A scooter variator is like a gearbox for a car. In principle, this is the gearbox. The rear variator is a manually operated continuously variable transmission. As a rule, a V-belt variator is installed on all modern scooters. The peculiarity of its work is that it works depending on the engine speed and despite the number of loads. If the rear variator of the scooter is worn out, it is easy to feel it while driving. The scooter loses its smoothness, acceleration speed and top speed decrease. The scooter is not comfortable to ride for the reasons mentioned above.
The rear variator of a scooter is also called a centrifugal clutch. The principle of operation of the centrifugal clutch is quite simple. At certain engine speeds, the clutch automatically connects the output shaft of the variator to the gearbox, this ensures a smooth start of the scooter from a standstill. To ensure ride comfort, the rear variator must always be in good working order.
The scooter variator (centrifugal clutch) usually serves more than one season. In Japanese scooters, this can be 5 or more years. But even in spite of such excellent service, sooner or later he becomes unfit for service. To make it last longer, you need to disassemble the scooter variator and assess its condition before each season. Even for a small tuning of the variator, it must be completely disassembled.
To disassemble the variator, you need to remove the variator cover, it is screwed on with several bolts. For example, in a Honda dio scooter, the variator cover is screwed on with 6 bolts for which you need a 13 head.
Now that you have removed the variator cover, proceed to disassembly. It is not necessary to remove the variator belt.
That is why we disassembled the variator of the moped (scooter). Now you need to check the variator rollers for wear.
The rollers of the rear variator are one of the main transmission parts of the scooter. The whole dynamics of the scooter is just the variator rollers and the driven pulley spring. what is the weight of the variator rollers ". But you need to understand that the weight of the variator rollers can vary significantly. It is necessary to choose the variator rollers exactly the same as those already installed on your scooter. If you cannot find the same rollers, then you need to replace the entire scooter variator kit, because:
15. Now that we have dealt with the rollers, it is necessary to inspect the drive pulley and its surface. We check the surface for damage and workings. The surface should be flat and the output from the variator belt should not be more than 0.5 mm. If the output is less, then it can be polished.
Next, we check the surface for other mechanical damage.
Assembling the variator takes place in the reverse order, but before that it is necessary to check that the oil seal is not damaged or leaking.If there is dirt or swamp, then we remove it all. We check the variator chamber for oil ingress, this is absolutely impossible with tolerances. If the oil seal leaks in a two-stroke engine, it will result in loss of power and interruptions in operation.
Before putting the rollers in place, it is necessary to lubricate them with a thin layer of grease or other grease of the variator rollers. It is also necessary to lubricate all the parts that rub. After that, we start assembling the scooter variator.
VIDEO
Everyone is good at the transmission, which is based on the variator: it is quite reliable, durable, repairable, works without steps and in fully automatic mode, but, as we all know: "there is nothing eternal," therefore, upon reaching a certain mileage of the scooter, the variator details wear appears and a number of malfunctions characteristic of this type of device.
By themselves, variator malfunctions are not as scary and critical as, for example, in the braking system or in the steering, but all the same - the variator is the main element of the scooter's transmission - it directly affects the maximum speed, dynamics, driving comfort, belt service life and the overall safety of scooter operation ...
It is advisable to carry out a full revision of the condition of the variator parts at the beginning of each season, or, in extreme cases, once every two seasons. Taking into account the fact that you bought a scooter in the store "from scratch" and no one had time to put their dirty paws there before you. For used scooters - the revision of the variator should be carried out immediately after purchase.
So, we remove both variators from the engine for edrenefen, prepare a workplace in advance, look for or take from someone an even metal ruler (preferably a curved one), buy some refractory grease, I use copper grease to lubricate the variator (if anyone has objections to this, then please express in the comments) or paste - no difference. The name is different, but the meaning is the same.
We take out all the rollers from the front variator case and carefully examine them. The rollers must be perfectly round (slight abrasions on the working surface of the rollers are allowed), not hexagonal (as is usually the case), the working surface of the rollers must be intact and free of cracks, the weight and size of all rollers must be strictly the same.
An example of "killed" videos that are unsuitable for further use:
Strong wear of the working surface
Crack on the work surface
We take the outer plate of the variator and carefully examine it for visible damage, wear of the working surface and pay special attention to the condition of the internal splines for the crankshaft journal.
