Trimmer Turns Back

Many motorcyclists have to synchronize carburetors after some periods of time. This is largely due to the fact that there are no permanent systems, including carburetor ones. All of them sooner or later begin to work asynchronously. Long operation of the motor on asynchronous power supply is quite dangerous, since such a practice causes increased detonation, which “kills” the power unit in a short time. In order to prevent such a confluence of circumstances, it is extremely important to periodically check and, if necessary, synchronize the operation of carburetors in a single power supply system. We will talk more about how to do this below.

Signs of need for synchronization

The synchronization of carburetors is far from the action that should be carried out at a time when it pleases. The first rule of working with elements of the fuel system is not to touch them until they themselves give you something to do, but what reason is needed to require synchronization of carburetors? In fact, there are several. In general terms, the list of signs signaling the need to check and adjust the synchronization of the functioning of carburetors is as follows:

  • Fuel consumption increased;
  • Single people started to “swim” and are not amenable to tuning;
  • Excessive vibration appeared in the motor;
  • The engine does not function smoothly;
  • Black smoke is coming from the exhaust system or the sound of gunfire is heard.

First of all, when such symptoms appear, it is enough to simply clean the carburetor. In the event that the problems have not disappeared, you will have to synchronize the operation of individual nodes. Repair measures of this kind do not require a mandatory visit to the service station, because if you wish, the synchronization of carburetors can very well be done by yourself. To do this, you need to know some of the subtleties of the procedure, which are described in detail in the following paragraphs of the article.

Preparing for synchronization

In order to synchronize several carburetors operating in the same fuel system, some preparation will have to be done. In particular, the following tools should be prepared:

  • A device for synchronizing carburetors (otherwise called a synchronizer);
  • Rags;
  • Set of wrenches and screwdrivers;
  • Gloves
  • A substitute (flask or other container for gasoline with a fuel line extending from it).

As a rule, to find the presented tools is not difficult for absolutely anyone.

Trimmer Turns Back

An exception is the carburetor synchronizer, which many may have heard about for the first time. Such a device is not particularly outlandish or complex in design, it only represents a set of elements that synchronize the operation of several fuel distribution units.

To date, the carburetor synchronizer can be obtained in several ways:

If everything is extremely simple with the purchase of the device, then questions may arise regarding its manufacture. In order to neutralize those, let’s look at how to make a carburetor synchronizer with your own hands:

  1. First of all, you have to purchase the following things:
    • A manometer or vacuum gauge (their number should be equal to the number of carburetors that will have to be synchronized, often 4 pieces are required);
    • A fuel line or, best of all, a system for droppers (the amount is selected in a similar way);
    • Bar 40 by 15 cm.
  2. Next, you need to screw the pressure measuring devices to the bar, and then attach dropper systems or separate fuel pipes to them through special fittings. On this the synchronizer is ready.
  3. After creating the device, just calibrate it. To do this, all hoses coming from pressure gauges or vacuum gauges must be connected to source of discharged air, and then check whether the readings converge on them. If not, you have to bend the arrow of the corresponding measuring device in the right direction. Based on the results of these manipulations, you can proceed directly to the synchronization of carburetors on a motorcycle or other unit.

    Synchronization procedure

    So, the carburetor of a motorcycle, for example, is cleaned and preparations for synchronization are carried out. What is done next? Now the procedure begins to synchronize the operation of several nodes. It is carried out in several stages:

    1. Since the synchronization of carburetors is the setting of equal values ​​of air discharge at idle, you will have to work with the settings of the throttle valves of each node. Given this fact, you need to access them. To achieve this goal, it is enough to dismantle all components of the motorcycle or other unit that interfere with full access to the carburetor;
    2. After this, the gas tank supplying the motor is disassembled, the carburetors of which are adjusted, and the previously prepared substitute is connected to the power channel. Removing the air filter will help to get the greatest effect from synchronization, of course, if there is one;
    3. Then the most crucial moment begins. The synchronization itself. To do this, firstly, to each special fuel line available in the design of the synchronizer is connected to special channels designed specifically for synchronization. Find the place where you need to connect them. To do this, find the plugs on the carburetor body and dismantle them. After installing the synchronizer, the motor of the unit starts up, warms up and the idle speed is adjusted to the minimum fluctuations that the manufacturer recommends. If the indicators on all pressure gauges or gauges are equal, then nothing should be done. Otherwise, it is enough to tighten or unscrew the corresponding screw that regulates the location of the throttle.

    Important! Synchronization is carried out first between 2 adjacent carburetors, and then between their pairs. That is, if the carburetor is 2, then you will have to tighten only 1 screw to the desired position, if 4. Then 1 screw for two adjacent carburetors and 1 more to synchronize the pairs with each other, and by a similar symptom further.

    According to the result of synchronization, it is necessary that the performance of all measuring instruments are equal. Only in this case, the setting can be called successful. On this, the most important information on today’s topic came to an end. We hope the material was useful to you. Good luck in synchronizing carburetors and on the road!

