Spark plugs intended to adjust the fuel and air mixture in the automotive engine, have several types of classification. First of all, it is a division according to the design, then there are differences on the materials of manufacture and the thermal parameters of the candles.

Construction of candles

By its design, candles can be:
- two-electro;
- Multielectrode.

What is the difference in spark plugs with two electrodes from those who have more than their number? A classic two-electrode candle has one electrode, protruding central, and one side, whereas in a multi-electrode structure, also includes one central electrode, the side will already be several. The more the electrodes, the more reliable the candle should work and the longer it is capable of listening. Although, of course, this version of the candles will be more expensive.

Materials of candles

Based on materials from which electrodes are manufactured, candles are:
- platinum;
- Iridiev;
- Classic.

In platinum ignition candles, the electrodes (and central, and side) are made of platinum with high resistance to temperature and corrosion. The platinum electrode practically does not fade, although it is naturally notice. Such a candle is much longer "classic", the electrodes of which are made of copper.

However, standard ignition candles can work for quite a long time if their copper electrodes are covered with rare metals, for example, yttrium. In this case, their cost will be less than that of platinum.

Thermal parameters

Another parameter for which you can split car candles - their caliper determining thermal parameters. What is the difference in the spark plugs with different caligic numbers? Those in which this parameter is higher is better working at high temperatures, less heat and are called "cold", the rest - "hot." "Hot" candles are quite reliable at a small load, so they are used at relatively short distances of the trip. For long journeys, during which the candle temperature can significantly climb, it will be more expedient to use the "cold" option.

However, at present, the range of gangs in various candles is not too large, and the difference between hot and cold candles is small. This is explained by almost the same fuel combustion processes in modern engines at any distances passing by the car.

(Function (W, D, N, S, T) (w [n] \u003d w [n] ||; w [n] .push (function () (ya.context.advmanager.render ((Blockid: "RA -136785-1 ", RENDERTO:" yandex_rtb_r-a-136785-1 ", async: true));)); t \u003d d.getelementsbytagname (" script "); s \u003d d.createElement (" script "); s .type \u003d "text / javascript"; s.src \u003d "//an.yandex.ru/system/context.js"; s.async \u003d true; t.parentnode.insertBefore (s, t);)) (this , this.document, "yandexcontextasynccallbacks");

Variety of spark plugs

To date, a large number of types of spark plugs are produced. Products each of the manufacturers has its own characteristic features. .

The main parameters on which the types of candles are distinguished:

• the number of electrodes is one or multoelectrode;
• the material from which the central electrode is made - yttrium, tungsten, platinum, iridium, palladium;
• the calil number is "cold" or "hot candles.

There are also differences in the form, in the size of the gap between the side and central electrode, in small structural features.

Standard candle

This is the most common and most affordable type. The resource of its work is not too large, the electrode is made from the heat-resistant metal, so over time, traces of erosion appear on it. Fortunately, the prices are very low, so their replacement will not be too expensive.

In principle, all the candles of domestic production, such as the Ufa plant, can be attributed to the standard - A11, A17DV, which goes to "penny". It is desirable to check their quality without departing from the cashier, because the percentage of marriage can be quite high. Nevertheless, if you choose good and high-quality products, they will work out its resource without problems.

Multielectrode candles

In such candles there are several side electrodes - from two to four, thanks to which the work resource increases significantly.

Engineers came to the thoughts on the use of several side electrodes, because one electrode heats up very much during operation, which significantly reduces its service life. If several electrodes are involved, they work as it were in turn, respectively, no overheating.

Interesting and the fact that the engineers of the Swedish automotive industry SAAB offered to use a pointed and elongated part on the piston itself instead of the side electrode. That is, it turns out a candle without a lateral electrode.

Advantages of such a solution mass:

• the spark will appear at the right moment when the piston is approaching the upper dead point;
• fuel will burn almost without residue;
• can be applied depleted mixtures;
• significant savings and minimization of harmful emissions into the atmosphere.

So far, this is still plans for the future, the multielectic candles are applied on racing cars, which speaks of their quality. True and the price is higher. However, one -electrode is gradually improving, so it's definitely, which of them are better, is difficult.

Iridiya and platinum candles

They first appeared in 1997, they released the company DENSO.

Distinctive properties:

• the central electrode from iridium or platinum has a thickness of only 0.4-0.7 millimeters;
• side electrode is pointed and shaped in a special way.

