Black carbon deposits on a chainsaw candle

About the chainsaw and its inoperability

Chainsaw – The installation itself is not that difficult. But having the smallest initial knowledge is extremely important in order to find and eliminate any defect..

Modern electronics has progressed so much that it has revolutionized the world of instruments. Saws of our days are light and at the same time powerful, equipped with electronic ignition systems ESZ.

Not so long ago, saw ignition systems were cam-type. This carried a lot of disadvantages: severity, complexity, high cost, and much more. And the main drawback of the archaic ignition system is the difficulty of the plant. Some saw model systems could not generate enough spark at all to flash at crankshaft speed..

Modern systems are nearly fail-safe. Saw models are lightweight and durable, the reel is made more professionally and will serve its life almost flawlessly. However, there are also problems, but in most cases they can be corrected on their own..

Consider the main types of chainsaw malfunctions associated with the flywheel and ignition system.

Black Soot Deposition: The Sinister Side of Scented Candles

As a rule, the most common ailment of modern chainsaws involves the absence of a supply spark. This also directly depends on the shift in the clearance (gap) between the bobbin and the flywheel..

Common installation failures are always associated with internal combustion engines. Problems arise in the fuel ignition system, the fuel intake module, in the internal elements of the engine itself.

As for other units of the chainsaw, malfunctions arise there, as a rule, due to failures of the brake mechanism, poor lubrication, etc..

If startup difficulties are associated with the engine, then the following symptoms are most often observed:

  • the motor does not develop the necessary power;
  • does not start at all;
  • starts, but quickly stalls;
  • functions unstable.

As always, experts recommend identifying fault factors in a way of elimination. In other words, you need to go through the chain, diagnosing each node, each link.

The gap between the ignition coil and the flywheel of the chainsaw

Internal combustion engines are installed not only on cars or motorcycles. They are widely used in various tools, for example, such as a chainsaw or a trimmer. In the event of their malfunction, poor start-up, it is often enough to establish the correct clearance between the flywheel and the ignition coil..

Ignition module

Inoperability of the SZ chainsaw is the most common reason why the engine of the tool does not start. It is recommended in most cases to start troubleshooting from here..

Here’s what to do:

  • first of all, carefully check the spark plug by carefully throwing off the armored wire from the head and unscrewing the plug from the socket using a special key;
  • the second is to check the spark supply by jerking the starter when the armored wire cap is put on the candle;
  • clearance check is the main topic of our article (more details below).

So, a malfunction of the spark plug will clearly indicate its phlegm. A wet spark device for igniting the fuel-air mixture indicates that there is an excess of fuel in the system, the carburetor is incorrectly tuned, or there are problems in the SZ.

The candle is checked only after drying. That is, it must be thoroughly cleaned with a napkin, the insides of the internal combustion engine should be dried, the supply should be blocked, and then the starter should be started a couple of times so that excess combustible mixture comes out.

Then the spark device is put in place and everything is checked again..

In general, a spark device can tell a lot about the entire ignition system. If black carbon is observed on the candle, then this indicates violations in the communications of the gasoline mixture supply. Here, either the ratio of gasoline and oil has been violated, or a carburetor readjustment is required. In some cases, this also happens due to low-quality oil..

A dirty candle is cleaned of black carbon with a needle or some other sharp object. Then the electrode is cleaned with emery paper (zero) until a metallic sheen appears. The spark device is returned to its place, everything is checked again.

The next step: checking the spark supply. The spark device skirt is brought up to the cylinder and the starter motor is started. If a bluish spark jumps at a distance of 2-3 mm, everything is fine. A spark distance of 0.5-1 mm is already considered a malfunction. There may be no spark at all, and this is also a big problem. Perhaps this is a wire break.

And now we come to the topic of our article. The chainsaw may not start due to a violation of the gap between the ignition and the flywheel magneto. This very gap should be within 0.2 mm. It is very simple to check: a special gasket is placed between the flywheel and the bobbin. If it comes in normally, not too loose and tight, then the gap is normal.

The saw flywheel itself is round, and checking the clearance with a conventional feeler gauge is impossible. It would be more qualified to set the gap according to a special template, but it is not always possible to acquire it. And not everyone can afford to buy a template that is not cheap for a single use..

