# Which grass trimmer is better two-stroke or four-stroke

## Which engine is more powerful

If we consider cylinders of equal size and speed of rotation of the shaft, then the theoretical power of a 2-stroke engine is 2 times higher than that of a 4-stroke engine. This is due to the fact that the number of operating cycles of the two-stroke is greater. But if we take into account the fact that the piston stroke for expansion is not fully used, and the residual gases are less efficiently released from the cylinder and the share of the generated power goes to purging, then in fact the power is about 60% higher.

## What is the difference between a two-stroke motor and a four-stroke

Still arguing which outboard motor is better? Learn how to quickly distinguish a two-stroke outboard motor from a four-stroke. 5 simple and practical tips will help you visually determine how many piston strokes a particular motor model has.

• 2-stroke outboard boat motor
• 4 stroke outboard boat motor
• How to distinguish a two-stroke outboard motor from a four-stroke
• Video

### The principle of operation of a four-stroke gasoline engine

When inlet, the piston goes from top dead center (TDC) to bottom (BDC). In this case, with the help of the camshaft cams, the intake valve opens, through which the fuel mixture is sucked into the cylinder.

During the reverse stroke of the piston (from BDC to TDC), the fuel mixture is compressed, accompanied by an increase in its temperature.

Just before the end of the compression, a spark ignites between the electrodes of the plug, igniting the fuel mixture, which, burning, forms flammable gases that push the piston down. A working stroke occurs, in which useful work is performed.

## Why ICEs are divided into 2-stroke and 4-stroke

The most obvious difference is the mode of ignition of the combustible mixture. This can be traced visually and by sound, since a two-stroke motor sounds loud and boomy, and a four-stroke one has a calm and uniform sound.

### Stihl FS 250 vs FS 130. Two stroke vs Four Stroke

The variability of the motors depends on the fuel intake and mining output. If in a two-stroke engine the combustible mixture passes and exits through the windows in the walls, then in a four-stroke engine this process takes place through valves. Therefore, you can find a four-stroke engine by the valve mechanism, since a camshaft box with a pulley is attached above the cylinder head. Plus, at the lower camshaft, the valve drive rods are extended to the valve box.

In addition to the above, the pipes of the four-stroke engine are located on the top of the cylinder. But the second type has one branch pipe (outlet) and is located at the bottom of the cylinder. It also happens that at the top of the two-stroke there is only the contact of the candle.

## What is the difference between a two-stroke engine and a four-stroke engine

Nowadays, it is impossible to imagine everyday life without internal combustion engines. They are used in everything from transportation to your lawn mower. Piston units, regardless of the fact that there are analogues, are recognized both among creators and among consumers. They, in proportion to the number of strokes required for the working revolution of the crankshaft, are divided into two-stroke and four-stroke. Two revolutions are equal to one revolution of the crankshaft. If we talk about fuel, that is, both gasoline and diesel models.

As for the four-stroke version, it is installed in vehicles, and the two-stroke version is found in structures where weight and dimensions play the main role.

## Stroke Outboard Boat Motor

There are so many good and bad things said about 2-stroke outboard motors that only the lazy motorboat owner does not know about it. The two-stroke works in two piston strokes, which are obtained in one revolution of the crankshaft.

HOW DOES IT WORK? The entire working process of a 2-stroke engine consists of a compression stroke and a combustion stroke. As a result of the fire, the air-fuel mixture ignites and the crankshaft starts to move, after which the exhaust is pushed out of the cylinder.

Exhaust gases are removed at the same time as receiving a new portion of the engine charge. Such amicable cleaning and feeding of a 2-stroke outboard motor is called blowdown. And the main regularity of the unit is its filling, which consists in preliminary mixing of oil and gasoline.

A two-stroke outboard boat motor is the most common option offered to domestic shipowners by the water engine market. Due to the cost-effectiveness of the production of these units with good power indicators, Chinese manufacturers are actively supplying 2-stroke models of different power and configuration options.

• Practical;
• Compact;
• Lightweight;
• Diverse;
• Competitive oriented;
• Noisy;
• Requires increased accuracy and lean operation;
• Not environmentally friendly due to the combustion of a mixture of oil and gasoline.

