How to identify engine problems based on the condition of the spark plug?

Why does the spark plug on a moped blow?

It happens that a moped or scooter does not start. One of the reasons is there is no spark, i.e. the spark plug is filled with gasoline. First you need to unscrew the spark plug, dry it well, screw it back in and try to start the moped. If this does not help and the candle is damp again, then there is another way. You need to unscrew the candle again, dry it and put it somewhere. After this, with the moped turned off, start it using the foot, this will help splash out the gasoline where the spark plug was screwed in. But a new candle often helps. Low-quality fuel also plays the role of a wet spark; a mixture of low-quality fuel will ignite poorly and splash the spark plug.

It is worth checking the position of the carburetor, because it may be tilted to the side, which leads to gasoline leaking onto the filter. Also check the vacuum valve, it may be leaking. Or the carburetor needs to be adjusted.

How to adjust the carburetor on a moped?

To adjust the carburetor, take a screwdriver and tighten all the jets, then unscrew them one and a half turns. After this, watch the spark plug; if it is light, then everything is fine, but if it is black, you need to turn up the gas supply or give more air.

Why does the spark plug on a moped blow? Link to main publication

How to adjust a spark plug for a moped, what is the gap and what to use?

First you need to decide on the model of the moped; there may be individual issues regarding the size of the gap.
In general, for many mopeds a spark plug gap of 0.7-0.75 mm is considered optimal.

Next, you need to decide whether to adjust the gap of a new spark plug or a working one (preparation for adjusting the gap depends on this).

If it’s new, then we simply wipe it with a clean rag; if the spark plug is already working, we unscrew it, clean it with a rag, you can moisten the rag with a little alcohol, fine sandpaper with fine grain, etc.

After we have cleaned the spark plug, we decide on the probes, you can buy this one that looks like a coin,

We insert the probe between the electrodes of the spark plug; if it fits tightly and does not “play”, then everything is in order, no adjustment is needed.

If the gap is too large, then you can knock out the electrode with a small hammer, pliers, or simply press it to the surface.

Next, insert the dipstick again and check the gap.

If the probe does not fit between the electrodes, then, on the contrary, you need to squeeze it out, and not knock it in; I usually squeeze it out with a flat-blade screwdriver.

We pressed it out and checked the gap again.

If the gap is very large, the probe “dangles” between the electrodes, then I advise you to tap it in several passes, and not at once.

Source

Overheat

Plug Type: Extremely white insulator with small black flecks and premature electrode erosion.

Consequences: loss of scooter power at high speed or under load.

Probable causes: the spark plug is not screwed in enough; The scooter's engine cooling system is not working properly; ignition of the scooter too early; The thermal range is incorrectly selected - the candle is too “hot”.

Remedy: check the torque of the scooter's spark plug; operation of the scooter engine cooling system; adjust the ignition timing; select the correct spark plug heat rating.

Type of spark plug: melted and burned central and grounding electrodes (or one of the electrodes) of the scooter spark plug; bubbling insulator with metal deposits on it.

Consequences: significant loss of scooter engine power; ignition interruptions. Continued use of such spark plugs may cause serious damage to the scooter engine.

Probable causes: thermal overload; significant overheating of spark plug parts due to glow ignition - combustion begins before a proper ignition spark appears; use of low-quality fuel; burning out of the remaining air-fuel mixture in the combustion chamber due to an incorrectly adjusted fuel system of the scooter or the ignition timing of the scooter; The thermal range is incorrectly selected - the spark plug is too “hot”.

Remedy: check the scooter engine, ignition system and fuel system, as well as the quality of the working mixture and the ignition timing of the scooter. Install new spark plugs with the correct heat rating.

Start the engine

Just yesterday, the scooter or moped was working normally, but in the morning its engine simply does not start. Probably the reason is a flooded candle. You can, following the instructions, take out and dry the candles, but if you are short on time, you should try the traditional method.

To use it, you first need to let the scooter stand for a little time - about 5 minutes. Then you should completely unscrew the gas handle and turn the starter. Continue for about fifteen seconds. At this time, there will be no fuel supply to the chamber, so it will be purged with air. Most likely, such a simple operation will be enough and the engine will start. This should work on both 2t and 4t scooters.

If the iron horse does not start, you will have to use another method. To implement it, you will need a little time, patience and a spark plug. First, you should unscrew the spark plug and make sure that it is the problem. It can be cleaned with a brush and then dried with a hairdryer. However, any heat source will do: hotplate, oven or gas burner. Next, it is recommended to blow out the cylinder in the same way as with the traditional method. Then insert the candle back. Now the engine just has to start. If this does not happen now, you will have to replace the spark plugs and carry out diagnostics.