However, instead of a foreign template, you can use a cut-out strip from a plastic container for 1-2 liters from under the juice.

A homemade template is put like this:

  • the ignition fixing bolts are loosened;
  • a plate is inserted between the flywheel and the bobbin;
  • the bolts are tightened.

How To Remove Carbon From A 2 Cycle Engine Exhaust Port

Advice. It is recommended to cut the plastic tape where there are no embossed irregularities.

How to check the magneto of a chainsaw

Magneto, babin, module is an ignition coil. It may have absolutely nothing to do with tool failures, and the reason is lurking only in the gap or in another. But in some cases, it is she who becomes a factor in violation.

To check the babin itself, you should, as in the above case, use it by excluding the components from the chain. Or in other words:

  • visually assess the condition of the bobbin case for cracks and other visible defects;
  • check the cleanliness of the current communications of various nodes and elements;
  • diagnose the insulation and serviceability of the armored wiring, the reliability of fixing the fasteners, the absence of rust, etc.
  • visually assess the condition of the spark device cap;
  • checking the condition of the candle;
  • circuit breaker diagnostics, which is especially important for Chinese-made chainsaws.

Again, as in the above case, certain points are excluded from this chain, thereby finding the cause of the problem.

Babin herself is investigated like this.

  • The resistance of the magneto is measured. However, this option is not always applicable, since it is necessary first of all to know the resistance parameters. In addition, for the formation of the required HE pulse, it is necessary to separate the indicators of various semiconductor elements. A sign of a malfunction, as a rule, is the ringing of the circuit through the BB wire and minus. Should show either “open circuit” or high resistance.
  • The check can be carried out as follows – use a device that checks for the presence of a spark. It is installed in the open circuit between the BB wire of the bobbin and the candles. The disadvantage of this method is that the device is so very expensive, it is used mostly in serious repair services..
  • “Dedovsky” method of verification, which will save on an expensive device. It is used at your own peril and risk when there are no other options. The method of checking is reduced to the fact that the cap is thrown off the candle, a carnation is inserted into it. The candle is re-inserted. The stud should be 6-7 mm from the cylinder. The chainsaw starts up. A spark is examined: it should be bright blue, if not, then this is a sign of a malfunction.

The “grandfather’s” method of checking a bobbin has many drawbacks. First of all, this applies to electrical components in the system, which can easily deteriorate. The distance between the cylinder and the stud may differ depending on the different models of the tool.

As for tuning the magneto, it boils down to examining the groove on the flywheel. UOZ for most of the current models of saws does not need to be adjusted. But it is possible to determine its exposure only by the angle between the mark after the groove on the flywheel and the magnets installed, again, on the flywheel.

Competently and accurately set the gap between the magneto and the flywheel – that’s what is more important.

black, carbon, deposits, chainsaw, candle

You should be aware that the bobbin on chainsaw systems is installed in the fan fuselage near the flywheel. The coil, in contact with the flywheel magnet, produces energy for the spark.

Replacing the coil itself will be much more difficult, since the installation location is too inconvenient. The installation of a new bobbin should be carried out so that the base of the coil is at a distance of 1-1.5 mm above the flywheel magnets.

In some cases, it is recommended to check also the crankshaft bearing for play.

How to test a spark on a candle?

Often, the chainsaw may not start due to the lack of a spark on the spark plug. How can you test a spark on a candle? The easiest way, which is recommended by experienced chainsaw owners, is to unscrew the candle, and then put a high-voltage wire on it. Then it is necessary to ensure the contact of the candle body in the part where the thread is located, and the cylinder block. Next, pull the starter handle, as usual when starting the tool..

After such actions, a bright blue spark should appear. If there is fuel in the tank and its supply is open, but there is no spark, the magneto is malfunctioning or there is a wire break. The integrity of the electrical circuit and magneto should be checked..

A popular question is also this: the chainsaw will not start, but there is a spark – what to do? The first thing to do is to check if the breather is working properly, if the air filter is in good condition. The filter is easy to clean from dirt, if it is worn out, just replace it with a new one.

The breather should be checked for blockage. If a part is clogged, it can be easily identified by disconnecting the fuel hose and observing how the fuel flows. If the flow of the gasoline mixture is normal, then the breather is working, if the flow is very weak or absent, clean the breather.