Their main advantage is a long service life, which can reach 200 thousand mileage mileage or 5-6 years of operation of the car.

True, so that they fully work out their resource, you must adhere to the manufacturer's instructions:

• use fuel with an octane number not lower than that indicated in the manual;
• installing the installation strictly according to the rules - tighten the candle to a certain point, but if you make a mistake, the whole result will be completely leveled.

To make it easier to twist such candles into the cylinder head, manufacturers put special limiters that do not allow them to tighten more than necessary.

The only negative point is a high cost. It is also worth noting that Iridium has a greater resource of work than platinum, therefore the price of it is higher.

Candles with a central electrode from other materials also serve much longer than the standard, but they are not presented so widely on sale.

Spores around the spark plugs today were noticeably dull. The reasons for us seem to be somewhat: the range of candles in the stores is widely as ever, the quality of fuel in the country is still somewhat improved, and the fleet has grown out and became more "foreign". Nevertheless, questions continue to enter the editor. Some interest in general information - why, for example, still need multieelectrode candles? Others are worried about purely personal problems: Look in the photo of the candles and make a diagnosis of a motor ... Answers to a dozen similar questions below.

What are the advantages of multoelectrode candles? Is it true that they are more sparks than "ordinary"?

Immediately dispel the living myth about the "Multisire" candles: they do not exist in nature. The side electrodes can be as much as you like, but one is always one sparkle. Sellers often demonstrate the "Multiser" mode on the stands where the impression of the simultaneous discharge in the form of a glowing ring is created, but it is just an illicit, like in the movies.

What is the advantages of multi-electrode candles, then they are. The first is a resource: due to the distribution of the load between the side electrodes, the pace of their erosion is reduced. By the way, that is why they are often installed in motors with difficult access to candles. The second is the presence of the so-called "open spark" at which the front of the flame is not stuck in the interelectrode space, and goes into the combustion chamber. The combustion rate increases that somewhat increases the power of the motor and improves its efficiency. The third dignity is a relatively small number of fakes of such candles.

Disadvantages? Relatively high price plus the impossibility to set the desired interelectrode clearance ...

Why do we need different kind of "jewelry" of the type of iridium electrodes?

The resource is 90-100 thousand km for such candles - the usual thing.

The resource is 90-100 thousand km for such candles - the usual thing.

Then, that the service life of iridium, platinum and other "thoroughbred" is several times higher than that of the "manless" ... while the refractory materials of the electrodes make it possible to increase the field strength in the interelectrode space, at the same time release the path of the flame front. And a more powerful spark discharge, among other things, contributes to a good self-cleaning of the candle.

Why don't the forkar candles come true?

What is happening that it has obvious advantages. In particular, a kind of "microfrocamera" - the removal in the electrodes of individual branded candles - contribute to the stabilization of the discharge on the edges of such recesses. Such recesses can be both on the side (DENSO) and on the central (NGK) electrodes. There is a certain technical effect.

As for the "full-fledged" forkarmic candles, they are often used in the Motors of sports cars of Formula 1. The fact is that such engines work at high speeds, in which problems with ventilation simply does not occur. But on the minimum speed of idling, and on low loads, the mixture in the cylinders moves much less intense, and therefore the internal candle camera is actually choking. This is what is observed, as a rule, when trying to stupidly install something pseudo-alone on your engine.

What kind of clearance should be in the candlelight?

Funny other: It can not even be one for all types of candles. Let's say, for the same Iridiev, he may know more than for classic! But no one usually gives such recommendations. Therefore, its concrete magnitude is always individual precisely for the candle tandem - the motor. In the general case, the greater the size of the gap, the stronger the spark and the focus of ignition. We also add that with the growth of the gap decreases the likelihood of shocking electrodes by the particulate bridges.

The danger of excessive increase in the clearance is obvious: more gap - more required breakdown voltage. And the discharge is all the same, where to "shoot": it can break through the coil, if he decides that he is so easier ...

What is plasma candles?

We do not know ... The question is resting exclusively into terminology, because any spark discharge can be called a cold plasma. Therefore, attempts by individual manufacturers to call their candles - this is a consequence of illiteracy, as well as the desire to play in the inexperience of consumers. All candles are either plasma, or not: the corresponding terminology simply does not exist. But to call plasma only candles of their own manufacture, without paying the same colleagues on the workshop, simply incorrectly.

