Trimmer Two-Stroke Or Four-Stroke Which Is Better
All the cons of electric trimmers
But you need to take into account some of the features of trimmers, which are often counted as disadvantages by them:
- Mobility is limited to network cable. But for a small lawn, this is not a problem.
- Engine power is lower than that of gasoline. In most cases, the trimmer is equipped with a 1 or 2 kW electric motor. Modern electric motors are reliably protected from overheating and from voltage drops in the network. They can work for a long time and efficiently without interruption.
- The trimmer can only be operated with a line. That is, it is most effective on soft and succulent grass. Attaching a cutting blade or disc to the trimmer will greatly increase the load on the engine, which can be damaged. And the connecting cable (in the curved bar) bursts right there. But a strong and well-tucked fishing line is not so bad: only with a fishing line you can carefully, almost jewelry mow the grass in hard-to-reach places: for example, mow curbs or trees (the line will not damage the trunk).
Petrol Lawn Mower vs. Electric Trimmer: Which Is Better? Trimmer price and lawn mowers performance: their main advantages
The lawn mower belongs to the category of those tools, the sales of which are gaining momentum every day. Banal envy of a neighbor who easily brought his lawn or plot into a picture from a landscape design magazine is becoming the driving force behind the popularity of lawn mowers. In addition, the recently developed lawn mower models are striking in their variety and design perfection.
Trimmers. ideal for small lawns
In addition to the well-known to the consumer and well-tried in business, lawn mowers running on a gasoline engine, the world’s leading brands today present to the market lightweight, almost weightless electric scythes. Trimmers.
The main trump card of trimmers, of course, is their price. The design of an electric motor is so simple that it costs several times cheaper than a gasoline one, which significantly affects the price of lawn mowers.
The advantages of the electric trimmer include the lightness and strength of the structure, the absence of a heavy fuel tank and the constant need for refueling with gasoline and oil. As a result. quietness and environmental friendliness. The handle of the trimmers is predominantly D-shaped, which allows you to grip the lever tightly with your palm. The vibration of the electric motor is almost not felt. Curved bar, adjustable to the user’s height.
And also, the trimmer is very convenient. If a knapsack belt from a gasoline scythe rubs and cuts your shoulders, your hands cannot withstand vibrations, your head cannot withstand engine noise, and the smell of burning and oil inherent in internal combustion engines. Unbearable, lightweight electric trimmer. just right for you.
There are no barriers to the lawn mower cutting system in the garden
Decide if your territory is large and how often you cultivate it. This is the first thing. It is clear that for mowing tall and tough grass in large areas you need a powerful gasoline scythe, equipped with a robust engine and a good cutting system (metal disc or knife).
The second is the presence of a power grid in the area. If there is no electricity at all, or interruptions to it are quite frequent, then, naturally, a good gasoline lawn mower will suit you.
Engine noise, vibration, the smell of burning oil and an uncomfortable cutting belt are the most popular accusations that fly towards the gasoline spit. But modern technological advances make it possible to reduce these inconveniences to zero.
The Better Gasoline Lawn Mower
First, there are two-stroke and four-stroke engines. Existing two-stroke engines from leading world brands, such as Hyundai, Makita, Honda, are covered with a noise-reducing casing, they have an excellent carburetor, there is no “shock-recoil” effect when starting, vibration is almost imperceptible. The four-stroke engine makes virtually no noise or vibration. He has a large motor resource. It is light, does not give off a burning and oil smell, since oil and gasoline do not mix in it. At the gearbox. Increased torque.
Secondly, all gasoline braids in the kit have a cutting system. a metal knife (2-3 or 4-toothed), which easily cuts tall or dead grass in the garden area. You can also use a saw blade of different diameters to cut shrubs and young trees.
Thirdly, the lawn mowers running on gasoline. Rigid, forged shaft (collapsible) for increased structural reliability, easily adjusts for height and even makes mowing easier by placing the cutting attachment parallel to the ground.