Read more:  Replacing the Chinese Chainsaw Oil Pump

A video with a simple way to check a spark on a candle:

Chainsaw ignition coil – we check, replace, adjust

Checking the ignition coil is performed in the following ways:

  • by measuring the resistance of the coil (a multimeter is used for this method), the disadvantage of this method is its relative complexity, because cold semiconductor elements will not show a coil malfunction, they require heating and special conditions for testing;
  • spark testing device. This device is inserted into the gap between the high-voltage wire and the candle. Usually, such devices are available only in service centers, they are not used in everyday life due to the high price..
  • By inverting the candle. In this way, the presence of a spark is checked. but it does not give an accurate idea of ​​the state of the ignition coil.

You can adjust the ignition coil of the chainsaw as follows:

  • after loosening the bolts holding the ignition system, the magnets should be brought to the coil;
  • an adjustment plate is clamped between the coil and the flywheel, then the bolts are tightened;
  • the plate is taken out;
  • the flywheel is rotated in full rotation 2-3 times, making sure that it does not cling to the coil, after which the chainsaw is assembled.

How to check the ignition on a chainsaw – using the Druzhba chainsaw as an example:

How to check the ignition coil with a multimeter – video

Reasons for the absence of a spark

The engine of each chainsaw is, in fact, a miniature power plant. She receives the primary impulse for the spark on the candle from the pull of the starter cord, from muscle energy.

Further, energy is generated due to the rotation of the magnetic rotor when the engine is running due to the combustion of fuel. In theory, spark problems can be found throughout the entire mowing line of a system, from generating power to transmitting it through wires and converting it to a spark plug from a chainsaw spark plug. In practice, there are fewer weak points.

Determine the availability of fuel and its supply.

First you need to make sure that there is a fuel mixture in the tank of a chainsaw that does not want to start, and it regularly enters the carburetor. With a full tank, we check how the mixture is fed through the gas line. We disconnect the fuel system pipe from the carburetor and try to pump it up. In the case of a complete order, when pumping up, gasoline will be supplied in jerks in accordance with the norms set by the manufacturer. Poor or no fuel supply may result from:

  • The fuel supply channel is clogged;
  • Debris-clogged fuel filter.
black, carbon, deposits, chainsaw, candle

Often the reason for a poor start of the chainsaw can be a tank that is too full. In this case, you should pay attention to the presence of smudges under the saw case cover. If present, see the connection of the gasoline feed pipe to the carburetor. Most often, it is squeezed out by pressure when the tank cap is screwed on, which is filled under the very neck, which prevents the engine from starting.

The quality of the fuel mixture can also be one of the reasons why the chainsaw does not start. If, after completing the work, the remaining gasoline is not drained, and the tool is left for long-term storage (more than 2 weeks), then the processes of resinification and polymerization of the components will begin to occur inside the tank. What can cause carbon deposits on the piston, rings and cylinder liner. Therefore, always prepare the mixture only in the required amount before work..

Weak spark reasons

A weak spark on a chainsaw is a relative concept. Most often, a spark is either present and the ignition is working properly, or it is not there at all. In modern chainsaws with electronic ignition, the spark visually seems to be weak..

On older models with a mechanical cam interrupter, the spark was large, with a strong blue color. On modern models with electronics, it is noticeably smaller and paler, more often yellowish. Therefore, when you need to make sure of its presence, it is better to do it in the shade. In direct sunlight, it is almost invisible.

Checking the spark on the spark plug and eliminating the causes.

The first step in looking for reasons why your gasoline saw won’t start is to check the spark on the spark plug. There are many factors that affect the performance of this element. However, the main ones at the initial stage of instrument troubleshooting are:

  • Incorrect carburetor adjustment;
  • The presence of more than it should be, the amount of oil in gasoline;
  • Clogged air filter.

All of them contribute to the formation of carbon deposits on the spark plug electrodes. In 50 cases out of 100, the saws do not start on a cold one due to the absence of a spark due to carbon deposits on the electrodes and their corrosion. As a result, the gap either decreases or increases..