## Features of the two-stroke

It was mentioned earlier that the main difference between these two engines is the ignition mode. A useful two-stroke process involves two phases: compression of the stroke and expansion. If in four-stroke engines the fuel is injected and the gases are released alternately in cycles, then two-stroke engines do this together with compression and expansion. The piston changes its position from the bottom position to the top dead position. After closing the air damper, through which the combustible-air mixture enters the cylinder and then into the exhaust compartment, it begins to compress. In parallel, the crank chamber restores the vacuum, which consumes fuel in portions. When the piston approaches TDC (top dead center), a spark is generated from a spark plug that ignites the mixture. As a result, gases are formed that move the piston downward and rotate the crankshaft.

The pressure in the crank chamber itself increases significantly, due to which the liquid mixture is compressed. Waste gases escape into the muffler when the piston seal touches the air damper. Further shifts open the damper, and the combustible mixture enters the cylinder due to pressure. The cycle starts again when the piston goes back to BDC (bottom dead center).

## The principle of operation of a brushcutter with a 4-stroke motor

How does a 4-stroke engine differ from a 2-stroke engine? The design of 4-stroke motors is more complex. In engines of this type, the process of filling the cylinder with a fuel and lubricant mixture, compressing it, igniting, working stroke and exhausting exhaust gases is carried out in 4 strokes.

• Inlet. The piston is in the lower position, the intake port is opened, gasoline enters the cylinder. As soon as the piston has reached the lower level, the intake valve closes.
• Compression. The piston moves up, both valves are closed. Gasoline is compressed. When the piston reaches the top position, the spark plug ignites the fuel.
• Working stroke. The heated gases expand, pushing the piston downward. Both valves remain closed.
• Release. The crankshaft rotates, the piston rises. The exhaust valve (muffler) opens, the combustion products go into the exhaust pipe.

These cycles take place in 2 crankshaft revolutions. The 4-stroke engine runs on gasoline only. The oil is poured into a separate reservoir.

## Fuel consumption

Combustion products in two-stroke power units are displaced by an air-combustible mixture. A small amount of working fluid escapes with the exhaust. In 4-stroke engines, the fuel burns out completely, therefore, the consumption of gasoline is less. 4-stroke grass trimmers are considered to be more economical to operate.

## Choice of grass trimmer: two-stroke or four-stroke

The gasoline grass trimmer is a useful device for summer cottages and personal gardens, farms, utilities and gardening. The lawn mower is designed to perform a wide range of tasks: mowing tall, tough grass, shrubs, young shoots, hay making, lawn maintenance, clearing thickets, etc. Gasoline units are more powerful and productive than electric models, they work autonomously.

The range of petrol trimmers is very wide and varied. Tools differ in technical characteristics, overall dimensions, configuration, reliability, price. The main criteria for the classification of a petrol brush include the type of engine. According to this parameter, all models are divided into 2-stroke and 4-stroke. Both have their pros and cons, which you should familiarize yourself with before buying a tool.

## Engine lubrication principle

4-stroke engines are equipped with two reservoirs, one for fuel and one for oil. 2-stroke engines run on a fuel / oil mixture. Before starting work, you need to prepare a working fluid by mixing a special two-stroke oil with gasoline in a ratio of 1:50 or 1:25. During operation, the mixture, which consists of gasoline, oil and air, circulates in the piston and crank chambers. The oil component of this mixture effectively lubricates rubbing parts, assemblies and mechanisms, ensuring their normal functioning. The oil burns along with the gasoline. Combustion products are removed along with the exhaust.

## Liter capacity

In 4-stroke engines, 1 working stroke is carried out in two crankshaft revolutions, in 2-stroke engines. 1 crankshaft revolution per 1 working stroke. Based on this, we conclude that a two-stroke engine should have a power 2 times greater than a four-stroke one. In practice, this indicator is only 1.5-1.8 times higher.

