How to check the ignition coil of petrol cutters

Chainsaw gap setting overview

check, ignition, coil

Overview of how to replace the reel on a chainsaw

Yakov Sinelnikov, 56 years old, Khabarovsk

“I bought an old chainsaw. Well, like the old one. she lay with his 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. “

Chainsaw ignition step by step:

  • We diagnose a malfunction;
  • We dismantle the protective cover;
  • We remove the module with a candlestick and an electric cable. We carry out their visual inspection, if necessary, we replace them with a new one;
  • Install the ignition module, but do not tighten the fastening screws all the way;
check, ignition, coil
  • Determine the area with the magnet on the flywheel;

  • We set the gap properly, in accordance with the parameters specified in the instruction manual;
  • We tighten the screws that secure the module to the stop, check the settings with a probe, and, if necessary, re-adjust;
  • Install the protective cover and check for a spark on the candle;
  • We screw in the candle, start the chainsaw;

Important: when repairing the ignition of a chainsaw, special attention should be paid to setting the correct gap between the module and the flywheel.

You should also check if the flywheel is clinging to the module with the counterweight. If this happens, you may have a bearing failure or a backlash on the shaft.

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

  • We expose 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 out normal readings, we come to the conclusion that the coil is in good order. If the measurement results are far from optimal, you will have to replace the assembly (coil) with a new one;

The device of the factory ignition system of the chainsaw

The ignition system of a chainsaw initially consists of several constantly working elements.

Their list includes:

Ignition coil test

  • standard spark plug;
  • magneto;
  • electrical wiring connecting both elements to each other;
  • control keys, which are needed to turn off a running engine.

Magneto is one of the standard alternating current generators. It is necessary to supply electrical non-variable energy to a standard spark plug. Directly, the magneto consists of a factory permanent magnet and a winding of an inductance unit, which is fixedly installed. The magnet is attached to the factory flywheel, which is set in motion simultaneously with the start of the crankshaft of the chainsaw engine.

Electronic magneto in factory ignition systems for household chainsaws can initially be of two types:

  • contact magneto. they have the first standard output of the factory high-voltage winding connected directly to the standard candle. In this case, the second terminal is oriented to ground directly through the built-in mechanical switch. At the right time, a separate element of the device forcibly divides contacts. To prevent overheating and accidental oxidation of the factory contacts of the breaker wiring, a separate capacitor is initially connected to the ignition system wiring.
  • contactless magneto. their main elements are control elements that act as voltage supply regulators. The device includes a tourist, which passes only the current, the voltage of which does not exceed a predetermined value. During the opening of the tourist, the capacitor begins to discharge, as a result of which a current is generated in the turns of the primary value. The entire electrical network of the non-contact magneto operates in the mode of short-term impulses. Each impulse is generated simultaneously with a full revolution of the engine crankshaft and the movement of the chainsaw cylinder. – Testing a Victa Ignition Coil

Regardless of the type of magneto, the system of every chainsaw requires regular inspection and adjustment. This helps to avoid complex breakdowns and makes it possible to extend the life of the unit.

Semyon Starodubtsev, 54 years old, Krasnodar

“I was cleaning the garden in the spring, the chainsaw began to sneeze, and then it completely stalled. I looked at the candle. it was completely wet, it was evidently flooding. I cleaned the carburetor, changed the plug. it won’t start. Looked. there is no spark. I disassembled the ignition and found the reason. the high-voltage cable was completely melted. Why this happened. I still don’t understand. I changed the cable with the module. now everything works fine. “

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 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.

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.).

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

The design features of the built-in ignition coil ensure 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 the internal combustion engine parts is equal to the speed of the planned ignition of the refueled 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 during which the burning gases are guaranteed to have time to create extremely high pressure indicators.

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.

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How to check the ignition coil if there are several

And it happens like this. You are driving your Civic EU, or CR-V of the II generation, or Accord CL, it pours rain, thunder and lightning, and suddenly. bam, and the engine seemed to stop pulling, there was an incomprehensible vibration, and the engine “zatroil”.

