How to fix the trimmer yourself

A benzokosa consists of a large number of nodes, each of which can fail. The most common breakdowns include:

• engine speed does not increase;
• ignition problems;
• uncharacteristic knocks in the motor during operation;
• malfunctions of the cylinder-piston group (CPG);
• damage to the connection between the engine and the trimmer.

Most often, malfunctions of the cylinder-piston group occur - rings, piston, spark plug, etc. wear out. Breakdowns of the carburetor, ignition system and starter may occur.

Usually, in order to fix such problems, you need the appropriate spare parts for lawn mowers. They need to be selected specifically for the model. There are parts that fit different models of lawn mowers.

Ignition system

If the ignition of the lawn mower is faulty, there is no spark on the candle or it is not supplied at the right time, as a result of which the combustible mixture does not detonate. It is not worth climbing into the coil itself right away. The control handle may be loose.

Check the spark plug for proper operation. Perhaps she has exhausted her resources. The distance between the central and side electrodes should be 0.5-0.7 mm. Check the condition of the sealing metal ring, due to defects in this place, air can be poisoned.

If the spark plug and the electrical circuit are in good condition, you need to proceed to checking the coil and other elements of the ignition system itself.

It is not always possible to repair this unit with your own hands, since it is impossible to repair the same coil without knowledge in electrical engineering. Usually the ignition model is completely changed to a new one.

Perhaps the ignition setting has gone wrong, in this case it is worth adjusting it by changing the position of the flywheel and controlling it with probes.

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Trimmer device and repair

General design

The appearance of my electric spit is shown in the photo with explanations of the main components.

The technical characteristics of the ECO GT-800L trimmer are presented in a table from the instructions.

When I chose it, I settled on power and engine speed. 800 watts is more than enough. A line with a diameter of 1.6 mm is enough for processing grass in the garden and on lawns. Just don't let her grow above her knees. Otherwise, you will have to mow in two steps, because the long stems begin to twist around the mowing head.

The body of the electric motor, the power button and the nameplate were shown in close-up with a photograph.

Disassembly

All mounting screws are located on one side of the motor housing. It is convenient for disassembly.

After turning out the fixing screws, it is necessary to carefully separate the body halves with your fingers, overcoming the adhesive force of the plastic locks. In difficult places, I put a screwdriver with a flat blade.

A general view of the electric motor after removing the top cover was presented with a photograph.

The sequence of inspection of the main components

Design flaws

Immediately upon disassembly, a weak point was revealed - the attachment point of the plastic case to the thin-walled pipe of the rod. A self-tapping screw with a large thread pitch is used. The socket immediately became loose and it is impossible to clamp the screw tightly: it turns and cuts soft metal.

Engine controls

The trim button acts on the microswitch lever - mikrik. The return is due to the force of the springs. In the photo they were installed incorrectly by me, I shot in a hurry and did not notice. The springs are completely located in the internal compartment of the housing.

To start the engine, the same principle is used as that of an electric drill. The work can be done in two ways:

1. continuously holding the button down;
2. using an additional lock.

For security reasons, I refused the second option and removed the retainer along with the spring. I believe that this mode should be used only for a permanently fixed power tool, when there are no cases of safety violations in everyday life, and the electric motor does not require an instant stop.

On the bottom half, the photo showed more clearly the mikrik button, which controls the operation of the electric motor.

The microswitch itself is conveniently placed in a separate slot-compartment, and its marking is shown below.

Motor brushes and plates

Inspection did not reveal any obvious defects.

Slight contamination of the contact surfaces of the brushes and collector plates is quite normal and corresponds to the operating conditions.

Motor stator and rotor windings

All surfaces are intact, mechanical damage and traces of overheating, no temperature effects.

No damage to the paintwork is visible.

Motor wires and bearings

It's all right too. All structural elements are in working order, although slight contamination of individual parts and traces of corrosion that have appeared on the magnetic circuit of the stator of the electric motor and metal parts are visible.

