Four-stroke petrol trimmers: features, manufacturers and tips for choosing

Mowing the grass for every owner of a country or private house is an important process, it allows you to give your site an aesthetic appearance. Typically, this is done with such a thing as a four-stroke gasoline trimmer. Let's try to figure out what these devices are and how justified their use is.

The main feature of such a motor is that here the work cycle is carried out in 4 strokes - 2 crankshaft revolutions. Here the piston is simply lowering from the dead center from the top to the bottom. At this moment, the intake-type valve is opened thanks to the camshaft cams. It is through this valve that the fuel is sucked in. During the reverse piston stroke, the fuel is compressed, which is accompanied by an increase in its temperature.

Before the end of the compression, a spark is generated between the spark plug electrodes, igniting the fuel. During combustion, in this case, flammable gases are formed, which push the piston to the lower position. A working stroke is in progress. The piston of the petrol cutter engine at the lowest point opens the intake valve, which makes it possible for the piston, which moves upward, to push out the gases that have already been exhausted from the cylinder. When the piston reaches the top position, the valve closes and everything is repeated again.

If you compare two-stroke and four-stroke motors for brushcutters, then you should start with the fact that the device of the two-stroke model does not provide for the presence of gas distribution with valves, which greatly simplifies its mechanism. Another important comparison criterion is the liter capacity. In the two-stroke model, the working stroke occurs at each revolution of the crankshaft, and in the considered one - by 2 revolutions. In practice, this shows about a higher liter capacity - about 1.6-1.8 times for a two-stroke model.

These motors also have an excellent lubrication principle. Two-stroke - by mixing engine oil with gasoline. In a four-stroke, gasoline and oil are supplied separately. They have a classic lubrication system consisting of a filter, valves, oil pump and pipeline.

The main parameters of these devices are as follows:

• liter power for two-stroke engines is almost 2 times higher;
• their specific power is also higher;
• in terms of fuel supply and cylinder cleaning, four-stroke have a special gas distribution mechanism, which the two-stroke model does not have;
• in terms of efficiency, four-stroke engines are better, because the consumption here will be 25-30 percent lower.

Now let's go directly to the review of manufacturers of gasoline trimmers and try to make a small rating of the best companies that produce such products. It must be said that the undisputed leaders in the production of this category of equipment are Makita, Hitachi, Echo, Stihl, Husqvarna. Trimmer models from these companies have such characteristics as:

• excellent functionality;
• high reliability;
• ergonomic design.

It is because of these factors that the trimmer models from these manufacturers are considered the best. And the technical qualities will also be at their best here. Amateur devices from these companies are not very expensive. Therefore, it can already be argued that in terms of price and quality ratio, they will be the best trimmers on the market.

If we talk about domestic manufacturing companies such as Energomash or Interskol, then their products are notable for quite good power and have a high technical level. If you carry out competent maintenance of this equipment and operate it carefully, then the trimmers of domestic manufacturers will be little inferior to foreign counterparts.

If we talk about Chinese companies, then with all their shortcomings, they have their customers due to the significantly lower cost of production. The fact is that consumers in this case usually think that they will only use a trimmer at the dacha a couple of times over the summer, so there is no point in purchasing a high-quality, but more expensive petrol cutter from a well-known manufacturer. In general, such an opinion has a right to life in the context of the fact that if the operation is as gentle as possible, then even a not too high-quality trimmer can last 1-2 years without breakdowns.

And let's say a little about specific models of lawn mowers that really deserve attention. One of them - Stihl FS 38... A distinctive feature of this model is small mass. Without fuel, it is just over 4 kilograms. And with fuel - about 4.5 kilograms, because the gas tank here has a volume of only 330 milliliters. But this does not mean that you have to constantly refuel the trimmer. The manufacturer tried to reduce the consumption of gasoline as much as possible, so that even with a small supply of fuel, the model can work for a long time.

High-quality rotation of the working mechanism ensures that the grass is cut the first time... And on the protective shield there is a special knife that removes excess fishing line and brings it to working length. The main drawback of the model, and perhaps the only one, is rather narrow line included. Therefore, it is better to immediately replace it with a thicker one.

Another model that deserves attention - Husqvarna 128R. It is distinguished by a fairly high power. She will cope perfectly even with serious loads. The complete set of the device includes a fishing line, as well as a blade knife. This allows you to adapt to different conditions. The model under consideration is very easy to use not only in terms of mowing grass, but also when cutting off overgrown bushes or tree shoots. The model is equipped with a simple control system that allows even an inexperienced person to easily use this brushcutter. The handle is also adjustable here and there is a harness. The mass of this model is relatively small and is only 5 kilograms.

Separately, it should be noted the presence of a fairly high-tech engine, which is equipped with a special system called E-Tech. It allows you to significantly reduce the harmfulness of exhaust gases and their amount, as well as save fuel.

First you need to decide how often the brushcutter will be used and how difficult it is to work. The power and performance of the streamer will depend on these points. And the service life of any equipment is determined by how its power corresponds to the tasks that it faces. If the loads are small, then there will be no particular difference between a professional trimmer and an amateur device.

But if you have to work 8 hours a day, then you need a powerful professional trimmer, the cost of which will be appropriate. And a small number of breakdowns, long operating time, high reliability will justify the high price.You should also take into account the type of grass that grows on the site, the size of the area to be processed, as well as the terrain.

Another important selection criterion is mass of the tool. It is difficult to overestimate the role of this criterion, because even a physically developed person will find it difficult to work with a heavy instrument all day. And if we are talking about a girl or a woman, then the factor of mass becomes almost priority. The trimmer's net weight can be up to 10 kilograms. But it will also be important here, whether the model is equipped with a so-called knapsack suspension. If we are talking about periodic use, then the simple shoulder straps, which are equipped with almost every model, are enough.

In addition, physical parameters such as the type of the rod, what type of shaft the rotation is transmitted - all-metal or flexible, the category of the cutting tool, as well as the complete set of the device. In addition, it is necessary to pay attention to the noise level during operation. If the device is too loud, then it will be extremely problematic to use it in the evening and in the morning, so as not to disturb anyone.

Another criterion is the degree of vibration. The comfort of work strongly depends on it. Most of the devices on the market have special mechanisms that reduce vibration during operation. Balancing will also be extremely important, because the preponderance of one side will greatly affect the work - this will be very noticeable when mowing the grass. Equally important will be easy start of the device. If you have to spend a lot of time to start a petrol cutter, then you should think about whether it is needed at all.

When working with such equipment, it is necessary to use only high-quality and special motor oils, which allow to ensure high efficiency of the considered devices. Otherwise, there is a high probability of damage to the device. The same goes for gasoline. It is better to overpay a little, but use quality fuel that will really allow the trimmer to do its job well.

Another important point - you should not neglect to read the operating instructions, because there you can find a lot of tips for working with a particular trimmer model. This will significantly improve the efficiency of its application. Another aspect - during long-term operation, even an expensive model should be given a certain respite in order to reduce the likelihood of engine overheating and its subsequent failure.

For information on which trimmer is better, two-stroke or four-stroke, see the next video.