An example of a variator impeller that is damaged by two broken fan blades. By and large, a couple of broken fan blades is not such a big problem. But, all the same, the problem, whatever one may say.
At high engine speeds, this weight imbalance can cause accelerated wear on the crankshaft main bearing and cause increased engine vibration. Therefore, in order to restore balance, one should strictly in the diametrically opposite direction - break out whole fan blades (marked with arrows) in an amount equal to the missing ones. And then the weight balance will be fully restored.
We take the second variator plate in our hands and carefully inspect the integrity of the guides for the support washer, roller slots, the degree of general wear and the presence of visible damage.
Particular attention should be paid to the condition of the guides for the support washer. Because the torque developed by the engine during the movement of the scooter has a direct effect on them and in case of critical wear or extreme loads on the engine - the guides break, the support washer turns in the variator housing, and then, as luck would have it ... Or it will grind the engine floor or just the variator ...
Examples of frequent damage to the inner plate, with such damage, these parts of the variator are unsuitable for further operation.
The absence of one guide (it was broken off when they tried to unscrew the nut on the trunnion without a puller).The absence of one of the guides is fraught with the fact that the entire load will be transferred not to three points, but only to two, which will lead to a significant increase in the load on the remaining guides.
Critical wear of the disc body at the point of contact with the support washer. As you can clearly see - the support washer gobbled up a decent piece of metal in the case.
Critical wear of the support washer guides. There is nothing to comment on, the thickness of the guide, together with the greatest wear, does not exceed one millimeter. A little more and the cymbal would turn in the body.
Not critical, but already the maximum permissible wear of the guide; for clarity, a ruler is attached to the place of greatest wear. In principle, it is still possible to ride with such wear, but not far ...
An example of a plate in perfect condition. As you can see, there are no signs of wear, all the guides are intact and not damaged, there is no visible damage either.
The support washer must be of the correct shape, the central hole for the crankshaft journal must be free of visible wear and damage
After all that has been done, we carry out one-by-one check of the working surface, variator plates for acceptable wear. To do this, we put a ruler on the work surface and look at the whole thing in the light. The ruler should lie on the surface with the entire plane of any gaps, and therefore there should not be any workings on the working surface.
An example of the working surface of the variator in perfect condition
The ruler lies along the entire surface without a gap
At first glance, it may seem to you that the presence of a working surface of the variator is not a serious problem and such a variator can still be operated and operated ...
In fact this is not true. With the wear of the working surface, the original geometry of the pulley is violated. The optimal angle at the place of constant belt operation becomes dumber, and the distance between the pulleys and the angle in different radii of the belt operation becomes different. Plus to everything - as wear and tear appear on the surface of the pulleys, cavities and sagging appear - the so-called "lips" passing through which - the belt is subject to severe wear.
What does all this ultimately lead to? To the fact that the belt in different operating modes of the variator will come into contact with the pulley plane not with the entire working surface, but only with a small part of it.
That is, at low engine speed (small radius) - the belt will come into contact with the pulley surface with its entire working surface (the contact patch will be maximum). Since, in the mode of low engine speed, the scooter is practically not used, therefore, the output at a small radius will be minimal, even with a high mileage of the scooter.
And as the engine speed increases, the belt will go to a larger radius where there is a strong depletion of the working surface of the pulleys, and therefore the initial angle and distance between the pulleys are violated.
All this will lead to the fact that the contact patch at the place of maximum development, between the belt and the pulleys, will decrease to a minimum and the belt will simply begin to slip, overheat and ultimately break or burn out.
An example of a terrible development, of the order of a few millimeters. A plate with such a huge output is not subject to further exploitation.
Another important point: many idiots like to undermine the end face of the variator guide bush, and they do it with very zealous zeal ... How many times have I asked these idiots: “FUCK YOU GRINDED IT. " Answer. it was almost always the same: "the belt will stretch better"…. I go crazy with these tusks ...
It is, of course, their business - they want to sharpen, they want not to sharpen. This is not the point, but the fact that with a decrease in the length of the sleeve, both up and down, the alignment of the central axes of the pulleys is disturbed, which is why the belt works with a sickly skew and, as a result, burns out or breaks prematurely.
An example of a broken-off bushing.On the left is the stock, on the right is the collective farm. By the way, as the belt burned out on a scooter in a week, it continued to burn, and the bushing was sharpened and sharpened until it was worn down a whole centimeter ...
