How To Check The Ignition Coil On A Husqvarna Chainsaw

How to set the ignition on a chainsaw Instructions for adjusting the ignition of a chainsaw. Possible malfunctions and their solutions.


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 the switch with cams and a moving contact, which supplied a spark to the spark plug, was engaged in ignition control.

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. Today, manufacturers have switched to non-contact ignition systems.

They have fewer moving parts and there are 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.

how to check the ignition coil on a Husqvarna 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 be faced with 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 question arises, what to do then?

Here are some common cases:

  1. The chainsaw won’t start;
  2. If it starts, it works intermittently;
  3. Insufficient power for proper operation.

The principle of operation of the ignition coil

As mentioned above, the ignition coil is a step-up voltage transformer that converts the resulting 12 V voltage into a voltage of several kilovolts. Structurally, the coil consists of two windings. Primary and secondary (respectively, low and high voltage). However, depending on the type of coil, the windings and their location are different.

Let’s start with the simplest common coil. There are 100.150 turns on the primary here. The winding is wound with insulated copper wire. Its ends are brought out to the coil body. The number of turns of the high voltage winding is 30.50 thousand (depending on the model). Naturally, the wire used here is of a much smaller diameter. The “minus” of the secondary winding is connected to the “minus” of the primary. And the “plus” is connected to the terminal on the cover. In this way, the resulting high voltage is removed.

To increase the magnetic field, the windings are wound around a metal core. In some cases, to avoid overheating, the winding and core are filled with transformer oil (it not only cools the system, but also acts as an insulator).

Now let’s move on to considering individual ignition coil. There are also two windings here, but the difference lies in their location. In particular, they are wound in reverse order. The primary winding is of an internal type and the secondary is of an external type.

Individual ignition coils are installed in electronic ignition systems. Therefore, their design is complicated. So, a diode is provided to cut off a significant current in the secondary winding. Also, a feature of the individual coil is the fact that the resulting high voltage goes not to the distributor (as in classical systems), but directly to the spark plugs. This was made possible by a design that included an insulated body, rod and spring.

Another type of coil. Two-pin. It supplies voltage to two cylinders at once. There are several varieties of them. Typically, such coils are combined into one common unit, which is essentially a four-lead ignition coil.

Regardless of the type of ignition coil, their main technical parameter, which should be guided by when diagnosing, is the resistance of the windings. In particular, the resistance of the primary winding is usually in the range of 0.5. 3.5 Ohm, and the secondary. 6.15 kOhm (these values ​​may differ for different coils, so it is better to find reference information for the exact model used in your car). Measurements are made using traditional instruments. Multimeters or ohmmeters. If the value obtained is very different from the specified, then there is a high probability that the coil is out of order.

You also need to be aware of the fact that each coil has different indicators:

  • Winding resistance;
  • Spark duration;
  • Spark energy;
  • Spark current;
  • Primary inductance.

Therefore, in order to understand how the coil readings correspond to the norm, it is necessary to clarify the technical characteristics of your individual coil. This is especially useful if the spark is missing, since the ignition coil is one of the first parts of the system to be checked.

There are several characteristic signs of a malfunctioning ignition coil. Among them:

  • The motor begins to “triple”, and this problem is aggravated over time;
  • In the cold, the motor “troit” until it warms up;
  • Interruptions in engine operation in wet weather;
  • When the accelerator pedal is pressed sharply, a failure of the motor is observed.

If the coil is faulty on cars with an ECU, the Check Engine icon is activated on the dashboard. However, these symptoms may also indicate other malfunctions, in particular, with spark plugs. But when at least one of them appears, you need to diagnose the ignition coil (s).