Reasons for the formation of black soot

So why are spark plugs black? The accuracy of determining the causes of soot entirely depends on the analysis of its structure. The main forms of soot are dry (soot) and oily.

Experts believe that the main reason for the formation of black soot deposits is excessive enrichment of the fuel mixture. A motorist who is concerned about the condition of his car’s spark plugs simply needs to know the factors influencing increased enrichment of the fuel mixture:

• Malfunctions or incorrect carburetor settings.
• Due to a lack of oxygen flow due to a clogged air filter, complete combustion of the fuel mixture does not occur.
• Problems with the starting enrichment.
• The presence of increased pressure in the fuel rail (for injection power plants) contributes to excessive fuel injection. Occurs due to malfunctions of the fuel pressure regulator.

• Low compression value in one or more cylinders.
• Weak spark.

However, excessive enrichment of the air-fuel mixture is not the only answer to the question: “Why are spark plugs black?” There are several other reasons that influence (albeit to a lesser extent) the coating of spark plug electrodes with black soot. Here they are:

• Malfunction of the ignition coil.
• The air filter element is clogged.
• Increased (reduced) gap of the breaker-distributor.
• Capacitor failure.
• Incorrect operation of the injection system.

Another reason that leads to the appearance of black carbon deposits on automobile spark plugs and requires immediate elimination is the installation of spark plugs whose heat rating does not correspond to the parameter specified by the manufacturer. In this case, two options are possible:

1. unburnt remains of the fuel-air mixture settle on the spark plug elements, forming a coating;
2. The spark plug heats up under the influence of high temperatures, and the power unit begins to operate in glow ignition mode.

If the carbon structure shows signs of oiliness, then the car owner receives direct evidence of excess oil entering the combustion chamber. The main reasons for the formation of oily deposits on the spark plug electrodes are excessive wear:

• oil valve caps;
• oil scraper piston rings.

Troubleshooting

First of all, you need to understand what it is. Even if the cause has been found, it is worth paying attention to other possible problems, since they may be related. Required:

1. Check battery charge. During the cold season, it is worth keeping it charged, since the power of the spark indirectly depends on this. This is especially important for older vehicles, since their battery life is already partially exhausted.
2. Make sure the quality of the fuel used. You should always buy gasoline only from reliable gas stations. With poor nutrition, the iron horse can fail at the most inopportune moment. It doesn’t matter whether the trip is planned on an Alpha moped or a Symphony scooter.
3. Choose the right oil. Its quality and viscosity also matter. In cold weather, winter oil should be used.
4. If the spark plug on a 4t scooter is flooded, be sure to check that the valves are adjusted correctly. If this is not the case, fuel may enter the chamber at the wrong time and not ignite.
5. Check if the air filter is dirty. It may require cleaning or even replacement.

• If a carburetor is used as a fuel supply system, its mixture quality screw should be adjusted.
• Make sure the spark plug is working optimally. If necessary, adjust the gap between the electrodes, replace the spark plug or ignition coil.

Alfa moped no spark

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• Publicado em 14 Out 2014
• After work we were going to go home, but my friend’s moped didn’t start. He unscrewed the spark plug, there was no spark, replaced it with another one, the same result. Since it was one o’clock in the morning, he pushed his moped to my garage, and I drove him home ( he lives in a neighboring village). In the morning I decided to see what the reason was. First, I checked all the contacts, then I rang the armor wire with a multimeter, then I changed the coil (I have it in stock). There was still no spark, then I changed the switch (I removed it from my moped) , but the spark never appeared. But when I checked, the current from the armored wire began to flow and I decided to try to install my own spark plug, as it turned out the whole problem was in the chip from the switch, the contacts went loose there, but when the spark disappeared, the owner changed the spark plug to a non-sparking one working. His second spare one was also not working. In the end, of course, I found a malfunction, but it could have been found faster. I concluded for myself that in any case it is necessary to check the functionality of the spark plug (even if they only installed another one before your eyes)) ), well, the owner didn’t draw any conclusions and I’m waiting for him again in my garage soon))). Naturally, not everything was included in the video, since it would have turned out to be a very long video, so I had to cut something out.
• Automoveis
• Moped (Product Category)Auto Show (Event)moped alphamoped deltaalpha rulitchina rulitalfa 120km/hrotates for alfemoped alpha tuningmoped alpha repairchinese moped alfairbis viragoalpha phantomirbis virago

Hello everyone, friends!

In villages and towns, Chinese mopeds of the “Alpha” type have become the most popular. Perhaps someone will dispute this, but there are a lot of “Chinese” in our village.