By the way, I did not like the design of the bearings. The plastic parts don't inspire confidence. I compare it with the design of a Soviet 300-watt drill, which I used for about thirty years, intensively loading it with work on a homemade wood lathe, drilling holes in concrete with the consistent use of a jumper and in other modes.

There metal bearings never failed. From intensive work, only the collector and brushes gradually wore out.

Trimmer motor electrical checks

Schema preparation

This job requires a tester. Disconnecting the electrical circuits on the trimmer is easy to do. The terminals on the motor, wires and mikrik are of the same type.

Checking the operation of the microswitch and its wires

Tester in ohmmeter mode. The circuit of the electric motor was not understood. I put the wire with a crocodile on a random contact of the power cord plug, and with a homemade probe went through the conclusions of the mikrik. The device showed different resistance readings.

It is already possible to draw a preliminary conclusion that some of the wires are not broken, and the mic is in the open position. When working, he turned on the engine. Let's check this moment.

The crocodile remains on the plug, I hold the probe on the contact of the mikrik, showing a break, and close the contact by pressing the button. This is not easy to do, because you still have to photograph everything with one hand.

Turning on the button showed zero resistance, which indicates that the switch is working.

Checking the working circuit for switching on the trimmer engine

The tester remains in Ohmmeter mode. I connected one of its outputs with a clothespin to the second contact of the power plug, and the other through a crocodile to the microswitch contact on the engine side.

The active resistance of the measured electrical circuit was 9 ohms. Its value was determined:

• connecting wires;
• windings;
• contacts of brushes and collector plates.

There was no obvious break in the circuit inside the electrical circuit. This is also evidenced by the fact of the initial inclusion of the trimmer in the work. But, something makes it turn off under load.

There are only two such switching devices with power contacts in the electrical circuit of the trimmer:

1. microswitch, which we checked with a dial;
2. thermorelay.

In fact, the likelihood that the mikrik is disconnected from the load remains. But, knowing its device and fixing the contact in the on state due to mechanical holding with fingers, we can safely assume that the reason lies not in it. The second element with power contact remains.

Thermal relay

If you carefully consider the connection diagram of the windings, you can see that some small plastic box located on the winding is connected in series with one of them. One wire goes in and another goes out. On the case there is a marking and an inscription of 110 degrees Celsius.

This is a protective relay that keeps the power contact closed at normal temperatures, and opens it at critical heating. I admit that something was broken inside it, it began to work incorrectly, the contact opens from shaking.

I decided to take it out of work for the duration of the test. To begin with, I removed a small section of insulation on its wires.

Then I just twisted these wires. Shunted the disconnect contact in this way. Engine temperature control took over. I check it out from time to time without it. Never felt warm. The power of 800 watts for cutting grass with a fishing line is more than enough even for a long time.

I wrapped the shunting place with a piece of old electrical tape and laid the thermal relay under the mounting screed, as it was before.

Assembling the Circuit and Closing the Case

All disconnected wires collected in the reverse disassembly of the sequence. In such situations, I do not rely on memory when dismantling mechanisms. For a long time I have been trying to sketch everything, draw up wiring or logical electrical circuits. And with the advent of digital cameras, photography helps a lot in this.

When assembling the case, before closing the top cover, check the laying of the wires, place them correctly between the compartments through the prepared grooves and recesses. Otherwise, you can pinch, damage the insulation with sharp plastic edges.

Snapping locks and screwing screws was not difficult. Trimmer assembled. Will work without thermostat. But this is a temporary phenomenon. I have already ordered this cover.

Fuel system failure

Fuel system problems can be caused by:

• pierced gas tank;
• clogging of the fuel filter;
• clogged carburetor.

For repair, it is necessary to completely disassemble each assembly included in the fuel supply system. The order of disassembly and assembly can be found in the photo of the repair of lawn mowers.

