The ratio of gasoline and oil for brushcutters

Benzokosa. a fairly common technique for combating weeds in summer cottages, in household plots, on the road, and in housing and communal services. These devices have two more names. trimmer and Lawn Mower. These units differ in their engines. The more expensive of them have four-stroke engines, all the rest are two-stroke. Of course, the latter are the most popular among the population, as it is both simpler in design and mass lighter and much cheaper than its four-stroke competitors. However, two-stroke models are inconvenient in that the fuel mixture for them must be prepared manually, withstanding a strict dosage between gasoline and oil. In four-stroke analogs, the mixing of these components occurs automatically, you only need to fill the gas tank and oil tank with the appropriate substances. Let’s look at the issue of the correctness of refueling just two-stroke motokos, as it depends on how efficient and long the operation of such an aggregate will be.

Standard proportions

First of all, it is necessary to take into account the information that the manufacturer recommends, since in the event of a failure of the brushcutter, you can make your claims to him, and not to an external source. If there is no instruction in the passport, and even more so if there is no passport, we recommend that you look for a different trimmer model from a more reliable seller.

For all other cases, when you had a model of a petrol brush in your hands and there is no way to find out its technical features, there are standard proportions of the most likely components of the fuel mixture for a two-stroke engine. Mostly for these units, AI-92 grade gasoline and special synthetic oil are used, which contains a solvent for better mixing with fuel. Such oil evaporates slowly and has the ability to completely burn in the cylinder without leaving a deposit.

The standard ratio of synthetic oil to gasoline is 1: 50. This means that for 5 liters of gasoline you need 100 ml of oil, and in accordance with this, the oil consumption per 1 liter of gasoline is 20 ml. Knowing the amount of oil needed to dilute 1 liter of fuel, you can easily calculate any norms when preparing fuel for the trimmer. When using mineral oils, the ratio of 1: 40 is most often standard. Therefore, 25 ml of such oil will be required per 1 liter of fuel, and 125 ml per 5-liter canister.

The ratio of gasoline and oil for brushcutters

During the operation of the brushcutter, a person who has little experience in operating such equipment will easily find and correct the actual amount of oil needed for a particular model. It is only necessary to pay attention to exhaust gases (their color, odor toxicity), cycle stability, engine heating and developed power. details about what consequences from the wrong proportions of mixing gasoline and oil can be expected are covered in another section of the article. There are options for motokos running on AI-95 gasoline. This should also be considered.

Video: The ratio of gasoline and oil for brushcutters


If the manufacturer recommends a fuel with such an octane rating, then you must follow the requirements so as not to reduce the technical life of the equipment.

Mixing rules

And now about how to mix components correctly. However, it will be more logical to start by analyzing common, but absolutely unacceptable errors that many owners of this mowing unit “sin”. The following actions are considered to be errors in mixing the fuel mixture.

  • Adding oil to the fuel that has already been poured into the fuel tank. Similarly, a homogeneous fuel mixture cannot be obtained. Perhaps it will turn out, if only then shake the trimmer for a long time. But hardly anyone will do this, given the severity of the unit.
  • First pour oil into the mixing tank, and then add gasoline to it. Gasoline has a lower density than oil, so if it is poured to the oil, it will remain in the upper layer, that is, natural mixing will not occur. Of course, it will be possible to mix later, but energy will be required much more than if it were done the other way around. pour oil into the gasoline.
  • Ignoring accurate measuring instruments to take the required volumes of ingredients used. In other words, diluting the amount of oil or gasoline “by eye” is a bad habit when operating motor vehicles.
  • Take empty bottles from under drinking water to prepare the fuel mixture. Such containers are made from too thin polyethylene, which can dissolve with gasoline.

Given all of the above, we recommend using the following rules when mixing the fuel mixture for two-stroke trimmer engines.

  1. To use for storage of gasoline, oil, finished fuel mixture and its preparation only clean containers made of metal or special plastic.
  2. Use to pour gasoline into the dilution tank with a watering can to avoid spillage, and to add oil, use a measuring container with volume risks or a 5 and 10 ml medical syringe.
  3. First, pour gasoline into the canister to prepare the fuel mixture, and then oil.
  4. To dilute the mixture, only half of the planned volume of gasoline is first poured into the tank.
  5. Next, add to the gasoline the entire amount of oil required to prepare the mixture.
  6. Thoroughly mix the contents of the dilution tank. It is best to interfere by making circular movements with a tightly closed container. Do not mix fuel inside the canister with any foreign object, since it is not known what material this object is made of, what reaction it can enter with the ingredients of the mixture, how clean it is.
  7. The remainder of the gasoline is added to the mixed mixture and again thoroughly mixed.
  8. You can refuel the fuel tank of the brushcutter with the prepared mixture.

It must be borne in mind that the finished fuel mixture should not be stored for more than 14 days, as it loses its properties, delaminates and evaporates, which leads to changes in the proportions, and hence the deterioration of the trimmer.

The consequences of a violation of the ratio

The working life of the engine of the motocosa depends on how accurately you comply with the proportions of the oil-gasoline mixture recommended by the manufacturer. The fact is that the fuel mixture enters the cylinders in the form of gasoline-oil mist. And the task of the oil composition is the lubrication of moving and rubbing parts and surfaces of various parts located in the cylinder. If it suddenly turns out that the oil is not enough, and somewhere it will not be enough to get enough, the parts in contact with dryness will begin to damage each other. As a result, galling, scratches and chips are formed, which will necessarily lead to complete or partial unsuitability of the engine (for example, it may jam).

In the opposite case, when too much oil enters the engine, it does not have time to completely burn out, settling on the cylinder walls and eventually turning into solid particles. coke, slag and the like. As you might guess, this also leads to engine failure. The most important thing that should not be allowed. even a single violation of the proportions in the direction of lack of oil. It is better to pour a little oil 10 times than not to add only 1 time. It often happens that this time is quite enough to break the engine.