Reasons why there is no spark on the trimmer

Walk-behind mowers are a popular seasonal tool designed to remove unnecessary vegetation in the local area. Like any other equipment, these devices break down periodically. Repairing the trimmer ignition coil is one of the popular problems typical for gasoline scythes. The ignition system itself is designed similarly for two- and four-stroke internal combustion engines, so troubleshooting is carried out almost the same way for tools of different brands, Huter, Husqvarna or another brand. Methods for restoring the functionality of the ignition coil or replacing it with a new one are in the material below.

No spark at trimmer

Many trimmer owners are faced with a problem when the device simply does not start.

One reason for this could be a lack of spark. This usually happens when fuel floods the spark plug. In addition, you need to check the spark plugs for serviceability, as this can also lead to a lack of spark.

The first sign of a faulty spark plug is the presence of a short circuit between its contacts, or, in short, no spark on the trimmer.

In addition, the spark plug is considered faulty if it is covered with a black, wet layer.

This layer appears from oil that has entered the combustion chamber. In such a situation, you have two options: either clean the spark plug properly, or buy a new one.

Sometimes it happens that the spark plugs are clean, but the problem may be in its insulation, which is often covered with black dry soot.

This may be due to a weak spark, too low spark plug temperature, poor fuel quality, dirty air filter or prolonged idling.

The solution here is the same - clean the spark plug or replace it with a new one. Moreover, the spark plug should be replaced even if the contacts are sufficiently worn out.

If there is no spark at the trimmer, professionals at the service station will tell you how to solve the problem.

Sometimes, the problem may be with the magneto. The magneto may become unusable due to the fact that you could pull the starter cord at a time when the ignition was turned off and the spark plug was not grounded to ground.

Such actions can easily damage the magneto. In such a situation, the only way out is to buy a new magneto.

In addition, the problem may lie in the ignition unit. This option can be considered if the spark plug and wire do not have any faults.

In such a situation, it is necessary to replace the ignition unit. It can be found attached with two screws to the engine cylinder.

To gain free access to the unit, it is necessary to remove the enclosing casing.

To correct the current situation, the entire assembly will have to be replaced, since, as practice has shown, replacing individual parts gives insufficient results.

If there is no spark on the trimmer, there is only one way to fix it - replace it.

Moreover, sometimes the problem should be looked for in the ignition coil. A lack of spark can result from a coil failure or a fault in the circuit.

To check the flow of current into the primary winding of the coil, you can use a light bulb, which must be turned on instead of the coil.

Then you need to carefully inspect the breaker contacts. If a strong spark occurs between the contacts at the moment of opening, you can be sure that the capacitor is broken.

You can also watch a video about starting a lawn mower

Rules for operating and storing lawn mowers

In order for the lawn mower to start well in the future, you need to provide it with good storage and operating conditions:

During operation, carefully monitor the cooling system, carefully and promptly clean the channels in the housing, as well as the starter fins;
if necessary, use solvents, kerosene and other detergents for cleaning;
Do not clean the tool “hot” - let it cool down;
strictly follow the operating instructions, otherwise you may overheat the engine;
if you do not plan to use the lawn mower in the next month, you need to drain the fuel mixture from it, because over time it breaks down into heavy fractions that will definitely clog the carburetor channels;
After draining the fuel, let the trimmer idle until it stalls, this will help completely remove the remaining working mixture.

Currently reading: Buy Knives for Makita trimmers in Moscow: best price from Makita Pro dealer

Before winter storage, take the following steps:

completely disassemble the braid, rinse and clean all the parts you can;
inspect the parts for damage, if necessary, eliminate distortions, tears, bends and any other defects;
pour a sufficient amount of oil into the gearbox and clean the air filter;
you can partially disassemble the motor, wash, blow and lubricate all moving parts;
in order to lubricate the piston, you need to unscrew the spark plug, use the starter to raise the piston to the dead center, pour a little oil into the spark plug hole and turn the crankshaft a couple of times;
If you store the lawn mower outside the house, wrap the engine with oily rags.

Remember, careful adherence to the rules will allow you to forget that it is difficult to start a lawn mower for several seasons.

Why

Petrol trimmer won't start? Prerequisites and their elimination

Coming soon: petrol trimmer

acquired the status of one of the main tools in the arsenal of summer residents. And this is logical, because a motorized scythe allows you to quickly get your garden plot in order. But from time to time it happens that the trimmer does not start in hot or even cool conditions.

Gasoline Trimmer Doesn't Start Reasons No Spark

How not to get confused if your lawn mower won’t start

The instrument, despite its small dimensions, is a complex technical device.
If you study the instruction manual, it turns out that the reasons why the lawn mower does not start are known and can be eliminated. It is necessary to eliminate one by one the reasons that make it difficult to start the tool. Usually they start with more accessible nodes with easy testing of serviceability.

How to remove the spool from the trimmer and remove the fishing line

Initially, before threading the fishing line into the trimmer reel, you need to remove it from there. The reel or pointer is a device that is located inside the mowing head, reel or drum. Heads come in different types (depending on manufacturers), but the principle of replacing line on a reel is the same for all. First of all, let's figure out how to remove the head from the tool, as well as how to get the drum with fishing line out of it.

This is interesting!
You can replace the equipment directly on the tool, but if you are doing this for the first time, it is still recommended to remove the head and study the detailed winding process.
After the technology has been mastered, replacement work can be carried out using a trimmer, lawn mower or lawn mower. The instructions on how to unscrew the manual head on a trimmer are as follows:

Turn the tool upside down and, if necessary, clean it of dirt. With two fingers of one hand, grasp the cover latches (on the mowing head), which are located symmetrically to each other. After lightly pressing them inward, remove the protective cover from the drum
Next, remove the fishing line spool from the drum shaft. It is mounted on a shaft without fastenings, so it can be dismantled with one hand
The main part of the drum is secured with a screw, which must be unscrewed with a screwdriver with an appropriate tip or bit
To unscrew, you need to hold the base of the drum with one hand and use the other to unscrew it counterclockwise with a screwdriver
After this, you can begin dismantling. To do this, you do not need to pull it with all your might, but by slightly rocking it to the sides, slowly disengage it from the metal shaft on which the drum is mounted
When reinstalling, the head should be seated in the tetrahedral slots

