Carburetor Adjustment Stihl TC 800

The fuel level in the Solex carburetor 21083

Hello! I wondered how to accurately adjust the carburetor, because after the last events, I realized that I needed to change the repair kit and clean and check everything (before that, as usual, there was a lack of time)

Naryl materials "from several sites. let’s go

The required value of the fuel level in Solex carburetors, indicated on most sites –24. 1 mm from the upper edge of the carburetor float chamber.If the measured fuel level differs from the required, you should adjust the position of the floats.

Float position adjustment

Measurement can be carried out with a round probe, a drill, a piece of wire of the desired diameter.

It should be 1-2 mm, which will achieve the above.24. 1 mm. If the measured distance does not meet the required, slightly bend the tab on the levers of the floats (the one that touches the ball of the needle valve) or the levers themselves and measure again. At the factory, a special template is used for a similar installation of floats (photo below).

Checking the correct fuel level

We put the carburetor cover upright. In this case, the tongue on the levers of the floats should immerse the damping ball on the needle valve and be approximately parallel to the plane of the needle valve and the punch line on the floats is parallel to the surface of the carburetor cover. If this does not happen, we will adjust the fuel level again, more carefully.

Notes and Additions

We raise the floats as high as possible and again measure the distance from the lower corner of the floats to the cardboard pad. 15 mm should be added. This is the free stroke of the floats.
If it does not meet the required, we achieve the desired value by bending the rear tongue on the levers of the floats.

P / S / Also on the Internet I found a subjectively correct table for the selection of nozzles (relatively fair, but not a fact) Solex maintenance book on my Yandex store. It’s here.
Summing up the settings of the carba, before selling the car, I found that with 1.3 the consumption on the highway was 5.5 liters, with 1.5 at about 6, the speed was 90 km / h gearbox 4

How to adjust and tune Solex carburetor

A carburetor is one of the most important parts of any car. Solex carburetor is considered to be one of the most popular, its modifications 21053, 21083, 21073, 21041 are especially common. These carburetors have calibration data and large cross-sections of diffusers.

The basic modification of the Solex carburetor is type 21083. It is designed for transverse teeth of engines, has the smallest cross-section of diffusers. All carburetor modifications are almost identical, however, they are used for different engines. Regardless of the type of carburetor, the setting of any Solex is the same.

Solex carburetor device

Solex refers to the emulsion type, which is initially installed on cars with a contactless ignition system. It is equipped with two chambers with throttle valves, as well as metering systems for the chambers, transition systems for the first and second chambers, and also an idle system only for the first chamber.

Solex has the following equipment:

  1. Semi-automatic trigger system.
  2. Accelerator pump.
  3. The economizer of power modes.

Solex setup

Many drivers are trying to install a Solex type carburetor on their car, as at the moment, this carburetor is considered one of the best. It works great in all conditions, even with a serious overflow. Many people mistakenly believe that the most difficult thing in this situation is the installation of a carburetor, but in fact, setting it up and adjusting also often causes difficulties.

Some prefer to transfer work on installing or tuning carburetors to specially trained people, however, most motorists tend to do all the possible work on their own, they are very interested in this.

The carburetor setting procedure is as follows:

  1. We set the level in the float chambers. As a rule, in the manual the level is set using special floats using a special template. This is not an easy method if there is no special factory setting. If there is no factory setting, you need to do it yourself. To do this, start the engine and give it a few minutes to warm up. Then we turn off the engine and remove the fuel hose. This must be done carefully, as a lot of gasoline spills out of the hose. If gasoline flows under pressure into the chamber, the readings will be blurred. Now unscrew the carburetor cover and remove the suction cable. Gently, horizontally, raise the carburetor cover. Otherwise, the floats will be damaged. It is necessary to measure the distance from the surface of gasoline to the cover of Solex itself. You need to measure in each camera, since the level in them is not the same, which means that the distance will be different. The norm is 25-35 mm. For calculations, the average value of two cameras should be taken. In case the level is less or more than the norm, it is necessary to bend the float in the right direction and drain part of the gasoline. An important point. you can not adjust the level of gasoline without starting the engine, since at the established end you will receive a gas overflow.
  2. The second tuning step is to set the engine idle. To do this, it is recommended to warm the engine to normal temperature. After that, the engine is turned off and tuning is started. Now, using a screwdriver, you need to find the mixture quality screw in the hole in the sole of the carburetor, this screw should be turned to the right until it stops, but without using force. After that, you should carefully start the engine and remove the choke. Using the screw set the permissible minimum number of revolutions. It should ensure constant, stable operation of the engine and at the same time its discharge should be minimal. The normal number of revolutions is 500. 1200, in this case we can say for sure that the carburetor is in order. We wrap the quality screw until the engine starts to work unstably. Then we return it to normal operation by turning 1-2 turns back. Now you need to set the speed, the optimal value is 800-900 turns, but this number should be adjusted individually. The screw is twisted until they catch the optimal ratio.
  3. There are some difficulties when setting up idle speed. It often happens that when the quality screw is rotated, the engine does not respond to it. In a normal case, it should work unstably, it can be adjusted with a screw. If this does not happen, then gasoline enters the idle channel and the screw cannot block it. The cause of this situation may be the nozzle that is too large if the plug is poorly twisted, and also if the nozzle itself is deformed. Diagnosis of the problem can be carried out as follows. when the engine is idling, the valve is removed. In this case, the engine must stall. If the engine turns off, the problem is in the large jet. If not, then gasoline goes past the nozzle. In this case, you need to check the locking screw of the second chamber, which ensures smooth opening of the throttle.

Check Solex carburetors

Before adjusting the carburetor, you should check whether foreign objects have fallen on the throttle valves. If a foreign object gets into the carburetor, this will inevitably lead to the need for major repairs of the engine.

