Why the lawn mower and trimmer won’t start: possible causes and solutions

If the trimmer or lawn mower does not start, then any desire to mow the grass disappears. Very often, owners of these tools encounter difficulties starting a two-stroke or four-stroke engine after winter, when the tool has not been used for a long time. If such a situation occurs, then you should not rush to return the instrument for repair. Start troubleshooting from least to most, and with 100% probability you will be able to start the gas trimmer engine. Let’s look at where to start troubleshooting when the lawn mower won’t start, step by step with all the details.

The trimmer won't start - what components need to be checked?

To start gasoline trimmers, manual starters are used. These starters are used to manually move the crankshaft. In this case, it is important to turn on the ignition so that when the crankshaft rotates, the fuel-air mixture entering the cylinder can ignite. Ignition of the first portion of the mixture will cause the engine to start, and the trimmer is ready for use.

However, it very often happens that attempts to start the engine are frustrated. Naturally, when after 5 attempts to start the engine you cannot achieve success, then you need to start diagnostic measures. There is a special sequence that should be followed in order to find the reason why the lawn mower does not start and successfully eliminate it. The check sequence has the following format:

Check the presence of fuel in the tank, as well as the quality of the mixture of gasoline and oil
Determine the color of the spark plug, as well as signs of its functioning
Make sure the air filter is working properly
Check the fuel filter, which is responsible for cleaning gasoline and oil entering the carburetor
Breather serviceability
The reason why the lawn mower does not start may be the exhaust duct or the muffler.

It is these nodes that are the main sources of the problem of difficult starting of the trimmer. A more complex problem involves a faulty carburetor that needs adjustment. Let's look at each unit separately to find out the reasons why the trimmer does not start and fix them with your own hands.

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The first step is to check the availability and quality of fuel

If you don’t understand why the lawn mower won’t start, then first make sure that there is fuel in the tank. Beginners often forget that they need to pause periodically to fill the tool with a gasoline-oil mixture. If the gas mower's tank is empty, then naturally it will not start, no matter how much you try to do it.

If there is fuel in the tank, but it is impossible to start the engine of the tool, then do not rush to disassemble the carburetor. Make sure that the trimmer motor is started correctly as indicated in the instructions. If the launch is carried out according to the instructions, then it is important to consider the following points:

Use not just high-quality gasoline with the maximum octane number, but exactly the brand recommended by the manufacturer. And this brand is not always AI-95 gasoline. If you don’t know what gasoline to use for your lawn mower, then choose AI-92
The oil must be special - for two-stroke engines. If the lawn mower has a four-stroke engine, then you need to fill it with pure gasoline without mixing it with oil. You should not skimp on the quality of trimmer engine oil, just like you should not skimp on gasoline. After all, the service life of the engine depends on the quality of the fuel used.
Proper preparation of the fuel mixture in the gas trimmer. Observations show that most mowers control the process of preparing oil and gasoline for the trimmer only at first. The more experienced the mower, the less attention is paid to the process of mixing gasoline with oil for a two-stroke engine. The ratio of gasoline to oil should be as recommended by the manufacturer. Usually this ratio is 25 to 1, that is, for 1 liter of gasoline you need 40 ml of two-stroke oil (motor oil for a car, much less used oil, cannot be used)
Proper storage of the fuel mixture. It often happens that after preparing the fuel mixture, it sits for a long time, more than 2 weeks. It is impossible to store a ready-made mixture of gasoline and oil for a long time, as this leads to the fact that the oil precipitates, and thereby the properties of both petroleum products are lost. Even thorough stirring after long-term storage of the finished mixture is not a reason for its further use. That is why it is not recommended to prepare more than 2 liters of mixture at a time.

Make sure that all of the above points have been completed, and only then can you start checking the condition of the spark plug. The trimmer does not start for various reasons, and most of them can be identified independently. It is simply irrational to resort to disassembling the carburetor if it is impossible to start the engine. The next step towards troubleshooting is checking the condition of the spark plug.

This is interesting!
During long-term storage of diluted gasoline with oil, these elements decompose into heavy fractions. These fractions clog not only the instrument’s fuel filter, but also the carburetor channels. The maximum duration of fuel storage is no more than 14 days.

