The ratio of gasoline and oil for a chainsaw
Household and professional chainsaws are powered by two-stroke ICEs operating on a dosed mixture of gasoline and adapted to the difficult operating conditions of engine oil. The correct proportions of oil and gasoline for a chainsaw is one of the important conditions for stable traction characteristics of the engine and low-cost development of its assigned resource.
The need to obtain a sufficiently high power from a small-cubic power unit makes it necessary to operate chainsaw engines in high-speed modes, therefore, high demands are placed on the quality of both components of the fuel mixture.
The main component of the fuel mixture for gasoline-powered engines is gasoline with an octane rating of at least 92. Consumables with expired storage made on the basis of gas condensate, having water and mechanical impurities in its volume, are not suitable for fuel preparation.
- Opinions of experts on the use of gasoline of various brands are mixed. On the one hand, incomplete compliance of domestic A-92 gasoline with European standards is recognized.
- On the other hand, the quality of A-95 gasoline is questioned due to the high content of anti-knock additives. Use this fuel for the preparation of fuel for a chainsaw is possible only with full confidence in its quality.
- The difficulty lies in the presence of various improving additives, with the help of which unscrupulous manufacturers and distributors increase the operational properties of motor gasoline with a lower octane rating.
Irreversible changes in the working properties of the fuel also occur when it is stored for a sufficiently long time in a plastic container, regardless of the level of its benzo and oil resistance.
Stringent selection criteria for the oil component. In the best case, this is a mineral or semi-synthetic engine oil recommended by the manufacturer, designed for use in high-speed two-stroke ICE with air cooling.
The advantage of mineral oils in their lower cost. Their more expensive semi-synthetic and synthetic counterparts stand out for their superior performance and environmental standards.
- Keep working properties in a wide range of working temperatures;
- Do not form soot;
- Contain detergents, antioxidants, preservatives and other additives useful for the operation of the power unit.
Benefits of Branded Oils
Many domestic and foreign manufacturers specialize in the production of special motor oils, but Stihl, Husqvarna and Makita branded products have the highest ratings.
Only in certain parameters are domestic motor oils of the Lukoil trademark inferior to the company’s assortment.
The list of advantages of branded motor oils:
- Economical consumption;
- Stability of performance in difficult operating conditions and during long-term storage;
- Minimum amount of toxic compounds in exhaust gases;
- Almost complete absence of soot.
According to the American classification, API-TB oils can be used to work in household and professional models. The Japanese counterpart is JASO-FB and JASO FD. The preparation of a combustible mixture using oil for 4-stroke engines is strictly excluded.
Red, green or any other color of oil determines the product belongs to the assortment of a particular manufacturer, therefore, it is not taken into account when determining the characteristics of the material. Extremely cautious should approach the choice of engine oil of unknown composition and origin.
Before receiving additional information about the quality and operational parameters, it is better to temporarily refuse to use such material.
It is allowed to mix motor oils of the same types and composition for the production of well-known brands of the quality of their assortment. Under no circumstances is it permitted to mix mineral and synthetic oils.
A large assortment allows you to choose oil that fully meets the class and characteristics of the chainsaw, the conditions for its subsequent operation.
- For budget models, you can use oils of the Standard category, for professional chainsaws, consumable lubricants of the Super and Ultra categories are recommended.
- To prepare a complete fuel mixture for a chainsaw, it is advisable to use branded oils recommended by the instruction manual or their brand analogues. In particular, Stihl and Husqvarna engine oils of the same composition and use are completely interchangeable.
Experts recommend that owners of chainsaws exclude motor oils intended for two-stroke engines of mopeds, boat engines and other mechanized appliances of the household group from the spotlight.
The power units of this equipment operate in more comfortable conditions, which makes the requirements for their operational characteristics less stringent.
Chinese oil dosage
Many Chinese chainsaws are simplified copies of popular models of European design. The lack of special materials and proprietary technologies helps to maintain an outdated proportion of gasoline and oil in a ratio of 25: 1.