This process is not difficult, and as you understand, there is no need to dismantle the entire head if you know how the replacement is carried out. When dismantling, consider the following nuances:

It is recommended to remove the head periodically to prevent corrosion of the threaded connection. If you never unscrew a screw, then if necessary, it will be difficult and even sometimes impossible to do so.
If the screw has a tetrahedral head bore, then for unscrewing you should select a screwdriver or bits of a suitable size to prevent the edges on the head from licking off
When assembling the unit, the threaded seat should be treated with lubricants, for example, grease or machine oil
If the edges on the screw are licked off, you can use special clamping pliers to unscrew it.
There are drums that do not require preliminary disassembly. To dismantle them, grab it and rotate it in the opposite direction clockwise

Knowing how to disassemble the drum, you should continue to figure out the process of replacing the trimmer line. The video below shows the detailed process of how to open the trimmer coil and disassemble it.

https://youtube.com/watch?v=d0I7X1FxQEc%3F

Troubleshooting

All the reasons why a lawn mower does not start can be systematized according to the specifics of the operation of individual components. At the service center, faults are systematized:

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

The user first needs to check whether there is fuel in the tank. Start up in accordance with the instructions, placing the saw on its side. Gasoline trimmer; starts without problems. It may not start. Set the air damper to the “closed” position, pump up the fuel, turn on the ignition and make 3-4 sharp jerks with the starter. If the engine starts, open the air damper. does not start - we repeat the operations with the air damper slightly open.

The brush cutter cannot work for a long time. The gearbox and engine will overheat. You can mow for less 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 find the cause of the failure:

check the quality of the fuel;
make sure the spark plug is working and the spark plug channel is clean;
check the cleanliness of the air filter ;
make sure that 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. Causes of gasoline breakdowns and why the gasoline trimmer does not start the internal combustion engine. Repairing a lawn mower yourself if it won't start will require patience.

First launch at the beginning of the season

In late spring, when the active use of gas mowers begins, before starting work, you need to inspect and check the functionality of your tool.
It is imperative to lubricate the rotating parts, inspect and, if necessary, replace the cutting elements (knife or fishing line). If this is your first time using a trimmer, be sure to read the instruction manual. Such instructions should be included with each lawn mower.

Starting most two-stroke engines is quite simple. Use the procedure described in your trimmer's manual if it differs from the following:

Move the choke lever to the "open" position. Place the trimmer on its side so that the air filter is on top.
Hold or lock the throttle in the on position (the throttle should be held until the engine warms up).
If the device has an on/off switch, move it to the on position (usually indicated by an "I" symbol rather than an "O").
Make sharp, quick jerks with the starter handle until you hear the engine try to start. This should happen between 1-6 jerks, but no more.
Close the throttle valve halfway and restart the starter. The engine should start after 2-6 additional pulls. If not, move the throttle lever to full position and pull the starter handle again. Return the lever to half throttle and pull 3 more times.
After starting the engine, continue to hold the start button and allow the engine to warm up for 10 seconds, then disengage the starting system.
When the trimmer warms up, it should restart with the throttle in the closed position.

You can also use another proven technique. If you remove the air filter before starting and pour a couple of drops of the mixture into the carburetor and reassemble it, the engine should start.

Eliminating the reasons why the lawn mower does not start

The fuel mixture must be prepared with exact adherence to the proportions of gasoline and oil. In this case, you cannot use another brand of fuel. To prevent dirt from getting in, gasoline should sit in a glass or metal container for 2 days. Do not use plastic containers to store fuel. Measure the oil accurately using a medical syringe without a needle. Use only freshly prepared mixture, without leaving unused fuel in the tank. If the engine is capricious, the lawn mower stalls; when you press the gas, the fuel may be to blame.

Maintenance and prevention of startup problems

To ensure your tool lasts longer and doesn't cause problems, keep it clean and perform regular maintenance.

Do not store a fueled lawn mower: if you leave it for more than 2 weeks, and even more so during the winter, drain the remaining fuel from the tank, then start the engine and let it run until it stalls. When leaving the tool in the shed for the winter, wrap the motor and knives in an oiled rag.

To lubricate a 2-stroke engine before storage, unscrew the spark plug and use the starter to lift the piston to the very top. Drop some engine oil from the syringe and use the starter to crank the crankshaft several times.

In the spring, before the first use after inactivity, it is advisable to check the spark plug and filters, disassemble and wash the carburetor, even if there are no problems with starting.

No Spark on the Lawnmower Cause

Build your own House!

No spark at trimmer

Many owners of trimmers are faced with a problem when the device simply does not start.

One of the reasons for this may be the lack of spark . This usually happens when fuel floods the spark plug. In addition, you need to check the spark plugs for serviceability, as this can also lead to a lack of spark.

The first sign of a faulty spark plug is the presence of a short circuit between its contacts, or, in short, no spark on the trimmer.

In addition, the spark plug is considered faulty if it is covered with a black, wet layer.

This layer appears from oil that has entered the combustion chamber. In such a situation, you have two options: either clean the spark plug properly, or buy a new one.

What to do?

It is important that there may be no spark on the chainsaw due to a malfunction of the fuel system. In order not to look for a problem in the working ignition, this issue must be dealt with immediately.

The Chinese brush cutter won't start. This is interesting.

Spare parts for Chinese brush cutters The Chinese one won't start

brush cutter.

If there is no spark at the trimmer, professionals at the service station will tell you how to solve the problem.

Such actions can easily damage the magneto. In such a situation, the only way out is to buy a new magneto.

The main thing is the fuel mixture!

Often gas trimmers

do not start after they are tried to be “put into operation” after a long period of storage. Startup problems in this case are often caused by incorrect user actions.

If you encounter this particular phenomenon, then during a cool start you need to close the damper, then pump a small amount of fuel mixture into the carburetor. After disassembling and assembling the Husqvarna 142 saw, the spark on the spark plug disappeared. What to do. Then pull out the starting handle until you feel resistance, then start the trimmer with sharp and energetic movements.