With the front variator, we figured it out a bit and it's time to move on to the rear, the so-called torcdriver. We put the rear variator on some table - disassemble it, wash all the parts and proceed to check.
We carefully inspect the working surface of the central axis, there should be no scratches on it, traces of wear, the surface of the axis should be smooth and shiny without the so-called faceting and metal sagging.
Thoroughly wash both halves from the remnants of old grease and dirt. We connect the halves to each other and use our hands to try to swing them. There should be no backlash between the two halves, well, maybe if you feel a slightly noticeable backlash, then, in principle, it's okay. But if you feel a pronounced backlash, then nothing can be done here, you will have to throw the variator into the trash.
We inspect the holes by pins, the holes should be perfectly even without signs of wear and damage. The pins, after installation in the hole, should be aligned along the axis without skewing.
Example of severely worn pin holes
Due to the strong wear of the holes, the pins during the operation of the rear variator were very skewed relative to the central axis and ate the spring guide with their lateral edge.
We inspect the guides along which the pins go. The working surface of the guides should be flat without pits, faceting, metal sagging.
An example of heavy wear of the guide, a deep groove has formed in the place of permanent contact between the guide and the pin. Such a guide is not suitable for further operation.
An example of a guide rail in perfect condition. There are no potholes, sagging, working out and wear on its surface.
We inspect the pins for wear. The pins must be of the correct shape without wear or damage.
We check the condition of the bearings, and there are two of them in the rear variator - one needle, and the second regular - ball. And the condition of the rubber seals, with any suspicion of wear on bearings or rubber rings - we change these parts without regret.
We put some high-temperature grease (I use copper) into a special recess on the inner surface of the movable variator plate, rub the whole thing evenly over the surface and remove excess grease.
We collect the halves and put a little of our grease in the guides.
Several times - we move-move apart the halves of the honey ourselves - we remove the excess grease that has come out from the working surfaces and we make the final assembly of the variator.
Great article, thanks! But it is not written, if the grooves or irregularities are on the rear shells of the variator, is this permissible?
Thank you, very clear and instructive.
The article is interesting and clear, there is only one remark. Coaxiality is a single center of rotation for different parts, and the drive and driven variators are different parts, each of which rotates around its own axis. However, the bushing cannot really be sharpened. when the length of the bushing changes, the belt on the drive and driven variator will rotate in different planes, which will cause it to be skewed and, as a consequence, overheated, skewed and broken.
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Manufacturers do this deliberately in order to get a big gain in convenience at the cost of a small loss in dynamics. Thanks to the slightly weighted weights, the standard transmission is more flexible, especially when starting from a standstill. And this is a very valuable thing for many new scooters.A kind of "golden mean". If you are not planning a more serious and complex tuning of the scooter, but you already feel confident enough in its saddle, then the first thing to try is to put lighter weights. This is the simplest and perhaps the only sensible transmission tuning for an all-standard scooter.
Before you go to a tuning shop for weights, it would be nice to know the weight and size of your “relatives”. The best sources of information here are the brochures of some tuning companies, for example, the hardware manufacturer Malossi or the post-shop Scooter Attack, but they contain information only on the models of the European market. Otherwise (if you have a "Japanese for Japan", let alone a "Chinese") you will have to measure the mass and size of the rollers. Ideally, the sellers of the tuning shop will gladly tell you this, but not all of them today are quite competent and responsible in this matter, so it is better to always play it safe.
So, we already know the weight and size of "native" videos, it remains to decide how much easier it is to take new ones. There can be no exact answer to this question: a lot also depends on your own weight, that is, the load on the transmission. But if you take three sets: half a gram, a gram and one and a half grams lighter than the original ones, then, most likely, that set will be among them. Which one exactly is determined experimentally, as well as many other parameters during tuning. It hardly makes sense to go below one and a half grams: too "short" gear range will not give an advantage in dynamics, and most importantly - there is a possibility that too light weights simply will not "push" the drive pulley to the "highest" gear, which means that the maximum speed will drop ...