And also-e-e-e-e…. It happens so. you go on your Fit, with a 1.3 engine. Weather. no, nothing pleases, no rain, no snow, no sun. And the car still twitches during acceleration, as if someone would grab it by the stern, then release it. And so for a week! And no joy, because the familiar masters said that the variator needs to be changed.

What do the above situations have in common? The same thing we talked about in the last article is a problem in the ignition system.

Unlike the example given in the previous article, in this case we are dealing with an excellent ignition system. Its essence is as follows. starting in 2001, Honda decided to abandon the distributor ignition circuit using one ignition coil for the engine. A new design was proposed, in which there was one coil for each spark plug in the engine. What is the advantage of the new solution? Let’s figure it out.

What were the advantages of the previous scheme? To be honest, only in one thing. in cost. The rest were solid cons. The distributor ignition system worked on a mechanical scheme and was very susceptible to wear and tear. Each element, slider, cover, high-voltage wires, had its own resource, by developing which, the part did not immediately fail, but created the possibility of excessive load on a single ignition coil. A “breakdown” on the slider, or on the distributor cover, or in the wires caused the spark intended for the spark plug to fire in the other direction. The situation was aggravated many times by the fact that all this could also happen on “tired” spark plugs. This could not but affect the stability of the coil itself, and since there was only one in the system, its sudden failure led to a complete stop of the car.

In the case of installing several ignition coils in the system, the following effect was achieved: firstly, the mechanical component of the entire work was removed, which significantly increased the resource of the system. The control of the ignition system was now completely transferred to the computer. Secondly, many “intermediaries” of the spark transmission were removed. the slider, the cover, the high-voltage wires. This not only made it possible to simplify the design, but also significantly increased the reliability of spark delivery. In the new scheme, the principle of supplying low-voltage wires to the ignition coil itself was applied to the open access. And the coil, located directly on the candle, generated a high-voltage discharge, as they say, “without leaving the cash register.” Thirdly, and most importantly, from now on, with the failure of any ignition coil, the car did not turn into a pile of stationary iron. the movement could be continued further, to the nearest dealer or auto center.

Of course, this design also had its drawbacks. So, the new coils that participated in this scheme turned out to be structurally more “finicky” to the quality of the candles. If the old scheme had a huge margin of safety of the coil, since the chance of “losing” the spark was very high, the new ignition scheme had to work right on the spot with the “client”, that is, with the spark plugs. And according to the calculations of the designers, the state of this candle should have been at least good, and the Russian scheme “I have not changed 80 thousand candles and will not change the same amount, let them drive!” clearly was not part of their plans.

Another disadvantage, more obvious to every owner of such a scheme, was the cost of each ignition coil. It was equal to or even more expensive than the cost of the ignition coil for the distributor, only unlike the distributor with its “solo” coil, here they could be required to replace two, three, and sometimes (for example, Honda Fit) and up to five pieces at once.

Of course, if you look at it, only one person could be to blame for such a mass extinction of the coils. the owner of the car, who at the wrong time, or incorrectly changed the spark plugs. Neither the enemies of the party and the government, nor the gremlins living in North America could influence this process.

So. We outlined the culprits, mentioned the symptoms at the beginning of the article, it’s time to tell you how to check the ignition coil for the condition.

It is worth saying that the problem of the “dead” ignition coil is difficult to localize on the one hand, but on the other, it seems to be simple. The inconvenience lies in the fact that the failed coil does not light the Check Engine light on the dashboard. Also, even official Honda scanners do not always show a problem with the ignition coil. Things are even worse with the cheap “generic scanners” found in almost every garage service. For example, a scanner “for all cars at once”, when connected to the Honda Fit connector, with a “dead” ignition coil, gives an interesting verdict. the problem of the crankshaft position sensor. The cost of the sensor is approximately equal to the cost of the coil, the operation of dismantling and installing itself costs half of its cost, but replacing it gives absolutely nothing! From the point of view of would-be craftsmen, this is one of the “unequivocal” confirmations of the need to go to the CVT repair station and give up. But we will consider this problem below. First, it’s worth talking about other cars, besides the Honda Fit, which have four ignition coils.