Reasons why there is no spark on the trimmer

Spare parts for chainsaws and trimmers with delivery by Russian Post throughout the country, cash on delivery. SDEK, PEK, Business lines by prepayment

Spare parts for chainsaws
Cylinder-piston groups of chainsaws
Chainsaw carburetors
Starters for chainsaws
Chainsaw ignition coils
Chainsaw chain brake covers
Chain tensioners
Chainsaw clutch
Oil pumps
Chainsaw crankshafts
Chainsaw flywheels
Chainsaw bearings
Seals and gaskets for chainsaws
Chainsaw shock absorbers
Other components and parts of chainsaws
Chainsaw tank plugs (caps)
Chainsaw mufflers
Spare parts for trimmers
Cylinder-piston groups of trimmers
Carburetors for trimmers (gasoline trimmers)
Starters for trimmers (gasoline trimmers)
Ignition coils for trimmers (gasoline trimmers)
Clutch of trimmers (gasoline trimmers)
Trimmer flywheels (gasoline trimmers)
Trimmer gearboxes (gasoline trimmers)
Crankshafts of trimmers (gasoline trimmers)
Bar and handle elements
Trimmer seals and gaskets
Mufflers for trimmers (gasoline trimmers)

Selection by models

Chainsaws
Spare parts for Chinese chainsaws 45, 52 cc
Spare parts for Chinese chainsaws 38 cc
Spare parts for Chinese chainsaws 25 cc
Spare parts for Chinese Shtil 660
Spare parts for Partner 350, 351, 352, 371
Spare parts for Partner 340S, 350S, 360S
Spare parts for Husqvarna 137, 142
Spare parts for Husqvarna 230, 235, 236, 240
Spare parts for Husqvarna 365, 372
Spare parts for Shtil 180
Spare parts for Shtil 210, 230, 250
Spare parts for Shtil 290
Spare parts for Shtil 361
Trimmers
Spare parts for Chinese trimmer 33, 43, 52 cc
Spare parts for Chinese trimmer 26 cc
Spare parts for Husqvarna 125, 128
Spare parts for Champion T283, T284

Consumables

Motors

Ignition coil (magneto). Checking serviceability and setting the gap.

We often encounter situations where tool users come in with a faulty ignition. Often it actually turns out to be faulty, but often the ignition coil has nothing to do with the breakdown of the tool. The steps to check the serviceability of the ignition coil are described below.

Assessment of the current state of the coil.

Before working on the ignition coil, it is worth checking the serviceability of the entire circuit. Do the following:

visually assess the absence of cracks and visible defects on the reel body
contamination of conductive elements and components
serviceability and insulation of high-voltage wires, wire contacts, reliability of their fastening, absence of rust at fastening points
check the condition of the spark plug cap: it is often torn off from the high-voltage wire and tried to be restored using “improvised” methods. Remember: any “snot” in this place reduces the quality of the electric arc of the spark plug
check the serviceability of the spark plug. The quality of our gasoline does not allow the spark plug to “live long”
Check that the circuit breaker is working properly. This is especially true for Chinese saws and trimmers.

The point of these actions is to exclude from the list of possible faults all circuit elements except the coil. If everything is ok, we move on.

How to look for mechanical faults

The transmission of rotation from the electric trimmer to the mowing head is carried out in the same way as in models with an internal combustion engine: a solid shaft operates inside the rectangular section of the bar, and a cable operates inside the curved section.
Their length, diameter and design are selected by the manufacturer for the specific dimensions of the composite rod.

Features of the connection point of the composite rod

It is made with an adapter with a screw clamp.

The large screw head is made for easy adjustment of the position of the mowing unit at the bottom of the bar. The rotation angle is selected individually.

It is convenient for me to set it so that the longitudinal axis of the protective casing and the axis of the electric motor are located in the same plane.

At this point, a malfunction may sometimes occur due to the transmission of torque from the direct shaft to the cable. It manifests itself in the fact that when the engine is idling, the trimmer works normally, but under a small load the mowing head stops rotating.

The method for eliminating it was well demonstrated by the owner of the video “Repairing an Electric Trimmer,” Roman Shapkov. I recommend watching it.

Method of fastening the mowing head and casing

On my trimmer, the bottom of the rod has an adapter secured with rivets, into which the fastening bolt of the protective casing is screwed.

The output shaft of the rotating cable has a hexagon at the end. A plastic mowing head is placed on it.

A return spring for automatic line release when mowing is inserted into it from the inside.

A spool is inserted onto it. It is screwed on top with a fixing nut.

The structure of the mowing head with fishing line is quite simple.

However, all plastic parts do not have high strength and are subject to wear. Their work surfaces are erased. After three seasons of working on my trimmer, the output holes of the line from the mowing head have widened, and the thickness of the fixing nut has decreased.

Applying protective measures to wear is difficult, and the easiest way to repair these parts is to completely replace the head. It is not difficult to buy: you just need to know the exact dimensions of the hexagon and evaluate the new design based on its performance characteristics.

Secrets of choosing fishing line

Among the common malfunctions of a trimmer reel, there are cases when the line runs out or simply gets tangled due to improper winding on the spool. Eliminating them is not difficult.

But in practice, I encountered another defect in the fishing line, which was sold in the state retail chain from Moscow. Its appearance is in original packaging.

As I understand it, it is specially hidden in a sealed bag: you cannot touch it when purchasing.

When I opened the packaging to install the fishing line into the spool, I immediately noticed its plasticity, not its elasticity. It bends easily and behaves like a soft wire: upon contact with grass, it immediately breaks. It is impossible to mow it: I managed to return it to the seller.

Since then, I only buy fishing line that I can crush in my hands and evaluate its performance properties.

I try to avoid varieties of regular round fishing line. I prefer a ribbed shape with edges: a star, trapezoid, square or triangle. They cut grass better.

How to eliminate increased vibration

The trimmer's reliably assembled mechanics are well balanced. It provides convenient operation. However, bearings can wear out over time and lose lubrication.

The assembled shaft, which transmits rotation from the engine to the spool, is capable of touching the inner walls of the rod, creating excessive friction with heating.

Such a defect can and must be eliminated. Repairman TV demonstrates this technology in his video “Vibration during operation of an electric mower.”