## Working principle of trimmers with 2-stroke engine

In 2-stroke power units, the procedure for filling the cylinder with a gasoline-oil mixture, its ignition and combustion, the working stroke, as well as the removal of combustion products is carried out in two cycles.

• The piston is directed upward, which entails the compression of the working mixture and its ignition.
• When gaseous substances expand, the piston is pushed downward. In this position, the windows located in the walls of the cylinder open. Combustion products are discharged through the exhaust duct.

This entire process is carried out in one crankshaft revolution. After the completion of the second cycle, the first is repeated again, and so on as long as the engine is running.

## Comparison of 2T and 4T by the main parameters

In 2T type engines, the cylinder filling and cleaning cycles coincide with the compression and expansion cycles of a gasoline-oil liquid. In this case, the location of the piston is near the dead zone at the bottom. Inlet and outlet openings are made in the walls of the cylinder. Through them, respectively, the inlet of the fuel-oil mixture and the release of combustion products are carried out. The design of a two-stroke power unit does not provide for a system responsible for the distribution of gases, therefore motors of this type are simpler and lighter than 4-stroke.

These cycles take place in 2 crankshaft revolutions. The 4-stroke engine runs on gasoline only. The oil is poured into a separate reservoir.

## The principle of operation of a two-stroke gasoline engine

When compressed, the piston moves from bottom dead center to top dead center. Two-stroke or four-stroke? Which outboard motor is better which is two or. After the purge window (2) is closed first, through which the fuel mixture enters the cylinder, and then the exhaust port (3), through which the exhaust gases exit, the compression of the air-gasoline mixture begins. At the same time, a vacuum is created in the crank chamber (1), which sucks in the next portion of fuel from the carburetor. When the piston approaches top dead center, the mixture ignites from a spark plug, and the resulting gases push the piston downward, rotating the crankshaft and doing useful work.

In the crank chamber during the working stroke, the pressure rises, compressing the fuel mixture that got there in the previous stroke. When the upper surface of the piston (its O-ring) reaches the exhaust port, the latter opens, releasing exhaust gases into the muffler. With further movement, the piston opens the scavenging port, and the fuel mixture under pressure in the crank chamber enters the cylinder, displacing the remaining exhaust gases (performing scavenging) and filling the space above the piston. Which electric grass trimmer is best for your garden? that cut, push-pull or. When the piston passes the bottom dead center, the working cycle is repeated.

Operational and design differences between two-stroke and four-stroke gasoline engines 2T or 4T? Advantages and disadvantages.

Lecture on the topic of 2-stroke and 4-stroke motors from the point of view of the consumer. Have questions?. go to the forum

## grass trimmer two-stroke or four-stroke which is better?

Differences between a two-stroke motor and a four-stroke

The working cycle of a gasoline engine (ICE) is a series of processes, as a result of which a portion of the effort (power) is made acting on the crankshaft of the engine. The working cycle consists of:

• filling the cylinder with a fuel consistency;
• its compression;
• inflammation of the consistency;
• expansion of gases and cleaning from their cylinder.

A stroke in an internal combustion engine is the movement of the piston in one direction (up or down). In one revolution of the crankshaft, two cycles are performed. The one in which the burnt gases expand and the necessary work is done is called the working stroke of the piston.

Engines in which the working cycle is completed in 2 strokes (one revolution of the crankshaft) are called two-stroke. Engines in which the operating cycle is completed in 4 strokes (two crankshaft revolutions) are called four-stroke. Two- and four-stroke engines can be both gasoline (carburetor) and diesel. What are the main operational and design features of gasoline two-stroke and four-stroke engines? What is the difference between a two-stroke and a four-stroke? To better understand this, you need to familiarize yourself with how they work.

## How to choose a grass trimmer, BUY a grass trimmer.

In a two-stroke engine, cylinder filling and cleaning are performed simultaneously with compression and expansion strokes. while the piston is near bottom dead center. For this, there are two openings in the cylinder walls. inlet or purge and outlet, through which the fuel mixture is injected and the exhaust gas is released. The two-stroke engine does not have a gas distribution mechanism with valves, which makes it much simpler and lighter.