The design may differ depending on the model. In the absence of experience, it is also advisable to take your own photos at all stages, in order to then correctly assemble the unit.

Quick start of the unit

1. Place the tool on its side so that the air filter is on top. In this arrangement, it is possible to ensure that the fuel mixture enters the very bottom of the carburetor. On the first attempt, the engine can start if, before starting, remove the air filter and pour a small amount of the mixture into the carburetor (it is enough to apply a few drops, and do not get carried away too much), and then install the recently removed parts back. This method has been proven in practice and works in most cases. Surely many owners of an old domestic car used a similar method on their car. The principle with a scythe remains exactly the same.
2. If the first advice did not bear fruit, then you need to unscrew the spark plugs and carefully look at them. We unscrew the candle, check it for performance, and then dry the combustion chamber. A candle that does not show signs of life must be thrown out and a new one put in. If everything is in order with the old one, then put it in its place and proceed to the next method.
3. If the candle is fully functional, the filter is clean, and the fuel mixture is fresh, then you need to resort to a universal way to start the lawn mower. It is worth closing the choke of the carburetor and pulling the starter handle once. Then we open the damper and pull the starter about 3 more times. This procedure is repeated 3 to 5 times. The engine should start. But do not pull the handle too hard, because in this case you will also have to repair the starter of the lawn mower. This will only be needed if the cable breaks or the handle breaks. In other cases, it is recommended to immediately replace the starter. This unit is sold immediately assembled.
4. And there is also a very simple way to start a braid. Many people forget to press the gas suction after filling the fuel mixture. It is usually located near the gas tank. On a household mower, it looks like an ordinary balloon with air, which must be pressed 5-10 times in order for the mixture from the tank to go to its intended destination. In most cases, this option works flawlessly. You just need to help the fuel go through the channel.

Proper replacement of spark plugs

Many people know that spark plugs should be changed periodically, but few do it correctly and in a certain sequence. To perform all the manipulations correctly, you should familiarize yourself with the correct procedure.

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• Stop the engine and wait until it becomes cold, otherwise severe burns may result.
• Disconnect the high voltage wire from the spark plug. We unscrew the candle with a special key. We examine the candle.
• The part must be replaced if it is in poor condition, very dirty, or a crack is found on the body.
• Check the gap between the electrodes. Their value should be 0.6 mm.
• We put a new candle and tighten it with a wrench.
• We carry out the installation of a high-voltage wire on the central electrode of the candle.

There is nothing complicated in this procedure , and absolutely any owner of a gasoline spit can cope with it.

Lawnmower stalls after starting

The engine may stall after starting the device if the carburetor is set incorrectly or misaligned. It's very easy to recognize. Vibrations may occur, which are clearly felt during operation. Adjustment can be done with your own hands, you should strictly follow all the instructions that are written in the manual.

The engine may also stall due to clogged fuel valve . In this case, it must be cleaned, and then the problem will be fixed.

If the scythe starts and then abruptly stalls, this means that the fuel supply to the carburetor is difficult. It is necessary to loosen the carburetor valves , then the free approach of fuel to it will be carried out in the required amount.

If there is excessive air leakage, then the engine may also stall. You should add a little speed so that air bubbles come out of the fuel system. You should also check the integrity of the fuel intake hose. If any damage is found in it, then the part must be replaced immediately.

Carburetor Troubleshooting

Carburetor problems, as a rule, are clogged jets and other elements. For repair, you need to disassemble the unit and clean it. You may also need to adjust the carburetor.

You can clean the jets and fuel channels using a pump or compressor. 3 screws are usually used for adjustment:

• maximum speed (H);
• minimum speed (L);
• idling (LA).

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The repair instructions are as follows:

• Fully tighten screws H and L.
• Loosen screws H and L by 1 turn, accuracy plays a significant role.
• Start the lawn mower and leave it running for 10 minutes to warm up the engine.
• When the engine warms up, turn the gas up to full throttle.
• Release the throttle stick and set the idle speed (LA). Tighten the screw after the start of rotation of the working body so that it stops.