The trimmer gets very hot

Overheating of the trimmer can occur for many reasons:

gasoline does not have the same octane number as indicated in the instructions for the unit;
the proportions of gasoline and oil were not observed during preparation of the fuel mixture;
the mixture of fuel and oil was prepared a long time ago (the mixture cannot be stored for more than 2 weeks);
the trimmer operates beyond the time specified according to the instructions;
a low-power trimmer is used on thick and hard grass, the device works with overload and heats up quickly;
has moved towards the rod or the cassette cover has become stuck.

The latter happens if you install a mowing head that is not suitable for a given unit, or when the axle moves inside the boom. These changes make it harder to rotate, the load on the engine increases, and it overheats.

Dry and wet spark plug, what does this mean and how does it affect engine starting?

Most tool owners immediately resort to checking the condition of the spark plug contacts. This is done in order to understand from the condition of the spark plug what could be the reason for the impossibility of starting the lawn mower engine. Based on the condition of the spark plug contacts, appropriate conclusions can be drawn about what may be causing the malfunction. Diagnosis of the spark plug on the trimmer is performed in the following order:

The spark plug is unscrewed, after which it is subject to inspection. The ideal condition of the electrodes is if they have a brown soot (brick color). If the spark plug is wet and has black or white carbon deposits, this indicates a corresponding malfunction
If the spark plug is wet, then there is a portion of unburnt fuel in the combustion chamber that does not need to be drained. Clean and dry the spark plug contacts, then make sure it is in good condition. To do this, connect it to the candle holder and place it on the surface of the cylinder. Turn on the ignition and pull the starter handle lightly. In this case, the spark plug should produce a high-quality and constant spark. If the spark is weak or absent at all, then the spark plug should be replaced.
The trimmer may not start due to a large gap between the spark plug contacts. The gap between the spark plug electrodes should be in the range from 0.7 to 1 mm. To set the gap, special feeler gauges are used

This is interesting!
Drying spark plug contacts by calcining them is strictly contraindicated, as this method will lead to damage to the part.
If there is a spark at the spark plug, but the trimmer does not start, then the reason lies in the supply of the fuel mixture to the combustion chamber. To make sure of this, you should do the following:

Take 20 grams of fuel into the cap of a PET bottle or into a syringe
Pour it into the combustion chamber through the spark plug hole
Screw in the spark plug
Put on the candle holder and start the engine

If the engine of the lawn mower starts after the above steps, then the cause of the malfunction should be sought directly in the fuel line and carburetor. If the engine does not start even after these steps, then you need to check the serviceability of the high-voltage wire. The high-voltage wire, like the spark plug, is a consumable item. If there is a suspicion that the trimmer's armored wire is faulty, it should be replaced. If, after the above steps, you cannot start the engine of the lawn mower, then you need to take into account the following recommendations:

If there is any doubt about the serviceability of the spark plug and high-voltage wire, it is recommended to replace them immediately
Check that sparking is working properly, and if there is no spark on the new spark plug, then the breakdown is related to the ignition unit - coil failure
The ignition coil is not repaired, but replaced. If the diagnostics really indicate a malfunction of the lawn mower’s ignition coil, then it is not difficult to replace it with your own hands

If there is a spark plug, and it is dry, and the trimmer does not want to start, then we move on to checking the next unit - the air and fuel filters.

This is interesting!
If the spark plug electrodes are red or pink, this indicates that the fuel used contains a large amount of additives. You should refuse such fuel by changing the gas station or brand of gasoline.

Troubleshooting

engine malfunction (piston wear, bearing failure, crankcase crack),
malfunction of the fuel mixture supply - clogged air filter pores or carburetor malfunction,
the ignition system does not work,
mechanical failure - leaking hoses, broken wires under the braid, rupture of tubes.

The brush cutter cannot work for a long time. The gearbox and motor will overheat. You can mow for no more than 15=20 minutes, taking a five-minute break. On a hot afternoon, the operating time is halved. When mowing weeds and sedges, the work time must be reduced.

If the launch fails, we begin to look for the cause of the failure:

check the quality of the fuel,
make sure the spark plug is working properly and the spark plug channel is clean,
check the cleanliness of the air filter,
make sure the fuel filter is not clogged,
check the cleanliness of the breather,
clean the exhaust channel.

More complex reasons will be those detected during diagnostics of a malfunction, leading to a major overhaul of the carburetor. Such reasons include clogging of the internal channels of the carburetor, wear of the gasket on it and a violation of the tightness of the internal halls with loss of vacuum. Repairing a lawn mower yourself if it won't start will require patience.