Checking the spark plug with an idle chainsaw

It is quite easy to check for a spark. This will require:

  • Remove the tip of the high-voltage wire;
  • Unscrew the candle;
  • Put the tip back on;
  • Lean the candle with a skirt against the cylinder;
  • Start with a starter.

If a good spark is observed between the electrodes at the time of starting the engine of the chainsaw, then everything is in order with the ignition unit. If it is not there, then it is worth cleaning the element itself and checking the gap of the electrodes. If necessary, use a special probe to adjust the distance between the contacts.

For candles from different manufacturers, the distance between the electrodes may fluctuate. For some, it may be equal to 0.5 mm. Others have 0.2 mm. Therefore, carefully study the manufacturer’s recommendations..

There may be no spark on the spark plug for other reasons. Of the main faults affecting the poor start of the chainsaw and the unstable operation of the internal combustion engine at idle, from which the tool can stall, the following can be attributed:

  • Overflow of the spark plug channel with fuel;
  • Lack of contact between the high-voltage cradle and the tip of the candle;
  • Failure of the ignition unit.

How to start a cold chainsaw if the spark plug channel is constantly flooding with gasoline? To eliminate the problem while starting the tool, you can use the following algorithm:

  • Unscrew the candle with a special key;
  • Wipe it with a clean and dry cloth;
  • Dry for 20 … 30 minutes;
  • Remove carbon deposits with a file and adjust the gap between the electrodes;
  • Drain the remaining fuel from the spark plug channel and dry it;
  • Collect everything and try to start the mechanism.

As a rule, these measures are enough to start the chainsaw and get the job done. However, this extreme measure does not eliminate the main reason why the engine does not start or stalls – improper operation of the carburetor, which needs fine adjustment..

If there is no spark and poor contact of the high-voltage cradle with the spark plug tip, check the connection. The check can be carried out using a conventional tester. If a defect is found and it is eliminated, the chainsaw should start without any problems.

If the check showed that the contact is reliable, and the saw does not start further, look for the cause in the ignition unit. As a rule, a faulty unit cannot be repaired and restored. A complete replacement is required here..

Testimonials

Vladimir, Rostov:

“As the owner of a chainsaw with little experience, I prefer to entrust all repair work to specialists. Despite the abundance of information, it is difficult to understand the repair yourself if you do not have basic knowledge of mechanics and electronics. While the chainsaw is under warranty, take the opportunity, it’s better not to make specialists anyway! ”

If there is no spark on the chainsaw, then you should not be upset, the malfunction is diagnosed and eliminated on its own very simply. The correct functioning of the ignition system and the fuel system are equally important for the trouble-free operation of the chainsaw engine. But the symptoms of both ignition and carburetor malfunctions are often very similar at first glance. In order to correctly find and eliminate the cause of malfunctions in the ignition system, in particular the absence of a spark, you need to know the principle of its operation, devices and diagnostics.

Black carbon deposits on spark plugs

The most common color of soot is considered to be black, and it is most difficult to correctly diagnose the malfunction to which it indicates. Black carbon can be presented in two variations, each of which indicates the occurrence of a certain malfunction in the engine. Distinguish black carbon deposits by structure, which allows you to accurately identify a group of causes of engine problems.

Important: An evenly distributed coffee or grayish carbon deposit indicates that there are no problems at the time of combustion of the working mixture. Such carbon deposits are typical for stable engine operation..

How to check the condition of the engine by burning candles

Spark plugs are considered to be the best diagnostic tool when it is necessary to detect a malfunction that is related to the ignition cycle of the propellant mixture. In this case, it is impossible to draw conclusions about the condition of the engine by unscrewing the spark plugs after 10-20 or more thousand kilometers. Diagnostics is carried out exclusively on “fresh” candles, but at the same time they must be run-in at 150-200 kilometers.

To check the condition of the engine by burning candles, you must:

  • Install new candles;
  • Drive 150-200 kilometers on them;
  • Unscrew the candles and look at the color of carbon deposits that began to form on them.

Attention: Check the color of carbon deposits on the spark plugs only on a warm engine..