Liter capacity. Unlike a four-stroke engine, in which one working stroke occurs for two revolutions of the crankshaft, in a two-stroke engine, the working stroke occurs at each revolution of the crankshaft. This means that a 2-stroke engine should have (in theory) twice the liter horsepower (power-to-displacement ratio) than a 4-stroke. In practice, however, the excess is only 1.5-1.8 times. This is due to the incomplete use of the piston stroke during expansion, the worst mechanism for releasing the cylinder from exhaust gases, the waste of part of the power for purging and other phenomena associated with the peculiarities of gas exchange of 2-stroke engines.

Fuel consumption. Outperforming the four-stroke engine in liter and power density, the two-stroke engine is inferior to it in terms of economy. The displacement of exhaust gases is carried out in it with an air-fuel mixture entering the cylinder from the crank chamber. In this case, a part of the fuel mixture enters the exhaust channels, being removed along with the exhaust gases and without performing any useful work.

There are two methods of mixing oil with gasoline. Simple mixing before filling the fuel tank and separate feeding, in which a fuel-oil mixture is formed in the inlet pipe located between the carburetor and the cylinder.

In the latter case, the engine has an oil tank, the pipeline of which is connected to a plunger pump that supplies oil to the inlet pipe in exactly the amount that is required depending on the amount of the air-gasoline mixture. The pump performance depends on the position of the gas feed knob. The more fuel is supplied, the more oil is supplied, and vice versa. The separate lubrication system for two-stroke engines is more advanced. With it, the ratio of oil to gasoline at low loads can reach 1: 200, which leads to a decrease in smoke, a decrease in the formation of carbon deposits and oil consumption. This system is used, for example, on modern scooters with two-stroke engines.

### 2 Cycle vs 4 Cycle trimmer: An In-Depth Comparison

In a four-stroke engine, oil is not mixed with gasoline, but is supplied separately. For this, the engines are equipped with a classic lubrication system consisting of an oil pump, filter, valves, pipeline. The role of the oil tank can be performed by the engine crankcase (wet sump lubrication system) or a separate tank (dry sump system).

When lubricated with a “wet” sump, pump 3 sucks oil from the sump, pumps it into the outlet cavity and then feeds it through the channels to the crankshaft bearings, parts of the crank group and the gas distribution mechanism.

When lubricating with a “dry” sump, the oil is poured into the reservoir, from where it is pumped to the rubbing surfaces by means of a pump. The part of the oil that flows into the crankcase is pumped out by an additional pump, which returns it to the tank.

There is a filter to clean the oil from wear products of engine parts. If necessary, a cooling radiator is also installed, since during operation the oil temperature can rise to high temperatures.

Since oil burns out in two-stroke engines, but not in four-stroke engines, the requirements for its properties vary greatly. Oil used in two-stroke engines should leave a minimum of ash and soot deposits, while oil for four-stroke engines should be stable for as long as possible.

Comparison of the main parameters of two-stroke and four-stroke engines:

• Liter capacity. 2-stroke engines have 1.5-1.8 times higher than 4-stroke engines.
• Specific power (ratio of power to engine mass). Also higher for 2-stroke.
• Providing fuel supply and cylinder cleaning. 4-stroke engines are equipped with a gas distribution mechanism, which is not available in 2-stroke engines.
• Profitability. Higher in 4-stroke, fuel consumption of which is about 20-30% lower than in 2-stroke.

## Comparison of two-stroke and four-stroke engine

Let’s compare the advantages of two types of engines in several parameters.

• Weight. The two-stroke engine weighs much less than its four-stroke counterpart, therefore it overloads the feed less.
• Dynamics. It also takes the lead for the two-stroke engine, which accelerates faster than the four-stroke.
• Price. Again, the first option is almost always cheaper.
• Repair and service. Fewer parts and simpler design allows owners of two-stroke engines to spend less money on maintaining the unit in working order.
• Reliability. The same simplicity of design ensures greater reliability and a long service life of a two-stroke motor, but the quality of a four-stroke device is also usually at its best.
• Noise level. The four-stroke engine is quieter.
• Fuel consumption. Also, owners of a four-stroke engine save on fuel.