If the trimmer does not start, check the serviceability of the filters

You will need to check the air filter, which cleans the air entering the carburetor. Clogging of the cleaning element leads to the fact that air enters in less quantity or completely stops supplying it to the carburetor. You can find out whether the air filter is the reason why the trimmer does not start in a simple way:

Remove the air filter and inspect it. The presence of blockages is already a reason to blame this part for everything
If clogging is not visually detected, then you need to try to start the engine without a filter. If the trimmer starts without a filter, then this part definitely needs to be replaced.
The air filter can be cleaned with a stream of compressed air, but if it has not been changed for a long time, then it is advisable to replace it with a new one

It should be noted that the trimmer may not start due to a clogged air filter, but these are extremely rare cases. Often, a clogged air filter affects the stability of the engine and also contributes to a decrease in performance.

This is interesting!
If the chainsaw starts up without an air filter, then working with the tool without a filter element is contraindicated, since contaminants will get into the cylinder, thereby reducing the service life.
The real reason why a gasoline trimmer won't start is that the fuel filter is clogged. This part is located in the tool tank, and if the scythe is more than 2 years old, then it’s time to check the serviceability of the fuel filter element. If the filter is clogged, then the fuel mixture will not flow into the carburetor, which means the trimmer will not start.

There are no difficulties with replacing the fuel filter, since to do this it is enough to remove this part from the tank and replace it. If you are going to clean the fuel filter with a compressor, then it is recommended to abandon this idea. It is better to buy a new filter for cleaning the fuel of a lawn mower, since there will still be blockages inside the old element. The video below shows the process of replacing the fuel filter on an Oleo-Mac brand lawn mower.

If you are not sure that the reason why the trimmer motor cannot start is the fuel cleaning element, then you should do the following:

Remove the fuel filter
Start the lawn mower
If it starts, and quickly, then the problem is really in the fuel filter.

The filter becomes clogged due to the following reasons:

During prolonged use of the tool
If low-quality gasoline or oil is used
When storing fuel in the tool tank for a long time
If you fill the tank with fuel that has been stored for a long time
If dust and small particles get into the tool tank. This usually happens while refilling the tool.

This is interesting!
If the fuel filter is working properly, but the lawn mower does not start, then you should make sure that the fuel hose is placed in the fuel. After all, there are cases when the hose together with the filter is simply disconnected from the main tube, which makes it impossible to start the engine of the tool.

Electric trimmer vibrates

Many users of mowers have noticed that after some time after the device starts operating, it begins to vibrate strongly. Some trimmers, mainly more expensive models, have an anti-vibration system in the form of shock absorbers located between the engine and the rod. But in some cases, even this cannot save you from strong vibration. The reason that strong vibration appears in the trimmer may be a small amount or complete absence of lubricant on the rigid or flexible shaft located inside the device’s rod.

Replacing the lubricant of the rigid shaft is as follows:

unscrew the gearbox located at the bottom of the rod;

after removing the gearbox, you will see the end of the shaft, which you need to pull to remove the part;

after removing the shaft, it must be generously lubricated with special grease “Shrus-4” or regular grease “Litol-24”;

Apply a small amount of lubricant to the shaft and spread it evenly along the entire length of the part, including the splines at the ends of the rod (if they are worn out, the shaft will have to be replaced);
After lubrication, insert the shaft back into the rod and put the gearbox in its original place.

Lubrication of the flexible shaft is carried out as follows:

unscrew and remove the mowing head;
remove the rod from the electric motor by unscrewing a couple of bolts;
pull out the flexible cable from the rod;
Lubricate the cable along its entire length.

This is done like this: first you need to lubricate the end of the cable, and then insert it into the rod, after which, as it moves inside the pipe, you should apply lubricant to the part and distribute it evenly over the surface. Then insert the flexible shaft rod into the electric motor and secure it.

If lubrication does not help and vibration continues to appear, you will need to change the flexible shaft.

How does the breather affect the ability to start a lawn mower engine?

Having ruled out malfunctions of the lawnmower filters, it is necessary to check the breather. A breather is a part that is responsible for normalizing the pressure in the tank. When the fuel gradually leaves the tank into the carburetor, the pressure increases (a vacuum is created). To relieve the vacuum inside the tank, a breather is used - a kind of valve that is located on the lid of the tool's tank. This valve has a filter element through which the air entering the tank is filtered.