Fourth: the straps of the petrol braids are now comfortable, like a "knapsack". They do not bump into the shoulders and do not rub, but on the contrary. Relieve stress during work and do not allow the spine to overwork.
Detailed technical characteristics of powerful gasoline lawn mowers and light electric trimmers can be found on the website of the Internet hypermarket of garden equipment "S Torgom".
How the four-stroke gasoline engine works
When inlet, the piston goes from top dead center (TDC) to bottom (BDC). At the same time, using 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, when burned, forms combustible gases that push the piston down. A working stroke occurs, in which useful work is performed.
After the BDC piston transitions, the exhaust valve opens, allowing the upward-moving piston to push the exhaust gases out of the cylinder. Release in progress. At TDC, the exhaust valve closes and the cycle repeats again.
The principle of operation of a two-stroke gasoline engine
When compressed, the piston moves from bottom dead center to top dead center. After the purge window (2) closes 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 the top dead center, the mixture is ignited by a spark from a candle, 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 window, 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. When the piston passes the bottom dead center, the working cycle is repeated.
Differences between a two-stroke engine and a four-stroke engine
The working cycle of an internal combustion engine (ICE). It is a series of processes that result in a portion of the force (power) acting on the engine crankshaft. The working cycle consists of:
- Filling the cylinder with a fuel mixture;
- Her compression;
- Mixture ignition;
- Expansion of gases and cleaning the cylinder from them.
ICE clock. This is the movement of the piston in one direction (up or down). For one revolution of the crankshaft, two cycles are performed. The one in which the burnt gases expand and useful work is performed is called the working stroke of the piston.
Engines in which the operating cycle takes 2 strokes (one revolution of the crankshaft) are called two-stroke. Engines in which the operating cycle takes 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.
Operational and design differences between two-stroke and four-stroke gasoline engines
In a two-stroke engine, the cylinder is filled and cleaned simultaneously with the compression and expansion strokes. While the piston is near bottom dead center. For this, there are two holes in the walls of the cylinder. Inlet or purge and outlet, through which the fuel mixture is inlet and 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 is performed with 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 by an air-fuel mixture entering the cylinder from the crank chamber. In this case, part of the fuel mixture enters the exhaust ducts, being removed along with the exhaust gases and not performing useful work.
Lubrication. Two-stroke and four-stroke engines have different engine lubrication principles. In 2-stroke models, it is carried out by mixing engine oil with gasoline in certain proportions (usually 1: 25-1: 50). The air-fuel-oil mixture, circulating in the crank and piston chambers, lubricates the connecting rod and crankshaft bearings, as well as the cylinder mirror. When the fuel mixture ignites, the oil in the form of tiny droplets burns along with the gasoline. The products of its combustion are removed together with the exhaust gases.
There are two methods of mixing oil with gasoline. Simple mixing prior to filling the fuel tank and separate feeding, in which a fuel-oil mixture is formed in the intake 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 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.
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, and a pipeline. The role of the oil tank can be performed by the engine crankcase (lubrication system with a "wet" sump) or a separate tank (system with a "dry" sump).
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 supplied to the rubbing surfaces using 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.
| Engine | Number of measures | Power, hp. | Fuel consumption (gasoline), kg / hour |
| BriggsStratton | 4 | 3.5 | 0.9 |
| Minarelli | 2 | 3.5 | 1.5 |
| Tecumzeh | 4 | 3.7 | 0.9 |
| BriggsStratton | 4 | 5.0 | 1.0 |
| Tecumzeh | 4 | 5.0 | 1.0 |
| BriggsStratton | 4 | 6.0 | 1.1 |
| Lombardini | 4 | 7.0 | 1.6 |
| Minsel | 2 | 7.0 | 2.1 |
- Lubrication system. Oil for 2-stroke engines is diluted in gasoline or (much less often) is fed from the oil tank to the intake manifold and burns along with the fuel in the piston chamber. 4-stroke engines have a complete system that ensures high-quality engine lubrication and long-term oil use.
- Environmental friendliness. The 4-stroke is higher. The exhaust of 2-stroke engines is more toxic.