Useful products

Sponge rod for cleaning rust
Pocket folding knife
Wi-Fi smart home module Sonoff

Useful services and programs

Design courses
Online learning English with a tutor or on your own

Why do you need a good spark?

The quality of the spark determines its ability to ignite a properly formed air-fuel mixture under operating conditions. A weak spark under conditions of high pressure and temperature in the combustion chamber cannot do this. Ignition occurs later or does not occur at all. Uneven operation of the engine occurs, the engine does not gain speed, vibration and detonation occur, and a “kickback” effect may appear in the starter.

The insidiousness of such a breakdown is that diagnostics using the methods given below does not give one hundred percent confidence in the operability of the ignition coil. Such an implicit breakdown, when there seems to be a spark, but it is not quite correct, often misleads and forces you to attribute problems with the ignition coil to a carburetor malfunction. Typical action in such cases is to increase the fuel supply. It turns out that such a spark can ignite an enriched mixture, but not the right one. But the use of an enriched mixture leads to rapid wear of the cylinder-piston group and muffler. Therefore, in such controversial situations, check both the carburetor and the ignition coil once again.

Why do you need ignition adjustment?

In some cases, when the engine does not start, ignition adjustment will be required. Of course, first you need to check the serviceability of the spark plug and the high-voltage cable with a cap.

It is necessary to regulate the ignition on a two-stroke engine in order to ensure timely ignition of the fuel in the engine combustion chamber. Below is a diagram from which you can understand the principle of operation of the internal combustion engine.

A spark in the spark plug should appear at the moment the fuel is compressed by the piston, when it just barely reaches top dead center (TDC). When the piston passes TDC, the fuel mixture ignites, causing the piston to move downward under the influence of the explosion energy.

Therefore, if for some reason (mostly this occurs due to the displacement of the flywheel on the shaft relative to its original position) fuel ignition occurs before the piston passes TDC, then it returns back, and the crankshaft rotates in the opposite direction. This movement may damage the starter assembly, break the starter cord, etc. In this case, early ignition of the fuel

It could also be late ignition.

on the trimmer: the piston, after compressing the fuel that has not ignited, goes down, and at this moment a spark appears. In this case, the engine either will not start or will significantly lose power and will have difficulty gaining speed.

But such problems with early or late ignition on two-stroke internal combustion engines are quite rare, since the flywheel with magnets is already installed in the correct position, which is perfectly synchronized with the movement of the piston. In addition, the flywheel is fixed to the shaft using a key and a nut. Therefore, incorrect installation of the part is excluded.

Basically, ignition adjustment consists of setting the correct gap between the magneto and the flywheel.

Checking the ignition coil.

To eliminate possible malfunctions from the wiring and shutdown buttons, it is possible to disconnect the control wires from the coil during the test.

Measuring coil resistances. This method is not always applicable: firstly, you need to know the resistance parameters of the coil windings. Secondly, in addition to the inductor, the ignition contains semiconductor elements to form the required high-voltage pulse. Therefore, when we try to ring the magneto through the high-voltage and negative wires, we will get either an “Open Circuit” reading or a huge resistance. If the circuit still rings, then most likely this is a sign of a malfunction.
Using a device that checks for the presence of a spark. It is mounted in the open circuit between the spark plugs and the high-voltage wire of the ignition coil. The device is expensive and is used mainly in serious service centers.
With the help of a candle. Remove the spark plug and place its body against the cylinder. Pull the starter and watch for a spark between its contacts. This method is approximate and does not give a complete picture of the condition of the ignition coil, since the spark plug is not “under pressure” and the flywheel will rotate faster due to the lack of compression in the engine (the spark plug is turned out)
"Barbaric" way . It is used at your own risk in hopeless situations.

remove the cap from the candle and insert a nail into it. Be careful not to damage the inside of the cap - then put it back on the candle and use it. It is better to bite off the head of the nail. Otherwise, it may be difficult to remove it.
position the nail 6-7mm from the cylinder.
“start” the engine, that is, perform the usual actions when starting the tool. This will force the ignition system to work. Please note that the candle must be screwed into the spark plug hole.
look at the presence and color of the spark. Ideally, the spark should be “strong” and bright blue. Everything else is a sign of a malfunction.
Important points:

— the spark plug cannot be unscrewed: the lack of compression will lead to faster rotation of the flywheel, which will not correspond to real operating conditions

- if there are electronic components in the ignition system, then this method can damage them

— the distance between the nail and the cylinder simulates the compression and dielectric properties of the fuel mixture. The distance of 6-7mm is approximate and may differ on different product models.

The philosophy of the method: there must be a large gap between the nail and the cylinder, the spark must be “strong” and bright blue

Ignition control algorithm

The ignition on the trimmer is adjusted quite simply.

If there is no spark, you need to replace the spark plug, and if the spark is weak and unstable, then it is better to clean it with fine sandpaper or a file. But, in 90% of cases, the cause of problems with the lawn mower lies elsewhere. Most often, problems arise due to a clogged carburetor, and later in this article we will tell you how to clean it yourself.

We will demonstrate the process of cleaning the carburetor using the example of a Craftsman gasoline lawn mower with a Briggs & Stratton engine. Most lawn mowers and their engines are very similar to each other, so this material will be applicable in most cases. So let's get to work!

Attention! Gasoline leaks may occur during operation. You cannot work indoors. Before starting work, make sure that there are no open sources of fire nearby. Don't smoke while working!

First of all, use a flathead screwdriver to remove the air filter housing from the engine. After unscrewing the screws, remove the plastic casing and take out the air filter. Pay attention to how dirty it is. A poor filter condition can also cause engine instability, so if necessary, replace the filter or at least clean it with a vacuum cleaner.

Why won't the trimmer start

petrol? Prerequisites and their elimination

What to do if the fuel mixture used is in perfect order, but still does not start

petrol trimmer? The reasons for the failure of the mechanism may lie in excessive moisture in the spark plug channel. To diagnose and fix the problem, you must do the following:

Unscrew the spark plug. Wipe it thoroughly and then dry it.
Drain excess fuel in the chamber through the appropriate spark plug hole.
Clean the old spark plug if there is carbon deposits on its surface. Using a regular ladies' nail file or a needle file will allow you to cope with the task.
When installing the element in place, set a gap of 1 mm. Interesting articles: what to do if a gasoline lawn mower does not start? Useful material on the website of the online store of gardening equipment, equipment and tools “gardener”. To check the parameter, just place any coin in the gap.
Reassemble the functional block.
Try to start the trimmer.