After completing the settings, you should check the operation of the accelerator pump. When opening the throttle from the sprayer, trickles of gasoline should appear. If they do not appear immediately, at the beginning of the movement the car will slow down significantly.

In order to clean the carburetor, it must be disassembled. First, we unscrew the air and fuel jets and emulsion tubes. The location of each element must be remembered, as it is important for the subsequent assembly of the carburetor.

To check the integrity of the diaphragm, you need to unscrew the cover economizer power modes. You can understand that the diaphragm is broken by the following symptoms:

  1. The engine does not stall completely even when the screw is tightened.
  2. When the ignition is turned off, self-ignition may occur.
  3. Unstable engine operation.
  4. Excessive fuel consumption while driving.

After checking the diaphragm, the carburetor should be cleaned. This must be done carefully, using only air or, if the contamination is very serious, using a soft copper wire. It is best to clean the Solex carburetor with a blowing method, with which all its parts should be purged trying to direct the pollution far out. Next, close the lid and lubricate all the friction surfaces of the carburetor. This should be done after washing its outer part.

Solex carburetor tuning

The reason why car owners want to pump the carburetor and carry out its tuning is that after performing such procedures, the car will become more powerful and dynamic.

Initially, when the carburettor is factory set, when the throttle opens abruptly, the air flow rate drops, because of this, less fuel enters the carburetor. As a result, the carburetor’s power drops when it is operating at low speeds. The reason for this phenomenon is that the simple carb design of the developers was combined with a sharp torque characteristic.

The simplest tuning of a Solex carburetor is a small amount of work to improve its power. The sequence of work is as follows:

  • Carefully disassemble the carburetor.
  • If you have not previously washed it, wash all the parts and blow it with air. We divide it into two halves.
  • Now pay attention to the axis of the air damper. Strong protruding screws are located on it, which create additional resistance when the car is moving. They need to be smoothed out.
  • At the top, get the axle and choke, sharpen the choke harder.
  • From the bottom you need to remove the throttles and their axes. Now, you need to make the dampers larger, for this you should use a file. We hide the screw caps inside the axis, you can solve this problem using the screws with a conical hat. After performing these procedures, the throttle mechanism is assembled again.
  • We turn to tuning diffusers. For small diffusers, an ideal option would be to create legs in the shape of a wing, since this shape has the best aerodynamic characteristics. You should also correct the casting error of the body and smooth out all sharp corners.
  • On a classic accelerator pump, it is recommended to install two tubes in one chamber. However, some experienced motorists claim that such an arrangement of tubes leads to "failures." You can try this option. install one tube in each camera. It is very important to put them between the wall and the throttle.

The most important point when conducting Solex tuning is that you should smooth out all the bumps and sharp corners on its surface. Particular attention is recommended to be paid to the mixing chamber. passing through it, air reaches tremendous speed and any unevenness can reduce it. Such tuning will significantly improve the dynamics of the car.

Fuel level adjustment in the float chamber of the carburetor 2108, 21081, 21083 Solex

One of the most frequent and common causes of problems with the engine, from which it may simply not work, is the incorrect fuel mark in the carburetor’s float compartment. It doesn’t matter whether the engine warms up or not. the wrong fuel level will be an obstacle for him. It is also possible an unexpected malfunction in the machine’s engine when you press the “gas” pedal, increasing the amount of fuel consumed and low power and engine throttle response.

To correct the fuel level in the Solex 21083 carburetor yourself, you will not need any extra knowledge and skills. Only a few tools will be enough.

The following tools will be required to adjust the fuel level:

  • Measuring instruments, like a regular ruler, or a more advanced version. a caliper;
  • Tools for checking the fuel level: dipstick, thin drill, or you can do with a small amount of wire, the main thing is that its diameter does not exceed one millimeter);
  • Small pliers;
  • The keys.

In order to correct the fuel level, it is not necessary to remove the entire carburetor, since only its cover will be necessary.

Preliminary work

Before starting the main work, it is necessary to prepare the working part.

  1. At the very beginning, the air filter housing is removed. To remove it, you need to unscrew the nut that holds the cover from the body. A ten millimeter key will help with this. Four latches hold the lid, they will need to be removed. After that, the hose clamp for ventilation is loosened and the hose itself and the filter element are actually removed. To completely remove the filter housing, it remains only to unscrew the four nuts (8 mm spanner) that attach it to the carburetor.
  2. This will be followed by the dismantling of the cover from the carburetor. To remove it, loosen the clamps on the fuel hoses and then remove these hoses from the carburetor fittings. Remove the wire and unscrew the screws that secure the cover to the housing. Then you need to lift the carburetor lid quite a bit. The main thing here is not to touch the floats of the chamber walls.
  3. The cover must be turned upside down and put on a flat surface without losing a single screw that will fall out of the cover.
  4. Check floats. There should be parallelism between the side surfaces of the floats and between the imprint of the walls of the float chamber. If there is no parallelism, then you need to create it by arching and divorcing these same floats. As a result: they will easily be located inside the camera and will not touch its walls.
  5. Measure against the cardboard pad and protrusion of each float. It is necessary to use a probe, a thin drill, or a wire with a diameter of one millimeter. If the measured distance differs from the required, it does not matter which way: to a greater or lesser extent. This indicates that the fuel level in the float chamber is incorrectly set and it is necessary to react to the fuel level with a new one.

Idle setting

After correctly setting the gasoline level, it is recommended to warm the engine to operating temperature. Then the engine is turned off and idle is carried out. A properly tuned engine must successfully display its optimum functional characteristics.

