How to remove the ignition on a chainsaw

Ignition adjustment

As we have already noted, you can adjust the ignition system both in the workshop and at home. To do this, you need ordinary wrenches, a screwdriver and a 0.4 mm dipstick (you can make a dipstick with your own hands from scrap materials. plain copier paper, a plastic bottle, etc.).

Ignition faults

Most often, we think about repairing after the chainsaw has stopped starting, or visual signs of serious damage have appeared.

With an increase in the power of the chainsaw, the amount of the fuel mixture increases, which should ignite when the chainsaw is started. In such a case, the number of jerks of the starter cord must be increased to start the engine. To speed up the return of the drum mechanism, manufacturers use a special steel starter return spring, which has excellent elasticity.

If the spring breaks, it is necessary to: remove the mechanism holder, pull out the spring, fixing its upper part with a finger and slightly pulling the starter handle to the side. Then, wind the new part, while avoiding kinks and twisting of the new spring element, then carefully fix the clip.

DIY How To Remove Chainsaw Flywheel Without Puller. Stihl Husqvarna, Echo, Poulan

Step-by-step diagnostics of ignition with a multimeter:

  • We set the multimeter to the position in which the arrow is at the 200 ohm mark.
  • We study the instructions for the chainsaw. We find out the optimal resistance for the coil winding installed on our model (in most modern chainsaws, this indicator fluctuates within 3-5 ohms.);
  • We connect the multimeter to the primary winding of the coil and measure the resistance, if it is normal, we continue testing;
  • We connect the multimeter to the secondary winding of the coil, compare the readings obtained with those indicated in the instruction manual;
  • We connect the multimeter to the coil hole into which the wires are inserted. If the device gives normal readings, we come to the conclusion that the coil is in good working order. If the measurement results are far from optimal, you will have to replace the assembly (coil) with a new one;

Diagnosis of malfunction with a multimeter

It is also possible to determine the malfunction of the ignition coil using the so-called hardware method. However, for this you must have a multimeter with which diagnostics are carried out.

Yakov Sinelnikov, 56 years old, Khabarovsk

“I bought an old chainsaw. Well, like the old one. she lay with my grandfather for three years in the garage. I tried to start it. nothing happened. He looked at the candle, it didn’t seem to flood, dry. Unscrewed, checked. there is no spark. I had to disassemble and expose the gap. Instead of a probe, I cut out a homemade product from a plastic bottle, inserted it and adjusted it. The chainsaw works perfectly. the main thing is to set the gap and assemble it correctly. By the way, I also changed the candle. “

How to check the ignition coil of a chainsaw?

There are several effective ways to check a factory ignition coil. The first one is visual. To do this, the operator must carefully remove the magneto from the saw structure, having previously disconnected all contacts connected to it. After that, you need to inspect the item.

Most often, its malfunctions consist in:

  • damage to standard insulation, initially caused by gradual or sudden overheating, increased vibration, as well as voltage surges in the created electrical network. All this leads to a short circuit in the factory windings of the coil;
  • violation of the integrity of standard high-voltage wires. this results in overload and breakage of electrical wires.

In any of these cases, you will need to immediately replace the electronic ignition of the gasoline chain saw.

The second way to check the coil is to test it with a multimeter.

  • Connect the device to the positive and parallel negative factory contacts, having previously configured it in the mode of constant measurement of the generated resistance;
  • After ringing the built-in coil, you need to look at the device. In household chainsaws from different manufacturers, the resistance values ​​may differ from each other. Typically, the average is around 0.4–2 ohms. If zero resistance is displayed on the multimeter used, then an accidental short circuit has occurred in its standard winding. In few cases, the device can show infinity. then the operator will need to find an open circuit.

In each of these cases, the repair of the factory ignition coil is carried out only through a complete replacement of the part.

Each of the methods allows you to obtain information about the health and stability of the factory ignition system of a gasoline saw. In some models of garden power tools, manufacturers provide for the possibility of replacing only the defective coil. In other cases, the owners of chainsaws are required to replace the entire ignition system.

How to determine the advance angle of the built-in ignition?

