of even 1 liter (only mineral Stihl does not have a shelf life limit).
The generally accepted oil content is 2% (1:50 by volume, i.e. 20 ml of oil for each liter of gasoline), but for your tool it must meet the manufacturer’s requirements (for Partner 1:40, for Chinese firms 1:25).
The ratio should be observed carefully, using the measurements of oil and gasoline. Lack of oil causes seizure of rubbing surfaces and accelerated wear of bearings, and excess reduces the octane number of the mixture, it burns with detonation (supersonic propagation of the combustion wave with shock loads on the cylinder-piston group) and increased carbon formation, the engine resource is reduced, and the user inhales exhaust gases with unburned oil.
Video: How To Cook Stihl Trimmer Fuel Mixture
The shelf life of the finished mixture is limited to weeks due to the destruction of oil additives during storage. Better yet, cut it to a few days. Ideally, the volume of the mixture is best prepared for use within one day. Not later than several days after the end of work, it is better to drain and use the remaining mixture from the saw tank for other technical purposes, and start the saw and at idle speed, work out the remaining gasoline in the carburetor.
Selling measurements allow you to prepare a fixed volume of the mixture, each one of its own (the smallest known to me. 1 liter). What if you need to cut 1-2 boards in size? Just make a measurement for yourself with a variable amount of the mixture being prepared. A laboratory graduated cylinder is used for calibration.
Making homemade measurements
As a measure of the mixture, a transparent plastic bottle is used (usually 0.5. 1 liter is sufficient), as rigid as possible. Otherwise, if you spontaneously crush the measurements with the mixture during refueling, you can douse your hands and saw.
Pour alternately 102, 204, 306, 408, 510, 612, 714, 816, 1020 ml of water (each time pouring the previous portion) into the bottle and so on with a step of 102 ml (cc), applying an indelible line to each serving. in gasoline paint on the wall of the bottle (on the lower meniscus). The bottle should be horizontal while not tilting. Near each line in the same order, apply the numbers 2, 4, 6, 8, 10, 12, 14, 16, 18, 20 and so on;
As a measure of oil, use a completely plastic syringe without a needle 10. 20 ml (corresponding to the highest number in the measurement for the mixture).
Attention, the measurement is calculated for a ratio of 1:50! The oil pitch for this measurement. 2 ml, although the calculation can be done for any step and oil ratio (for example, you need a 3 ml step: 3, 6, 9, 12, etc. Multiply each number by 51 (1 part oil 50 parts gasoline = 51 parts mixture ) and make marks on the measure corresponding to 153, 306, 459, 612 ml, etc., about which you write 3, 6, 9, 12., respectively).
Fuel mixture application
Evaluate the amount of work for the saw, for example, assume that you have enough volume, against the line of which there is a figure 4. Use a syringe to draw 4 ml of oil, pour into a meter, then add gasoline to the syringe, shake it and pour it into the meter (this is necessary to clean the syringe from oil). To measure to line 4 add gasoline, close the lid. Stir the mixture thoroughly. Refuel the gas tool. That’s all!
A measure with a variable amount of the mixture is inconvenient only because you need to manipulate the syringe to dispense the oil.
I will give an example for the manufacture of a fixed volume measurement (1:50)
A clear plastic bottle should be with a high narrow neck, like a classic glass bottle. In the upper part of the neck under the cover, apply a line indelible with gasoline. Pour the water to the line (on the lower meniscus), then pour the water into a graduated laboratory cylinder and determine its volume in ml. Against the line, draw the number of volumes of water (so that you can imagine how much you prepare the mixture with this measure). Divide the volume of water by 51 and multiply by 50. The result will correspond to the volume of gasoline. Pour into a measure the volume of water corresponding to this number. On the lower meniscus of the water level, draw the second line. The measure is ready (the difference in volume between the upper and lower lines corresponds to the volume of oil).
Application: pour gasoline to the bottom line in the measure, add oil to the top line. Stir the mixture thoroughly. Refuel the gas tool. To prepare different volumes of the mixture, you need to have a set of such measures from bottles of different volumes.
Keep the measure or measurements between uses tightly closed (tightly closed is deformed due to a decrease in internal pressure during the gradual leakage of gasoline vapor through plastic), and the syringe is better in some plastic tightly closed box or film (from pollution by atmospheric dust).
Vladimir Skatintsev, Forestry Engineer, Ural
Read more about motor oil and other fuels and lubricants for cars and motorcycles.
Discussion on the forum: Fuel mixture