So, we have several sets of weights, but to replace them we still have to get inside the variator. To do it efficiently, if you have never done it, is not so easy. Moreover, the typical consequence of a poor-quality variator assembly - torn crankshaft splines - ends with the replacement of the latter (and this is up to € 300 along with high-quality work). European post-shops like to place good instructions for tuning the main components of the scooter, including the variator, in their catalogs - it certainly does not hurt to get one. This will save time and effort. There is always a fallback - to rely on the mechanics of some service. The option is not the best, since today there is not ANY serious scooter workshop in Moscow, believe me. An equally risky option is to rely on some private craftsman, unless he is a kart driver or cross-country rider with many years of experience! For independent work with the variator, most likely, you will also need several special tools, for example, a variator puller (although experienced mechanics do without it - ed.).
They're inexpensive, but they'll help a lot. This is where the tuning (that is, changes that have a real result, and not a simple waste of time and money) of the transmission of a standard scooter ends. It would seem that the very little has been done - the variator weights have been replaced, a penny, in fact, a detail. In fact, a lot has been done. First of all, it was not a stupid installation of some part that was made, but the transmission was configured, albeit quite simple. This, in fact, is the beginning of real tuning, while many scooters are used to seeing it as just buying new parts.
But this only ends with the tuning of the transmission of a standard scooter. It is unlikely that your scooter will stay like this for a long time: you will definitely want a good exhaust soon. And as soon as the scooter ceases to be standard, the importance of tuning the transmission increases many times over, which means that our conversation continues.
ABOUT GROOVES AND SPRINGS
As a first approximation, this is a readjustment of the standard transmission, which is achieved, as we already know, by replacing the variator weights. But not only. As practice has shown, native scooter variators do an excellent job only with the standard characteristic of the engine. When it changes in the direction of the prevalence of higher rpm, the native variator begins to pass: it fails to keep the rpm constant throughout the acceleration. Having reached the optimal speed at the start, already by 60 km / h the engine “twists” (develops the speed higher than the maximum power speed), there is a loss in power, and hence in the intensity of further acceleration and maximum speed. Having neutralized the "twist" with heavier weights, we get a failure at the start - there is not enough speed. Here it is no longer possible to get off with a readjustment - more perfect and accurately working transmission parts are required. In tuning catalogs, these positions are designated as a variator (an internal, moving part of the driven variator pulley) and a torquedriver (an external, moving part of a driven variator pulley).
It should be noted separately that the concept of "variator" has received at least two different meanings in the lexicon of scooters. On the one hand, the entire transmission system of a scooter is called a variator: the drive and driven pulleys, connected by a belt, and the clutch in addition. Actually, there is nothing to find fault with here, because the variator is, first of all, just a specific type of transmission, which is based on two V-shaped pulleys connected by a trapezoidal belt. On the other hand, the name "variator" was given to the tuning kit, which is a moving part of the drive pulley assembly, the very one in the belly of which the weights are located. The phrase "I bought / installed / replaced a variator" will most likely only talk about one part of the transmission. But the phrase "the variator is perfectly tuned" already speaks of the entire transmission system. Unfortunately, there is no way out of this inevitable confusion with concepts. Do not say now "I bought a tuning moving part of the drive variator pulley." By the way, the situation is similar between the British and the Germans: the words variator and variomatikTaM are also used in a narrow and broad sense. All that remains is to follow the context.
Manufacturers of tuning parts have specially developed variators and torcdrivers, designed to successfully combat other than standard engine characteristics. Their differences from standard parts are a different profile of the grooves for the rollers (for the variator) and straightened cutouts for the pin driver. Both give a different algorithm of operation, better suited to the "failed in the middle" characteristic of the forced motor, and as a result - smoothing out this very failure at the output.
The transmission, which has been modernized with the help of these parts, is already precisely tuned without any problems in accordance with the requirements that have changed after the installation, for example, of a tuning muffler. "Dips" and "twists" are neutralized (although not always to the end), thus providing a smooth and maximally effective acceleration.
It is very important to understand that tuning requires not only obtaining "hypothetical" horsepower, but also successfully implementing them. The process of tuning the transmission clearly demonstrates this: it does not add horsepower to your engine, but it allows you to better realize the potential of the engine, that is, it translates "hypothetical" horsepower from the crankshaft into "real" horsepower on the rear wheel.
Tuning variators are the main (but not the most effective) means for smoothing out "dips" when forcing the speed.