Honda has an absolute majority of such cars. almost all that were designed and created after 2001. So, the main symptom of a failure of the ignition coil is a sharp failure in the normal operation of the engine, “tripping” (for those who do not really understand this, if you are used to your engine running smoothly and properly, know that it works according to the principle of counting “one-two-three-four”, according to the number of flashes in the cylinders; triplet is when the flash in one cylinder is skipped, and the motor works like this: “one-two-brrrr-four”). From this moment on, the most correct will be a leisurely drive towards the nearest car service, or to the garage. If it is warm outside, you can check the condition of the coils right on the spot, fortunately, it is much easier than in the case of the distributor system, but we would recommend getting to the service, as they say, “in order to avoid”. If you have the opportunity to go to a car service with an original Honda scanner, it is better to check the car on it. The fact is that the problem may not be entirely in the coil, and having a scanner capable of checking the car before your check may simply save you time. If not, and the engine of the car is “troit”, you can try to check the ignition coils yourself.

It is necessary to start checking this system with candles. To do this, it will be necessary (with the car turned off!) To unscrew all the candles and visually check their condition. A normal, working spark plug will have a working gap (it is difficult to catch the parameters of 1.1 mm or 1.3 mm by eye, but a gap of more than 1.5 mm is clearly visible, which means that the candle has worked out).

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If your engine has iridium spark plugs, you should pay special attention to the condition of the iridium tip of the main electrode. Often, under conditions of ultra-long operation (iridium candles can walk up to 100 thousand km, but this does not prevent our fellow citizens from driving 150 thousand km without changing the candles), the iridium tip burns out, and, despite the outwardly normal state, the candle is no longer working.

It is imperative to check the white insulator at the top of the plug. There is a widespread legend that the white insulator on a normal candle should be white at all times, and any stains on it indicate a failure of the candle. In fact, this is not the case. The yellow crown on the bottom of the insulator (at the junction with the threaded part), this is just the normal state of the candle. And the need for an urgent replacement (and, as a rule, a 99% probability of a coil failure) is indicated by black breakdowns on this electrode.

Ignition Coil Primary & Secondary Resistance Testing

Ideally, replace the spark plugs before testing the coils to maintain a clean experiment. If you have recently changed spark plugs, this is not a reason to leave them in place, since, unfortunately, a certain percentage of defects in production is quite possible, especially if we are talking about non-original spark plugs.

If the candles were recently changed, correctly selected, and no black breakouts are observed on any of the candles, they can be conventionally considered “whole and new”.

The second stage is visual diagnostics of the ignition coils. A whole and working ignition coil at the junction with the candles will not have any black markings, it will not smell like burning, burnt winding or something like that. If one of the coils on your motor has similar signs, mark it, it will be the main “suspect”.

Put everything back (that is, put the candles in place, put the coils on each of them, and connect to the power).

Try to start the car. If the “triple” disappeared, congratulations. So you had working ignition coils, and the problem was in one of the spark plugs, and it was eliminated along with its replacement. If the engine continues to tweak, we look further.

Now, actually, how the coils are checked. In order to fearlessly start testing, one thing should be understood. this design minimizes the likelihood of coil failure due to high voltage breakdown. If in the previous article, describing the story with the prohibition of checking the spark on the case, we emphasized in every possible way the inadmissibility of this event, then the operations that we describe below will not be able to damage your ignition coil in any way, since all actions will be performed BEFORE the high-voltage generation process.

So, if you carefully did everything with replacing the candles, you could not help but pay attention to the wires with a connector, suitable for each coil and snapped into a special groove on it.

These are the low-voltage (standard) voltage wires of the vehicle’s on-board network, which supply current to the coil to convert it into a high-voltage spark. We have four cylinders and four ignition coils, one of which is supposedly not working. To “catch” it, you need to do the following operation. disconnect the first wire that supplies voltage to the coil from the ignition coil itself. If the coil was (and, we hasten to reassure, remains) working, the engine will dramatically change the sound of its operation and try to stall (now it works on two cylinders altogether). Plug the coil back in and the sound of the engine should return to its original triplet. Disconnect the next coil.