Method # 1: Spark Testing the Ignition Coil

  • Disconnect one high voltage wire from the spark plug. A separate cable leads to each candle. If you turned off the engine not too long ago, it is likely to be very hot. To avoid injuries and burns, wait 10-20 minutes and get to work.
  • Remove the spark plug with the spark plug socket. Do this carefully to prevent debris from entering the candle hole. If dirt or debris gets into the spark plug bore, it could damage the engine. Removing debris from a cylinder is a rather complicated operation. So be extremely careful at this point.
  • Attach the wire you pulled back to the candle. The plug should be connected to the ignition distributor, but not screwed into the engine. Only hold the candle with insulated pliers to avoid electric shock.
  • With the threaded side of the candle touch the bare metal. Touch the threaded portion of the spark plug to a bare portion of your vehicle. This could be an engine or an area with no paint.
  • Ask an assistant or friend to turn on the ignition. When the ignition is turned on, all electrical systems of the car begin to work, and if the ignition coil is in good working order, then voltage will be applied to the spark plug.
  • Make sure you can see the blue sparks skipping by. If you don’t see the blue spark, then the problem is obvious. Your coils are not functioning and need to be replaced. If the spark is orange, it means that insufficient voltage is being supplied to the spark plug. This could be due to weak current, poor contact, or damaged coil.
  • Replace the plug and reconnect the wire. Switch off the ignition and reassemble in the reverse order.

This is the first way to check the ignition coil with your own hands. Be careful when working with voltage and follow all safety precautions.

How to test ignition coils

The most common problems with a broken ignition coil:

  • Damage to the winding. This factor leads to breakdown of the insulating layer, resulting in a short circuit.
  • Open circuits and overload. The reason lies in a malfunction of the spark plugs or due to defects in high-voltage wires.

Basically, ignition coils fail quite rarely, but sometimes such troubles do happen. As a rule, the insulating layer of a coil can be damaged by an instantaneous voltage rise of up to 35,000 V. As a result, the secondary voltage drops and misfires occur under load. As a result, the coil cannot emit the voltage that is needed to start the motor. Next, we will tell you how to check the ignition coil with your own hands.

Breakdown of the ignition coil

The ignition coil is designed to create a high voltage, which is then used by the spark plug. Therefore, its proper operation is necessary for the normal functioning of the ignition system. In fact, the coil is a small transformer, to the primary winding of which comes standard 12 V from the battery, and a voltage of several kV comes out. It is used in all ignition systems. Contact, contactless and electronic. The reasons for coil failure are typical. As a rule, this is a wire break, insulation damage, mechanical deformation. Next, we will look at the symptoms of a malfunction and methods for diagnosing the ignition coil.

Symptoms of malfunctions

There are several characteristic signs of a malfunctioning ignition coil. Among them:

  • The motor begins to “triple”, and this problem is aggravated over time;
  • In the cold, the motor “troit” until it warms up;
  • Interruptions in engine operation in wet weather;
  • When the accelerator pedal is pressed sharply, a failure of the motor is observed.

If the coil is faulty on cars with an ECU, the Check Engine icon is activated on the dashboard. However, these symptoms may also indicate other malfunctions, in particular, with spark plugs. But when at least one of them appears, you need to diagnose the ignition coil (s).

Causes of malfunctions

There are several reasons due to which the ignition coil completely or partially fails. Among them:

  • Mechanical damage. This can be trivial aging, due to which the destruction of insulation occurs. There is also the possibility of oil leaking through the seals, which gets on the insulation or coil body and destroys them. Repair in this case is hardly possible, so a complete replacement of the assembly would be the best option.
  • Contact connection damage. In warm weather, this may be due to moisture entering the engine compartment. For example, during heavy rain, driving through deep puddles, car wash. In winter, it is likely that the composition sprinkled on the surface of the road to combat icing is likely to hit the coil.
  • Overheat. Individual coils are often subject to it. Overheating can significantly reduce the life of the ignition coils. Overheating is difficult to control, but try to use good quality coolant and keep the engine cooling system working properly.
  • Vibrations. They are especially detrimental to individual ignition coils. Vibration typically comes from the cylinder head (cylinder head). To reduce the number and amplitude of vibrations, make sure that the engine runs in normal mode (no detonation and with serviceable airbags).