Another part involved in tuning the transmission is the center spring, or the driven pulley spring. It is sometimes also called the "clutch spring", although it has nothing to do with its work - it just sits on the same shaft as the clutch. As you know, the task of this spring is to provide the necessary belt tension, preventing the sliding of the driven pulley cheeks. As a rule, the need to replace this spring arises after installing a piston with an increased volume due to a significant increase in engine torque throughout the entire rev range. The increased torque makes higher demands on the belt tension, otherwise the belt starts to slip, especially at the start, and this prevents good acceleration from a standstill. In addition, at the same time, the drive pulley overheats, in which, usually, the belt slips. This is often evidenced by the melted plastic sheath of the variator weights. To neutralize slippage, a stiffer driven pulley spring is installed. But here, as in the case of weights and springs, it is important to achieve balance. Excessive pulley spring stiffness also causes problems: a drop in maximum speed and an incomprehensible fluctuation in engine speed at start.
Leafing through the tuning catalogs of European scooter shops, you will most likely stumble upon another detail in the section concerning the variator. This is the outer part of the drive pulley, or, in current terminology, the impeller. Equipped with special blades that pump air during the operation of the variator, this part also performs the function of cooling it - for this it received the name "impeller". The position is inexpensive, but it does not give a big effect by itself, in comparison with the native part. However, there are exceptions: on some scooters, the standard impeller is designed in such a way that it is, in fact, a factory "choke". In this case, of course, it must be replaced almost in the first place. In other cases, the impeller is changed to a tuning one, as a rule, when the splines on the standard one are already worn out.
Speaking of the clutch, we have mentioned so far only its readjustment with the help of stiffer springs, however, with deep tuning, when the engine power doubles or more, this is no longer enough: often the massive pads of the standard clutch do not work fast enough, "skidding" at the start ... And most importantly, with deep tuning, adjustments may be required that are much more accurate than those that can be achieved by simply replacing the springs. All these problems are solved by replacing the clutch entirely with a tuning one. At the same time, it is recommended to replace the clutch drum as well - the more tenacious pads of the tuning clutch will eat up the "native" drum very quickly. Tuning drums also often have special ribs that improve drum cooling, which is especially important for an overloaded transmission of a "charged" power unit.
Another important part of the transmission is the gearbox, which is also changed during tuning, but this is already a topic, albeit a small one, but a separate article. In addition, the choice of the required gear ratio of the gearbox in the case of not too deep tuning is usually recommended by the manufacturer of the components for the variator, and for racing you have to experiment with your own head.
INSERT
A scooter based on a standard piston piston with a tuning muffler, as well as a scooter based on a piston 70 cm3 Sport class: variator or torcdriver, variator readjustment using variator weights, driven pulley spring and clutch springs. A scooter based on a piston 70cc Racing class: the same as in the previous case, plus a tuning clutch and a clutch drum or an overrange system.
High-end 70cc piston scooter: overrange system, tuning clutch and clutch drum. That, perhaps, is all about tuning the variator. I deliberately did not touch upon the problem of choosing parts from certain manufacturers. This is more a matter of taste and, to a lesser extent, the peculiarities of one or another component of a given company for a given motor, therefore, such conversations are much more interesting and effective to conduct on some Internet forum of scooter-tuners. There you will find out which grip is better: Malossi Delta or Polini Evo 2G, or rather, which one is better to prefer in what cases. The main thing to remember when tuning a transmission is balance. It should manifest itself in everything: from the choice of tuning parts to their customization. Only then will the horsepower of your newly-made motor be not in the air, but on the rear wheel!
Chinese scooter sports variator - installation and tuning basics
In general, this is a workhorse, one of the best engines for Chinese fifty dollars today. In stock, it shows very mediocre results, both in dynamics and in speed. The problem is solved in various ways, among which the most popular, perhaps, are:
Increased piston;
Replacing the stock CVT with a sports one;
Replacing the gearbox with a "longer" one;
Some of the tweaks that will be covered in a separate article.
In this article, we will consider the feasibility of using a sports low-cost CVT on Chinese-made scooters with 139QMB engines.
So what will it give us variator tuning in this case? The stock transmission of a Chinese scooter is designed strictly for a specific engine size. In addition, since small-capacity equipment is bought not only by young people, but also by women, as well as ordinary workers, aged people, etc., the dynamic indicators should be soft, without undermining and sharp acceleration. The maximum speed of the scooter is limited by the cut-off in the commutator and the technical features of the variator. Simply put, after the belt reaches the maximum radius of the drive pulley, the speed can only be increased by increasing the speed or replacing the gearbox.