It is recommended to dry the spark plug channel for at least half an hour. However, in no case should you resort to calcining its elements. After all, heating the spark plug can lead to its final damage. What to do if the functional unit has been serviced in accordance with the above recommendations, but the trimmer does not start

, is there a spark? In this case, it is worth treating the threaded connection with gasoline. The latter does not need to be heavily soaked in fuel. It should be only slightly moistened. Such actions should be taken to ensure ignition. Gasoline is your new lawn mower if the lawn mower is no longer new. After all, no matter how strong a spark the candle gives, in a completely dry chamber there will simply be nothing to ignite.

Setting up the ignition system.

Most modern models of chainsaws and trimmers do not require setting the ignition timing. This angle is determined by the position of a special groove on the flywheel for keyed fastening to the crankshaft and magnets installed on the same flywheel.

It is only necessary to correctly set the gap between the flywheel and the ignition coil. Depending on the tool model, the gap size may vary. Usually it is 0.2-0.4mm. Since the flywheel is round, a regular car feeler gauge will not work for this purpose. It would be technically correct to set the gap according to a special template. But it is not always possible to purchase it. It is unwise to buy such an expensive template for one-time use. Instead of a corporate template, you can use a strip from a plastic water bottle. Cut a strip from the bottle in the place where there is no relief embossing. Further steps for setting the gap are approximately the same for both chainsaws and trimmers:

Loosen the ignition mounting bolts.
Connect the magnets on the flywheel to the ignition coil
Holding the bottle plate between the flywheel and the reel, tighten the mounting bolts.
Remove the strip
Rotate the flywheel 360 degrees several times, making sure that it does not catch on the reel anywhere.

All. The gap between the coil and the flywheel is set.

Repairing the ignition coil is impossible and impractical. Below is a list of ignition coils that can be purchased on our website

Repair and lubrication of the lawn mower gearbox

The role of the gearbox is to transmit torque from the motor shaft to the cutting tool through 2 toothed gears with different numbers of teeth. Torque is transmitted at an angle of 30 0. The speed of the lower cutting disk is 1.4 times less than the engine speed. Gears must be clean and lubricated. There is a hole under the screw on top to supply oil to the teeth.

The lawnmower gearbox is lubricated at least once a season. If the work is intensive or there is extraneous noise in the lower unit, it is necessary to lubricate more often.

First, you should clear the area where the plug covers the hole from soil and grass. Unscrew the plug with the appropriate tool, it is included with the saw. We use grease from a tube. Either the original lubricant from the manufacturer or well-known high-quality compounds, such as Oleo-Mas, Litol-24, Azmol 158, is selected.

Too little or too much lubrication can cause the gearbox to heat up. An audible knock and play indicate the destruction of the bearing or the ingress of dirt due to damage to the anthers. Bearings must be replaced using a puller, without using the heating method.

If the gearbox wobbles and moves along the rod, it is necessary to replace the housing, or temporarily tighten the assembly with a clamp to secure it to the pipe. If the knife stops rotating, it means that the gears are not engaging - the teeth have become worn out or chipped. The pair will need to be replaced with complete disassembly of the unit.

Disassembly of the gearbox with removal of the shaft and bearing units cannot be carried out using heat. When heated, the metal loses its strength qualities and subsequently the unit becomes unreliable. To remove bearings, use a puller.

When replacing a gearbox, it is necessary to select a new unit, guided by:

pipe diameter;
drive shaft diameter;
drive shaft cross section;
method of securing protection

How to check a spark - a selection of methods for different engines

If there is no spark in your car's engine (injection or carburetor), it will stall or not want to start at all. This is not surprising, since if there is no spark on one or more spark plugs, the ignition process does not occur in the engine cylinders, and the fuel simply flies into the exhaust pipe. In this article we will look at the main reasons why the spark disappears. You will also learn which elements of the ignition system need to be checked in case of such a malfunction and how to solve the problem.

How to prevent sudden breakdowns during operation of the trimmer?

To ensure that the unit is always in functional condition, you should follow a few simple rules:

Conduct timely, regular technical inspection of the main mechanical components of the device.
Refill the trimmer exclusively with fresh fuel, the quality and origin of which is beyond doubt.
After each use of the tool, check whether oxides and carbon deposits have formed on the surface of the ignition system elements.
Avoid heavy load on the trimmer during work.

In order for the unit to remain in working condition, it is necessary to properly prepare it for storage during the winter. First of all, you should completely disassemble the tool, and then rinse and clean the components. It is also important to inspect the functional units for damage, if necessary, eliminating deformations of parts, all kinds of distortions, and tears in materials.

When storing the trimmer, it is worth filling the gearbox with a sufficient amount of oil. Then you need to clean the air filter, partially disassemble, blow out and wash the engine of the unit. After drying all the mechanisms, you should lubricate the moving elements. To treat the piston system with oils, you must first remove the spark plug. Then you need to move the piston to the extreme position, then pour a small amount of oil into the spark plug hole and scroll the crankshaft. If you plan to store the gasoline trimmer outside of the house during the off-season, it is recommended to tightly wrap the engine of the unit with an oily rag. This will avoid the development of corrosion on the surface of important components of the mechanism.

Typical causes of spark loss

Depending on the type of powertrain, there are several factors that can cause the spark plugs to fail to spark. In most cases the reasons are as follows:

Low battery.
Damage or failure of spark plugs. They can also be filled with gasoline or oil.
Malfunction of the module, switch or ignition coil.
Poor contact or damage to the insulating layer of high-voltage wires.
Malfunction of the crankshaft position sensor (CPS).
Malfunctions in the operation of the distributor.
Problems in the low voltage circuit.
Poor ground contact.
Malfunctions in the operation of the engine ECU (electronic control unit).

Magneto - design and operating principle

The purpose of the ignition coil is to convert rotational energy into a high-voltage discharge and form a spark that ignites the fuel mixture. In an internal combustion engine, this part is called a magneto, since in it alternating current is generated from the rotation of a permanent magnetic rotor or armature.