- Noisy work. 4-stroke engines are quieter.
- The complexity of the design. 2-stroke engines are much simpler than 4-stroke engines.
- Resource of work. Higher in 4-stroke due to a more perfect lubrication system and lower crankshaft speed.
- Speed of revving. 2-stroke engines pick up speed faster.
- Service. It is more difficult for 4-stroke ones due to the presence of a gas distribution mechanism and a more complex lubrication system.
- Weight. 2-stroke is much lighter.
- Price. 2-stroke cheaper.
Due to their high power density, light weight, ease of maintenance, two-stroke engines have a fairly wide range of applications. With regard to some petrol equipment, the question is which engine to use. Two-stroke or four-stroke. Doesn’t even arise. In chainsaws, for example, a two-stroke engine, due to its low weight and high power density, is out of competition compared to a four-stroke engine. 2-stroke engines are also widely used in scooters, motor vehicles, aircraft model building.
And yet, due to the toxicity of the exhaust and noise, 2-stroke engines are losing ground in front of 4-stroke ones. Their greater competitiveness is possible with the use of new technological solutions. Such, for example, as the idea of Aprilia and Orbital companies to use clean air to purge a two-stroke engine. The fuel in their model is fed through a nozzle located in the engine head and oil is added to the purge air. Such an engine even surpasses a four-stroke in terms of efficiency, its environmental friendliness also meets modern requirements. This is just the main advantage of 2-stroke engines. The simplicity of their design. Suffers somewhat from innovation.
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) closes 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 the top dead center, the mixture is ignited by a spark from a candle, 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 window, 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 trimmer is best for giving? What is 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
Two-stroke or four-stroke trimmer which is better? Trimmer two-stroke or four-stroke which is better?
Differences between a two-stroke engine 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;
- Her compression;
- Flaming consistency;
- Expanding 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). For one revolution of the crankshaft, two cycles are performed. The one in which the burnt gases expand and the necessary work is performed 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 takes 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 trimmer, BUY TRIMMER.
Even more information about repair and selection of tools on our website www.Looktool.Ru visit we are glad to everyone.
In a two-stroke engine, cylinder filling and cleaning are performed simultaneously with the 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 is performed with 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 by an air-fuel mixture entering the cylinder from the crank chamber. In this case, part of the fuel mixture enters the exhaust ducts, being removed along with the exhaust gases and not performing useful work.
There are two methods of mixing oil with gasoline. Simple mixing prior to filling the fuel tank and separate feeding, in which a fuel-oil mixture is formed in the intake 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 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.
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, and a pipeline. The role of the oil tank can be performed by the engine crankcase (lubrication system with a "wet" sump) or a separate tank (system with a "dry" sump).
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, oil is poured into a reservoir, from where it is supplied to the rubbing surfaces using 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.
So which motor is better. two-stroke or four-stroke?
What can you add to the tons of material written on this topic? Another commonplace?
Nevertheless, having stumbled upon another forum battle in the framework of the permanent war of "pointed and blunt points", I decided to speak out and give some figures.
Let’s try to figure it out quickly.
Pros of four-stroke outboard motors
- Less noise during operation (especially at low revs);
- Less fuel consumption.
Not all 2-stroke engines require petrol and oil to be mixed first. Therefore, the absence of this procedure during the operation of 4-stroke units, I did not write them down as an advantage. I also do not cite the traditional argument about the stunning resource of 4 bars due to the lack of both strong evidence of this statement and the irrelevance of this problem for the overwhelming number of motorboats.
He also did not mention anything regarding the environmental friendliness of engines. This is not relevant for now. Good or bad, but the question is not put bluntly, and there is no reason to think that in the near foreseeable future something will change here.
Dry residue
So, when asked why should we overpay so much for four clock cycles, it turns out, we can answer: "It is quiet and economical.".
Now let’s decide if this "quiet and modest girl" is worth the cost of the wedding?