Ignition coils are fairly reliable and durable units, and their failure is most often associated with aging and / or insulation breakdown. Next, we will consider methods for diagnosing coils.

Basic malfunctions and their elimination

If you cannot start the saw the first time, there may be several reasons. The most common problem is with the spark plug:

  • Electrode wear or damage to the ceramic insulator;
  • Loose fitting of the removable cap (if any);
  • Sparks running along the ceramic winding, a sign of which is a brown residue on the outer shell;
  • Cracks in the cap of the candle (a saw with this problem will continue to work, but it may hurt the user when touched).

If no problem was found with the spark plug, it is recommended to inspect the wires coming from the coil. They can be cut off or have other mechanical damage. There may be wire breaks inside the insulation, so sometimes these violations cannot be detected by visual inspection.

The cause of the breakdown may lie in the shutdown switches. It is not difficult to check them. To do this, disconnect the wires from the module, and then check the ignition. If a spark appears after shutdown, the switch must be replaced.

Check the ignition coil on the chainsaw

If the preliminary actions did not help in identifying the cause of the chainsaw malfunctions, then it is necessary to check the saw ignition coil. Diagnostics is performed in several stages:

  1. Measure the resistance of the coil using a multimeter. To do this, you should know the optimal parameters, which are indicated in the operating instructions. However, due to the use of semiconductor elements in the system, an attempt to “ring” the coil will result in an open circuit reading. This is normal. A positive test result is a sign of a malfunction. That is, if it was possible to determine the resistance of the coil using a special tool, then it is definitely faulty.
  2. Check for spark with a special device. This device should be installed in the open circuit located between the spark plug and the high voltage terminal of the saw ignition coil. The readings will be visible on the display. This method of verification is more commonly used in service centers, since the device required for this is expensive and the costs will not be comparable to the benefits rendered.
  3. Testing the coil with a spark plug, i.E. Making a homemade ignition. To do this, it must be turned out, and then the body must be attached to the cylinder. Now you need to pull the starter and observe the spark. But this method gives only an approximate result, since the flywheel turns faster due to the unnatural position of the candle.

If none of these methods work, or if you need to perform a check in the field, you can proceed as follows:

  1. Remove the cap from the candle, insert a nail without a cap into the core at a distance of 6-7 mm from the cylinder. This must be done as carefully as possible so as not to damage the part.
  2. Carry out the steps to be taken when the tool is manufactured. Now you need to look at the presence of a spark and its color. If there is no fault, then the spark will be strong and the color will be bright blue.

This method can be used as a last resort and only if there are no electronic components, while it is important to follow the rules:

  • You cannot completely unscrew the spark plug, as this can lead to faster rotation of the flywheel, which is not the correct mode of engine operation;
  • You need to place it at a distance that corresponds to the compression model and the dielectric properties of the fuel mixture, therefore this parameter can be viewed in the instructions (the value of 6-7 mm is average).

How does the ignition of a chainsaw work and how does it work?

The carburetor engine design does not depend on the tool model. Therefore, we can talk about a standard chainsaw ignition system. It consists of the following elements:

  1. Magneto. It is an alternating current generator. Required to supply the spark plug with electrical current. Outwardly, this part looks like a stationary winding of an inductor and a permanent magnet, which is fixed on the flywheel. The latter rotates simultaneously with the engine crankshaft.
  2. Spark plug.
  3. An electrical cable that connects the 2 previous elements.
  4. Device shutdown buttons.

The chainsaw ignition scheme is simple. After starting the tool, a rotating magnetic field is generated due to the movement of the flywheel and crankshaft. It creates a moving force in the existing winding, which is transformed into voltage. This potential is enough for the formation of a spark.

Differences in different models of chainsaws may only be whether a contact or non-contact magneto is used. In the first case, one terminal of the winding goes to the candle, and the second goes first to the shutdown button, and then through it to the ground. In the second case, the device has a capacitor, which, when discharged, forms a current.