The magneto is structurally composed of two windings: high and low voltage. A capacitor with breaker contacts is connected in parallel to the latter. While the leads of the high voltage winding are connected to the spark plug and the housing. They are both wound on a core, between the poles of which a rotating magnet, magnetized longitudinally, is installed.

On a note! The whole structure looks like a large coil mounted on a U-shaped core.

Battery diagnostics

The most common reason is a dead battery. If the indicators on the instrument panel dim when you turn the ignition key to start the engine, the battery is discharged. Sometimes the reason lies in poor contacts at the battery terminals. These problems can be solved simply:

if the battery is simply discharged, you need to recharge it or replace another battery;
if the problem is in the terminals, it is necessary to thoroughly clean them from corrosion and tighten them securely (to avoid further oxidation, it is recommended to apply graphite lubricant to the contacts).

Methods for checking an injection and carburetor engine in the absence of a spark

If there is no spark on the engine, different diagnostic methods are used:

checking for ground;
checking with a digital multimeter (tester);
using a special tester with a piezoelectric element.

It is recommended to use the ground test only on vehicles with a carburetor. To do this, you need to take a spark plug and bring it to any metal part of the engine (the cylinder block is good). Another person in the cabin should try to start the engine by turning the key in the ignition. This determines the supply of a spark to a specific spark plug.

Important! It is not advisable to use this method to check the spark on injection machines, since they use expensive electrical equipment that can fail due to such “diagnostics”.

Using a multimeter allows you to check the spark plugs themselves. The diagnostic principle does not differ from the first method, but the likelihood of damage to the engine ECU is minimized. A special device called a “discharger” allows you to check the spark on a carburetor engine. Using such a device, you can easily determine in which segment of the car's ignition system there are problems.

If there is no spark in all cylinders, the culprit may be the controller, ignition coil/module, or center wire. First you need to check the condition of the fuses. After this, we check the ground connection and high-voltage wires.

If there is no spark at the coil, you need to check the condition of the central high voltage wire. The presence of damage to the insulating layer, breakdowns and other defects is unacceptable. If they are found, this element must be replaced.

In addition, while searching for a spark, do not forget to check the spark plugs. But it is advisable to do this only after you have reliably established that the spark definitely reaches the spark plugs. The check is performed using the method mentioned above. The spark should be white with a slightly bluish tint. If there is a spark, but it is weak, check the condition of the spark plug contacts. In any case, replacing spark plugs is inexpensive, so it won’t be superfluous.

And again the carburetor.

If even after such abuse your trimmer does not start, you cannot do without disassembling the carburetor. It may very well be that the needle stuck in it is to blame. In any case, disassembling and washing this capricious mechanism certainly won’t hurt. You can do it yourself to adjust the carburetor of a gas trimmer. Gasoline mowers, like all gas-powered tools for the garden, are not difficult to maintain equipment. It is possible and necessary to repair and configure without the help of others. For example, adjusting the carburetor of a lawn mower with your own hands takes 5 minutes. The carburetor from a lawn mower is a component in the power system. Idle…

Gasoline trimmers use both two-stroke internal combustion engines (ICE) and four-stroke ones. But the ignition system in them is no different from each other, so the repair and adjustment of this fuel ignition system will be the same for different types of internal combustion engines.

The ignition system of a two-stroke internal combustion engine consists of 2 elements: a flywheel and a coil (magneto). The picture below shows what they look like.

The flywheel contains an impeller that acts as a fan to cool the engine. Also on one side of the flywheel there are permanent magnets, shown with an arrow in the figure.

When the flywheel rotates, an electric current is generated in the coil, which serves to produce a spark at the spark plug. The spark appears when the magnets are directly under the magneto.

Checking the ignition coil for spark

It is necessary to remove the wire from the distributor. After this, the wire must be brought to the metal element and the engine rotated with the starter. If there is a spark, then the ignition distributor-distributor has failed. If it is not visible, you need to proceed to checking the coil.

If the problem is in the distributor, you need to start checking with its contacts. Problems can be caused by oxidation, breakdowns in the insulating layer, or rotor malfunctions. If you notice problems with the rotor, it must be replaced with a new element.

When diagnosing the ignition coil, check the condition of the winding. Usually the lack of spark is caused by a short circuit inside this part. If you find any signs of it, we advise you to buy a new coil and install it on your car. Also, the ignition coil can be damaged by overloads caused by faulty high-voltage wires or spark plugs.

Checking the coil is done as follows:

the car must be parked in a dry room;
it is necessary to remove dirt from the ignition distributor-distributor cover and remove it;
turn the engine crankshaft so that the distributor contacts are in the closed position;
turn on the ignition and bring the high-voltage wire of the distributor 3-7 mm to the metal part of the engine.

This will also tell you if the ignition coil needs replacing. The most suitable option is to test the coil on special equipment in workshops. This procedure checks the operation of the coil in different modes.

To check the spark on the spark plugs, you need to unscrew them. Pay attention to the condition of the contacts, the presence of carbon deposits or oil. All elements of dirt must be removed before performing the diagnosis. Do not forget about the correct gap between the electrodes. If a discrepancy is detected, the side electrode is carefully bent. Like the coil, spark plugs can only be properly checked using special equipment.

Common causes of breakdowns

The first step is to make sure of the simplest things: the availability and quality of fuel, the correct procedure.

Use only those fuels and lubricants recommended by the manufacturer. Gasoline with too high an octane number is sometimes no less harmful than 80 octane. Didn't keep the instructions? AI-95 from a gas station with a good reputation can be called universal.

Only fill with suitable engine oil. The vast majority of gasoline trimmers have a 2-stroke engine, so regular car oil cannot be used. For a 4-stroke engine, oil is poured separately from fuel. Moreover, you should not pour in “waste” – used, used oil.

Remember, repairing the piston group will cost 30–70% of the cost of a new lawn mower. Savings on the quality of fuels and lubricants are unlikely to cover these costs

Observe exactly the mixing proportions of gasoline and motor oil, do not pour “by eye”. For most lawn mowers, the recommended ratio is 1:25, that is, 40 ml of oil for every liter of gasoline.