Red, white, black carbon deposits on spark plugs: causes, diagnostics, problem elimination

Spark plugs are installed in a car to perform two functions – igniting the working mixture in the combustion chamber and removing excess heat after detonation. Their competent work seriously affects the traction properties of the engine, and if the engine began to idle unstably, with difficulty to start or “twitch”, you should pay attention to the condition of the spark plugs.

Car manufacturers prescribe information in the data sheet about how often the spark plugs need to be replaced. But these values ​​are most often exaggerated for marketing purposes, and the driver has to change the candles more often than the car developers plan. If you suspect a spark plug malfunction, you can check their condition quite simply by paying attention to the color of carbon deposits formed on the electrodes. This will allow you to determine which vehicle systems have led to the failure of the spark plugs..

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Dry black carbon deposits in the form of soot

The second type of black carbon deposits on spark plugs is commonly referred to as “velvety”. In this case, carbon deposits are not distinguished by the presence of oil smudges. Most often, this type of soot indicates that a fuel-air mixture, highly enriched with gasoline, enters the combustion chamber. If dry black carbon deposits appear on the spark plugs, the following malfunctions are possible:

  • Incorrect spark plug operation. It is possible that there is not enough energy to generate a spark of the required power;
  • Low compression in the engine cylinders. If black velvety carbon deposits appear on the engine plug, it is recommended to check the compression in the cylinders;
  • If the engine is carbureted, the problem may be due to improper carburetor setting;
  • If the engine is injector, the malfunction indicates a problem with the fuel pressure regulator, which excessively enriches the air mixture. In such cases, you may notice an increased fuel consumption of the car;
  • Clogged or defective air filter, which does not allow enough air to pass through, which leads to incomplete combustion of fuel, and it settles on the spark plug electrode.

This type of carbon is characterized by the fact that it settles more on the electrode of the spark plug and practically does not penetrate the threaded connection..

Red carbon deposits on spark plugs

If a car owner uses a variety of fuel or oil additives, they may notice red carbon deposits on the spark plug. This is due to the combustion of chemical additives filled with excess. If the driver regularly uses certain additives and notices that his spark plugs are covered with red deposits, it is recommended to reduce the amount of additives to be added next time..

The problem is typical if the additives used in the car contain additives of manganese or lead. If you ignore the red soot on the spark plug, a layer will form on the electrode, which will reduce the likelihood of sparking, which will lead to unstable engine operation..

If red carbon deposits appear on the spark plugs, it is recommended to remove it, and also change the oil or gasoline, depending on where the additive was poured..

Glossy white carbon deposits

Glossy white carbon deposits are harmful to the car engine and indicate that the spark plug is not getting adequate cooling. In addition to the spark plug, the pistons can also overheat, which will lead to cracks in the valve and turn out to be an expensive replacement for the driver. Most often, the reasons for overheating the spark plug and the appearance of white soot lie in the insufficient amount of fluid in the cooling system. Also, white carbon deposits with a “glossy” sheen may appear for the following reasons:

  • A lean fuel mixture enters the combustion chamber;
  • The intake manifold draws in excess air;
  • A misfire occurs or the spark plugs sparks too early due to a misconfigured ignition;
  • Incorrect spark plug selected for this engine type.

If a glossy white carbon deposit with traces of metal inclusions appears on the spark plug, you should show the car to the diagnosticians as soon as possible or figure out the problem yourself. It is not recommended to operate the car with such a soot..

Oily black carbon

A pronounced oily black carbon deposit formed in the area of ​​the threaded joints and on the electrode often manifests itself simultaneously with another symptom – blue smoke from the exhaust pipe when the engine is started. This type of carbon deposits on the spark plugs indicates that excess oil is entering the combustion chamber. This can happen for one of the following reasons:

  • Worn valve stem seals;
  • Worn piston rings on the piston;
  • Worn valve guides.

As you can see, the problem is associated with worn parts of the cylinder-piston group. In case of such malfunctions, it is required to replace worn parts.

Carbon deposits on the insulator

Red carbon deposits on a candle

In some cases, carbon deposits that naturally occur in the combustion chamber can come off the piston at high engine speeds and stick to the spark plug insulator. The consequence of this will be gaps in the operation of the corresponding cylinder. In this case, the engine will “triple”. This is the most innocuous situation, why spark plugs turn black. You can eliminate it simply by cleaning their surface or replacing them with new ones..