The design of the built-in ignition coil ensures coincidence between the factory optimal position of the moving piston and spark plug discharge. During the operation of 4-stroke power units, the spark must jump before the piston returns to the uppermost position. This is due to the fact that such engines take longer to burn fuel. In their factory device, the speed of operation of the internal combustion engine parts is equal to the speed of the planned ignition of the filled fuel. In this regard, the piston manages to pass a certain path from the moment of instantaneous breakthrough of the created spark to the place where the candle is located. until the period for which the burning gases are guaranteed to have time to create extremely high pressure indicators.

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During the mass assembly of engines under standard factory conditions, manufacturers do not perform ignition adjustments. Instead, markings are left on the rotating elements that must be aligned during installation.

Factory Ignition System Design Features

The ignition system for a domestic or professional chainsaw initially consists of:

  • magneto, or factory ignition coil;
  • candles with a pre-installed cap;
  • electrical high-voltage wiring, pre-connecting the spark plug to the coil;
  • keys that instantly turn off the running power unit of the chainsaw.

In the device of a household gasoline tool, magneto is a kind of generator responsible for the continuous generation of alternating current with the subsequent transfer of energy to the built-in candle. The design of the magneto initially consists directly of a standard stationary winding of an inductive coil, as well as a permanently operating magnet pre-installed on the built-in flywheel.

Magneto, provided in the standard built-in ignition device for household and professional gasoline saws, are divided by equipment manufacturers into:

  • contact. in the design of these nodes, the first output of the built-in factory high-voltage winding is connected to the spark plugs. In the basic design of the contact magneto, a capacitor is initially provided, which prevents overheating and gradual oxidation of the contacts of the standard breaker;
  • non-contact. the principle of operation of units of this type is based on the operation of the built-in control coil of the factory, which, at the same time, plays the role of an element that regulates the supply of voltage. During the regular opening of the thyristor, the standard capacitor begins to actively discharge. As a result, a sufficiently high current is continuously generated in the turns of the high-voltage factory primary winding, which is inducted into the high-voltage voltage. It leads to instantaneous breakdown at the built-in spark plug located in the cylinder of the power unit. The electrical network of the non-contact magneto operates stably in the mode of continuously generated short-term pulses generated in time with each forward movement of the factory cylinder and the corresponding rotation of the engine crankshaft.

Manufacturers of chain garden equipment use different types of factory magneto in the configuration of chainsaws. The main difference between them lies only in the principle of action. At the same time, contact and non-contact magneto have approximately the same working efficiency.

Chainsaw ignition

In order for a gasoline saw to start running stably at idle, the fuel located in the factory cylinder of its power unit must ignite. For this, a standard ignition system is provided in the basic configuration of any branded chain tool. The ability of the internal combustion engine to make the first cold start and steadily gain momentum when the operator presses the gas trigger largely depends on its serviceability. The ignition of a household saw is distinguished by a simple device and a constant operating principle. Having studied their features, it will be easier for the operator to carry out maintenance and self-repair of the unit.

How to set the ignition on a chainsaw?

As in the case of the constant need for self-adjustment of the carburetor, a chainsaw used in a private economy or on a forest shaft must be amenable to timely adjustment of the built-in standard ignition. The essence of this procedure is to install the gap originally provided between the flywheel of the power unit and the standard ignition coil. The size of this gap may initially be different. it all depends on the purpose, as well as the design features of the saw. The average distance is considered to be not less than 0.2 and not more than 0.4 mm. In the event of a violation of the correct gap, the base ignition system will not be able to generate the spark required for timely instantaneous ignition of the filled fuel mixture in time.

In order to initially correctly adjust the appropriate clearance between the flywheel and the ignition coil on the chainsaw, its owner will need a special plate template. However, buying it for a one-time use is not always profitable. In some cases, the template can be replaced with a homemade one. To make it, the operator will need a plastic smooth bottle, from the side of which a thin strip must be cut. At the same time, there should be no embossing on a homemade template.