Why do candles make more subtle? Even the turnkey size used to be 21 mm, and now - 14.

Candles with thread M14x1.25 and a large hexagon were used on engines with two valves per cylinder. At the same time, the candle most often approached the combustion chamber on the side and place to accommodate it was abound. On modern engines with four, or even five valves, the only place to accommodate the candle is the center of combustion chamber. The candle is applied to the head of the cylinder block through the candle well, which "steals" the space in the valves and the shirt of the cooling system. That is why you have to make more and thinner candles and wells of small diameter.

Candle turned out of the engine covered with a layer of oil. What is the reason?

Ground candles can be a sign of relatively easily eliminated problems, for example, too high oil level in the engine or clogging of crankcase ventilation channels. But perhaps, this is caused by much more formidable, such as worn piston rings, broken guide sleeves of valves and defective valve seals.

The candle managed to twist with great difficulty, and the new candle does not turn to the end. What to do?

Obviously, the former candle was not wrapped in the head of the cylinder block. Therefore, part of the thread in the head was covered with Nagar and does not allow screwed a new candle. In such a situation, the best supfil along the threaded part of the old candle to perform grooves. This will turn the candle in the semblance of the tap. Next, applying a candle with a thin layer of plastic lubrication on the thread, we screw it into the hole, periodically "handing it back" until we pass all the threads. We wipe the candle hole with a lint-free vehicle and screw the new candle. It is advisable to apply a special high-temperature lubricant or simply rub the thread with graphite.

Candle insulator acquired an incomprehensible reddish color, although Nagar is practically no. What is it?

Should you brush the candles from Nagara between replacements?

With a good car, a little is formed a little and cleaning the candles is not required. If the candles are covered with plentiful nagar with small runs, it is a reason to do the repair of the engine, and not cleaning the candles. In addition, the threaded holes for the candles are made in aluminum, and countless turning-screws can lead to a breakdown of the thread.

Colleagues-motorists, tell me whether you met with some unusual candle defects?

Engine launch, its smooth operation, efficiency and turnover can be associated not only with the normal functioning of all systems. In this case, the spark plugs are played, on which the ignition of the fuel and air mixture depends. Therefore, it is worth knowing the characteristics of these elements, the rules of choice and brands offered on the market.

The importance of choosing a choice

If you competently approach the selection of candles, such problems can be avoided:

• regular spending on the purchase of new candles due to the rapid failure of the recently acquired;
• high spark efficiency for a long time;
• cleaning a candle nest;
• increase fuel consumption.

Therefore, it is worth considering many parameters when purchasing a set of candles.

Types of spark plugs

Spark plugs are classified as applied to the number of electrodes on the types:

• Two-electrode - there are two electrodes (central and lateral);
• Multielectrode - contain several side electrodes.

Multielectrode structures allow you to increase engine stability. When there are additional side electrodes, the sparking will necessarily happen. Indeed, in case of non-session of one element, another will work. The presence of several electrodes increases the service period.

You can find candles on sale with auxiliary electrodes located on an insulator. They create several discharges at one point. But the price of such elements is higher compared to the classic design.

By type of candle manufacturing material are divided into:

• Classic - based on manufacturing used alloy steel, complemented by manganese, chrome and nickel;
• Platinum - there is a sprayed layer of platinum;
• Iridium - top are covered with iridium film.

Classic (standard) option appeared long ago. Nickel electrode provides long service life. The core made of copper is characterized by good indicators of heat leading, which prevents the emergence of thermal load. The standard variety is considered an inexpensive option through the use of cheap materials.

Platinum candles are an innovation in the automotive industry. They have a long period of operation due to the use of noble metal - platinum. In addition, this admission favors the achievement of constant power under diverse working conditions. The electrode in such a variety is characterized by a thin form in comparison with the standard candle.

Iridia candles were designed to lower the ignition tension and improving the distribution of the flame during combustion. Metal iridium has an increased hardness and is not corrosion. Thanks to these properties, manufacturers were able to perform a subtle rod of the electrode, which is very durable. Such candles can be operated for a long time. But the price of products increases at times.