  1. A flat-shaped screwdriver needs to grope for the mixture quality screw located at the bottom of the carburetor.
  2. The screw is fully turned clockwise. You cannot use force. Otherwise, the thread will be broken.
  3. From the achieved position you need to do 5-6 turns back.
  4. The motor must be started, after which the suction is eliminated. The screw sets the minimum speed, taking into account the fact that the motor must work stably. The nozzle should be set to a minimum vacuum. The optimal speed indicators are 500–1200. If the indicator fits into the specified limits, the carburetor is corrected and tuned, so it is ready for full work.
  5. Now you need to tighten the screw. The main indicator of the achieved result is the beginning of unstable motor operation. For stable operation of the engine, you will have to make 1-1.5 turns back. It is advisable to perform such actions slowly. If in a hurry, good results cannot be achieved.
  6. The screw must be set at about 850-900. We set the fuel level for maintenance. Solex carburetor 2181 or whatever. Most often, these characteristics on the VAZ are successfully perceived, allowing you to count on a decent ride in a car. If any deviations are noted, you need to unscrew the screw a little and guarantee the correction of standard indicators.
  7. Paragraphs 5 and 6 are repeated until you can find the optimal ratio for the stable operation of the motor and the minimum vacuum in the car tube.

Fuel level adjustment in Solex carburetor 21083, 2108, 21081

When the carburetor cover is removed, then everything should look as follows. The approximate fuel depth should be approximately twenty-nine millimeters plus or minus one millimeter. You need to measure the level immediately after the carburetor cover is removed. It is necessary to do this immediately only so that the gasoline does not evaporate. But you need to understand that the numbers given in the article are not an exact number, this is just an average value.

Sometimes those who are engaged in car repair use conditional values ​​in order to correctly set the fuel level. Such repairmen spontaneously control the tongue located on the lever of the floats. They also sometimes pump fuel in order to achieve its optimum level in the float chamber.

However, they are not guided by anything to do these actions. Such an approach has a place to be, but in order to achieve more accurate and accurate results, it is necessary to perform the usual standard fuel adjustment. At a minimum, factories recommend the standard adjustment, and also, to carry out it, no special skills are required. Such adjustment is carried out in two simple steps on an upside down, horizontally located carburetor cover.

Second stage: level setting

To determine how different it is from what is needed, you can measure the depth of gasoline: it should be 29 mm (plus or minus 1). You just need to do this right away, the cover is barely removed: the fuel evaporates quickly, and after 5 minutes the data will become unreliable. Naturally, the measurements are not particularly accurate. The adjustment consists of 2 stages.

. The caliper is set at 34 mm. The upper measurement bar is the carburetor cover, the lower is the crown of the float. If the distance is greater (less), then by bending the tongue and levers it is necessary to achieve the indicated indicator. In the absence of a vernier caliper, you can take a ruler (preferably metal: plastic in gasoline and can dissolve, wooden fragments may remain that remain in the fuel).

Full Float Pass

. The measuring tool is placed strictly vertically next to it; the number of centimeters to the bottom edge is noted. The float rises; The new position height is measured. Both numbers add up. this is a complete move. The same manipulations are made with the second float. If the data does not match, the protrusion at the back is bent. There is a corresponding tongue.

Height adjustment for floats

The caliper will need its depth gauge, which will need to be pulled out to a length equal to thirty-four millimeters. If at hand there is no necessary tool in the form of a vernier caliper, then a simple and ordinary ruler can help out. It will need to be attached to the cardboard gasket on the carburetor cover and measure the distance from the top of all the floats to the cardboard gasket. The distance should be equal to the thirty-four millimeters that were measured. If the numbers are not equal to this value, then you will need to bend the levers and tongue until the number reaches thirty-four millimeters.

The device and purpose of the carburetor float chamber

A carburetor is a device that mixes fuel with air and delivers it in a strictly predetermined portion to the combustion chamber of the engine.

The main part of the carburetor is the float chamber, which is constantly filled with gasoline. It generally determines the principle of operation of the carburetor. Average, the volume of a standard float chamber can reach 100 cm3.

The float chamber consists of a float, which is suspended on an axis, with a lever. At the top of the chamber is a needle valve through which fuel is supplied. The camera itself is a cavity located at the bottom of the carburetor. On the side there is an outlet through which gas enters the feed system.

When the level in the chamber decreases, the float drops down and releases the needle valve with its lever, which opens and passes gasoline. In the process of its supply, the float chamber is filled, gradually raising the float, at the end of which a lever is installed. Upon reaching the normalized level, the lever raises the needle of the valve and closes it, thus, the supply of gasoline to the chamber is stopped. This cycle continues until the motor stops.

Adjusting the full stroke of the floats

To do this, you need to pick up a measuring tool in the form of a ruler and place it parallel to any float. The ruler should be vertically positioned. After that, the float must be raised, and the lower part will have to rise by fifteen millimeters. This value will be the entire course of the float. The same actions will need to be turned for the next float, and if the stroke is not equal to fifteen millimeters, it will be necessary to bend the rear ledge.

To summarize

The steps to adjust and adjust the Solex carburetor described above are basic. In other words, if you wish, you can adjust the carburetor with your own hands, based on this information. Note that the accuracy of the settings can be further checked on the gas analyzer, after which you can make the necessary adjustments yourself instead of constantly contacting specialists. Finally, we add that the metering device of this type lends itself to various types of tuning, all kinds of improvements and improvements. For this reason, when choosing a carburetor on a VAZ, many motorists not in vain prefer Solex.

Verification of work done

After all the work has been completed, you will need to make sure that it is correct. To do this, you will need to turn the carburetor cover and make sure that the ball located on the needle will not be sunk. If the punched lines on the sides of the floats will create parallelism with the cover, this will mean that the work is done correctly and everything is right. If everything is done correctly, and there is no parallelism, then the problem will be in the malfunction of the needle.