    How to make a carburetor synchronizer with your own hands? Our option

    Many motorcycle owners are interested in how to make a carburetor synchronizer with their own hands. Such a device is simply necessary in the garage of any motorcyclist, as well as the owners of some carburetor cars. With it, you can configure multi-chamber carburetors. It is used to normalize the enrichment of the mixture, which allows the engine to work as evenly as possible. Of course, you can purchase a ready-made assembly, but this is an expensive pleasure.

    Therefore, most masters make the synchronizer on their own. The benefit of making it is not difficult. This requires minimal assembly skills for various devices. As a result, you will get a good device for minimal money.

    How to make a carburetor synchronizer with your own hands? Before answering this question, you should first clarify when such an adaptation is necessary. Owners of vehicles with multiple carburetors know that idling often enough. The reason usually lies in the inconsistency of the carburetors. Use a synchronizer to configure. It allows you to fine-tune the air supply to the cylinders.

    For self-assembly of the synchronizer, you will need to purchase some of its components. In general, such a device can cost from 1,500 to 3,000 rubles. But, in any case, it is still cheaper than acquiring a factory synchronizer. First of all, you will need vacuum gauges, their number should equal the number of carburetors. The easiest option would be to purchase medical dropper systems. You will also need a hose to connect this entire farm.

    Suitable for washers “Lada”, the amount depends on your unit. On average, 5 to 8 meters are required. A brake pipe is useful for making fittings. In general, this is enough. A vise, a metal file, and some other tools are also useful.

    Making a device is half the battle. It should be used correctly. Many inexperienced mechanics make one mistake, which does not allow them to fully synchronize carburetors. The fact is that tuning should be done at well-defined speeds. They are indicated in the technical documentation for the carburetor or motorcycle. Motorists who have installed a multi-chamber carburetor need to find this information on the Internet. If the car has a battery of two carburetors, then you should focus on the idle speed adopted for the model.

    To work, you must connect the synchronizer to the carburetor. To do this, find special holes that are usually covered with rubber plugs. After connecting, start the motor and bring it to the desired speed. Look at the gauges. If they differ, then by turning the screw to adjust the air supply to achieve their coincidence. To check the correctness of the setting, it is necessary to turn off the engine and after restarting to see the readings of the device, if necessary, repeat the adjustment.

    Conclusion. Services synchronization services are quite expensive, it will cost you less to buy a special device. Therefore, the question of how to make a carburetor synchronizer with your own hands is quite relevant. It will cost you relatively inexpensively, and the ability to independently synchronize carburetors will help you save money.

    DIY carb synchronizer

    To make the synchronizer we need:1. Tube (similar to a hospital-dropper, sold on the construction market), diameter `6. 7 meters (approximate price of 4 hryvnia meter)2. Three pieces under this tube. 4 pieces (approximate price is 12 UAH / piece)A piece of plywood (meter to 60 centimeters), or something else as a basis.

    We cut 4 tubes of 1.5 meters each. We connect the tubes below with tees, plug the side tees with bolts or something else. Then, using a wire, we fasten the tubes to the plywood (as in the photo). Pour automobile or motor oil through any tube (you can plug two, lower the third into a jar of oil, and through the fourth suck it out of the can into the system) That’s all! The synchronizer is ready!

    For two cylinders. Two tubes and two adapters, the principle is the same

    Now about the synchronization itself.We remove the tank, but do not disconnect the fuel line (the engine must be heated before synchronization before the fan operates for the first time, or to the operating temperature for air vents, and indeed it works during synchronization, which means we need gasoline). The tank can be put on a chair, as I didThere are special fittings between the carbs (there are 4 in total for each carb). There are 3 adjusting bolts next to them (for synchronizing the first and second, third and fourth and, in fact, between the pairs). So they synchronize. First, the first and second, then the third and fourth, and then a pair of carbs among themselves. Hoses are simply connected to fittings from which air comes. It is necessary to make sure that this same air exits from all carbs with the same pressure. This is the whole principle of synchronization. The device is one integral system in which all hoses are connected by adapters. Consequently, the carb in which the pressure is greatest will squeeze the oil out into the remaining hoses evenly and vice versa. The purpose of synchronization is to maximally equalize the oil levels in all hoses on a running engine, thereby aligning the air pressure in the carbs and the position of their throttle valves with each other.

    I am very pleased with the result. Over, carb synchronization costs from 2000 to 4000 rubles and is done every 5000 km.,

    Here is what happened before the synchronization: (mileage after the last 6000 km)

    And this is what happened after:

    Good luck everyone! And do not pay money for air!

    _taken from here

    This option is also possible

    Instead of droppers, I wanted to make chokes from cutters for water treatment systems.

    Of flow restrictors for reverse osmosis chtoli?