Characteristics of spark plugs

Deciding with the type of candle, one should also familiarize themselves with additional characteristics:

1. The calil number is a parameter indicating the pressure in the cylinder at which the rolling ignition appears. The mixture lights up from a large temperature. This temperature should come from the spark. If the temperature comes from the heated electrode, then the gauge ignition occurs. The calil number indicates the temperature mode of the candle itself. In the case of a large magnitude of this indicator, a smaller heating of the candle itself occurs. A low calic number increases the ability of the candle to heating, which results in the extension of the pistons and gaskets. Apply candles with a lowered calil number, the value of which is lower than recommended in the operating manual, is prohibited.
2. The thermal indicator is a parameter that means the dependence of the temperature mode of the candle in working condition from the motor operation mode. The tip of the insulator must be heated within 500-850 ° C. At temperatures below the minimum point of the specified range, the surface of the insulator will not be able to self-recess from the airborne residues. Subsequently, they will create an obstacle that will affect the ignition skip. At temperatures above 850 ° C, the candle will not be able to remove heat and overheat. As a result, the ceramic shell will crack, and the electrodes are deployed. According to thermal parameters, the candles are "hot" (more heated) and "cold" (well remove heat). "Hot" elements are required in situations when with a large load of the motor, a high temperature of the candle is needed. The "cold" candles are applied to achieve a smaller temperature mode at the time of the peak loads of the motor, but they are fasterly covered by nagar. Manufacturers marked candles with different digital code corresponding to the coefficient of heat value. In various firms, a large coefficient may indicate the candles to "hot" or "coldness".
3. Spark gap is a segment between the central and side electrode. Increased distance affects ignition skipping. With a decrease in distance, the spark energy cannot "locate". The factory gap does not need to be changed, as the adjustment will reduce efficiency or interruptions when working.
4. Size - determined by diameter and thread long. The diameter of the thread is 10.12, 14, 18 mm. But modern motors are manufactured with smaller displacements for candles to save the cylinder space for the location of the fuel injector and additional valves. And also new models of engines are designed for increased thread length. After all, aluminum heads for candles are made, and not strong cast iron. Due to the increased thickness of the head walls, the likelihood of turning the thread is reduced to zero.

An important candle characteristic is service life. If you take into account all the above parameters, then the period of operation depends on them to some extent. If the candle is chosen correctly, it will serve as laid 20-30 thousand km. But provided that there are no problems in the operation of the fuel system or engine.

Manufacturers and their serial editions

Today, such manufacturers are popular:

What you need to consider when choosing a spark plug

Universal candles do not exist. Different models of the car suggest the use of special species. Therefore, it is necessary to navigate such nuances:

• Read the car manual, where the required characteristics are indicated.
• View information in manufacturers catalogs on the use of candles in certain engine structures, as well as learn about the marking of products.
• Take into account used fuel.
• It is not necessary to proceed from the price of products, since expensive platinum or iridium options are distinguished by a long service life.
• A small candle will not screw into the nest, and large can damage the internal parts of the unit.
• When a strong burnout of the electrode is detected, the "ulcerative surface" of the insulator should be selected the next time elements with an increased calil number (first it is necessary to eliminate the valve hang, overheating, insufficiency of the motor cooling).
• If driving style assumes a permanent relief, the replacement of the candles will not help get rid of the yellow plaque. It is required to exclude a sharp start and "kick-down".

The use of candles implies their proper installation. No need to re-mount the previously used candles. Also excluded the replacement of individual elements.

You can learn more about the types, parameters, marking of spark plugs. Still described violations in their work.

Having read the instruction manual for your car, and consider all the shortcomings in the work of the engine, you can buy the right spark plugs. As a result, the engine will work without failures, and develop excellent power. And the cost of fuel will be associated only with price increases.

Read more:

In contact with

The ignition candle is the main part of the internal combustion engine and performs two main functions:

• Flexion of fuel and air mixture
• Heat discharge from combustion chamber

The main task for spark plugs is the ignition of the fuel and air mixture. The ignition candle is an electrode that transmits electrical energy from the ignition system into the combustion chamber in the form of a spark. The ignition system should generate a sufficient voltage value for the formation of a spark in the candle gap.

The temperature of the working end of the candle must be maintained quite low to prevent early ignition and, at the same time, high enough to prevent Nagar formation. This property of the candle is called a thermal characteristic, and is determined by the choice of the thermal range of the candle.

It is important to remember that the spark plugs do not generate, but only remove heat. The ignition candle functions as a heat exchanger, removing excess heat energy from the combustion chamber and transmitting its engine cooling system. The heat range is characterized as the ability of the candle to the dispersion (transmission) of heat.

