How to Install a Piston on a Trimmer

Lush vegetation between houses in a residential quarter or cottage can clutter paths and areas under fences. Unlike a neat lawn, tall grass looks ugly. At enterprises, uncut areas of greenery create an unfavorable impression. To correct this situation, use lawn mowers. But due to their limited maneuverability and high cost, not everyone can afford to buy it, especially in the country or in the public utilities. Now there are their lightweight counterparts – grass trimmers that can do the same job, but are more compact and inexpensive. To correctly choose this garden tool, you need to know the main types of trimmers and what parameters they must meet in order to cope with grass on a specific landscape.

How to Install a Piston on a Trimmer

The best trimmer manufacturers. Which company to choose

Good trimmers are produced by companies that have proven themselves in the high-quality manufacture of other electric and gasoline tools.

Those who do not have time to delve into the features of this product can be recommended to purchase a device from any of the companies in the following list:

  • Echo;
  • Bosch;
  • Makita;
  • Stihl;
  • Triton.

For those who want to see the advantages and disadvantages of specific models from these brands, a corresponding article has been written with a detailed review. Well, for those who want to understand everything on their own, the parameters and features of this garden tool are given below.

The principle of operation and the device trimmer for grass

The grass trimmer is a garden tool for cutting green vegetation with a soft stem and not thick dead wood. Unlike lawn mowers, the devices have a small weight and are worn by the operator on belts, and do not roll on wheels on the ground. Light weight makes it easy to transport the devices to the place of work and quickly move from site to site.

Using the cutting part of the trimmer, you can:

  • Maintain a low grass height on the lawn;
  • Mow it between houses and along paths;
  • Remove deadwood thickets near the carriageway;
  • Cut vegetation directly under the fence;
  • Cultivate the green shores of ponds.

Trimmers have a low cost, unlike lawn mowers, and increased maneuverability makes them more convenient to use. Both residents of the private sector and utilities, as well as enterprises, buy such an instrument in order to take care of the existing territory.

The operation process of the garden tool consists in putting the case on the operator’s body through special belts. The trimmer head is brought to the grass and the button on the handle starts the engine. Torque is transmitted to the bobbin through a rigid shaft in the apparatus tube. The head contains a cutting element that cuts grass stems at high speed.

To prevent impacts on solid objects and sticks flying out in the face, a protective casing is provided, covering 40% of the circumference of the diameter of the action of the cutting part of the tool.

Most modern trimmers have the following device:

1. Motor (electric or gasoline);

2. Fuel tank (in the case of an internal combustion engine);

4. Handle for direction (1-2 pcs);

5. A rigid shaft for transmitting rotation from the motor;

6. A bobbin with a cutting element (fishing line or knife);

7. Protective cover;

8. Belt fastening.

Types of Grass Trimmers

The cutting unit of the trimmer has a removable or non-removable design. Depending on this, the functionality of the models differs. But all trimmers are divided into three categories.

Electric trimmers

This type of tool works from a household network in 220V. The electric motor rotates the shaft and starts the cutting mechanism. To use the device, a power outlet and carrying device must be nearby. This partially hampers the maneuverability and scope of the tool, but allows you to work silently.

Still, such a device has no harmful emissions into the atmosphere. Such models are well suited for summer cottages and private firms with a small territory, where you can get by with one carrying coil.


  • Lungs;
  • Make little noise and do not interfere with neighbors;
  • Inexpensive;
  • There are powerful models;
  • No harmful emissions;
  • Handle height adjustment;
  • The possibility of setting different knives.


  • Inconvenience from a wire that can be accidentally cut;
  • Limited area to carry length.

Petrol trimmers

The principle of operation of this type is similar to electric, but the rotation here is provided by an internal combustion engine. To do this, an additional tank with fuel is attached to the rod, as a result of which the device receives a large mass.

With such a tool, you can freely move around the territory and even work where there are no buildings and electricity. There is no need to constantly remember the cord and be careful not to cut it. It is actively used for mowing grass on the sidelines, maintaining the beautiful condition of yards in high-rise areas and on the territory of large enterprises.


  • Powerful models;
  • Replacement of knives;
  • No area restrictions;
  • High performance;
  • Robust construction;
  • Wide area of ​​commercial use.


  • Heavy;
  • Additional fuel costs;
  • More noise;
  • Air emissions.

Cordless Trimmers

A less common type of garden tool is trimmers working with an electric motor, but on battery power. This allows you to cut the grass all the same silently, but not depend on the length of the carry.

Due to limited time use, such models are bought for caring for country houses where there is no electricity or for landscaping kindergartens and similar institutions.


  • Silent
  • Setting up different cutting systems;
  • No area restrictions;
  • Lungs;
  • The energy reserve is enough for 30-45 minutes;
  • Fast charge;
  • Powerful models are available.


  • Runtime is limited by battery capacity;
  • Are more expensive than electrical.