Do not prepare a lot of mixture at once: ideally, it should be worked out in 1 day and the equipment should be stored in a dry tank. The maximum shelf life of the finished mixture is 2 weeks, so it makes sense to mix more than 2 liters at a time except for utility workers who mow city lawns.

If you haven’t used the scythe for a long time and there is gasoline in it, it’s better to pour it out. The mixture has already divided into fractions and lost its properties; even the most thorough mixing will not save it.

After making sure that the gas tank is in order, try starting the scythe. To do this you need:

Pump fuel into the carburetor using the primer button 5-6 times.
Close the air damper.
Turn on the ignition on the handle.
Pull the starter cord 1-7 times until it starts.
After 5-10 seconds, turn off the starting system.

After idle time, if you cannot start the engine normally, try opening the throttle and pressing the gas trigger. Without releasing the trigger, pull the starter cord.

A fully functional trimmer starts up within 1-2 times, even if the cord is pulled calmly and not pulled as sharply as possible.

It is also recommended to start the engine with the throttle held down if it has not yet cooled down after the previous operating cycle.

If the engine still does not start after 5-7 jerks, you should look for a breakdown.

Option number 1 - problem in the ignition system

The first thing suspicion falls on is that the spark plug does not produce a spark, and therefore the fuel mixture does not ignite. Most often the problem is in the spark plug itself.

To check, unscrew the spark plug from the cylinder, first disconnecting the wire from it.

A thin layer of brown soot indicates normal engine operation, red or pink soot indicates an abundance of additives in the fuel, change the gas station. If the element is covered with black or white scale, the motor did not work correctly.

A wet spark plug indicates overfilling or excessive pumping of fuel with primer. In this case, the candle needs to be dried, but not heated. Pour out excess gasoline from the cylinder by turning the brushcutter over.

When cleaning, pay most attention to the part of the top electrode that faces the center contact, but do not go too hard

The contacts of a dried spark plug should be cleaned of carbon deposits using a file, sandpaper or a nail file. The gap between them should be 0.7 - 1 mm - this is the thickness of a standard coin. If necessary, bend the top electrode.

Before assembly, it is worth checking the functionality of the spark plug. Connect it to the power supply (put on the cap), apply the body to the cylinder or any metal part of the engine, turn on the ignition, pull the starter. At the end, between the electrodes, with each jerk a bright, powerful spark should jump.

It is very important to follow safety precautions. When checking, there should not be a drop of gasoline on the neck of the spark plug hole and the body of the brush cutter!

If after drying, cleaning and setting the gap there is no spark, buy a new spark plug. It happens that a spark does not appear on a new spark plug. In this case, check the quality of the contacts, try replacing the armor wire - it’s inexpensive and simple.

If there is no spark even with the new wire, you need to buy a new ignition coil. It happens that the cable is not disconnected from the reel; they are sold only assembled. It is somewhat more difficult to replace it yourself, because you need to accurately set the gap to 0.25 - 0.4 mm to the starter flywheel.

The normal gap corresponds to the thickness of a plastic bottle (cut a piece out of it to measure) or 4-5 layers of masking tape

Install the reel with spacer and try it on. Spin the starter until it touches the spacer but turns completely. Remove the paper tape or plastic and finally assemble the assembly.

It happens that when checking, the spark plug produces a small but stable spark, but starting does not occur. After you screw the spark plug into the cylinder, a weak spark may disappear in a closed space. In such a situation, it is also worth replacing the coil: a new one will produce a more powerful impulse.

Option number 2 - you need to replace the filters

If there is a spark, but the scythe does not start, the problem is most likely in the fuel supply. The easiest way to check the air and fuel filter is to start with that.

Testing their condition is quite simple: remove the filter elements and try to start the engine. If it works, it needs replacement or at least cleaning.

The fuel filter may become so clogged that its housing is no longer visible. Naturally, cleaning attempts are useless in this case.

When removing the fuel filter, do not accidentally disconnect the fuel supply pipe from the line - in some models this is possible

The fuel filter is located directly in the tank, at the end of the fuel supply tube. Carry out the following operations:

Pull out the gas tank cap along with the restrictor.
Take a piece of stiff wire and bend one end into a hook.
Feel around with the wire and pull out the tube with the filter.
Assess its condition by eye. In case of visible blockages, replace immediately.
Try blowing it in both directions. The air should exit through the mesh on the sides, with small bubbles of gasoline, minimal resistance.
If it’s a long way to the store with a new filter, but you need to mow it urgently, try washing the old one with clean gasoline and blowing it with compressed air.
Insert the filter into the tube, securely clamp it with a clamp and return it to the tank.

The air filter often causes unstable operation and floating speed, but if it is heavily clogged, it can also prevent starting. It is located on the side, above the carburetor (fuel pre-pumping button).

Do not use the scythe with the air filter removed - you risk damaging the motor with dust! If the cover above the filter does not have a grille, but an air intake valve or just a hole, clean it with a needle

The plastic cover is held on by a latch - remove it. The filter itself usually consists of 2 layers: thick, dense foam rubber and a flat, rigid mesh. If it looks dirty or the engine will only start without it, replace the cleaner or blow it with compressed air.

On average, it is recommended to replace both filters with a new one every 2 years.

Option No. 3 - clogged breather and muffler

The breather is a check valve that allows air into the gas tank, but does not let fuel out. It is most often located on the lid, but sometimes on the body of the gas tank.

When it becomes clogged, the tank becomes sealed, a vacuum is created inside and the power of the carburetor valve is not enough to suck in fuel.

The following signs indicate a malfunction:

The trimmer starts up normally the first time, but after a short period of time it stalls and will not start again.
The outer hole of the breather is clogged with dirt.
The scythe works fine if the gas tank cap is not screwed on completely.
If you disconnect and point down the fuel supply pipe from the carburetor, gasoline drips from it in a thin stream or does not flow at all.

The problem can be solved simply: clean the hole from the outside with a needle, slightly pressing the valve inward, and blow it out with a compressor. If this does not help, you can pick it out of the lid along with the rubber seal.

Disassemble the breather above the table, there are several small parts in it. Try to pull it out with your fingers so as not to damage the thin rubber.