Over time, the filter becomes clogged and causes a vacuum to be created in the gas tank. It’s trite, but in 30% of cases, a trimmer malfunction in the form of the inability to start it is associated with a clogged breather. The breather on the trimmer can be cleaned and the tool can be used again. You can make sure that the cause of the trimmer malfunction is the breather as follows:

Unscrew the gas tank cap
If air bleeds out when unscrewing, then we can assume with 100% certainty that the breather has failed
Screw on the cap and start the lawn mower engine. If the trimmer starts, but after a while (when the amount of fuel in the tank decreases) it stalls, then it is necessary to clean the breather

You can clean the breather using a regular sewing needle. Many people don’t even know about this important detail, so they often don’t understand what to do when the engine of the mowing gas trimmer does not start. Answering the question of the effect of the breather on starting the engine, it must be said that it has a direct effect. Excessive pressure in the tank prevents fuel from flowing to the carburetor, so the engine does not start.

Basic malfunctions of gasoline and electric trimmers

For gas trimmers and electric trimmers, if we do not consider breakdowns associated with the bar and mowing head, malfunctions mainly occur in the engine area.

Gasoline trimmer breakdowns

Typical breakdowns of a gasoline trimmer that owners of this unit most often encounter are the following:

engine breakdown;
problems with the carburetor;
problems with fuel supply;
muffler malfunction;
gearbox failure;
the starter is broken;
problems with the air filter;
The breather on the gas tank is clogged.

Malfunctions of electric trimmers

Since the design of an electric mower is much simpler than a motor trimmer, there are few reasons for its failure.

It should be noted that it is better to entrust the elimination of some of them to a specialist.

Basically, the trimmer stops working normally in the following cases:

electrical cable fault;
control button is faulty;
burnt out motor stator winding;
broken contact connections on the engine.

The muffler is clogged and the gas trimmer cannot be started

What else could be the reason why the gas trimmer engine cannot be started? Even before resorting to more drastic actions, you should check the serviceability of the muffler or exhaust duct. This does not apply to new trimmers, which have practically no special output. If the trimmer is already many years old, and the tool has not been subjected to diagnostic measures, then the muffler should be checked for clogging.

If the muffler on your lawn mower is clogged, there is nowhere for the exhaust gases to escape, making it impossible to start the engine. The exhaust channel cannot become clogged overnight, so the following signs should have appeared the day before:

An increase in the sound of the engine, which is associated with overcoming great resistance by the exhaust gases to release them
Black smoke from the muffler is carbon deposits that settle on the walls of the exhaust system
Unstable engine operation
The engine stalls on its own when idling

This factor can be excluded or confirmed by inspecting the exhaust system. If the anti-spark mesh is significantly clogged, then undoubtedly the reason for the inability to start the engine lies in the exhaust channel. The mesh must be cleaned, but this must be done carefully, since black soot is a very dangerous carcinogen that can cause serious diseases of the human respiratory system. To clean the anti-spark mesh and the walls of the trimmer muffler, special products should be used, and work should be carried out using protective equipment.

Basic rules for operating a lawn mower

A petrol mower requires high-quality and careful operation. Its expected service life and the absence of any serious problems depend on this.

When using it you must:

monitor the cooling system during operation;
promptly clean the charter channels and starter fins, and for cleaning you should use special detergents or regular kerosene;
Allow the instrument to cool down before cleaning.

If the fuel is drained, you need to let the lawn mower run at idle speed until it stalls. This will allow you to promptly remove all remnants of the working mixture, regardless of the power of the device.

The trimmer does not start when cold, what are the reasons?

First, let's look at the situation when it is impossible to start the engine of a lawn mower when it is cold. What does this mean? Surely mowers have encountered a situation where the trimmer starts up just fine when hot, but as soon as you take a short break, a problem arises. This is a problem with starting the engine after it has cooled down. What could be the reason? Of course, no one excluded all the factors described above, but if the situation occurs constantly, then there is no need to check them. If the lawn mower starts well when it’s hot, but problems arise when it’s cold, then you should look for the reasons inside the CPG (cylinder-piston group).

To identify the problem, you will need to use a compression gauge. We screw the compression gauge into the hole instead of a spark plug, and then activate the starter handle. We measure the pressure inside the cylinder - compression. The compression value should be on the order of 8-12 atmospheres. After the tool has warmed up (it is enough to work for 15-20 minutes), you should repeat the checking procedure. If the compression on a hot engine is below 8 atmospheres, then a CPG malfunction is likely. This means that the rings, piston and cylinder walls are worn.

The situation can be corrected by replacing the CPG. When replacing, it is important to take into account such a recommendation as generously lubricating the parts with engine oil inside the cylinder. This is necessary to ensure that scuffing does not occur in the first minutes of starting a new cylinder with a piston.