If black and red spark plugs appear in your engine, it means that you are filling fuel with an excessive amount of metal additives. It cannot be used for a long time for the reason that over time, metal deposits form a conductive coating on the surface of the insulator of the candle. Sparking will deteriorate and the plug will soon fail..

Cleaning spark plugs

Why are black spark plugs

The appearance of black carbon deposits on the spark plugs can tell the car owner about the problems that are in his car. The reasons for this phenomenon can be low-quality fuel, ignition problems, a mismatch in the air-fuel mixture or an incorrectly tuned carburetor, and so on. All of these problems can be diagnosed quite easily by looking at the black spark plugs..

What to do if carbon deposits appear

First of all, it must be remembered that oil contamination and overheating, which results in soot on the spark plugs, are very harmful to the ignition system. Overheating is especially terrible, because it causes the possibility of failure of the electrodes on the candles without the possibility of their restoration..

If only one blackened candle appears on your car, then you can diagnose a breakdown by simply swapping the candles. If, after that, the new candle also turns black, and the old one becomes clean, it means that the point is not in the candles, but in the cylinder. And if nothing has changed, then questions arise about the performance of the candle itself..

Cleaning spark plugs from plaque

Candles must be cleaned regularly, as well as inspected their condition. It is recommended to do this after approximately 8.10 thousand kilometers. It is very convenient to do this when changing the engine oil. However, with the onset of the symptoms described above, you can do this earlier..

It should be noted right away that it is not recommended to use the old method using sandpaper to clean the electrodes. The fact is that in this way there is a risk of damage to the protective layer on them. This is especially true for iridium candles. They have a thin central electrode covered with iridium, which is a semi-precious and rare metal..

To clean your spark plugs, you will need:

  • detergent to remove plaque and rust;
  • disposable plastic cups (after the end of the cleaning procedure, they must be disposed of; they cannot be used for food in the future);
  • a thin brush with a hard bristle or a toothbrush;
  • rags.

The cleaning procedure is performed according to the following algorithm:

  • A cleaning agent is poured into a glass prepared in advance to a level so that the electrodes of the candle are completely immersed in it (without an insulator).
  • Immerse candles in a glass and leave for 30.40 minutes (in the process, a chemical cleaning reaction occurs, which can be observed with the naked eye).
  • After the specified time has elapsed, the candles are taken out of the glass, and using a brush or toothbrush, plaque is removed from the surface of the candle, especially paying attention to the electrodes.
  • The candles are washed in warm running water, removing the chemical composition and dirt from their surface.
  • After rinsing, wipe the candles dry with a previously prepared rag.
  • The final stage is to dry the candles on the battery, in the oven (at a low temperature of 60 … 70 ° C) or using a hair dryer or fan heater (the main thing is that the water remaining in them completely evaporates).

The procedure must be followed carefully, cleaning and removing all dirt and plaque present on the surface. Remember that washed and cleaned candles work 10.15% more efficiently than dirty ones..

Oil deposits

In some cases, candles can be wet and black. The most common cause of this fact is the ingress of oil into the combustion chamber. Additional symptoms of this malfunction are as follows:

  • Difficulty starting the engine;
  • gaps in the work of the corresponding cylinder;
  • the engine twitches during operation;
  • the appearance of blue smoke from the exhaust.

Oil can enter the combustion chamber in two ways – from the bottom or from the top. In the first case, it enters through the piston rings. And this is a very bad sign, because it often threatens to overhaul the engine. In rare cases, you can get by with the engine decoking. If oil enters the combustion chamber through the top, then it flows out of the cylinder head along the valve guides. The reason for this is the wear on the valve stem seals. To eliminate this malfunction, you just need to replace the caps.

Possible causes of carbon deposits

Before answering the question of why the candles are black, you need to decide how exactly they turned black. After all, it depends on which direction to search. In particular, the candles can all go black together, or only one or two of the set. Also, the candle can turn black only on one side, and maybe over the entire diameter. They also distinguish between the so-called “wet” and “dry” carbon deposits..