This was the main difference between a two-stroke outboard motor and a four-stroke one. Usually, in a dispute, one of the arguments in favor of four strokes is that you do not need to mix gasoline with oil before refueling. We did not take this into account as an advantage, because there are two-stroke models that also do not need this procedure.

## The main differences between two-stroke and four-stroke internal combustion engines

One of the main differences between the units under consideration is the presence of a gas distribution mechanism on a 4-stroke engine. There is no gas distribution mechanism on 2-stroke devices. Instead, there are holes in the cylinder walls through which the finished fuel-air mixture is supplied, as well as the exhaust gases are removed.

Timing not only increases the weight and size of the engine, but also significantly affects its cost. The lack of timing leads to the fact that the engine has only two cycles of operation. The presence of channels in the cylinder walls leads to increased wear on the rings and the engine piston. That is why two-stroke engines have a short service life. Next, let’s look at the design differences between 2-stroke and 4-stroke motors.

• Fuel consumption. despite the fact that the two-stroke unit has a simple structure, in terms of gasoline consumption it loses to the four-stroke one. This is due to the number of measures. While a 4-cycle unit makes 2 revolutions of the crankshaft, while consuming one portion of fuel, a two-stroke engine makes only one revolution. The increase in fuel consumption is approximately 1.5 times. In addition, do not forget that the 2-stroke unit has an imperfect system, and during operation there is a loss of the fuel mixture thrown into the muffler. This is the part of the mixture that “flies into the pipe” when the piston moves upwards at the moment of compression
• Fuel type. 4-stroke engines run on pure gasoline, which is mixed with air in the carburetor. 2-stroke units operate on a mixture of oil and gasoline. The use of pure gasoline is unacceptable, which will entail a quick failure of the cylinder-piston group
• Lubrication system. many people know that it is on this principle that the units in question differ. The 4-stroke engine has a separate lubrication system, consisting not only of a container, but also an oil pump, filters and a pipeline. The lubrication system is not interconnected with the fuel delivery mechanism, which speaks not only of efficiency, but also a long service life. Two-stroke engines run on petrol and oil. The proportions of mixing gasoline with oil for chainsaw and lawn mower are described on the website. Gasoline, together with petrol, is fed into the engine, where the mechanism is lubricated. It should be noted that not all two-stroke motors have a common lubrication system, but there are also units with a separate mechanism, where mixing occurs automatically depending on the number of revolutions
• The type of lubricant or the difference between the oil for a two-stroke motor and a four-stroke one. For two-stroke engines, special oils of the “combustion” type are used. This oil is mixed with gasoline, and enters the KShM system, providing lubrication to moving parts. After that, the oil in the composition with gasoline enters the cylinder, where it ignites and burns. This oil is called two-stroke oil and is available in red or green color. Color does not play a big role, and indicates the use of additives in the composition. Four-stroke engines run on pure gasoline, since they have a separate mechanism responsible for lubricating the KShM. These motors use ordinary engine oil, which must not be mixed with gasoline and must not be poured into two-stroke units. This will lead to rapid clogging of the spark plug electrodes and failure of the internal combustion engine. It turns out that the difference between oil for two-stroke engines and four-stroke engines lies in consistency and composition. Combustible types of oils are used on 2-cycle internal combustion engines, which lubricate the entire system before burning

As for the lubrication system of four-stroke engines, it should be noted that they are of two types. with dry and wet sump. They differ in the way they are lubricated. In the wet type, oil is supplied from the crankcase to the KShM. The pump pumps oil from the crankcase, which is part of the engine.

On a dry sump ICE, a separate oil tank is used. From it the oil is pumped into the KShM system, providing lubrication of the parts. The accumulated oil is transported back to the tank using an additional pump.

Knowing the main structural and fundamental differences of the mechanisms under consideration, one should understand their advantages and disadvantages that both options have.