    30.5 cm according to international documents) with a cross section of ¼ inch (2.54 cm), and some transmission oil (or oil for two-stroke engines). Attach the tubing to the gearbox control lever with adhesive tape so that the tube bends to one side, bend it in the middle in the form of the letter “U”, then bend it in the opposite direction on the other side of the box. Make sure that a few feet of the tube protrudes upward, not snug against the lever. Collect some gear oil into the tube and you can start. Insert each end of the loose pipe into the vacuum openings of the carbs and adjust the carburetor timing screw until the oil level is the same at each end of the pipe. Voila! Everything is simple. And it works great.The picture for 4 pots, for 2, respectively, is even simpler. “”

    DIY carb synchronizer

    Neither I am the first, nor I am the last who does not want to pay a few tr. For a device of 4 x vacuum gauges and hoses with fittings. Not long searching, I found a description of a homemade device for synchronizing carburetors, the principle of which is based on communicating vessels with a liquid. My assault was held back by the scale of the city. It’s hard for us to get what’s in the big city “sold in any market“. Again, I am not the first to write about this. I want to insert “my 5 cents” in the subject =)


    For those who do not yet know what the desired device looks like, I will give a few examples:

    Another park in the literal sense of the word is temperature. The hot engine softened the hoses and collapsed under vacuum. I used a metal braid from the shower as a heat shield. The result is this:

    The tubes are filled with engine oil, which runs my horse. This is in case I miss a moment and the engine sucks the contents of the device. If the hose was 10mm, then the weight of the oil would not allow it to rise so high. But on the other hand, changes in levels will not be so obvious again, due to the weight of the oil.

    The sensitivity of the device. I won’t say that I react directly to the touch of a screwdriver (I read it somewhere), but a 1 degree rotation is immediately displayed in the overall picture of the synchronizer. When I connected the device to my bike, I just went nuts from the picture I saw. # 128577; The second cylinder sucked in air so briskly that in a few seconds it drove the level to the top of the tube! I used this synchronizer on another bike, there the situation turned out to be much less critical. 5cm in the same time.

    How synchronization is done

    We will twist the adjusting screws, they are the number screws. Each bike has it somewhere on the bar of carburetors, I can’t say more precisely # 128512; If you removed carbs from your horse at least once, you probably saw them. Three screws for a screwdriver (with four carbs) are located between the carbs on a metal rod, springs are put on the screw on both sides of the rod.

    Finding cogs is not everything. Before you just take up the creation of the device, consider in practice, how you will turn the quantity screws directly on the bike. For example, in order to get to the middle screw on Fura, I had to assemble a cunning screwdriver (see on the right). Find a better way, tell me, because I didn’t have% (

    I twisted all the screws at once with three screwdrivers. It’s simple: the two extremes regulate the balance inside the pairs of carburetors, 1-2 and 3-4, the middle. The adjustment between the pairs. I did not achieve an absolutely even picture, because with prolonged use, the levels crawled a little. I accepted such a desync as acceptable.

    Information for consideration: if you filmed carbs, it is very likely that the bike needs to be synchronized. I’ll explain why: carburetors are not completely fixed to each other, there is some backlash. And while you pull them back and forth, the position of the rod with the number screws may change slightly, which is theoretically enough for desynchronization. I read this thought on the forum, and I agree with it. On the other hand, vibration of the bike should also lead to a shift of the carbs and lead to desynchronization. It turns out that she always is, but not big, probably. Decide for yourself what to do.

    The last part

    On the expanses of Runet it is said: “Synchronization is done every 6000 km or a couple of times a season. It is advisable to prevent the fuel system before synchronization. Synchronization greatly affects the response, idle and start of the motorcycle, not significantly on power and fuel consumption.»I do not agree with fuel consumption. I still can’t confirm the words with numbers, but after I blew the carbs (before synchronization), my bike at 400cc began to eat 6.25l per 100km o_O. According to the manual, 3.7-4.2l per hundred. I didn’t measure it after synchronization, but I think that it will be less.

    [UPD] Checked, no less. The fuel consumption is significantly influenced by the driving style, i.E. What speed to drive, and just at that time I began to unscrew the gas # 128578; When you need savings, keep the momentum lower. Yes, it’s not good for a bike, but you have to save money infrequently.

    On the forums there are different opinions about the oil (liquid) synchronizer: some praise, others consider such a device garbage, someone even could not make it normally. Out of curiosity I will buy 4 vacuum gauges, for example here, I will collect the device and compare the synchronization accuracy.

    It should be noted that if you assemble the synchronizer on vacuum gauges, then you will need to either add krantiki to the connections, or limit their throughput by inserts into the hoses to a minimum. And all because the working engine cylinders will greatly swing the instrument arrows. The liquid synchronizer is spared this problem.

    Another plus in favor of a liquid synchronizer is that you do not need to calibrate the device, the level is always accurate. The device on the vacuum gauges will have to be set up: separately connect each pressure gauge to the same cylinder and set the devices to the same value.

    One more note about the synchronizer on vacuum gauges. Instrument readings are unimportant, most importantly. The same values. The specific indications are affected by the quality of the fuel, the wear of the piston group, and the condition of the carbs.

    The cheapest factory carburetor synchronizer with gauges found this KINGTOOL KA-7200. The link is out of date, therefore I do not quote it. I can not vouch for accuracy or proper operation, but I read an article in Runet using this particular device. He still doesn’t roll me, the fittings included in the kit are not suitable for the Truck.

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