The essence of this check boils down to the fact that a non-working coil, even when disconnected from the onboard power supply, will not affect the sound of the “triple” engine in any way. if the coil is already “dead”, then the presence or absence of power will not affect it in any way. You can start checking directly from the suspicious (marked on visual inspection) coil. Often, suspicions are confirmed on the first try. Once you have managed to localize the problematic element, you can safely go for a new one. Coils cannot be repaired.

Now it’s worth finally talking about the Honda Fit.

A distinctive feature of the Fit (and similar cars, such as the Mobilio) is the presence of eight spark plugs and eight ignition coils. The location of the front row of spark plugs is very easy to replace and does not cause any problems. The presence of the back row of candles, despite the existence of these cars on the market since 2001, is a secret not only for most car owners, but also for the masters of many services. As a result, the back row candles sometimes do not change for 100 thousand km, although they must be replaced every 20-30 thousand km. All this leads to problems with the rear row of coils. However, in contrast to the usual scheme with four coils, the problem of “triplet” of the engine manifests itself only when TWO coils on one cylinder (that is, both the front and rear coils) fail simultaneously, which happens extremely rarely! Usually, the front row coils are monitored, so the “extinction” of the coils is accompanied by other symptoms.

often than not, the car starts to twitch when accelerating, as if the problem is in the variator. This is followed by a sad story about a trip to “inexpensive, but very good service”, where good guys-masters, having looked at the behavior of the car, connect it to the scanner they have, and give a verdict about the error of the crankshaft position sensor. Replacing the sensor did not lead to anything, except for the loss of money, and the “good guys” advised to contact the “box” service to repair the variator.

Why do all the masters (and car owners) sin on the variator in this situation? Yes, because a failed ignition coil on an “eight-coil” engine does not lead to “triplet” of the engine, but significantly changes the quality of combustion of the fuel mixture, and the computer tries to react to this! The resulting dips during engine operation are caused by incomplete combustion of fuel in one of the cylinders. In fact, if there were four candles in the engine, the same triple effect would be observed, but in this case, one candle, at the very least, ignites the mixture, however, this differs from the optimal operating mode. This is where jerks are taken during acceleration, which, due to lack of knowledge, or unwillingness to understand the problem, many “masters” are “fooled” towards an innocent variator. The logic is that the engine does not troit? Not troit! Does it kick when overclocked? Kicking! So it’s in the box! Many “victims” in this situation first, on the recommendation of the masters, wash the variator, which finally kills it. After that, having given a huge amount of money, they change the box, but they still do not get rid of the problem.!

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How do you check the ignition coil? Our simple answer is the same as on the four-coil motor. You should start by replacing all eight spark plugs, inspecting them, and also inspecting the ignition coils. You should look for the same symptoms as described above. If one of the coils looks bad, mark it, it may be because of it. Further, after replacing the candles and installing the coils in place, begin to turn off each of them in turn, disconnecting the lead wire of the on-board network. However, a small trap will await you here. Since the mixture in the combustion chamber will ignite even with one ignition coil, it is almost impossible to catch the changing sound at low speeds.

In this case, it is necessary to act according to a different principle. Start detaching the coils from the near (front) row. Most often (and we mentioned this) representatives of the back row fail. So, when you get to the cylinder, in which one of the rear row coils is out of order, and you yourself also turn off the front row coil, you will get one hundred percent effect of a “triple” engine. The principle is the same. on one coil the cylinder will somehow work, without coils at all. it will not work in any way. the engine will start to fever.

If alternately disabling the front row coils did not work, the problem may be in one of them. Then you should also try to turn off the back row one by one. In any case, if the problem is in the coil, you will find it immediately. There is only one method of eliminating the problem. replacing the failed coil. It is useless to repair it.