It is easy to talk about "silence" to a person who is not familiar with the subject of discussion. Yes, at low rpm, up to 1000-1200, the four-stroke is quiet, and at idle it is even almost inaudible. I remember a couple of times, at first, the already working engine tried to start with a key. # 128578;
However, everyone who has exploited both 2-ton and 4-ton PLM will tell you that starting from 4000 rpm. The difference in noise disappears and becomes insignificant towards the upper limit of the maximum.
If it is significant (there are also "tractors" among 2-stroke engines), how long do we listen to the noise of our engine? Most of the rest / departure, the engine is muffled.
But low noise was never the decisive argument of the apologists of the four bars. The concrete argument in the dispute with thinkers from the opposite camp has always been economy.
The economy must be economical
Four-stroke engines consume less gasoline. and this is an indisputable fact. Less gasoline. less loading of the boat, less cost of departure.
However, 4-stroke engines of the same power are usually heavier and more expensive than their 2-stroke counterparts. Thus, whatever one may say, we must know:
- Does the fuel economy pay off the high cost of the motor itself;
- Does the difference in the weight of the required fuel compensate for the difference in the weight of the motors.
Yamaha, like some other manufacturers, publishes messages with the results of evaluating the performance of their PLMs. This information is freely available on the Internet at http://yamahaoutboards.com/owner-resources/performance-bulletins
To assess the economic effect of using a four-stroke engine, I needed data on the consumption of a pair of 2-ton and 4-ton PLM with the same number of horses. I chose two medium power engines:
- 2-t: Yamaha 50TLR (we know as Yamaha 50HETOL).
- 4-t: Yamaha F50TLR (we have Yamaha F50HETL).
The two-stroke "fifty kopeck piece" was tested on the Sundance FX 17 Flicker boat (length 5.21 m; width 1.98 m; gross weight during tests 710 kg).
Four-stroke. on Key West 166 SK boat (length 4.95 m; width 1.83 m; gross weight when tested 623 kg).
Please note that the boat on which the two-stroke is mounted (Sundance FX 17) is slightly longer and wider than the other and is also heavier by 83 kg. But these are the closest in parameters and type of watercraft that I was able to find for a given power. Okay, let’s give a little head start to four bars. # 128578;
The test results were as follows:
| rpm | speed km \ h | consumption l \ h | consumption l \ 100 km | rpm | speed km \ h | consumption l \ h | consumption l \ 100 km |
| 1000 | 6.28 | 1.89 | 30.16 | 1000 | 6.44 | 1.51 | 23.52 |
| 1500 | 8.53 | 3.41 | 39.94 | 1500 | 7.72 | 2.27 | 29.40 |
| 2000 | 10.94 | 4.54 | 41.51 | 2000 | 9.17 | 3.79 | 41.27 |
| 2500 | 12.07 | 6.44 | 53.32 | 2500 | 11.59 | 4.92 | 42.47 |
| 3000 | 19.31 | 7.95 | 41.16 | 3000 | 16.74 | 6.81 | 40.71 |
| 3500 | 29.29 | 9.46 | 32.31 | 3500 | 28.97 | 6.81 | 23.52 |
| 4000 | 37.82 | 10.98 | 29.03 | 4000 | 35.89 | 8.71 | 24.26 |
| 4500 | 44.42 | 11.73 | 26.42 | 4500 | 42.16 | 10.60 | 25.14 |
| 5000 | 51.98 | 16.28 | 31.31 | 5000 | 46.99 | 13.25 | 28.19 |
| 5500 | 57.78 | 21.58 | 37.35 | 5500 | 51.34 | 17.79 | 34.66 |
| 5600 | 58.26 | 21.96 | 37.69 | 5950 | 54.88 | 18.93 | 34.49 |
Let’s transform the table a little so that we can operate with both absolute and relative values:
| Rpm | consumption, l \ h Yamaha 50 | consumption, l \ h Yamaha F50 | difference in consumption,% |
| 1000 | 1.89 | 1.51 | 25.00 |
| 1500 | 3.41 | 2.27 | 50,00 |
| 2000 | 4.54 | 3.79 | 20,00 |
| 2500 | 6.44 | 4.92 | 30.77 |
| 3000 | 7.95 | 6.81 | 16.67 |
| 3500 | 9.46 | 6.81 | 38.89 |
| 4000 | 10.98 | 8.71 | 26.09 |
| 4500 | 11.73 | 10.60 | 10.71 |
| 5000 | 16.28 | 13.25 | 22.86 |
| 5500 | 21.58 | 17.79 | 21.28 |
RPM range from planing to
5000 is preferable for the boatmaster who does not like to drag in half-gas, but does not intend to spend too much. Golden mean. And in this range, the four-stroke, as you can calculate, consumes on average 20.27% less than its two-stroke counterpart. In absolute terms, this savings will be approximately 2.65 l / h. By this amount, the F50 will consume less gasoline, operating at optimal speed.