When engine compression decreases, fuel consumption increases and tool performance also decreases. It is possible to work with such a tool, but wear increases with each subsequent hour of work. One day it will be impossible to start the lawn mower at all, even when warming up.

This is interesting! You can warm up the engine of a lawn mower with low compression by pulling the starter handle. When warmed up, the metal expands, thereby increasing compression.

Second - carburetor

There is no need to disassemble the unit right away, especially if the engine stalls after starting or does not hold idle. First try changing the fuel, there may be too much oil in it. You can inject a cleaner into the air filter and let the engine “sink” a little at maximum speed.

Next we go in order - the air filter, the fuel filter (it can be outside or in the tank), the fuel pumping button, the integrity of the hoses. Gas tank plug - the ventilation valve may be clogged, the motor simply does not pump gasoline. Blow everything out and it will work!

Be sure to look at the connection between the carburetor and the intake manifold! If there is air sucking there and there is no seal - fix it!

The dosing needle freezes - also a problem in some models. It is enough to push it down, or remove it and sand it with velvet.

You can pull the hose off the carburetor and see if fuel flows to it when pumping. It is clear that often to check you need to remove the plastic covering and break your fingers on the latches, but sooner or later you will have to climb there anyway.

The lawn mower engine does not want to start after winter

Often, with the onset of spring, most owners of lawn mowers complain about the inability to start the engine of this lawn-mowing tool. With what it can be connected? In order for the trimmer to start up well in the spring after winter storage, you need to learn how to properly care for it. How to properly store a lawn mower in winter is described in detail at the very end of the material. Now let’s figure out why it’s impossible to start the tool’s motor after winter.

One of the main reasons why a lawn mower won’t start after winter is fuel stagnation in the gas tank. If you do not drain the fuel from the tank and leave the tool for a long time, it will naturally be impossible to start the lawn mower. The properties of the mixture of gasoline and oil decrease, so as a fact we get a malfunction of the tool. Even if there is fuel mixture left in the trimmer from last year, it is recommended to drain it and refill with freshly prepared one. After this, launch the tool.

Another reason could be a faulty air damper. When closing it manually, the valve itself may not work, so you start the lawn mower with the air damper fully open. In this case, the tool will not start when cold, as there is a large air leak. The video below explains why the trimmer does not start when cold.

In addition to these reasons for the impossibility of starting the engine of a lawn mower, there are others that are also important to mention:

Dampness of the spark plug electrodes - before starting the trimmer after winter, you should unscrew the spark plug, inspect it, clean it, dry it and set the gap
Damage to the high voltage wire. During storage of the instrument, the high-voltage wire could crack, become damaged, or be chewed by mice. Make sure the armored wire is intact if the trimmer does not start after winter
Oxidation of wire contacts. This usually happens if the instrument is stored in a room with high humidity.
Check the serviceability of the ignition coil. Over the winter, this part could fail and cause difficulty starting the tool.
Carburetor adjustment - it is recommended to adjust the carburetor after winter. To do this, the tool must start, so if it is impossible to start, it is recommended to pour 20 grams of fuel mixture into the spark plug hole and start the engine
Carry out all the above actions, since during long-term storage the breather hole, filters could become clogged, and corrosion could form on the walls of the exhaust system

Carry out diagnostics of the tool, and only after that resort to more serious repairs - cleaning the carburetor.

Where does the search begin?

A trimmer is a complex piece of equipment, so after purchase it is recommended that you thoroughly study the instructions that come with the device. Many owners, saving time or simply ignoring advice, skip this stage. Therefore, they often find themselves in an unpleasant situation when they have to wonder why the trimmer does not start.

Common causes and procedures

When any equipment malfunctions, they are first interested in the reasons that may interfere with its operation. The next step is diagnosis. As a rule, the check begins with the simplest “culprits” and ends with the most complex versions of the problems.

One of the most common reasons for trimmer failure is a long break in the operation of the equipment. The same consequences can result from improper storage of the unit, lack of maintenance, or work carried out incorrectly. It's no secret that any type of equipment needs quality care, and lawn mowers or electric trimmers are no exception.

How to understand why the trimmer does not start? In this case, proper diagnosis is extremely important. To quickly identify the source of the problem, you need to carefully check all key elements of the device. These include the tank, fuel system valves, spark plugs and filtration system. It is their malfunctions that most often provoke the failure of equipment to start and operate.