Summarizing the article, we can say the following. The above method is a bit similar to the “collective farm” method, but, unfortunately, it is the only available way to check the coils even for official Honda dealers in Russia. For coils, such a check is safe, since the on-board voltage of the network, in the absence of a short circuit (poorly fixed contact), does not affect the performance of the coil. it is “killed” by a high-voltage spark that pierces the wrong point. This method is a kind of “secret” of masters in good car services, who strive to make this process difficult and inaccessible to the uninitiated. On the one hand, it is really “difficult” for the unprepared, on the other, if you can carry out this check yourself, “why pay more?” (FROM)

I hope that the masters of auto-kung fu will not be offended by me for divulging their professional secrets.

P.S. than a year after writing the article.

A year’s experience of working with a car repair shop specializing in Honda car repairs allowed us to add some adjustments to the methods described above.

First, as it turned out, the method of checking the “dead” coil on the Fit does not always give positive results. The fact is that dips in ignition that occur at speeds of more than 2500, and even under load, are extremely difficult to imitate in a car service, and even more so in a garage. In neutral gear, it is not always possible to “catch” a burned-out coil.

Secondly, it is more priority, after all, to identify the problem coil (or candle) using a scanner. The fact is that sometimes the coil is not so “dead” so as not to work constantly, and tangible misfires begin only in certain modes. In other cases, there are misses, ignition, but they are simply “lost” on the other seven candles. But the scanner sees them, and displays them on the computer screen in the form of the line “Misfire” (“Misfire”).

Thirdly, we finally made sure that there is no way of normal “ringing” of individual ignition coils.


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Device check

Checking with a multimeter is performed by measuring the resistance of the coils and the voltage on the power supply circuit of the ignition module. This method will help to assess the state of the module, as well as its serviceability.

First, it is necessary to check the integrity of the control circuit of the MV. We set the switch on the device to measure DC voltage in the 20V range. We turn on the ignition on the car and connect the instrument probes to the first two contacts on the connector (as shown in the photo). The device should show the presence of voltage in the range from 11 to 13 volts.

Checking the power supply circuit

Next, we proceed to check the module itself. To do this, set the switch of the device to measure resistance in the range up to 200 ohms. We connect the probes of the device to the module terminals, namely to 1-3, 2-4 (as shown in the picture). The resistance on the device should be no more than 5 ohms

Checking winding resistance

The next step is to check the resistance at the input of the ignition module. To do this, you also need to set the multimeter switch to measure resistance in the 200 Ohm range. The multimeter probes must be connected to the extreme contacts of the module, the device must show a resistance of no more than 5 Ohm.

Checking winding resistance

If in the first and second cases of measuring the resistance, the device shows infinity, that is, one, this means that the coil winding is in an open circuit and, therefore, it is faulty.

Ignition module

The following describes in detail the device of the ignition module, the symptoms of its malfunction, as well as methods of checking to diagnose this part on your own.

IKZ malfunction symptoms

Below is a list of indirect signs, in the presence of which it can be assumed that the ignition coil is faulty.

  • The engine is troit;
  • Loss of power;
  • Jerks when picking up speed;
  • Difficult starting of the engine;
  • “CHECK ENGINE” lights up;

If such signs are found, it is necessary to check the ignition coil.


Checking the ignition module is divided into two stages: checking the external condition and checking with the device.

IKZ device

The ignition coil, like the MZ, has two secondary and primary windings between the turns of which a metal core is placed. The coil has a rubber cap that fits over the spark plug and prevents the spark from escaping to the side of the engine body.

Individual ignition coil

This coil is installed on a 16-valve engine, structurally different from the MZ, in that it is responsible for the operation of only one cylinder. Installed directly in the spark plug well and put on the spark plug.

If it breaks down, the cylinder to which it has a direct relationship fails.

MZ device

The ignition module is a square piece inside with two coils. They are copper wire windings, inside which a steel core is placed. Each coil is responsible for the operation of two cylinders.

MZ has a secondary and primary windings designed to increase the voltage, which is necessary for the formation of a powerful spark and ignition of the fuel mixture in the combustion chamber.