The operator can adjust the ignition on the chainsaw directly in the following order:

  • First, you need to slightly loosen the plastic bolts designed to fix the standard ignition element;
  • Further, the magnets provided on the flywheel will need to be brought to the factory coil;
  • Then, a homemade or previously purchased template must be installed between the base high-voltage coil and the built-in engine flywheel. After that, the coil fixing bolts will need to be tightened in the opposite direction;
  • Next, the operator must carefully remove the template.
  • At the end, you will need to scroll the built-in flywheel. At the same time, you need to make sure that when rotating, the element does not touch the coil and other parts of the chainsaw.

The question arises, what to do then?

Here are some common cases:

  • The chainsaw will not start;
  • If it starts, it works intermittently;
  • Not enough power to work properly.

Constructive components

All engines, whether automotive or other tools using an internal combustion engine, have similar operating principles.

There are no exception such famous chainsaws and are used with pleasure by consumers like Goodluck, STIHL or Husqvarna.

The drive in them is a familiar internal combustion engine, respectively, a fuel tank, an engine and a working body that directly performs work, as well as other attachments that help in control.

HOW-TO Fix A Chainsaw With No Spark. Ignition Module Replacement

Sometimes during operation, some problems may arise, in this rather reliable tool like a chainsaw.

How to set the ignition on a chainsaw

In this review presented to your attention, we will try to reveal the question that arises among many owners of chainsaws. In the process of using such a tool, the consumer may encounter a situation in which it is necessary to correct the ignition timing. Over time, the breaker may fail, the coil also does not last forever, although it serves much more and it is quite difficult to disable it. So let’s figure out how to set the ignition on a chainsaw.


The main problem in this group is the engine.

Ignition is one of the main elements affecting the trouble-free operation of the tool. Therefore, we will first consider this particular block.

Gone are the days when a cam-moving contact breaker was in control of the ignition, which supplied a spark to the spark plug.

It was not a very reliable system due to the many elements that affected the operation of the engine. The chainsaw, with no visible malfunctions, could simply stop starting. And we could observe a picture of constant tugging at the winding cord. To date, manufacturers have switched to contactless ignition systems.

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They have fewer moving parts and no contacts that need to be exposed periodically, often failing. The reel used on a modern chainsaw will work until the end of the service life of your tool. The chainsaw has become much more reliable and easier to maintain.

Possible malfunctions

If the saw does not start, the first thing to check is the spark plug that ignites the fuel in the cylinder. Start by removing the high voltage wire that the candle is connected to. Then unscrew the candle itself from the cylinder cover and inspect its condition. When working properly, the candle should be dry and small deposits on the light-colored ceramics:

  • If the plug is wet, there is a problem with the carburetor. It is necessary to adjust and set the fuel level in it;
  • Carbon deposits on the walls of the plug are dark or black in color, it means malfunctions in the piston group.

If you did not find any visible reasons for the malfunction here, the candle is dry, light carbon deposits continue to go from the opposite direction. Since this is the final point of ignition of the working mixture. Now check if the spark is coming to the spark plug. This is the ignition system block.

Checking if there is a spark will not pose any particular problems, for this it is enough to take the high-voltage cable to which the candle is connected, bring it to the cylinder block with a small gap between them, so that you can notice the spark slipping between them. Then we pull the starter starter cord, and watch, there is a spark and what color it is. A working spark plug should give a spark that looks like lightning. How it looks, look at the photo offered to your attention, everything is clearly visible on it.

If no spark is observed, check with a control lamp, if there is no probe, high-voltage cable. A break is possible in the place where it was bent most often. If the wire is in order, it is possible that the problem is an incorrect ignition angle. It may be too early or too late in both cases, the chainsaw starts well and will not work.

Now let’s try to set the correct gap between the movable and fixed contact. Ideally, it should be 0.2 mm. You can check with a probe, since it is not a deficit.

remove, ignition, chainsaw

This was a description of the malfunctions of the older generation of chainsaws. The new generation includes modern chainsaws from Goodluck, STIHL and Husqvarna.

Modern systems

Modern systems are equipped with chips that handle all of the above problems. The method of self-setting the ignition timing depending on the engine speed and the power transmitted to the cutting element. This significantly saves fuel without sacrificing power. It is also much easier to start the saw, regardless of weather conditions.

The chainsaw itself has become simpler and more efficient and does not require expensive repairs. Ignition coils made using modern technologies and using new materials have literally become eternal.