This moped is quite convenient for rural areas due to its lightness. Going to the forest and fishing is a nice thing. You can move the moped through any dirt, so as not to “tear” it too much, without bothering.

But where there are pros, there are also cons.

A lot of our men complain about spark plugs. I'm not an exception. I did everything I could: I adjusted the carburetor according to every need, changed different spark plugs from different manufacturers. The result was the same - the spark plug is black and often the moped may not start at the most inopportune moment.

Previously, I always carried spare working candles with me and one completely new candle in case the already working candles did not give the desired effect.

Now I have found the reason. One of my friends told me that it’s all about the glow of the candle. The heat number in the marking is always the first after the letter designation.

The photo shows that the glow number of the candle is 7. This is the most common candle for sale.

An acquaintance advised me to buy candles with a heat number of 6. I settled on a well-known manufacturer and purchased such a candle for 200 rubles.

And now I couldn’t be happier. The jalopy now starts perfectly. As it was explained to me, these “sixes” heat up faster and thus self-cleaning occurs faster. You can, of course, take the “five”, but as I was told, the engine will work with some glitches. Although it will also start just fine.

Therefore, it is better to choose a middle ground.

And one more nuance. All spark plugs are sold with a standard gap. Reduce it slightly by tapping it on a hard surface. And, of course, heat the candle, for example, on a gas stove.

Next time I’ll write: which drive chain is better to buy?

Thank you for your attention and happy travels everyone!

Two friends meet. One says: “My husband is a sex machine.”

- And mine is a sex moped. - Didn't understand? - It’s simple. Two strokes and injection.

Source

Soot contamination

Type of spark plug: dry soft soot of intense black color on the insulator, electrodes and spark plug body.

Consequences: poor start of the scooter engine; poor operation of a cold scooter engine; interruptions in ignition of the air-fuel mixture; bad reaction to gas.

Probable causes: excessively rich air-fuel mixture; The scooter's air filter is very clogged; The thermal range is incorrectly selected - the candle is too “cold”.

Remedy: adjust the working mixture; adjust the cold start system of the scooter engine; change the scooter air filter; clean the spark plugs or replace them with new ones - with the correct heat rating.

Cleaning carbon deposits

Having found out why there is a black spark plug on the Alpha moped and what the problem is, you need to fix the problem. After this, you can install a new part or try to restore the functionality of the old spark plug. To do this, you need to rinse it by performing several sequential steps:

• Rust cleaner is poured into a glass.
• The candle is dipped into the prepared liquid for half an hour.
• When the carbon deposits soften, it must be carefully cleaned off (use a brush).
• Under the pressure of water, the candle is washed to remove any remaining dirt.
• Wipe the part dry with a clean rag and leave to dry at temperatures up to +70°C (in the oven or on a radiator).

Do not use sandpaper when cleaning. Aggressive impact will damage the protective top layer. Because of this, the part will quickly become unusable.

How to avoid flooding spark plugs with gasoline?

The most important criterion is to maintain the battery charge and the functionality of the starter. For this, sufficient conditions are created for the scooter to start even on the frostiest morning. In addition, you should fill in high-quality oil and use high-quality gasoline with a sufficient octane number, as specified in the operating manual of the purchased scooter. As a preventative measure, it is worth cleaning and adjusting the injector nozzles.

People's Council

To prevent the spark plug from flooding with gasoline during the cold season, you should occasionally “spin” your scooter to maximum and move at a speed slightly above average, thus increasing the load on the scooter’s engine at high speeds, due to which self-cleaning of carbon deposits and excess in the combustion chamber occurs.

By fulfilling all these basic requirements, you can not only eliminate problems associated with filling spark plugs with gasoline, but also increase the service life of your scooter’s engine significantly. By following all the above instructions, you will not have to contact a car service center again for expensive service.

Experienced vehicle owners know that in the cold season, for some reason, sometimes the scooter does not start. Some people find themselves in such an unpleasant situation in the summer, but much less often. The problem can have many causes, but the most common is a flooded spark plug.

This can happen regardless of the fuel injection system, injector or carburetor, installed on your scooter. The design of the spark plug and methods for troubleshooting the problem do not change significantly.

In the case of an injector, the fuel supply is regulated by an electronic control unit. Cold air has more oxygen. Realizing this, the ECU increases the supply of gasoline. If the spark in the plug is not strong enough, unignited fuel will remain on the spark plug electrodes. Then it will no longer be possible to start an iron horse.