Another possible reason is improper preparation and low quality of the fuel mixture. This applies to a greater extent to two-stroke engines, which are more sensitive to various impurities. To prevent any malfunctions, you must strictly follow the manufacturer's recommendations. Otherwise, the owners will face expensive repairs, as the damage will be serious. For example, fixing problems with the piston group of an internal combustion engine will cost a tidy sum: repair costs in this case can amount to approximately 70% of the price of a new trimmer.

First way to troubleshoot: checking the spark plug

Often, owners have to deal with a very unpleasant situation. The trimmer carburetor is in order and the fuel mixture is of high quality, but the unit still refuses to work and the engine cannot be started. In this case, suspicion falls on the spark plug, so the following actions are taken:

First, the device is turned inside out, wiped and dried;
fuel is removed from the trimmer, then the spark plug channel is also dried for at least 30-40 minutes;
then they get rid of all traces of soot: for this operation they use sandpaper or a needle file;
the cleaned spark plug, freed from the slightest contamination, is returned to its rightful place, having previously set the required gap.

If the seat is dry, there are no problems with the spark plug, but the engine still refuses to start, then lubricate the threads with gasoline. When these actions do not resolve the problem, a spark does not appear, check the contact between the spark plug and the wiring. If everything is in order with it, then you will have to test the ignition system control unit. This stage will require the help of a specialist.

The second step is checking the status of the filters

Another potential problem with gasoline brush cutters is a clogged air filter. In such a situation, the unit either starts very reluctantly or refuses to work at all. This stage involves a simple check - the filter is pulled out, and the equipment is tried to be started without protection.

If the trimmer starts up without it, then the dirty element is cleaned or replaced with a new one. To avoid such troubles, it is recommended to regularly blow out the filter. This simple procedure will significantly extend its service life. A dirty fuel filter is another reason why the lawn mower won’t start. However, in this case, the easiest way to restore the operation of the equipment is to replace it.

What else needs to be checked? If the described operations do not bring results, then check the breather, which stabilizes the pressure in the fuel tank. The exhaust channel and the muffler mesh also require attention. These problems are common with older trimmer models.

The trimmer does not start due to a carburetor malfunction

One of the most difficult reasons for the inability to start a lawn mower is the carburetor. This mechanism is responsible for preparing and properly supplying the fuel-air mixture to the cylinder. If the carburetor is clogged or incorrectly adjusted, the lawn mower may not start or may not work properly. Detailed instructions on how to adjust the carburetor on a lawn mower are described in this material.

If the adjustment does not help restore stable operation of the tool’s engine, or the trimmer does not start at all, then you should remove the carburetor and repair it. All carburetor repairs involve disassembling it, cleaning all channels and components. If necessary, replace failed parts - membranes, filters, etc.

If suspicions fall on the carburetor, then you should pay attention to the following types of malfunctions:

The channels and jets are clogged - special liquids can be used for cleaning, but it is best to disassemble the mechanism and thoroughly wash it. The cause of clogging of the carburetor channels and jets is storing the tool with fuel in the tank.
Wear of carburetor gaskets - rubber seals contribute to the leakage of the mechanism, resulting in poor functioning
Malfunction of carburetor membranes - they are responsible for pumping fuel into the device

To ensure that the CPG is faulty, you should perform a compression test as described above.

Other tool malfunctions

If all the problems described above have been checked and corrected, and the trimmer still does not start, there is probably a problem with the engine itself. Compression may be reduced due to destruction of the crankshaft seals or damage to the piston group.

This often happens with trimmers that are used very actively or for a long time: for example, in public utilities. For diagnostics, use a compression meter.

The oil seal protruding from the crankcase body must be replaced - it has already hardened too much, has lost its elasticity and cannot fully perform its function

In most cases, such repairs should be entrusted to a workshop, if only because in almost all trimmers, in order to access the oil seals and the cylinder, you need to unscrew the nuts with a thread lock. This can be done either with an electric impact wrench or by warming them up thoroughly.

The oil seals are located on both sides of the crankshaft: under the starter and on the drive, and it is better to change them in pairs. Having reached the place where they are installed, assess the condition by eye: they should fit tightly, without play, and not bulge or be cracked. Oil leaks around also indicate the need to replace the seals.

When reassembling, be sure to use thread lockers wherever they were - this is a safety issue.

To easily remove the seal, screw 2 screws into it from opposite sides. Pull the screws one at a time using pliers.