Article author: Yuri Veselov
Publication date: 02/11/2019

Transient mode

Throttle opening is not permitted even at idle speed of the motor. Under them, a significant vacuum is always created for the successful exit of gasoline and engine start. A sharp opening leads to a sharp decline in rarefaction, but it turns out to be excessively weak in order for the main system of the first chamber to work successfully. The idle system and the accelerator pump functionality ceases to be sufficient for a successful and stable carburetor operation. This leads to failure. A transition system is required to eliminate the resulting failure. When you press the gas, the hole can go into the area of ​​strong rarefaction, as a result of which the gas mileage increases. This hole can also receive fuel through the jet.

Before you understand how adjust transition mode for a successful ride, it is recommended to deal with potential problems. Motorists often complain about the following problems:

  • motor failure at startup;
  • dull engine when driving;
  • the motor can just sneeze, shoot and even stall.

Transitional mode leads to such violations. To eliminate various troubles, it is recommended to choose the most suitable location for the nozzle of the accelerator pump and the nozzle. As a rule, the need to adjust the feed carburetor lawn mowers Stihl. The engine should receive the optimum amount of high-quality mixture. Otherwise, it may choke.

A successful engine start is only possible if the correct transient settings are made. From the very beginning, the motor should gain its momentum without delay and reach the desired rate.

Broken ratios of indicators lead to a violation of the engine. In this case, it is necessary to carry out the adjustment until the acceleration occurs according to the correct scheme.

If, in spite of all the actions taken, serious problems are noted with a set of revolutions and the motor can only run, shake and hum, the nozzles of the first camera are not configured correctly.

The most tedious situation is to go over the carburetor jets, the nozzle of the accelerator pump. This is done before setting up the correct car factory. In addition, the motorist adjusts idle speed, since the nozzle affects the idle speed.

How to properly configure a VAZ-2109 carburetor

The main number of VAZ cars of the Samara family, and in particular the VAZ-2109, came from the conveyor with a carburetor power system, and only later a small series received injectors. The carburetor system has a simple design and is quite reliable, but its main component. the carburetor, requires periodic adjustment. VAZ-2109 and other models of the family were equipped with Solex carburetors, characterized by a relatively simple adjustment technology that every motorist can perform.

Carburetor Adjustment Stihl TC 800

There are two main carburetor settings. the fuel level in the float chambers and the engine idle speed (XX). These adjustments are carried out in case of unstable engine idling and even when certain symptoms of improper operation of the power system are manifested:

These problems indicate that the fuel level in the chamber is not normal.

Fuel level setting

Adjusting the amount of fuel in the Solex carburetor chambers is a simple procedure and does not require specialized equipment. Although in the factory this adjustment is performed using a special template that simplifies and speeds up the work. But at home, you can do without this template.
For independent adjustment work you need:

  • screwdrivers (Phillips, flat);
  • ruler (preferably a caliper);
  • round bar with a diameter of 2 mm (wire or drill is suitable).

With this equipment, you can quickly complete all the work.

Recommended Method

The level adjustment technology includes a number of stages:

  1. Dismantle the housing of the air filter element. To do this, unscrew the fixing nut of the housing cover, snap off the latches, remove the cover, remove the filter and twist the 4 nuts securing the housing to the carburetor.
    Carburetor Adjustment Stihl TC 800
  2. We lift the case, disconnect the rubber pipes. We remove the case to the side.
    Carburetor Adjustment Stihl TC 800
  3. Weaken the clamps securing the fuel pipes, suitable for the carburetor, and disconnect them.
  4. Remove the wire suitable for the idle solenoid valve;
  5. Disconnect the drive cable of the air damper (handle "suction");
  6. Unscrew 5 screws securing the carburetor cover;
    Carburetor Adjustment Stihl TC 800
  7. Having dismantled the cover, we immediately determine the fuel level in the chambers, dropping a ruler or caliper into one of them until it stops (using its depth gauge). If the measurement shows a level of 25-26 mm. it corresponds to the norm and adjustment is not required;
    Carburetor Adjustment Stihl TC 800

In the case when the amount of fuel in the chamber is lower or higher than normal, we perform a visual inspection and a series of measurements on the floats, if necessary, we correct their position.

To carry out adjustment work, put the removed carburetor cover on a flat horizontal surface with the floats up.

First, look at the position of the elements from above. The outer side surfaces of the floats are parallel to the special prints on the gasket. Deviations can cause floats to touch adjacent elements and surfaces, which is why the fuel level is not normal. If necessary, adjust the position of the floats by bending their mounting levers.
The next step is to measure the gap between the floats and the gasket. A bar with a diameter of 2 mm is useful here. so much should be the specified gap.

Carburetor Adjustment Stihl TC 800

If it does not match, bend the tongue of the floats with which they act on the locking needle. After this adjustment, we check the total height of the floats, which is normally 34 mm. If this is not so, check the gap again, if necessary, correct it and measure the height again.

Carburetor Adjustment Stihl TC 800

The last setting step is to determine the stroke of the floats. To do this, put the caliper near the float, mark the distance from its lower corner to the surface of the lid, then raise the float with your hand and mark where the bottom corner is.

Carburetor Adjustment Stihl TC 800

Video: Carburetor Adjustment Stihl TC 800


A normal stroke of 15 mm is considered normal; if it differs, it is adjustable by folding the tongue.

Carburetor Adjustment Stihl TC 800

Alternative way

There is a simpler method for determining the correct position of the floats, which does not require measurements.
Put the carburetor lid on a flat table and look at the stampings made on the side surfaces. With a normally adjusted position of the floats, these strips are parallel to the cover.