Let’s count the money now. I will make a reservation right away, I do not take into account oil for 2 tons and oil and 2 filters for F50. The introduction of these variables into the calculation will not greatly affect the final result, but for F50, in this case, you will have to build a whole graph of the function.
So, let’s count gasoline. At the time of this writing, the cost of the "participants" in the test was as follows: Yamaha 50HETOL. 346,000 rubles, Yamaha F50HETL. 423,000 rubles. The four-stroke costs 77,000 rubles. expensive, but it saves gas.
So we decide to bet on savings. Let’s calculate when our "investments" for a start will simply return to us.
As already mentioned, for a given pair of engines, gasoline savings are
2.65 l / h in favor of the F50. The cost of the 92nd gasoline at the time of writing
36 rubles \ l. Let’s translate liters into money: 2.65X36 = 95.4. So, the average savings in rubles per hour will be 95.4 rubles.
Let’s calculate how many hours we need to return the money overpaid for a four-stroke engine on the saved gasoline:
807 hours! Do you feel the swing? This is exactly how much the F50 should work so that the overpayment when buying, in comparison with the 50 2-t, is completely returned to your pocket.
What is 807 m3 / h? I think you will not mind that there are not many people who roll more than 50 hours per season. And this is still quite optimistic. I personally have not even gained 40 lately. We count the seasons: 807: 50 = 16.14. Think about this figure: 16 years! So much time must pass for the difference in the cost of the considered pair of motors to pay off.
And this is an economical motor!?
Benefits
What are the advantages of 4 and 2-stroke engines?
Pros of two-stroke outboard motors
- Less weight;
- Better dynamics;
- Lower price;
- Ease of maintenance and repair (as a consequence of the simplicity of the design);
- Greater reliability (also as a consequence of the simplicity of the design);
Engine features
The main feature of such a motor is that here the work cycle is carried out in 4 cycles. 2 crankshaft revolutions. Here the piston is simply lowering from the dead center upwards downwards. At this moment, the intake valve is opened by 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 mowers engine at the lowest point opens the intake valve, which allows the piston that moves upward to push out the gases that have already been exhausted from the cylinder. When the piston reaches the upper position, the valve closes and everything repeats again.
Comparison with push-pull
If we compare two-stroke and four-stroke engines for lawn mowers, 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 with each revolution of the crankshaft, and in the considered model, by 2 revolutions. In practice, this indicates 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 power density is also higher;
- In terms of fuel supply and cylinder cleaning, four-stroke ones 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 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 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.
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 have a fairly good capacity 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 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 exist 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 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 this does not mean that you have to constantly refuel the 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 the 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 model worth considering is the Husqvarna 128R. It is distinguished by a rather high power. She will perfectly cope even with serious loads. The 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 lawn mower. 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.
Criterias of choice
To begin with, you need to decide how often the lawn mower 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 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 a priority. The trimmer’s net weight 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 that are equipped with almost every model are enough.
In addition, one should take into account such physical parameters as the type of 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 it is needed at all.
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 perform its functions well.
Another important point is that you should not neglect reading the operating instructions, because there you can find a lot of tips for working with a specific trimmer model. This will significantly improve the efficiency of its application. Another aspect is that 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.