The magnitude of heat transfer is determined by the following factors:

• Long insulator working tip candle
• The volume of the gas cavity around the insulator of the working tip of the candle
• Material and design of the central electrode and ceramic insulator

The heat range of spark plugs does not depend on the actual voltage of the ignition transmitted through the candle. Rather, the thermal range is the magnitude of the ability of the candle to the heat removal from the combustion chamber. The thermal range is determined by several factors: a long ceramic central insulator of the working tip of the candle and its ability to absorb and transmitting heat of the combustion process, the material of the insulator and the central electrode.

Heat power and thermal flow through NGK spark plugs

Read also

If the tip temperature is below 500 ° C, the surface of the insulator surrounding the central electrode will be insufficient for the combustion of carbon and other deposits. The accumulation of deposits may cause candle contamination, which leads to ignition pass. If the tip temperature is above 850 ° C, the candle will overheat, which can cause damage to the ceramic shell of the central electrode and melting electrodes. This can lead to early ignition / detonation and serious engine damage. For the same types of spark plugs, the change in the heat range by 1 unit leads to a change in temperature in the combustion chamber by value from 70 ° C to 100 ° C, and the tip temperature of the spark plug with the ground electrode of the protruding form changes at 10 ° C-20 ° C .

The temperature of the tip of the insulator and the appearance of the spark plug

The appearance of the spark plug also depends on the temperature of the spark plug tip. There are three main criteria for the diagnosis of spark plugs: normal, contaminated and superheated. The border of the section between pollution areas and optimal functioning lies about 500 ° C and is called the temperature of the self-cleaning of the candle. At this temperature, the accumulated carbon and other deposits burn. It must be borne in mind that the length of the insulator of the working tip of the candle is the determining factor in the thermal range of the candle. What it is longer, the smaller the heat is absorbed and, in the future, heat should be transferred to cooling water in the channels of the cylinder head. This means that the candle has a large inner temperature and is a candle of hot-type. The hot-type candle supports high internal operating temperature, providing combustion of oil and carbon deposits, and does not depend on the intensity or quality of the spark. Conversely, the cold-type ignition candle has a smaller length of the insulator and absorbs more heat combustion chamber. The warmth passes a smaller distance, allowing the candle to operate at a lower internal temperature. The cold range is necessary for hard-loaded functioning or working at high speeds during a long period of time. Cold-type candles make more quickly heat and, thus, reduce the likelihood of early ignition / detonation and melting or damage to the candle's work tip. (The engine temperature can affect the operating temperature of the candle, but not on the thermal candle range).

Below is a list of some possible external factors affecting the working temperature of the candle. The following symptoms or conditions may have an impact on the actual candle temperature. The candle cannot create these conditions, but must be able to withstand thermal loads, otherwise the operational capabilities and the engine may fail.

Relationship / quality of the fuel and air mixture It has a significant impact on the operational possibilities of the engine and the operating temperature of the spark plug.

• The rich fuel mixture causes a drop in the temperature of the tip of the candle, provoking the occurrence of a car and low operating capabilities.
• The poor fuel-air mixture causes an increase in temperature in the combustion chamber and the tip of the candle, as a result, leading to the emergence of early ignition, detonation and the possibility of serious damage to the spark plug and engine.
• It is important to repeat the state of the ignition candles in the process to achieve the optimal ratio of the fuel and air mixture.

High compression / supervision Raise the temperature in the combustion chamber and the temperature of the spark plug tip.

• Compression may increase with the following modifications:
  • reducing the volume of the combustion chamber, that is, the use of dome-shaped pistons, the heads of the cylinder block of the altered design, etc.
  • additional supervision (Nitrous, TurboCharging or Supercharge)
  • modification of camshaft
• As an increase in compression, it follows: to use a lower temperature range candles; apply high-octane fuel; It is necessary to carefully and carefully select the moment of ignition and the ratio of the fuel and air mixture. An error in choosing a cold-type spark plug can damage the candle / engine.

Ignition displacement in the direction of ahead

• Displacement of the moment of ignition in the direction of ahead of 10 ° will cause heating the tip of the candle by about 70 ° -100 ° C engine speed and load.
• Increasing the temperature of the candle tip in proportion to the increase in engine speed and its load. When working on high speeds or with a large load, install candles of a colder thermal range.