Carburetor Adjustment Stihl TC 800

Then we raise the floats up and look at their bottom, which after lifting should be parallel to the surface of the lid. If necessary, adjust the position of the floats by bending the tongue.

Carburetor Adjustment Stihl TC 800

After adjustment, we collect the carburetor.

Idle adjustment

The second setting of the VAZ-2109 carburetor is idle speed, it can be partial and full. The first is for insignificant adjustment of revolutions, the second. with the adjustment of the amount of air (installation of CO emissions in exhaust gases).

Partial adjustment is performed using the “quantity” screw of the air-fuel mixture. This screw sets the opening angle of the throttle valves, which ensures the flow of air-fuel mixture into the cylinders with the accelerator pedal released. The “quantity” screw rests against the throttle control lever and when screwed in, it pushes the lever out, as a result of which the flaps open.

Carburetor Adjustment Stihl TC 800

Partial adjustment of idling is performed on a warm engine and with the creation of a load on the on-board network of the car, by turning on the high beam headlights and the interior heater at full power.
Correction is carried out on a running motor by screwing / unscrewing the “quantity” screw until the optimal idle speed is established, which for the VAZ-2109 is 800-900 rpm (this can be tracked using a standard or plug-in tachometer).

If it is not possible to establish the required speed or the motor is unstable on them, a full adjustment is made, which is done with two screws. “quantity” and “quality”.

Carburetor Adjustment Stihl TC 800

The algorithm for this adjustment consists of the following steps:

  1. We warm up the engine, and then we turn off;
  2. We find the quality screw (it can be closed by a plug, which will have to be removed), wrap it all the way, and then unscrew it by 3-4 full turns;
  3. We start the engine, turn on electrical consumers (lighting and stove) to create a load in the on-board network;
  4. Rotating the “quantity” screw, we achieve 700-800 rpm on the tachometer;
  5. Rotating the “quality” screw we set the maximum possible speed (they will increase to a certain level, and afterwards they will stop. The moment of termination of the increase in speed is considered the maximum);
  6. We expose the “quantity” 900 rpm screw;
  7. Screw "quality" lower them to 800 rpm;
  8. Slowly wrap the “quality” screw until interruptions occur in the operation of the power plant, after which we turn it back 1 turn;
  9. We adjust the revolutions with the “quantity” screw, bringing them to the normal level. 800-900 rpm;

After adjusting operations, we verify the correctness of their conduct. This is done by abruptly pressing the gas pedal, followed by a quick release. With a properly tuned carburetor, the engine should respond quickly to pressing, without any dips or hitches. And after releasing the pedal, the speed will drop to the idle level, without subsidence or instability of the motor.

Video: HOW TO PROPERLY ADJUST THE FUEL LEVEL

Solex carburetor 21083: device, adjustment, tuning

Front-wheel drive cars VAZ 2108-09-099 were equipped with carburetor engines for a long time, and only closer to the beginning of the 2000s, an injection fuel system began to be installed on VAZ cars.

Carburetor Adjustment Stihl TC 800

In this article, the Solex 21083 carburetor will be considered: the device, adjustment, tuning of the unit, its features, as well as the main malfunctions.

The carburetor device Solex 21083

Solex-type carburetors have been used on Russian (Soviet) cars since the mid-80s of the last century, at first they were put on a VAZ-2108 car. The first carburetors were designed to work with 1100 and 1300 cm³ engines, and they were marked DAAZ-2108. Later, the Solex 21083 model was developed, and the digital index means that the device is intended for installation on VAZ-21083 engines with a volume of 1.5 liters.

The carburetor is used to prepare the fuel mixture, on which the engine is running, ensures uninterrupted stable operation of the power unit at any speed and load. Solex-21083 consists of the following main parts:

  • the main body, in which there are diffusers, the main dosing system (GDS), the idle system, the economizer and the accelerator pump;
  • covers with an air damper, floats, an electromagnetic valve, a cold ICE starting device.

The Solex carburetor is a two-chamber, GDS fuel jets are located in the middle of the chambers in the very depths of the main building, air GDS jets are installed on top of them. The Solex 21083 carburetor device has a block for heating the air-fuel mixture, to which hoses of the cooling system are connected. Throttle valves are located at the bottom of the main body and open sequentially, the opening of the valve in the second chamber is provided by the drive levers.

There are two nozzles in the lid. one of them is used to supply fuel to the carburetor, the second is the return one and serves to return excess fuel to the gas tank, and the pressure in the fuel system also decreases due to the "return".

Carburetor Adjustment Stihl TC 800

Carburetor Solex 21083: jets, types and selection

For carburetors 21083, industry provides repair kits that include GDS fuel and air jets for the primary and secondary chambers. Depending on the size of the cross-section of the diffusers, there are different repair kits designed to work with engines 2108, 21081 or 21083, so the jets in the sets have different cross-sections.

Often, VAZ carburetors are installed on other brands of cars (for example, UAZ, Volga GAZ-31029/3110), and if you leave the "native" GDS jets, their cross-section will not be enough, since the air-fuel mixture will enter the cylinders in the wrong proportion and the amount that the engine requires.

Often, to improve the acceleration and dynamics of the car, some motorists put fuel jets of a larger cross section, but it should be borne in mind that in this case fuel consumption can significantly increase, and the experiment with the installation does not always give the desired results. The most correct decision is not to engage in experiments, and to install in the carburetor the repair kit that is designed specifically for this brand of carburetor (for example, for a 1.5 liter engine, nozzles designed for model 21083 should be installed).

Carburetor Adjustment Stihl TC 800

If the engine dynamics are not satisfied, you should look for the reasons for the slow acceleration of the car, and there can be quite a lot of them:

  • weak compression in the cylinders;
  • ignition not adjusted;
  • spark plugs do not work well;
  • break through high voltage wires.