Wash both the rubber parts and the built-in filter with clean gasoline. Blow everything out, dry it and put it back together. If you still cannot blow air through the breather after this, buy a new cover.

The muffler or exhaust port is located on the side opposite the carburetor. On older models it often becomes clogged with soot and carbon deposits. As a result, the engine is choked by exhaust gases and cannot start or stalls almost instantly after starting.

The problem lies in the anti-spark mesh on the engine exhaust. It can be cleaned with a needle or completely removed.

Option number 4 - problem with the carburetor

Many owners, at the first problem with starting a lawn mower, immediately disassemble the carburetor. We recommend that you first check whether the problem is really in the fuel supply, and also rule out simpler breakdowns, above.

To check, fill a syringe with 3-5 ml of a mixture of gasoline and oil, unscrew the spark plug and pour fuel directly into the combustion chamber.

To deliver fuel directly into the cylinder without scratching or staining anything, place a thin silicone tube on the syringe instead of a needle.

Install and connect the spark plug, and then try to start the trimmer 6-8 times. If the engine starts and soon stalls, the problem is really in the fuel system (carburetor, fuel filter, gasoline supply pipes). This often happens after winter, especially if the gas mixture is not drained: it breaks up into fractions, heavy oils literally seal small holes and parts.

If direct refueling of the engine does not help the start, return to checking the ignition, and also make sure that the combustion chamber is tight, there is compression, and the piston group is in good condition.

Once you determine that the problem is with the carburetor, disconnect it from the body. To do this, remove the air filter and unscrew the 2 or 4 long bolts. Disconnect the 2 fuel pipes and the throttle cable. Remove the carburetor, do not lose the paronite gasket between it and the engine.

To disassemble the carburetor, remove the 4 bolts located around the fuel pre-priming button. Carefully disassemble and fold all layers in order so as not to lose anything. You can immediately soak them in a bath of gasoline to clean them.

It is not necessary to remember which side the parts were turned: they have an asymmetrical contour and will not be turned upside down

Assess the condition of the gaskets, if necessary, buy a repair kit and replace them.

On a metal plate with a round recess there is a needle on a spring-lever. It is located on the edge of the circle and is responsible for supplying fuel. To check whether it is stuck or moving, press the opposite end of the spring lever into the center of the circle. If mobility is limited, use special liquid and compressed air, or just gasoline for flushing.

It is very convenient to fill a special spray gun with gasoline. With this “high pressure washer” even a very old engine can be cleaned to a new state.

In addition to the needle, the inlet spray valve is located on the same part. It is better visible from the back of the part - a hole in the center, often cross-shaped. To check the functionality of the valve, attach a flexible thin tube, rubber or silicone, to it and try to blow in both directions. Air should pass only when inhaling - from the concave side of the part to the flat one.

If air does not pass through, cleaning is needed. A simple way is with a match, not a toothpick or a needle, only with a blunt end, from the side of the hole. A more complex and reliable option is with disassembly. Unscrew the small screw next to the needle and pull it and the spring out.

Find a small hole in the center of the circle and carefully, using a blunt object, such as a cut wire, push the spray membrane out of the valve through the hole on the opposite side.

The valve itself is tiny, push it over a clean, light-colored surface or plastic container to avoid losing it. It is not sold separately and is not included in the repair kit.

After thoroughly washing with gasoline, blowing and drying all the parts, replace the membrane and needle with spring.

Reassemble the carburetor in reverse order: rubber gasket, transparent gasket, metal part with needle and valve, thin rubber membrane, thick membrane in a plastic case, primer button.

Screw it to the trimmer body through the gasket, connect the fuel pipes and the throttle cable. Try to start the lawn mower as usual. If the problem is resolved, be sure to reinstall the air filter.

Most likely, you will need to adjust the fuel mixture parameters using the adjusting screw on the carburetor. Start the trimmer and, periodically accelerating, tighten the screw to a position in which the engine reaches maximum speed (by ear). Then make a half turn back so as not to overload the motor.

No spark - checking the ignition module

Possible signs of ignition module failure:

engine tripping at idle;
drop in power, poor acceleration dynamics.

If the wires and spark plugs are ok, you need to test the ignition module. We connect one multimeter probe to the module connector, and connect the second to ground. After this we try to start the engine. If the device display shows a value of about 12V, the module is working.

Low Voltage Circuit Diagnostics

For this method, you need to find a test lamp with a power of 2-3 Watts and a voltage of 12V. We connect one contact of the lamp to the low voltage contact of the distributor, and the second to ground.

The next step is to close the contacts of the distributor and turn on the ignition. If there are no problems in the low voltage circuit, the lamp will go out when the contacts are closed and light up when the contacts are open. If opening the contacts does not cause the lamp to glow, the cause of the breakdown is the primary winding of the coil or low voltage wire.

If the lamp glows continuously, regardless of the position of the contacts, this indicates the following possible breakdowns:

oxidation of distributor contacts;
damage to the wire connecting the distributor body and its movable disk;
damage to the wire between the lever and the distributor terminal.

Basic malfunctions and their elimination

If you cannot start the saw the first time, there may be several reasons. Most often the problem is related to the spark plug:

wear of the electrode or damage to the ceramic insulator;
loose fit of the removable cap (if any);
sparks flying along the ceramic winding, a sign of which is a brown residue on the outer shell;
cracks in the spark plug cap (a saw with this problem will continue to work, but may cause pain to the user when touched).

If no problems were found with the spark plug, it is recommended to inspect the wires coming from the coil. They may be torn or have other mechanical damage. Wire breaks inside the insulation are possible, so sometimes these violations cannot be detected by visual inspection.

The cause of the breakdown may lie in the shutdown switches. It's easy to check them. To do this, you need to disconnect the wires from the module and then check the ignition. If a spark appears after switching off, the switch must be replaced.

Signs of ignition malfunction:

The chainsaw starts, but works unevenly (troits), often sneezes and shoots;
The power of the chainsaw has noticeably dropped;
When you sharply press the accelerator trigger, failures in engine operation are observed;
The chainsaw does not start well when cold, it stalls violently until it warms up;
Fuel consumption has increased significantly;

If such flaws appear in the operation of your chainsaw, then it’s time to diagnose, adjust, and possibly repair the ignition system.