Grass trimmer selection options

Understanding the key features of a garden tool, you can choose a model that is well suited to specific tasks and does not cause unexpected problems. Here are the main options for choosing grass trimmers.


The trimmer power rating is indicated in kW and affects performance. The higher this value, the faster the cutting element will rotate and the larger the area will be processed.

1. Garden tools can have a small indicator of 0.25 kW and reach 1.8 kW.

2. For utility services to care for the adjacent territory in the quarters and along the roads along the roadsides, where you have to work all day and mow large volumes of grass, it is advisable to purchase models 0.9-1.8 kW.

3. For giving and caring for a small lawn, an engine with parameters of 0.25-0.7 kW is enough.

Video: How to Install a Piston on a Trimmer

Cutting width

The length of the knife and the possibility of maximum extension of the fishing line affect the width of the cut. The last parameter is limited by the dimensions of the protective casing. There are various models whose range can be from 200 to 420 mm.

1. For continuous lawns over a large area, trimmers with a cutting width of 300-420 mm are suitable.

2. 250-270 mm are enough for a summer cottage and care for the blocks of high-rise buildings.

The mass of the device affects the usability and operator fatigue. The weight of the tool varies from 1.5 to 9 kg. Of course, it’s logical to take models lighter for long-term employment, but often this involves remote work from the mains, which requires the most severe gasoline models.

1. If you can connect to the mains, you should buy electrical devices weighing 3-5 kg.

2. For the cottage, an option of 2.5 kg is suitable.

3. If it is impossible to connect to the mains, you should buy gas trimmers with a weight of 7-9 kg.


Another performance indicator is the cutting speed of the cutting element in one minute.

1. In low-power versions, this parameter is not prescribed because there they are below 7000 per minute.

2. More professional models have an acceleration of 7,500-12,000 rpm.

3. For a summer house or a small business, 6000 rpm is enough.

4. For large volumes of work, 9000-12000 rpm is required.

Diameter of fishing line

This indicator varies from 1.4 to 3.3 mm and indicates the ability of the cutting element to cut through a certain thickness of the stem and branches of the bush.

1. 1.4-2 mm is enough for a country courtyard, which will allow you to remove grass and maintain a neat appearance of lawns.

2. Workers who monitor the condition of the curb, where dense grass often grows, need to purchase 2.4-2.7 mm.

3. To improve the neglected area, a strong fishing line of 3.0-3.3 mm is required, capable of dissecting the stiffened stems and bushes.

Cutting system

Trimmers work by rotating the cutting elements, which can be solid knives (metal, plastic) or soft fishing line (cord).

1. Thick knives are more suitable for a flat open landscape and dense grass with hard stems. The tool will create an even cut. This type is practical for lawn care along businesses and next to a private home.

2. The fishing line is necessary in case of work on hilly terrain and near fences. Beating against solid obstacles will not cause damage, and contact with the ground will not stop the process. But such trimmers do poorly with dense vegetation and get confused.

Type of fastening

To operate the device, it is hung on the operator’s case. For this, one or two belts are provided.

1. The use of a trimmer with a single belt is used to give or ennoble a small area of ​​the company.

2. In the case of a large area, a satchel mount will be required to evenly distribute the load and reduce vibration.

Hold comfort

The shape and number of handles, as well as the balancing of the device, are responsible for this.

1. The main and auxiliary handles are convenient for short use in a garden or a small company. To work all day, it is better to purchase models with a cross frame and two equivalent handles.

2. The position of the engine below the cutting part increases the load on the back and is suitable for mowing only for several hours. If the engine is installed at the top of the rod, this makes it easier to control the tool and is suitable for professional use.

Tank volume and battery capacity

In the case of autonomous fuel trimmers, tank capacity plays an important role. It happens from 0.3 to 1.5 liters. Manufacturers calculate its volume based on the capabilities of the engine to work continuously for a certain amount of time.

1. With a minimum tank, it will be possible to mow for 20 minutes, after which a stop for a break will be required to cool the motor and refuel.

2. It is possible to work with a maximum rate for more than an hour, which is convenient for commercial use in large areas.

For battery models, the battery is measured in amperes / hours. 1st unit A / h is enough for 15 minutes of work. Charging will require three times as much time.

1. For cosmetic care of a small lawn away from the outlet, 2 A / h is enough.

2. To care for the territory of a kindergarten or a small company, 3-4 A / h are required.

What grass trimmer to choose

1. To work on uneven terrain along the fence, you need a device with a fishing line of 2.7 mm thick. For productivity, a cutting width of 250 mm and a speed of 7500 per minute are sufficient. The device will be more convenient to control with two equivalent handles. If the size of the territory allows you to use an extension cord, then it is better to purchase a model with an electric motor.

2. In utilities, on the balance of which there is a large territory with paths and courtyards, as well as road services, you will need a trimmer working on gasoline with a tank of 1.5 liters, 12000 rpm, with a power of 0.9-1.6 kW, 300 mm wide and 3.0 mm thick fishing line.