It should be noted that the rate of occurrence and nature of carbon deposits directly depends on the existing faults (if any):

  • Carbon deposits on new candles begin to form after at least 200-300 km of run. Moreover, it is desirable to drive along the highway with approximately the same speed and engine load. So the candles will work in optimal mode, and it will be possible to more objectively assess the condition of the car’s components..
  • The amount and type of carbon deposit depends on the quality of the fuel used. Therefore, try to refuel at proven gas stations, and not drive on gasoline or similar mixtures. Otherwise, it will be difficult to establish the real cause of carbon deposits (if any)..
  • In a carburetor engine, the idle speed must be correctly set.
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Now let’s move on directly to the question of why black carbon deposits appear on the spark plugs. There may be 11 main reasons:

  • If you notice blackening on only one side, then most likely this is caused by a burnout of the valve. That is, carbon deposits on the candle fall from the bottom to the side electrode (and not to the central one).
  • The cause of black candles can be valve burnout. The situation is similar to the previous one. Carbon deposits can penetrate the lower electrode.
  • Incorrectly selected glow number of the spark plug causes not only its damage in further operation, but also uneven blackening at first. If the mentioned number is small, then the shape of the carbon cone will change. If it is large, then only the top of the cone will turn black, and the body will be white.

“Dry” carbon deposits on a candle

As a rule, when the late ignition is set and operating on a rich air-fuel mixture, the following consequences occur:

  • misfiring (error P0300 appears on injection engines);
  • problems with starting the engine;
  • unstable engine operation, especially at idle, and, as a result, increased vibration level.

Next, we will tell you how to fix the listed malfunctions and how to clean the spark plugs.

A black spark plug on a carburetor or injector can be caused by a variety of reasons. As a rule, there are several of them at once. For example, incorrectly selected plugs, prolonged engine operation at high speeds, incorrect ignition, faulty valve stem seals, and so on. Therefore, we recommend that, when the symptoms described above appear, and just periodically check the condition of the spark plugs on your car..

This not only extends the life of the engine, but also maintains power and driving comfort. For more information on how you can diagnose a car engine by the color of spark plug carbon deposits, you can look additionally..

Advice! RED, WHITE, BLACK SPARK PLUG BURN: CAUSES, DIAGNOSTICS, TROUBLESHOOTING

Spark plugs are installed in a car to perform two functions – igniting the working mixture in the combustion chamber and removing excess heat after detonation. Their competent work seriously affects the traction properties of the engine, and if the engine began to idle unstably, with difficulty to start or “twitch”, you should pay attention to the condition of the spark plugs.

Car manufacturers prescribe information in the data sheet about how often the spark plugs need to be replaced. But these values ​​are most often exaggerated for marketing purposes, and the driver has to change the candles more often than the car developers plan. If you suspect a spark plug malfunction, you can check their condition quite simply by paying attention to the color of carbon deposits formed on the electrodes. This will allow you to determine which vehicle systems have led to the failure of the spark plugs..

WHY BURNING ON SPARK PLUG ELECTRODES

Car candles work in a “harsh” environment, where they are exposed to not only thermal, but also chemical action. When the fuel burns, a gray coating forms on the spark plug electrodes, which signals the stable operation of the system. At the same time, red, black or white carbon deposits can also appear on the spark plug, which should make the driver of the car think not only about replacing the spark plugs, but also about the need to urgently check the engine for certain malfunctions..

The color of the carbon deposit of the spark plug electrode clearly signals what kind of malfunctions may have occurred in the engine. Most often they are associated with the moment of sparking, the composition of the fuel mixture or the temperature in the combustion chamber. We will consider in more detail each color of spark plug carbon below..

HOW TO CHECK THE STATE OF THE ENGINE ON BURNING CANDLES

Spark plugs are considered to be the best diagnostic tool when it is necessary to detect a malfunction that is related to the ignition cycle of the propellant mixture. In this case, it is impossible to draw conclusions about the condition of the engine by unscrewing the spark plugs after 10-20 or more thousand kilometers. Diagnostics is carried out exclusively on “fresh” candles, but at the same time they must be run-in at 150-200 kilometers.

To check the condition of the engine by burning candles, you must:

  • Install new candles;
  • Drive 150-200 kilometers on them;
  • Unscrew the candles and look at the color of carbon deposits that began to form on them.

Attention: Check the color of carbon deposits on the spark plugs only on a warm engine..