There are many more different reasons why engine power is lost. Car owners have different opinions about tuning the carburetor, but practice nevertheless shows that it is better to put on the car the carburetor that is recommended by the manufacturer.

At one time on the GAZ-31029 or 3110, in order to save fuel, the owners of these cars often installed VAZ Solex, but this installation basically did not justify itself. even if it was possible to save gas, it was only with very careful driving and weak acceleration. So in the Solex 21083 carburetor, the jets should be selected those recommended by the manufacturer. It should also be noted that many repair kits from different manufacturers are now being sold for VAZ Solex, including China that also produces parts. In such sets, the cross section of the nozzles may not correspond to the declared parameters, so you should try to purchase parts of the original production, or at least from trusted companies that have proven themselves in the market.

Solex carburetor adjustment 21083

There are several types of adjustments in the Solex carburetor, and you can adjust:

  • gas level in the float chamber;
  • number of minimum idle;
  • high-quality composition of the fuel mixture (TC) using the idle quality screw (XX).

Adjusting the quality of the vehicle is very simple, and any car owner can do it yourself. To do this, you need to warm up the engine well and set the rotor speed within 800-900 rpm. Then:

  • tighten the quality screw until the ICE starts to work with some interruptions and reduce the number of revolutions;
  • we unscrew the screw so that the motor again runs smoothly, usually it is enough to make one revolution. If the screw is released too much, fuel consumption will increase.
    Carburetor Adjustment Stihl TC 800

In other cases, it is necessary to loosen the screw of the quantity more, since dips appear in the operation of the engine.

One of the most common idle problems. the inability to adjust the Solex 21083 carburetor with a quality screw. when it is twisted and unscrewed, the engine speed does not change. There are several reasons for this malfunction:

  • the nozzle in the solenoid valve is clogged;
  • clogged channel XX, which is under the "quality" screw;
  • the solenoid valve (EC) itself is faulty.

The performance of the EC itself is quite simple to check, we do it as follows:

  • on an idle engine, remove the wire from the valve;
  • twist EC;
  • remove the fuel jet from it, it is pulled off by hands;
  • turn on the ignition;
  • we connect the wire to the EC. at the moment of contact there should be a clear, dry click, and the valve stem is recessed. If there is no click and the stem does not move, such an EC must be replaced.

It is also necessary to immediately blow out the nozzle. in some cases, it gets so small a speck that it is practically invisible. There is also the Solex problem. the idle channel under the quality screw is clogged so that it cannot be blown.

Carburetor Adjustment Stihl TC 800

It is possible to check the EC operation in another way. during the operation of the engine at idle, you need to remove the wire from the electromagnetic valve. if the motor stalls, it means that the electromagnetic valve is working properly.

If the channels XX are clogged, the engine at minimum speed starts to work intermittently, stalls when the gas is discharged. When there is no time to repair, and it is urgent to reach the destination, there is one way that you can make the engine work stably at idle. To do this, during the operation of the internal combustion engine on the twentieth, weaken the key by 13 EC, we find the position in which the engine works most stably. But you shouldn’t drive like that all the time. with this position of the solenoid valve, fuel consumption increases sharply, since the idle system works bypassing the fuel jet XX.

The fuel level in the Solex carburetor 21083

In order for the carburetor to work smoothly, it must be adjusted, first of all, you must set the level in the float chamber. To perform such adjustment, it is not necessary to remove the entire carburetor; it is enough to remove only the top cover of the assembly.

Carburetor Adjustment Stihl TC 800

On a VAZ-2109 car, we adjust the fuel level as follows:

  • we stop the engine, dismantle the air filter housing;
  • disconnect the wire of the solenoid valve, release the suction cable;
  • we untwist the clamps and pull off the fuel hoses (main and reverse) from the carburetor cap;
  • unscrew the five screws that secure the cover;
  • remove the lid and turn it over, hold it horizontally, look at the gap between the floats and the horizontal surface of the lid itself — it should be between 1.0-1.5 mm;
  • the required clearance is adjusted by folding the plate holding the floats. When adjusting, it is necessary to achieve the same location of the floats above the surface of the cover.
    Carburetor Adjustment Stihl TC 800

According to the book instruction, the fuel level in the Solex 21083 carburetor is measured using a caliper. the distance between the upper surface of the main body and the level of fuel available in the chamber is determined, it should be 24-26 mm. Measurement should be carried out immediately after removing the carburetor cap, since gasoline evaporates quickly.

Setting Solex carburetor 21083

All the above adjustments relate to the settings of the Solex 21083 carburetor, and the nature of the engine’s operation, fuel consumption, depends on how well the unit is adjusted. There are some more settings that you should also pay attention to.

The solenoid valve contains an idle jet, and its cross-sectional diameter can be different. from 39 to 42 mm; there are also accelerator pump nozzles with different “nozzle” cross-sections (35×40, 40×40, 45×40, 35×35). By selecting the required diameter of both elements, you can achieve the carburetor without fail, good throttle response. It is difficult to recommend something specific here, in each case an individual approach is needed, and the best result is achieved by trial and error. By the way, the "nozzles" of the spray can be directed:

  • both into the primary chamber;
  • one spray gun into the first chamber, the other into the second.
    Carburetor Adjustment Stihl TC 800

Often, many motorists make one mistake when installing a carburetor. the suction cable is not installed correctly, and therefore it is problematic to start a cold engine 21083, especially in frosty weather. After securing the suction cable, before installing the air filter, it is necessary to check whether the air damper is closed using the cable. If the choke remains ajar when the suction is extended, it is necessary to fasten the cable braid in a different position.