3. For a large private area or enterprise with green areas, you must buy a garden tool with a 1 kW internal combustion engine, 10,000 rpm, an iron blade or fishing line 2.4 mm and a cut width of 420 mm.

4. In a small courtyard to the cottage, an electric model with a power of 0.25 kW, 6.500 rpm, a fishing line thickness of 1.4-2.0 mm, and a zone coverage of 250 mm across the cut width is sufficient. The mounting method is suitable for one belt with a lower engine.

5. To care for the territory of kindergartens, boarding schools and recreation centers, it is practical to buy battery versions that silently perform their functions over a vast territory. A model with a power of 0.7 kW, a battery capacity of 3 A / h, 7500 rpm and a fishing line of 2.0 mm is suitable.

How much does a grass trimmer cost

1. To work on the hilly terrain and along the fences, the model will cost 3200 – 7000 rubles.

2. Trimmers for 10,000-14,000 rubles are purchased in utilities.

3. To care for the green territory of companies, the tool will cost 15,000-20000 rubles.

4. To give the model start at 1200 rubles.

5. In kindergartens and recreation centers, a battery-powered device will cost 3,000–25,000 rubles.

Would you like to receive current ratings and selection tips? Subscribe to our Telegram.

One of the most serious scooter failures is the failure of the cylinder-piston group, which immediately makes the scooter inoperative. It is the CPG of the scooter that is responsible for its movement, the slightest damage will lead to the impossibility of further movement. That is why if you encounter a non-working piston, immediately take care of its repair.

In general, any CPG has a certain lifespan, with a certain mileage its wear increases and the buyer will have to replace the part. Often enough to replace the piston, but sometimes more serious problems occur. Where you have to change the piston, rings and cylinder. Depending on the model of scooter and manufacturer, the installation may be slightly different, but we will consider the basic steps. Also, piston scooters may vary in power, but this does not affect the replacement process.

CPG removal

If you don’t know how to properly install the piston on a 2t or 4t scooter, first remove the old part. To get to the piston group is not easy, you have to disassemble the scooter, and sometimes remove the plastic. In general, the steps to replace the CPG are as follows:

  1. Removing the engine, disconnecting the wires;
  2. Removing the old piston;
  3. Installation of a new part as required;
  4. Similar assembly of the engine and the connection of electrics and hoses.

After you have disconnected all wiring and made sure that the oil and benzo hose are closed, remove the engine. In different scooter models, the removal of the engine may be different, so proceed according to the situation. Having received the finished engine, start to remove the plastic cylinder cover, it protects the CPG from external dirt, dust, etc. The next step is to remove the cylinder head. Depending on the type of scooter (2t or 4t), the head can be more complex, 4t scooters also have valves, which will then have to be adjusted. But the procedure for removing the head occurs by loosening 4 nuts.

Important: The nuts must be loosened gradually using a cross-wise method. That is, as shown in the picture below. Otherwise, you will break the threads and the piston will be damaged. This also applies to the installation of a piston, the nuts are tightened as well.

Then you have to remove the cylinder, in some cases it is problematic to do this due to the large formation of soot or a piston defect. If the cylinder is whole, but the piston is defective, proceed to replacing the piston. How to install the piston on a scooter

Replacing the piston involves a number of difficulties, because the piston will come with a few more basic parts. In the kit you will find snap rings, a finger and several rings (depending on the scooter – 2t or 4t). In 2-stroke scooters, they usually put only two rings, they are compression, the third thin ring is practically not necessary, but we recommend placing it under the lower ring for springing. In the case of 4-stroke mopeds there are three main rings, two of them are compression, the third is oil scraper.

The assembly of rings is presented on the basis of a 2t scooter, it has a simpler design. So, put the two rings on the piston, then take your finger and insert it into the crankshaft hole so that the piston holds firmly. Be sure to secure the finger with retaining rings on both sides, this is necessary so that the finger does not come out during operation. Also, the snap rings should not stick out, they should lie tightly in a special hole. Important: you need to install the piston exactly with the arrow (or EX inscription) to the exhaust pipe, otherwise the whole procedure will be useless. The next step is to install the cylinder on the piston.

Cylinder installation

This procedure is quite complicated, because putting the cylinder on the piston is ideal. First of all, do not forget to put gaskets on both sides, they are both included with the CPG, and are bought separately. There are usually two gaskets, one placed down between the cylinder and the engine, the second is installed between the cylinder and the head. After installing the lower gasket, try to put on the cylinder so that the rings meet in the groove. To do this, during the installation of the cylinder, it is enough to press the rings, after lubricating the cylinder and piston with oil.

Then put on the gasket and fix the head with nuts. Tighten the nuts in a cross order. After that, check the piston’s kickstarter operation, if the installation is successful, the piston should walk along the cylinder evenly and have noticeable compression.

That’s all, reassemble the scooter in the reverse order, connect all wires and hoses.