Disassembly of a gasoline scythe, lubrication of its parts and replacement of faulty elements

To disassemble the lawn mower for repair work, in the general case, the following devices will be needed:

• a set of screwdrivers (with different tips) and wrenches;
• a small puller for removing bearings;
• special candle key;
• hammer.

In each case, you will need to disassemble individual nodes.

It should be borne in mind that the starter (starter) in a number of models is non-separable - in this case, in case of problems with it, only the replacement of the element is possible. If the knot is disassembled, then it can be repaired by removing and replacing the rope and spring, or by installing the latter in place (when it disengages).

Disassembly and replacement of the rod

Quite often, it is required to repair the trimmer bar. It is a structure of the following parts:

• a drive shaft made of steel, having polyhedral or square splines at the upper and lower ends;
• aluminum tubes;
• a plastic sleeve designed to maintain the centralized position of the drive shaft in the tube (so that it does not vibrate);
• a rubber shock absorber needed to connect the rod to the motor;
• steering wheel with a handle used for steering, and a rack, a belt.

Some models have a shock absorber between the steering column and the stem. All control elements (lock lever, ignition switch, gas button) are located on the handle.

A bevel-bevel gearbox is connected to the lower end of the rod, but some lightweight models are available without it. This is due to the fact that their rod has a curved shape, and the shaft is a flexible cable.

How to disassemble the rod and then assemble it to lubricate the shaft or replace it, is shown in detail in the video below. In the same way, a broken bar is replaced with a new one.

It often happens that the multi-faceted or square splines of the drive shaft “lick off”, while the working mechanism does not rotate or does it with slippage. Then the shaft is changed.

When a knock appears in the tube, you should disassemble the rod and check the condition of the bushing, and if necessary, replace it. How to properly assemble the throttle on the trimmer is discussed in the video below.

If there is no whole rod suitable for installation, then you can tighten the fracture site with a clamp or apply a semblance of a tire. This is a temporary measure and should be replaced as soon as possible.

Clutch repair

When a knife or fishing line, when the engine is idling, is almost constantly spinning, and uncharacteristic sounds come from the front of the engine, this indicates a breakdown of the clutch. The cause is a broken spring. At the same time, the technique mows normally.

If slippage occurs, then the pads are also worn out.

The trimmer clutch is repaired as follows:

• remove the cover from the muffler;
• remove the metal stand;
• then remove the cylinder and starter caps to gain access to the clutch;
• unscrew the side screws to remove the shock absorber cover;
• remove the tube from it, having previously let in the tightening bolts;
• unwind the clutch (shown in the photo below);

• inspect the condition of the spring, pads and bearings;
• a new spring is hooked by threading the hooks into the corresponding holes;
• to replace the pads, you need to remove the spring, and then unscrew the bolts on them.

If necessary, lock the crankshaft using, for example, a rope.

Carrying out repair of a gasoline engine, carburetor and gearbox

Engine problems can be caused by problems with the piston system, seals, rings. To eliminate them, it is necessary to remove the drive motor.

Determining what exactly caused the breakdown is not easy. If there is a guarantee, the mechanism should be taken to a service center for diagnostics and repair. If it is not possible to turn to specialists for help, then it should be borne in mind that replacement of piston rings is most often required. To do this, you need to disassemble the engine, get the piston. Do it in the following sequence:

• remove the cover of the plastic case by unscrewing the screws or pressing the clamps;
• disconnect the rod with the crankshaft;
• remove the cylinder head;
• take out the piston and rings;
• if necessary, replace them;
• assemble in reverse order.

Rings should be installed carefully, because they are quite fragile.