Carburetor Adjustment Stihl TC 800

Removing and installing Solex

In order to repair or purge (rinse) the carburetor, it must be removed. The unit is removed quite simply, it can be done by almost any motorist on their own. We remove the device as follows:

  • turn off the ignition, first of all, we remove the air filter housing;
  • dismantle the return spring from the throttle actuator;
  • disconnect the gas cable;
    Carburetor Adjustment Stihl TC 800
  • we turn off the fastenings of the suction cable;
  • unscrew the four nuts on which the carburetor body itself is attached;
  • dismantle the node.

Installation is carried out in the reverse order.

Main malfunctions of Solex 21083

There are malfunctions that are most characteristic of Solex carburetors:

  • clogging of the GDS fuel jet;
  • ingestion of specks in the idle system, the nozzle XX in the solenoid valve is especially often clogged;
  • deformation of the lower surface of the main body due to overheating;
  • failure of the diaphragm of the accelerating pump;
  • solenoid valve defect;
  • weakening the fit of diffusers in the housing.

If the case is deformed, air is sucked in between the carburetor and the intake manifold, and the engine starts to intermittently, as the air-fuel mixture is depleted. Idling is difficult to adjust, and to correct a defect it is necessary to grind the surface on an emery wheel. If the warpage of the surface is significant, grinding will not help anymore; case replacement is required.

The diaphragm of the accelerator pump may crack over time, lose elasticity, and breaks appear in it.

Carburetor Adjustment Stihl TC 800

Checking the state of the diaphragm is quite simple, for this, removing the carburetor is not required. To get to the diaphragm, you need to unscrew the 4 screws of the accelerator pump cover and remove the part. The condition of the diaphragm is checked by its external examination.

Carburetor Float Chamber: Adjusting Gasoline Levels

The carburetor is an independent power mechanism for an internal combustion engine. It is designed to prepare a combustible mixture of the desired consistency, which is achieved by mixing in the right amounts of fuel and air. This mechanism is necessary to regulate the amount of fuel mixture that goes directly to the engine. However, carburetor type engines gradually began to be replaced by more modern fuel injection systems.

Carburetor Adjustment Stihl TC 800

What is a float chamber for?

In order for the engine to function properly, it is necessary to maintain the set level of gasoline in the carburetor, which is what the carburetor float chamber does. A stable fuel level is necessary for the correct operation of the engine at various degrees of load.

If the carburetor did not have a device that regulates the fuel level, it could not work normally. The amount of fuel in the carburetor’s float chamber is one of the key reasons for its stable operation. The operation of the motor at low speeds and in other transient modes of the primary and secondary cameras depends on it, therefore, the functioning of the entire motor depends on the proper functioning of the float chamber.

Setting the idle system affects the operation of the motor in all its modes. The amount of fuel in the float chamber is calculated by the manufacturer so that there is no spontaneous leakage of gasoline into the combustion chamber from the carburetor atomizers. In vehicles with a transverse motor, there is a need to compensate for tidal phenomena. In order to compensate for this, manufacturers install economizers. In more expensive carburetors, paired float chambers are used, which are located on both sides of the carburetor. These cameras are interconnected by a transverse channel or a common plane.

Most often, two float valves are used, which are located at the edges of the device. The design of the floats can be hollow from two bronze halves, which are soldered together, or made of porous plastic. To compensate for the effect of engine vibration on the level of gasoline, dampers for float chamber valves are used. This mechanism is called a damper spring and is equipped with a rod or ball. In some carburetors, a float valve is located at the very bottom of the chamber. At this location, it is possible to control the fuel level by removing the upper carburetor cover. Many carburetor models for this mission are equipped with sighting windows that are placed on one of the walls of the float chamber. With such glasses, it is possible to monitor the level of gasoline directly when the engine is running.

The mechanism of operation of the carburetor float chamber

Gasoline enters the float chamber through a pipe in which the gas pump creates pressure. A needle-shaped valve and a plastic or brass float are responsible for the amount of fuel in the chamber. When the level of gasoline decreases, the needle of the valve that contacts the float opens the needle valve, after which the gas enters the float chamber. With an increase in gasoline level, the float rises and pushes the rod with its tongue. That, in turn, covers the valve. This cycle is repeated all the time when the motor is running. If differences occur in the fuel level, it will be impossible to achieve stable engine operation.

Features of the mechanism of the carburetor float chamber

The float chamber is located in the frontal lobe of the carburetor body. It closes with a lid from above, and gasoline enters the chamber through the fitting. After the fitting there is a filter made in the form of a mesh, the purity of which is worth periodically monitoring.

The carburetor float most often has a cylindrical shape, made from two brass halves that are soldered together. The float fixture is made of the same alloy and is fastened by soldering. The float is attached to the carburetor cap by a joint.

There are two tabs on the fastener of the float: one is responsible for adjusting the opening of the valve needle, and the second is designed to limit the stroke of the float (so that it does not touch the bottom of the float chamber). The valve is a mini case, twisted into the upper cover of the carburetor, inside of which is a needle. A spring damping ball is installed at the end of the needle. This mechanism protects the needle from shocks against the valve body. In order that the needle does not get stuck in the closed state, a specific bracket is put on it, which stretches the tab of the float mounting down.

From time to time it is necessary to check the density of the needle valve, since damage to this device can lead to unstable operation of the motor and increased gas mileage. The height of gasoline in the float chamber affects the quality of the fuel mixture that enters the combustion chamber. A low level slows down the fuel supply, while a high level increases its amount. That’s why you need to properly adjust the fuel level in the carburetor’s float chamber.