BLACK SPARK PLUGS

The most common color of soot is considered to be black, and it is most difficult to correctly diagnose the malfunction to which it indicates. Black carbon can be presented in two variations, each of which indicates the occurrence of a certain malfunction in the engine. Distinguish black carbon deposits by structure, which allows you to accurately identify a group of causes of engine problems.

Important: An evenly distributed coffee or grayish carbon deposit indicates that there are no problems at the time of combustion of the working mixture. Such carbon deposits are typical for stable engine operation..

OILY BLACK BAR

A pronounced oily black carbon deposit formed in the area of ​​the threaded joints and on the electrode often manifests itself simultaneously with another symptom – blue smoke from the exhaust pipe when the engine is started. This type of carbon deposits on the spark plugs indicates that excess oil is entering the combustion chamber. This can happen for one of the following reasons:

  • Worn valve stem seals on the piston;
  • Worn piston rings on the valve;
  • Worn valve guides.

As you can see, the problem is associated with worn parts of the cylinder-piston group. In case of such malfunctions, it is required to replace worn parts.

DRY BLACK SOOOT

The second type of black carbon deposits on spark plugs is commonly referred to as “velvety”. In this case, carbon deposits are not distinguished by the presence of oil smudges. Most often, this type of soot indicates that a fuel-air mixture, highly enriched with gasoline, enters the combustion chamber. If dry black carbon deposits appear on the spark plugs, the following malfunctions are possible:

  • Incorrect spark plug operation. It is possible that there is not enough energy to generate a spark of the required power;
  • Low compression in the engine cylinders. If black velvety carbon deposits appear on the engine plug, it is recommended to check the compression in the cylinders;
  • If the engine is carbureted, the problem may be due to improper carburetor setting;
  • If the engine is injector, the malfunction indicates a problem with the fuel pressure regulator, which excessively enriches the air mixture. In such cases, you may notice an increased fuel consumption of the car;
  • Clogged or defective air filter, which does not allow enough air to pass through, which leads to incomplete combustion of fuel, and it settles on the spark plug electrode.

This type of carbon is characterized by the fact that it settles more on the electrode of the spark plug and practically does not penetrate the threaded connection..

RED SPARK PLUG BURNER

If a car owner uses a variety of fuel or oil additives, they may notice red carbon deposits on the spark plug. This is due to the combustion of chemical additives filled with excess. If the driver regularly uses certain additives and notices that his spark plugs are covered with red deposits, it is recommended to reduce the amount of additives to be added next time..

The problem is typical if the additives used in the car contain additives of manganese or lead. If you ignore the red soot on the spark plug, a layer will form on the electrode, which will reduce the likelihood of sparking, which will lead to unstable engine operation..

If red carbon deposits appear on the spark plugs, it is recommended to remove it, and also change the oil or gasoline, depending on where the additive was poured..

WHITE SPARK PLUGS

Like black carbon, white has different manifestations. It can have a glossy surface, due to the presence of grains of metal in the soot, or settle on the electrode in the form of large white deposits..

GLOSSY WHITE BOND

Glossy white carbon deposits are harmful to the car engine and indicate that the spark plug is not getting adequate cooling. In addition to the spark plug, the pistons can also overheat, which will lead to cracks in the valve and turn out to be an expensive replacement for the driver. Most often, the reasons for overheating the spark plug and the appearance of white soot lie in the insufficient amount of fluid in the cooling system. Also, white carbon deposits with a “glossy” sheen may appear for the following reasons:

  • A lean fuel mixture enters the combustion chamber;
  • The intake manifold draws in excess air;
  • A misfire occurs or the spark plugs sparks too early due to a misconfigured ignition;
  • Incorrect spark plug selected for this engine type.
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If a glossy white carbon deposit with traces of metal inclusions appears on the spark plug, you should show the car to the diagnosticians as soon as possible or figure out the problem yourself. It is not recommended to operate the car with such a soot..

LOW-EXPRESSED WHITE BOND

If a white carbon deposit forms on the spark plug and evenly settles on the surface of the electrode, the problem lies in the fuel poured into the car. In such a situation, it is recommended to check the quality of gasoline and replace it completely, and then refuel from another manufacturer..