Ambient temperature

• When the ambient temperature decreases, the density / volume of air increases, as a result, the fuel-air mixture is depleted.
• This contributes to the increase in temperature / pressure in the cylinder and causes an increase in the temperature of the candle tip. Thus, the fuel supply should be increased.
• With increasing temperature, the density and volume of the absorbable air decreases, thus reduce the supply of fuel.

Humidity

• With increasing moisture, the volume of suction air is reduced.
• As a result, compression and combustion temperature decreases, causing a decrease in candle temperature and available power.
• It should be deleted the fuel-air mixture depending on the ambient temperature.

Barometric pressure / height above sea level

• Also affects the temperature of the work tip of the candle.
• Compression is reduced with an increase in height above sea level. Due to the temperature of the combustion temperature, the temperature of the candle's work tip decreases.
• Many mechanics are trying to change the thermal range of candles.
• The most real option is to adjust the jets or the ratio of the fuel and air mixture in order to increase air supply to the engine.

Options for abnormal combustion process

Early Ignition Moment

• Determined as: ignition of the fuel and air mixture before the pre-installed mark.
• Caused by hot sections of the combustion chamber, the reason may be: an early ignition moment, overheating of the candle, low-fuel fuel, depleted fuel-air mixture, excessively high compression, insufficient engine cooling.
• An increase in the octane number of fuel can help, the use of a cold thermal range candles, enrichment of the fuel and air mixture or decreased compression.
• You may also need to offset the moment of ignition towards the delay and checking the cooling system.
• Early ignition moment usually leads to detonation. The early moment of ignition and detonation are two separate cases.

Detonation

• The worst enemy of the spark plugs! (Along with Nagar).
• May cause damage to insulators or grounding electrodes.
• In most cases, the early moment of ignition leads to detonation.
• The temperature of the working tip of the candle in the combustion process can exceed 1650 ° C (racing engines).
• Most often caused by overheating areas of the combustion chamber.
• Preheated areas will lead to the early moment of the ignition of the fuel and air mixture. When the piston moves up under the action of the connecting rod, the premature ignition of the mixture will cause an effort in the opposite direction. If the piston cannot rise up (due to premature ignition) and can not move down (due to the effects of the connecting rod in the upper direction), it will range from side to side. As a result, the shock wave will be embodied in an audible deaf sound. This phenomenon is called detonation.
• The destructive impact for the engine is more critical of the occurrence of detonation, rather than on overheating.
• Spark plugs are damaged both from elevated temperatures and on the concomitant shock wave or concussion.
Ul\u003e

Interruptions / Ignition Pass

• It is believed that the candle gives a ignition pass when at the right moment of the stroke of the piston in the combustion chamber is a spark discharge disadvantage for complete ignition of the fuel-air mixture (several degrees to the top dead point).
• The ignition candle can generate a weak spark (or do not generate a spark at all) for various reasons: a damaged ignition coil, too high compression with an incorrect candle clearance, dry or wet falling on candles, a shot down moment of ignition, etc.
• Minor ignition passages can cause power loss for obvious reasons (energy is not permanent fuel supply).
• Frequent ignition passages will cause increased fuel consumption, low operational capabilities and can damage the engine.
Ul\u003e

Nagar.

• It occurs when the temperature of the operating tip of the candle is insufficient for burning carbon, fuel, oil and other sediments.
• It will cause shocking the electrodes to the ground, so that the spark will not slip through the candle clearance, respectively, the ignition passage will arise.
• Wet candles should be replaced, since the formation of sparks does not occur.
• Sometimes a dry flask candles can be cleaned by an increase in engine operating temperature.
• Before replacing stuck candles, make sure to eliminate the reasons for their contamination.
Ul\u003e


Ignition Candle Diagnostics Method

With the competent diagnosis of spark plug, it can be an assistant in various engine settings. Analyzing the color of the insulator of the working tip of the candle, an experimental mechanic can get a lot of information about engine operating conditions.

In general, a light yellowish brown / gray candle color says that the engine functions in normal mode at an optimal temperature. Dark color, for example, black wet or dry deposits, may indicate an overly rich mixture, too cold thermal range of candles, possible vacuum decrease, low compression, lateral moment, or too big spark candle clearance.

The presence of a wet laid may be caused by damage to the gasket of the cylinder head, wear of the oilmaging ring, or the occurrence of problems in the gas distribution mechanism, or the operation of the engine on an excessively rich mixture - depending on the composition of wet sediments on the work tip of the candle. Footprints of nagar or overheating must be detected as quickly as possible in order to prevent deterioration of running capabilities and damage to the engine.