## Weight-to-power ratio

Two-stroke engines are better suited for applications that require quick, sudden bursts of energy rather than running smoothly over long periods of time. For example, a jet ski with a two-stroke engine accelerates faster than a truck with a four-stroke engine, but it is designed for short trips, while a truck can travel hundreds of kilometers before it needs rest. The short duration of operation of two-strokes is compensated for by a low mass-to-power ratio: such engines usually weigh much less, so they start faster and reach operating temperature. They also require less energy to move.

## What is the difference between a two-stroke engine and a four-stroke engine. comparative analysis

Comparison of a two-stroke engine with a four-stroke in the “khod” company Sale, tuning, repair of boats and boats Affordable All types of maintenance of boats and boats

## Application area

Four-stroke motors are installed on cars, tractors and other equipment. Light equipment, motor vehicles, boats, aviation models, etc. are equipped with power units that have two working strokes. The selection of the engine type is carried out based on its design features.

Two-stroke power units are simple in design. The device of the power unit includes a minimum number of parts. This helps to reduce the cost of overhaul and reduce the total weight of the power plant. The motor can be repaired by a person with minimal technical knowledge.

REFERENCE: The absence of a gas distribution mechanism eliminates the need to adjust the thermal gap.

## Which motor to choose?

The final decision is always yours, in this article we just tried to give an objective assessment of these motors, so weigh the pros and cons of the above and make your choice yourself. An unequivocal answer to the question: which of the motors is better you will not find in any of the books on any of the forums, it all depends on what you want from the motor you are purchasing, the conditions for its use and, of course, your capabilities.

## Manufacturers overview

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 quite powerful and have a high technical level. If you carry out competent maintenance of this equipment and carefully operate it, then grass 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 believe that they will only use a trimmer at the dacha a couple of times over the summer, so it makes no sense to purchase a high-quality, but more expensive lawn mower from a well-known manufacturer. In general, such an opinion has the 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 grass 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 is STIHL FS 38. A distinctive feature of this model is its low weight. 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 that doesn’t mean you have to constantly refuel your grass trimmer. The manufacturer tried to reduce gasoline consumption 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 a rather narrow line in the kit. Therefore, it is better to immediately replace it with a thicker one.

Another noteworthy model is the Husqvarna 128R. It is distinguished by a rather 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.

In addition, the model has a very low noise level, which will allow you to work even in the evening, without creating discomfort for others.

## Engine features

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 lawn mower engine at its lowest point opens the intake valve, which allows the piston that moves upward to push the gases that have already been exhausted out of the cylinder. When the piston reaches the top position, the valve closes and everything repeats again.

## Comparison with push-pull

If we compare two-stroke and four-stroke motors for brushcutters, then we 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 indicates a higher liter capacity. about 1.6-1.8 times for a two-stroke model.

In terms of fuel consumption, the four-stroke analogue is inferior to the two-stroke analogue in efficiency due to the fact that part of it during operation enters the exhaust channels and is removed along with the gases, without performing useful work.

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.

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

Mowing grass for every owner of a country or private house is an important process, it allows you to give your site an aesthetic appearance. This is usually done with a thing like a four-stroke gasoline grass trimmer. Let’s try to figure out what kind of devices they are and how justified their use is.

## Criterias of choice

First, you need to decide how often the lawn mower will be used and how complex the work is planned for it. The power and performance of the grass scythe 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 grass 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 the 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 net weight of the grass trimmer can be up to 10 kilograms. But here it will also be important whether the model is equipped with a so-called knapsack suspension. If we are talking about periodic use, then the simple straps, which are equipped with almost every model, are enough.

In addition, one should take into account such physical parameters 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 equipment 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. Easy startup of the device will be equally important. If you have to spend a lot of time to start the lawn mower, then you should think about whether you need it at all.

By the way, the launch mechanism is one of the most vulnerable systems of such devices, which have a low cost. Therefore, it may be useful to make a choice in favor of a slightly more expensive model, where there will be no such problem.

## Operating tips

When working with such equipment, it is necessary to use only high-quality and special engine 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 is that you should not neglect to read the operating instructions, because there you can find a lot of tips for working with a specific model of grass trimmer. 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 subsequent failure.

In addition, the device should be serviced from time to time to keep it operating at a high level.

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