In addition to everything read here, a video is offered for a complete acquaintance with the material given.

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I bought a STIHL chainsaw, it practically did not work for it. just repairing. Can’t get.

The device and principle of operation of the chainsaw ignition system

The standard ignition system for a carburetor engine consists of:

  • magneto;
  • spark plug;
  • an electrical cable connecting them to each other;
  • engine shutdown keys.

Magneto is a type of alternator that supplies electricity to spark plugs. It consists of a stationary winding of an inductor and a permanent magnet attached to a flywheel that rotates with the crankshaft of a gasoline engine. A moving magnetic field creates an electromotive force in a low-voltage winding, which is converted by a transformer into a voltage with a potential sufficient to generate a spark.

For contact magnets, the first terminal of the high-voltage winding is connected to the spark plug, and the second is connected to the ground through a mechanical switch. At a certain moment, a special structural element divides the contacts, which leads to a sharp increase in the voltage in the network and a spark slip in the interelectrode space of the candle.

To prevent overheating and oxidation of the breaker contacts, a capacitor is connected to the electrical circuit.

The ignition circuit of a chainsaw with a contactless magneto is based on the operation of a control coil, which plays the role of a voltage supply regulator. The electronic unit also includes a diode, a capacitor and a thyristor that transmits a current with a voltage of a certain magnitude. When it is opened, the capacitor is intensively discharged, forming a current in the turns of the primary winding, which is inducted into a high-voltage voltage, giving a breakdown on the spark plug installed in the cylinder. The electrical network operates in a pulsed mode in time with the rotation of the crankshaft and the translational movement of the cylinders.

Ignition timing

The mechanical device and the factory setting of the magneto ensure that the discharge time of the spark plug coincides with the optimal position of the moving piston. For four-stroke gasoline engines, spark breakthrough must occur even before the piston reaches top dead center. this is due to the fact that the process of complete ignition of the air-fuel mixture takes a certain time. The speed of movement of engine parts is comparable to the speed of fuel ignition, so the piston has time to travel a certain distance from the moment the spark breaks through to the moment the burning gases create extremely high pressure.

There is an ignition timing for each engine. It is equal to the rotation of the crank, expressed in degrees, from the moment of breakdown in the interelectrode space of the spark plug until the moment when the piston is at top dead center. This indicator depends on many parameters, including the design features of the engine and the properties of the fuel mixture.

In practice, during the mass production of an engine at the factory, individual adjustment of the ignition of each product is not made, but the corresponding marks are set on the rotating parts, which must be aligned during installation.

When is the ignition setting required? There are the main symptoms of a system crash:

  • the engine will not start;
  • the motor works, but with noticeable interruptions;
  • there is a decrease in tool power.

In these cases, you should not rush to contact the service center. Try to adjust the ignition yourself first.

The procedure for checking and adjusting the correct operation of the engine

The most vulnerable element of a carburetor engine is the spark plug. It also allows you to judge the probable causes of malfunction of individual units of a gasoline engine. The following procedure is recommended.

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    Dismantle the spark plug and inspect it. A dry candle with a slight brown tint of the electrodes can be considered serviceable.

When installing a new electrical module on the engine, the magneto gap must be adjusted. The optimal distance between the flywheel and the ignition coil is 0.2-0.4 mm for most chainsaws.

To be sure, it is recommended to carefully study the documentation for the purchased model and follow the manufacturer’s requirements.

With such a small gap, it will not be possible to use an available measuring tool for direct measurement. In practice, a Husqvarna saw uses a template in the form of a spacer cut from thin, flexible sheet material of the required thickness. It is clamped in the space between the flywheel and the coil when it is installed, and then pulled out.

In order not to have to resort to adjusting the ignition, operate the tool carefully, avoiding knocks. In particular, this applies to chainsaws with electronic chips in the ignition system, since they are very sensitive to mechanical damage.

How to check a coil with a multimeter

Most often, we think about repairing a chainsaw when it already stops starting. If you’re having trouble starting, it’s worth checking the ignition coil. The main symptoms of a malfunction:

  • The chainsaw does not start or it is difficult to start “cold”, troit until it warms up;
  • The chainsaw starts, but it works unevenly, sneezes, shoots, etc.;
  • The power of the chainsaw has dropped;
  • Increased fuel consumption.