But there is also a way that requires less money and labor costs - this is replacement of the variator with a sports one ... Of course, it will not replace you all the potential that can be obtained by replacing the gearbox, but the speed will increase.
Sports variator , as a rule, eliminates dips at medium speeds, slightly increases dynamics and maximum speed. It unlocks the full potential of the scooter transmission at the time of replacement, which is not the case with the stock part. How does this happen?
The developers of the tuning variator are not guided by the requirements of the legislation on maximum speed, various restrictions and the purpose of a particular model of the device. The main challenge is to realize the full potential of the transmission. Of course, scooters cannot be the same. Different degrees of engine wear and the condition of other units cannot recommend one set of "variator-rollers-bushing-springs" for all 139QMB engine models, therefore, in most of them you can find several sets of rollers for fine tuning the pulley for each specific case.
All the potential CVT tuning on 139QMB engines can be obtained only after replacing the piston with a larger one (for example, 82 cubic centimeters). From the point of view of the final return, this is the most expedient option that requires minimal investment.
Speaking about tuning a Chinese scooter by replacing the variator, it makes no sense to use expensive and branded tuning components, such as Malossi Multivar, Polini, Stage6, etc. The cost of individual parts can reach half the cost of the entire scooter. And the installation of such parts on Chinese-made scooters looks at least ridiculous. Therefore, it is more rational, in this case, to look towards budgetary decisions.
Recently, especially popular sports variators of Taiwanese and Chinese production. They are usually supplied complete with rollers of various weights, clutch springs and bushing. The cost of such kits usually varies around 35-40 US dollars, and you can buy a sports variator, for example, here: 139QMB sports variator. There are many similar analogues and they show much better results compared to the stock CVTs originally installed on the scooter. It should be understood that you should not expect anything supernatural from these details, but the difference will certainly be noticeable right away.
You can replace the entire kit on your own, but you need to know important aspects and have at least some experience. All that is required in the end is to unscrew the variator cover, unscrew the nut of the drive and driven pulleys. On the drive pulley, the moving pulley itself, the rollers and the bushing, which is designed specifically for this particular model, are subject to replacement. In the clutch basket, only the springs holding the clutch pads must be replaced. Replacing them will contribute to a more dynamic start and harmoniously combine with the settings of the drive pulley.
Most likely, you will need to play a little with the weight settings of the variator rollers included in the kit. Usually, the delivery set includes 9 rollers (3 sets of 3 each of different weights). Their combination allows you to select the required weight for optimal transmission performance. It is imperative to remember about their correct installation, namely the distribution in the grooves through one. Otherwise, crankshaft imbalance and engine vibration throughout the entire rpm range cannot be avoided.
How to properly install two pairs (3 pcs.) Of rollers of different weights into the variator can be seen in the photo below.
The same information can be found on the seller's website, as well as in the instructions for installing the tuning part.
If, after installing such a budget kit, the dynamic and speed indicators of your scooter do not suit you, you should think about increasing the pistons (if you have not done so yet) and look for other malfunctions that do not allow you to realize the full potential of the scooter for stable and correct operation. ...
You can also check out other articles on the topic:
The popularity of scooters is growing every year. And this is not surprising. Low cost, ease of maintenance, good performance make the moped an irreplaceable thing in the life of many.
In many countries of the world, the number of scooters on the streets exceeds the number of cars.They have high maneuverability, which allows residents of megacities not to think about traffic jams. However, sometimes situations arise that the moped breaks down and does not want to start.
You can repair the scooter yourself or take it to a workshop. This is everyone's personal decision. Having decided to repair it yourself, you need to prepare the space for this. Most often, repairs are carried out in the garage.
The most common malfunctions associated with changing oil and filters ... Improperly selected oil can be the reason that the engine will not start.
First you need to drain the old oil through the drain hole. Then the carburetor is completely disassembled.
The device and repair of Chinese mopeds should not cause big problems for a person who understands at least a little about this.
In order to identify a scooter malfunction, it is necessary to check all the elements in turn. The performance of any scooter depends on the proper functioning of components such as compression, fuel and spark. If one of the elements does not work, the scooter will not run.
Fuel can cause the moped not to start if gasoline has been filled for a long time. Studies show that from a long stay in the tank, the octane number of gasoline decreases, that is, its quality deteriorates noticeably. There is only one result: a spark does not ignite such gasoline. If you know that you have been pouring fuel for a long time, it is best to Drain the old gasoline and fill in new one in its place .