Dry and wet deposits

Although there are many different options, but if the resistance between the central and ground electrode is higher than 10 ohms, the engine can be started normally. If the insulator resistance drops to a value of 0 Ohms, the ignition candlest end is contaminated with either dry sage or wet oil sediments.




Causes of generating seals: Wrong adjustment of the carburetor; too enriched fuel and air mixture; severe air filter pollution; weak spark; Incorrect operation / hot air damper; The problem most often occurs when using the engine to move short distances; Spark plugs have too low operating temperatures; Spark plug thermal range is too low. Result: Corrections: adjust the settings of the carburetor and air damper; Check the condition of the air filter. If only one or two sets of set are contaminated, then check for the presence of the valves or malfunction of the ignition system output. After fixing the cause of the malfunction, it is necessary to maintain the spark plug and install them again.



The reasons for the formation of oil sediments: High oil content in combustion chamber. Increased oil level in the engine crankcase; Wear piston rings, cylinder block sleeves or valve guide sleeves. It may occur during the period of running a new engine or engine after overhaul (such contaminated candles can be maintained and installed again). Result: Skipping in the ignition, difficulties in the start of the engine. Corrections: Conducting the overhaul of the engine, adjust the ratio of fuel and oil mixture (2-stroke engines), replace the spark plugs to new ones.




Lead sediments and overheating

If you overheat the spilling candles, which accumulate on the working tip of the insulator, melted and give it a glazed or glossy appearance of brown-yellow color.

The reasons: A sharp rise in temperature in the combustion chamber caused by a sharp acceleration with a high load leads to the formation of lacquer sediments. Also, the use of fuel with lead-containing additives leads to the formation of varnish sediments. Result: With a large load, lacquer deposits become electrically conductive and lead to ignition. They cannot be detected by measuring resistance between central and ground electrodes at room temperature. Corrections: Replace spark plugs on new ones. When repeating such phenomena, it is recommended to use candles with a colder range and maintain them more often.

The insulator has a mute white or gray and looks stronger. Electrodes have undergone erosion and sediments are not observed. The reasons: Using a spark plug with a too high heat range; Excessive ignition advance; Malfunction of the engine cooling system; depletion of the fuel and air mixture; The leakage of the intake manifold or the jealous of the valves. Corrections: Check correctness: the heat range of the ignition candle, the ignition moment setting, the adjustment of the carburetor; Check the intake manifold tightness and valve status. Replace spark plugs.




Solo deposits

Abundant powder sediments of white or yellow on an insulator and grounding electrode. It is recommended to check engine serviceability, in some cases it is recommended to replace the spark plugs to new ones. Perhaps it will be necessary to change the type of machine oil used.




Skol, Crown, destruction of the insulator

The reasons: The destruction of the insulator is usually caused by thermal expansion and thermal impact, due to sudden heating or cooling; mechanical damage caused by a drop in the spark plug, or with applying excessive effort on the central electrode when placing the gap; In exceptional cases, the formation of deposits between the central electrode and the insulator, as well as corrosion of the central electrode can lead to the destruction of the insulator (this is more often occurring at a very large period of engine operation). Result: Passing in the ignition, the spark is scattered in the gap, inaccessible to ignite the fresh portion of the fuel and air mixture, which is fed into the combustion chamber. Corrections:

Lead erosion Typical lead erosion causes the grounding of the grounding electrode, and the tip of the central electrode looks split. The reasons: Lead erosion is caused by the presence of lead impurities in the fuel, which at high temperatures come into a chemical reaction with the material of the electrodes (nickel alloy); The structure of the nickel alloy is destroyed, due to penetration and separation of the structure of seeds of nickel alloy lead compounds. Result: Pass in the ignition, difficult launch. Corrections: Replacing the ignition candle to the new one.




Melting electrodes

The engine operation with an excessively high temperature in the combustion chamber leads to an overly early ignition and melting of electrodes. The melting point of the nickel alloy is 1,200 ~ 1,300 ° C. The first melts the central electrode, then the grounding electrode. Most often, the surface of the electrode is glossy and uneven, insulator - white, has a porous and soft structure, but it can be dirty if the ignition pass was present. Electrodes can be partially molten with the presence of molten extraneous inclusions on them (extreme right image).

Result: ignition passage; Power loss (engine damage).