To diagnose a breakdown in the ignition system, we will use a device such as a multimeter. For these purposes, any model of a digital multimeter complete with probes is suitable for us. DT brand models have proven themselves well, such as the basic DT9205A or the multimeter of the same brand. DT9205A, with more advanced functionality.

Digital measuring instrument. multimeter

  • Be sure to study the instructions of our chainsaw: we find out the working indicators of the average resistance for the circuit winding (standard resistance is 0.2. 4 ohms);
  • We install the device so that the arrow shows 200 Ohm;
  • We connect the multimeter to the winding of the circuit (probes for “” and “K”. the coil body) and measure the resistance. If the indicators are normal (0.2. 4 ohms), we continue to test;
  • We transfer the multimeter to 20 kOhm mode, transfer the probe from the case to the candlestick, and perform a check. Acceptable values ​​6-15 kOhm (depending on the model).
  • If the indicators differ greatly from the set values, the coil should be replaced.

Chainsaw ignition system. from the device to checking the coil with a multimeter

A chainsaw, like any tool, has its own structural features. We will talk about how to extend the life of the tool and troubleshoot the ignition system right now.

What to do if you don’t have a multimeter at hand?

If you are far from home or you simply do not have a multimeter, you can use the express diagnostic method.

remove, ignition, chainsaw

In the field, you can carry out an independent express diagnostics of the coil health. To do this, it is necessary to unscrew the spark plug and attach the body to the cylinder. Pull the starter and watch: is there a spark? If there is a spark, the coil is working.

This method is not ideal and has errors due to the fact that if the candle is in an unnatural position, without compression, the spark can be very good. But when installed in a cylinder, when compression appears, it will simply disappear. Therefore, this verification method does not provide any guarantees.

Ignition system of a modern chainsaw

Modern chainsaws are becoming simpler and more efficient, they practically do not require maintenance and expensive repairs. The modified ignition coils have become durable, their service life has increased tenfold in comparison with the old contact systems. The main function of this unit is to timely ignite the fuel inside the cylinder.

  • magneto;
  • spark plug;
  • buttons that turn off the motor;
  • BB wires connecting the elements to each other

Chainsaw contactless ignition circuit Another chainsaw ignition circuit, with a description

Magneto is a special kind of generator that produces alternating current. When working properly, it generates and directs its energy to the candle.

remove, ignition, chainsaw

The magneto device includes an inductor ignition coil. A winding is wound around the coil, and a magnet is attached to the flywheel. During operation, the flywheel rotates with the engine crankshaft. At a certain moment, the existing contacts are divorced within the system, which leads to a spark.

To avoid overheating, with a sharp surge of energy, the device has a built-in capacitor.

There is also an ignition system with contactless magneto, adjustable by a coil. This part is supplemented with a thyristor and a diode, which help to regulate the energy process, make it easier to start the saw, regardless of climatic conditions.

Description of the operation of the ignition system of a modern chainsaw. The main elements are highlighted in red: a candle, an explosive wire, a coil, magnets on a magneto.

In order to keep the saw running smoothly and economically, it is worth checking and adjusting the clearance between the spool and the flywheel periodically. Here is a table of the recommended value of the ignition coil gap depending on the manufacturer’s brand.

Brand name Recommended clearance, mm
Partner 0.2
Ryobi 0.2
Bison 0.2

As we can see, for all popular brands, one common value of the ignition coil gap is relevant.

Broken explosive wire

If the new plug also does not give a spark, it is necessary to test the explosive wire. To check the integrity of the wiring, it is best to use a special tester. a multimeter, which was discussed at the beginning of the article.

Open circuit in the coil, you can see by checking it with a multimeter in resistance mode, the value will tend to infinity.

Large clearance between ignition module and flywheel magnet

In the case of a large gap in the coil, you need to set the value yourself using the algorithm given above.

If you have a breakdown in the ignition system and do not have enough experience in repairing a tool, do not seek to repair everything yourself. Simple malfunctions, which we talked about above, can be eliminated by yourself, but it is better to entrust more serious diagnostics and replacement of expensive parts to specialists.