Causes of the problem

Even if the engine was able to start, the problem will occur again. If this is not the first time a spark plug on a scooter has been flooded, it’s worth finding and fixing the problem. The culprit could be:

• Dirty air filter. If there is not enough oxygen in the fuel mixture, the gasoline will not burn completely and will remain on the spark plug.
• Mixture quality screw. If the carburetor is not adjusted correctly and the screw is too tight, a similar problem will occur.
• Poor quality fuel. Gasoline diluted with another liquid can also cause this.
• Defect in the ignition system itself. There is no spark, or it is not powerful enough to ignite the mixture.
• Low battery. On days when the temperature drops below zero, you need to make sure that the battery is well charged, otherwise a similar problem will arise.

Flooded candle Sometimes, if a candle is wet, it is enough to simply dry it. But this will not eliminate the problem and will not prevent this unpleasant situation from occurring in the future. While almost any of the problems described can be dealt with on your own.

What to do if soot appears

First of all, it is necessary to remember that oil contamination and overheating, which results in soot on the spark plugs, are very harmful to the ignition system . Overheating is especially dangerous, since it causes the possibility of failure of the electrodes on the spark plugs without the possibility of their restoration.

If your car only has one blackened spark plug, you can diagnose the breakdown by simply swapping the spark plugs. If after this the new spark plug also turns black and the old one clears up, it means that the problem is not in the spark plugs, but in the cylinder. And if nothing has changed, then questions arise about the performance of the candle itself.

Oil deposits

In some cases, the candles may be wet and black. Most often, the reason for this fact is oil getting into the combustion chamber. Additional symptoms of this problem are as follows:

Oil on candle

• difficulty starting the engine;
• omissions in the operation of the corresponding cylinder;
• the engine jerks during operation;
• the appearance of blue smoke from the exhaust.

Oil can enter the combustion chamber in two ways - from below or from above. In the first case, it enters through the piston rings. And this is a very bad sign, because it often threatens a major engine overhaul . In rare cases, you can get by with decoking the engine. If oil enters the combustion chamber through the top, it comes from the cylinder head along the valve guides. The reason for this is the wear of the valve stem seals. To eliminate this problem, you just need to select new, high-quality caps and replace them.

Carbon deposits on the insulator

Red carbon deposits on a candle

In some cases, carbon deposits that naturally appear 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. The engine will “trouble” in this case. This is the most harmless situation why spark plugs turn black. You can eliminate it simply by cleaning their surface or replacing it with new ones.

If black and red spark plugs , this means that you are pouring fuel with an excessive amount of metal additives. It cannot be used for a long time because over time, metal deposits form a conductive coating on the surface of the spark plug insulator. Sparking will deteriorate and the spark plug will soon fail.

Cleaning spark plugs

Valve adjustment on Alpha:

Thank you! I finally found an article where everything was explained in detail about valve adjustment, and I learned a lot of useful things for myself.

The exhaust valve requires different clearances.

Thank you for your comment. I checked the instructions for my moped: yes, indeed the gap is 0.03 mm for the intake valve and 0.05 mm for the exhaust valve. Corrected the article.

the authors made me laugh))))) first write that “By and large, it is not necessary to clearly combine these marks, because both valves close already at the beginning of the compression stroke and do not open until almost the end of the power stroke, that is, at least half a turn the valves are closed.”, and then write the standard instruction “4. By rotating the crankshaft, we align the mark on the head sprocket with the mark on the head body. ..." IMHO it is necessary to set marks in any case to prevent the timing chain from being pulled out

What's so funny? I wrote that there is no point in looking at the mark on the crankshaft; it is enough to align the mark on the head to be sure that the valves are closed. And by half a revolution I mean crankshaft revolutions. I don’t argue that it is sometimes necessary to check whether the crankshaft marks match, especially when there are problems with the engine’s operation. But this has nothing to do with valve adjustment.

Timofey, you are right….that’s what marks exist for, to tune in to them.

These marks are needed to check and correctly install the timing chain. If, when adjusting the valves, you accidentally slightly overshoot the mark, it’s not a big deal. This was exactly the point of the paragraph about marks.

Guys, I encountered the same problem. When assembling there are 4 guides. Two short and two longer. Where to put which ones? Who knows, write thanks

short ones between the engine and the cylinder and long ones between the cylinder head

Timofey, you are right….that’s what marks exist for, to tune in to them.

the author clearly described everything and about the marks, too, the main thing is that both valves are closed and criticism here is not appropriate at all;

I watched a lot of videos, everyone unanimously claims that the gaps should be: vp. 0.05, issue. 0.07. Here the indications are different. Who to believe?

“You can't trust anyone. Absolutely no one. But I can"