How the piston is installed and the seals are replaced during engine repairs is clearly shown in the videos below:

With regular use of lawn mowers, the gearbox may break. Gears, bearings wear out in it (they can also break). To keep this from happening infrequently, this assembly should be lubricated regularly. The frequency is almost always indicated in the operating instructions for the model used (at least once per season). The video below can serve as a repair guide.

To lubricate the gearbox, unscrew the plug and simply squeeze out a suitable lubricant inside the assembly by scrolling the shaft.

On your own, the carburetor can only be removed and cleaned, as well as replacing the gasket between it and the engine. The tightness of the node at home is quite problematic to determine. The main thing is to properly assemble the equipment after repair so that the trimmer works without problems.

Starter malfunctions

The starter in the lawn mower fails in such situations:

• damaged drive cord;
• defective or misaligned band spring.

For repair, you need to disassemble the start unit and replace the faulty element. If the band spring is broken, it must be replaced.

A damaged cord should also be replaced with a new one. In the case of a displacement of the tape spring (it has come out of the hook with the pulley), it should be returned to its original position, which will require a certain effort.

Sometimes the drive cord gets on the shaft, as a result of which it not only breaks, but also damages the starter housing. In such a situation, the unit cannot be repaired, it must be replaced with a new one.

Gear lubrication

If during operation there are knocks and other extraneous sounds (grinding, etc.), the problem is most likely in the gearbox.

Gearbox repair in most cases involves lubricating its mechanical elements. Otherwise, the gears may jam, as a result of which the repair will cost much more, the assembly may have to be completely replaced with a new one.

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It is advisable to use the lubricant that is recommended by the manufacturer of the lawn mower. Usually, the relevant information is present in the passport for the unit.

Exhaust system

Due to a malfunction of the exhaust system, unstable engine operation can be observed. As a rule, it manifests itself in a drop in power when increasing speed.

Simply put, when you try to increase the power of the lawn mower, it stalls. This may be due to a clogged exhaust system.

In most lawn mowers, mufflers are of a collapsible design. Therefore, to eliminate the breakdown, it is enough to disassemble the assembly and clean it from soot and other contaminants.

In the case of a non-separable design, leave the muffler in a special detergent for some time. After washing, it is advisable to dry the assembly with a building hair dryer so that rust does not form.

If the engine does not start

When the lawn mower does not start, you must first check if the fuel tank has run out. If everything is in order, then you need to check its quality - you may have purchased a cheap type of gasoline that does not fit the equipment. For a braid, it is best to use good gasoline, which is purchased at gas stations, the brand must be at least AI-92.

You should not save and buy cheap fuel, as this will lead to the fact that the cylinder-piston group will fail , and much more money can be spent on repairs than on high-quality gasoline.

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It is also very important to properly prepare the fuel mixture and combine oil and gasoline in the right amount. The proportional ratio should be stated in the manual. That is why it is so important that it be written in Russian, because it is likely that different mower models require slightly different proportions for successful operation.

It is not necessary to use the fuel mixture in large volumes, because if the unused volume is stored indoors for a long time, it will lose its properties. It is better to use a freshly prepared solution.

• A problem in the operation of the engine may be contamination of the fuel filter. The first thing to check is the filter. If necessary, replace it. The inlet pipe must never be left without a fuel filter. Also check the air filter at the same time. If dirty, it must be removed, washed in gasoline and put back in place. If you are in a country house or in a private house, then it will be enough to rinse it in clean water using various detergents. Then rinse, wring out and let dry. The finished filter is wetted in a small amount of oil, which is used to prepare the mixture. Excess is removed by squeezing the filter with your hands. Then the part can be put back.
• If all these procedures did not help and the engine still does not start, then you can try to adjust the idle speed, for this, start tightening the carburetor screw. This is very similar to setting up a similar part on a car. If there is no experience in adjusting the carburetor, then you can study the videos on the Internet, which are very understandable and accessible. They will clearly show how you can adjust the carburetor of lawn mowers with your own hands.

Photo repair lawn mowers

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