Restoring the piston group requires specialized tools. If you are not an auto mechanic at a service station, entrust the restoration of the trimmer motor to a specialist.

When opening the cylinder, check all surfaces for chips, burrs, and scratches. To determine whether the piston rings are worn, rock the connecting rod. The slightest play in the piston indicates the need to replace the rings.

How to properly store a lawn mower and eliminate problems with starting it

Its launch depends on the correct approach to storing the trimmer. Moreover, this applies not only to long-term winter storage. How to properly store a gasoline trimmer, in order to protect yourself from problems with difficulty starting it, you need to take into account a number of the following recommendations:

Before putting the tool away for winter storage, you should drain the fuel from the tank. In addition, remaining fuel also needs to be removed, and this can be done by starting the engine, letting it run for a while until it stalls
It is advisable to store the instrument in a dry place
Before starting the engine after a long pause of more than 2-3 months, it is necessary to first inspect the spark plug electrodes, as well as check the main components - the air filter, high-voltage wire, etc.
When using the tool, you need to take into account that overheating of the motor negatively affects the service life, so you need to take breaks while working, especially if a trimmer with a two-stroke engine is used for work. Units with four-stroke engines are not only more powerful, but also more durable
After winter, the first thing you need to do is pour a little oil into the spark plug hole, first moving the piston to its dead center. This is necessary in order to lubricate the CPG parts when starting the engine, thereby preventing their rapid wear.

Only with the right approach to finding the reasons why the trimmer does not start can you find and fix the problem yourself. Moreover, for this you do not need to be a specialist or thoroughly understand the design of gasoline units. Proceed in order in the sequence presented in the material, and restoring the functionality of the lawn mower will be as easy as shelling pears.

Checking filters

Another common reason why the trimmer does not start

, is the presence of a blockage in the filter area. To confirm your guess, it is enough to dismantle the indicated block and try to start the unit without it. If the trimmer engine starts, most likely you will have to replace the air filter or at least thoroughly blow out the old one. If there is heavy contamination on the surface of the filter element, it is necessary to use a new mesh. When resorting to such actions, you should not leave the suction pipe completely without a filter. After all, haste in this case can lead to the need to repair the entire piston group of the unit’s engine.

Remedies

It is best to start repairing a lawn mower with a step-by-step check of the main components. The first thing worth checking is the fuel in the tank, as well as the presence of lubricants on the main components of the tool

It is also important to know what quality and proportion of fuel and oil used. If something is wrong, the piston system may fail, and replacing it is expensive

Next, it is worth assessing the serviceability and performance of the spark plugs. The result is assessed by the presence of a spark when there is contact with the tool body. If the fault is in the spark plug, then you need to remove the voltage wire from it.

In case of contamination, it is recommended to replace it with a new one and dry the spark plug channel. This is also done if there are cracks or chips on the spark plug body. The gap between the electrodes is set to 0.6 millimeters. The new spark plug is also clamped using a special key. At the end, a voltage wire must be connected to it.

It would be a good idea to inspect the filters, both fuel and air. If the blockages are severe, then the best solution is to replace them. You can try washing the air filter with water and detergent and then drying it. It is also sometimes soaked in gasoline

After drying and installation, it is important to moisten the filter with oil, which is used in a mixture with fuel

It is very easy to fix the problem of a stalled lawn mower immediately after starting - just adjust the carburetor according to the diagram given in the documentation. Sometimes it is necessary to loosen the carburetor valves to facilitate the flow of mixture into it.

Sometimes the lawn mower stalls due to the intake of a large amount of air. In this case, it is necessary to increase the engine speed to release it. You should also check the fuel hose for possible damage. If necessary, it is replaced with a new one.

It is important to keep the gearbox clean, and its gears should always be treated with a special lubricant. It is worth noting that it is not always possible to repair the gearbox and starter on your own, therefore, if these components break down, it is more advisable to replace them with new ones

When reducing engine power, you should pay attention to the exhaust muffler, or rather, to the mesh in it. It can become clogged due to soot resulting from burnt oil.

This problem can be solved by cleaning the mesh. This can be done using a small brush with wire or nylon bristles and compressed air.

The clutch in lawn mowers can break due to worn out pads or a broken spring. In both cases, faulty spare parts are replaced. Sometimes the clutch becomes unusable; it can also be replaced with a new one. Moreover, both fully assembled couplings and individual elements for them (washers, drums, etc.) are available for sale.