Twice the consumption of engine oil is offset by its lower cost. According to the assurance of the developers, the original components are introduced into the composition of Chinese oils, which contribute to increasing the wear resistance of power units and real extension of their designated resource.
According to independent experts, the best brands of Chinese motor lubricants in quality correspond to analogues of European manufacturers in the mid-price range. This is the level of standard engine oils of the Standard group and partially Super.
Small private companies from China and other Asian countries specialize in the production of motor oils, which are sold at lower cost in the markets under the brand name of leading manufacturers.
- Characteristics of fake products are much lower than branded originals. The constant use of counterfeit negatively affects the operation of the chainsaw and the durability of its operation.
- Only an experienced specialist can determine the status and quality of oil, so you can avoid possible risks by buying consumables in a network of branded and licensed retail outlets.
- The use of substandard lubricants for service professionals is a legitimate reason for depriving the owner of a faulty saw of warranty repair and restoration obligations.
The working proportions of the fuel mixture
The standard ratio of gasoline and oil in the fuel mixture for chainsaw carburetor engines of different models is 40: 1 and 50: 1. This proportion provides a complete lubrication of the rubbing parts of the crank mechanism and the piston group, and also does not interfere with the complete combustion of the gasoline-air mixture.
Taking into account external factors, the fuel mixture can be adjusted in the direction of increasing the amount of oil. Such a need arises at the break-in stage of a new tool, as well as at high air temperature. In this case, the standard dosage of oil is increased by 20%.
In practice, an increase in the percentage of oil in the fuel mixture is applied if its characteristics do not fully meet the stated requirements. How much oil per liter of gasoline is needed in each case, the sawmill himself determines.
To maintain the correct proportion of gasoline and oil, a spreadsheet applied to the saw body may be used. The branded packaging of leading manufacturers of motor oils is equipped with built-in measuring devices that provide an accurate dosage of oil for different volumes of the fuel mixture.
Measuring utensils are included in the factory kit of many budget chainsaw models. In some cases, a medical syringe with a volume of 20 cm3 will help dilute gasoline with oil in a predetermined proportion.
Features of the preparation and storage of the fuel mixture
Safety regulations require that gasoline and oil be diluted in a metal canister. This eliminates the risks of static electricity and fuel ignition.
Experts advise pouring oil into an incomplete container, mix thoroughly, and then add pure gasoline to a predetermined level. It should be excluded from everyday practice the saving of working time by preparing the working mixture directly in the gas tank of a chainsaw.
This technology is fraught with fuel system failures due to the ingress of a large amount of oil into the carburetor, the need for disassembly and thorough washing.
It is better to cook the mixture in an amount that should be enough to perform one-time work. The problem is the irreversible deterioration of the working properties of the mixture during storage. The finished composition is recommended to be used over the next few days.
A mixture of gasoline with a monthly oil degrades the engine’s traction capabilities. There is also the formation of resinous compounds in the fuel system and intense carbon formation in the combustion chamber, loss of mobility of the piston rings.
- With minimal damage to quality, it is advisable to store gasoline with oil for no more than 2 weeks. At an ambient temperature of 25 or more degrees of heat, this period is reduced to 8-10 days.
- In order to save, the expired mixture can be gradually consumed by mixing in a fresh composition in an amount of not more than 10% of the total volume.
In order to avoid problems associated with the failure of the fuel system, it is recommended to filter the prepared mixture through non-fiber material such as suede, or fine-mesh twill weaving, a metal mesh.
Features of running a new tool
This concept includes the gentle operation of a chainsaw at the initial stage of its operation. The technology also provides for engine operation on a mixture with a 20% increase in engine oil content.
Break-in time in hours is indicated in the attached instructions. In practice, for the tool to reach the working level, it is enough to develop 3-5 gas stations for the saw’s gas tank.
New models do not need a run-in, but the first hours of operation of the chainsaw are not recommended for use with heavy loads.