The second reason that the scooter will not start may be a dirty filter - fuel or air. The fuel filter is necessary in order to purify gasoline from various impurities and rust. The engine must be supplied with clean gasoline, since the wear of many parts of the moped depends on it.
The air filter is designed to clean the air that enters the carburetor. It must be changed quite often, since dust, dirt, etc. constantly settle on it.
The third reason the engine won't start may be a lack of spark. Checking whether the candles are to blame for this is as easy as shelling pears. It is enough to replace them with new ones. If it was not possible to start, and the gasoline is filled with fresh gas, you need to look for the reasons deeper.
Having determined that neither candles nor gasoline are the cause of the malfunction, let's move on.
As noted earlier, engine performance problems can vary. Very often, these problems are associated with candles or with a carburetor. The spark may not skip due to carbon deposits on the candle, which occurs due to the use of a rich mixture.
There may be a small gap, which also does not contribute to a normal spark. In a two-stroke engine, this gap is 0.6-0.7 mm. With a smaller gap, there is a greater likelihood that the electrodes will melt. Increasing the gap causes the current consumption to increase and more voltage is required to generate a spark.
There are situations when the moped stalls while driving, and then continues to go further. This is due to the detachment of carbon deposits from the electrode. The spark is lost for a while and the engine stops working. After self-cleaning, performance is restored.
Interruptions in engine operation can be associated with moisture ingress on electrical appliances and wiring. This leads to a loss of voltage. After drying these parts , engine operation should be restored.
A fairly common reason in our climate is water entering the fuel and then into the carburetor .
The reasons considered are easily eliminated by the driver himself. However, if these actions did not bring the desired solution and the engine does not work, the scooter engine should be repaired.
With regard to the carburetor, the causes of malfunctions can be caused by inadequate mixture quality.If the mixture is poor or rich, the performance of the moped will be compromised. The quality of the mixture can be checked by the condition of the candle. Black color will indicate that the mixture is rich, that is, there is an overconsumption of oil. White color will indicate a poor mixture and a decrease in engine power for this reason.
Repair of the scooter carburetor is performed on a warm engine. Before that, if there is a possibility of clogging, it should be cleaned and rinsed. The carburetor adjustment itself consists of the following actions:
1 action - it is necessary to adjust the idle speed.
This action is performed using the idle screw. In order to increase the speed, the screw is tightened, and to decrease, it is unscrewed. After warming up the scooter, using simple manipulations, you can set up stable engine idling.
Step 2 - check and adjust the quality of the mixture for the carburetor using a special screw.
The combustible mixture that enters the carburetor must clearly have the proportions set by the scooter manufacturer. If the mixture is too lean, the scooter loses power and overheats. With a rich mixture, fuel is used uneconomically. This problem can be solved by turning the screw. Turning the screw clockwise enriches the mixture, counterclockwise depletes it. The color of the candle will indicate the quality of the mixture. The candle is black and soot, which means the mixture is rich. If, on the contrary, it is white, the mixture must be enriched.
3 action - set the quality of the mixture by moving the needle.
The following manipulations are performed with the needle: when the needle is raised, the mixture is enriched, and when the needle is lowered, it is depleted.
4 action - regulation of the fuel level in the float chamber.
Checking the fuel level is done with a transparent tube on the bottom of the carburetor. The procedure is as follows: unscrew the cream screw, lift the pipe up and check the fuel level. The fuel level is monitored with the engine running. The tube should be held above the carburetor. The fuel level should be slightly below the curb on the carburetor cover.
Repairing Chinese engines does not pose any particular difficulties for most scooter owners. It should be remembered that the main attachments of the "Chinese" are more delicate than in domestic mopeds, so you do not need to pull anything with all your might.
For example, sudden movements when repairing the carburetor of a Chinese scooter can cause the pipe will be damaged ... Then the muffler is removed. Many Chinese scooter manufacturers use plastic soldering. This must be taken into account when parsing a moped.
Manufacturers have foreseen that many scooter owners will want to carry out repairs on their own, so there is simply nothing complicated in the design of such scooters. Chinese scooter repair manual will allow you to do all the steps yourself. Everyone will be able to deal with the main problems and repair the engine of a Chinese scooter.
A scooter repair video will answer most of the questions.
Video (click to play).
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