Proper care of a chainsaw

There are no unnecessary phrases in the operating instructions; everything that is offered is aimed at trouble-free operation of the lawn mower. Cleaning all parts after each work cycle allows for easy removal of unhardened residues and dirt. Only cooled components need to be cleaned. This technique contributes to the quality of air cooling of the engine and gearbox.

To refuel, you must use fuel with the oil recommended in the instructions. If the combustible mixture is left in the fuel tank, the oil will float to the surface and land on the damper during startup, impairing its adjustment. The mixture may form sediment and clog the fuel supply in the carburetor.

When storing equipment for the winter, inspect it, lubricate the gearbox and piston system, wrap the entire saw in an oiled rag and store it in a dry place.

It is impossible, as it is dangerous for the tool and the health of the mower, to use a metal cable instead of a fishing line. It cuts more efficiently, but the load on the gearbox and engine increases. When a piece of wire breaks away, it flies at the speed of a bullet. Effective mowing can lead to rapid wear of the engine piston group. For greater mowing efficiency, it is suggested to use a “star” fishing line profile.

Is everything intact, clean, and working?

Let's try to adjust it. We take a long screwdriver, find the idle speed adjustment bolt (it is located on the throttle valve), tighten it a couple of turns so that the valve opens slightly. Let's start it up. Does it work smoothly? Then let's move on. Won't start or stalls? Opens the throttle slightly until it starts reliably.

Next, we adjust the quality of the mixture with screw L. We need to achieve maximum idle speed. Here the principle is the opposite - the more the bolt is unscrewed, the richer the mixture. After this, the quality of the mixture is adjusted at maximum speed with screw H.

If adjusting the carburetor does not bear fruit, then it needs to be disassembled. Inspect the membrane, clean the jets and internal passages. To do this, you need not only to have a repair kit, but also, preferably, a spare carburetor.

What resource does a Chinese lawn mower have?

A Chinese or Russian brush cutter can work for about 500 hours. But this is with the right mixture, good oil, good factory assembly. If a person fills with gasoline from one good gas station, accurately measures the same oil using a beaker, adjusts the carburetor to the same mixture, and the fuel burns correctly, then the coveted five thousand hours of service life is quite an affordable bar.

But here we must not forget about Chinese marriage. They even balance the shafts on a knee, install the cheapest bearings, and stamp carburetors with clogged channels. If a person understands the principle of operation of a two-stroke engine and carburetor, and understands how to rebuild it, then he can eventually assemble an almost perfect trimmer.

In general, if we consider the Chinese brush cutter as a space for creativity, then even its breakdown is a reason to learn something new, this is a construction kit for a man.

If you just need a tool, then you should look for a Japanese equivalent, or switch to an electric model.

Briefly about engine repair

Problems in the engine begin after several years of proper operation due to wear of components or suddenly when the trimmer is used incorrectly. Unfortunately, people regret improper operation when they repair gasoline trimmers with their own hands after an engine breakdown. And this happens in cases where the dosage of oil in the fuel is not observed or the device operates to the point of terrible overheating. Overheating may cause the crankshaft to jam, the piston rings to break, or the piston to completely burn out. In order to perform a piston inspection, it is enough to remove the cylinder head, from under which the piston will appear, clearly reflecting the condition of its working surface. The rings themselves do not protrude from the cylinder, so it does not matter whether you change the rings or the piston, in both cases you will have to remove the cylinder. When repairing gasoline trimmers with your own hands, it is worth remembering that they are fragile and can easily break if you lack experience. Installing the piston itself on the crankshaft is not too difficult. The main thing when repairing an engine is to assemble everything the same way as it was before disassembly, and then everything will work again.

Trimmer repair is necessary when the device does not turn on or functions incorrectly. All owners of private houses and suburban areas are familiar with the problem of excessive vegetation, which is sometimes difficult to get rid of. As you know, progress does not stand still and new developments and useful inventions appear in all areas. This also affected agriculture. You no longer need to mow the grass with old, inconvenient devices; modern gas mowers have come to the rescue, capable of getting rid of vegetation in the most inaccessible places.

With a gasoline trimmer you can mow the grass even in cloudy weather. Taking care of your garden plot with the help of this unit is very simple, and any adult man can cope with this task.

Despite their versatility, like any equipment, trimmers tend to break and fail.

Not everyone can do the repair of a trimmer with their own hands, because this requires skills in repairing electrical appliances, but today we will try to figure out how to start a trimmer without a starter and how you can generally debug its operation with your own hands.