Carburetor Adjustment Stihl TC 800

Correction of gasoline level in the carburetor float chamber

An incorrectly set fuel level in the carburetor’s float chamber can cause the engine to not start. Possible malfunctions when you press the accelerator, increased fuel consumption, loss in engine power, spark plugs, etc. Correcting the fuel level in the Solex carburetor chamber is not so difficult, and does not require special experience and tools.

Carburetor Adjustment Stihl TC 800

Solex carburetor adjustment

Tools required for work:

In order to adjust the fuel level, there is no need to remove the carburetor from the motor, only the top cover of the carburetor needs to be unfastened.

Work execution order:

  1. Remove the air filter housing. First, remove the filter cover by snapping off the four latches and removing the hose from it. Then we take out the filter itself and unscrew the four nuts that attach the filter housing to the carburetor, and remove it;
  2. Next, remove the carburetor cover. First of all, remove the fuel supply hoses and disconnect the wiring from the solenoid valve. Then, using a screwdriver, unscrew the screws that secure the top cover. Then carefully remove the cover, trying not to touch the carburetor body with floats;
  3. The lid must be turned upside down and put on a flat surface. In this case, the fastening screws that are advisable not to lose;
  4. Check if the floats are correct. The floats should leave a parallel imprint on the cardboard lining of the top cover. If this is not the case, they must be bent to the correct position. The floats must not touch the walls of the carburetor’s float chamber. The tongue, which is located on the float, must be parallel to the needle valve;
  5. Next, you need to measure the distance between the tab on the float and the upper cover of the carburetor. This is done using a 1 mm thick probe. If the gap does not match, it is necessary to adjust the fuel level.

Carburetor Adjustment Stihl TC 800

Fuel level adjustment

Many motorists monitor the level of gasoline on the lines located on the body of the float chamber, bending the tab of the float in one direction or another. In this case, the check is that when lowering the float into the chamber, the gas supply stops, and when removed, the level coincides with the marks on the body of the float chamber. This method is good enough, but for best results it is worth making the regulation recommended by the manufacturer.

  1. First you need to adjust the height of the floats. Using a vernier caliper, set the size to 34mm from the gasket of the carburetor cover to the top of the float in the inverted state of the upper carburetor cover. Adjustment is made by bending the tab of the float;
  2. Then adjust the stroke of the floats. Using a ruler, measure the gap to the bottom corner of the float. Then we raise the float and re-measure the same distance. This distance will be the full speed of the float. We measure the work of the second float in the same manner. If there is no match, bend the tab on the floats.

After the adjustment is completed, it is necessary to check its correctness. To do this, put the carburetor cover in a horizontal position and check that the needle is in the open position. We control that the floats are parallel to the plane of the carburetor cover. If they are in parallel, then the setting is done correctly.

Possible malfunctions in the operation of the float chamber

If the adjustment was error-free and there is no parallelism, then the needle is malfunctioning. In such a situation, replace the valve and make the adjustment again.

If there is any doubt about the serviceability of the needle valve, it should be replaced, since you will not be able to correct the fuel level (for example, if the fuel level is correctly adjusted, it will overfill).

At the end of the work of regulating the fuel level, we collect the carburetor in the opposite order. If necessary, adjust the idle speed.

How to adjust the Solex carburetor

Solex carburetor (DAAZ) is one of the most popular devices in the list of carburetor dosing systems, since with the right approach, the possibility of quite flexible tuning of this type of carburetor is realized. For this reason, car enthusiasts install Solex carburetors on different engines, and then additionally adjust them, achieving the necessary indicators of fuel economy, the quality of mixture formation at power and other modes of engine operation.

After installing Solex on the engine, it is often necessary to configure this device. To solve the problem, you can contact the service, where a specialist in carb setting will perform all the necessary operations. You can also customize the carburetor yourself. In this article we will talk about how to adjust the quality of the mixture on the Solex carburetor, how to adjust the fuel level and the float chamber of the Solex carburetor, adjust the idle speed, etc.

Read this article

Solex carburetor: tuning and adjustment

Before starting adjustment work, if you need to adjust the carburetor air damper, fuel level in the chambers, set idle speed and other manipulations, you must separately study the carburetor system layout, the location of the nozzles and other basic elements (eco.ostat, economizer, float, first and second camera, shutters, etc.) You should also pay attention to how the cover is removed and the carburetor is disassembled.

It is necessary to begin the adjustment with the fact that the fuel level is set in the float chambers. The recommended method is to set the indicated level according to the position that the floats have in relation to the carburetor cover. All manipulations are carried out using a separate template. Note that, as practice shows, this method cannot be considered optimal, since when installing Solex on a car, it should be taken into account that the gas pump on one particular vehicle may differ from the fuel pump on another car. There may also be other differences in the power system. The result is that the pressure on the carburetor needle (carburetor shutoff valve) is also different. Most often, after tuning according to the template, fuel enters the carburetor in a large excess. In order to accurately set the gasoline level in the carburetor and the adjustment of the Solex carburetor float was successful, the following steps must be performed.

  1. Usually, immediately after installing Solex on different internal combustion engines with a different displacement, even without preliminary adjustments, the engine should still start. The motor must be started, after which the power unit should work for about 10 minutes. While working on the twentieth, you can lightly press the gas and increase the speed to avoid the engine firing at the carburetor or the exhaust system.
  2. Then the power plant can be drowned, after which it is necessary to remove the hose for supplying fuel. It is recommended that a rag be prepared to remove residual gasoline that splashes after removing the specified hose. The hose is removed so that after removing the carburetor cover, gasoline, which is in the hose under pressure, does not spill into the carburetor chamber. In other words, excess fuel entering the chamber can interfere with the accuracy of the measurements.
  3. Now you can unscrew the screws securing the carburetor cover, then you need to remove the cable that controls the "suction". The next step is to carefully lift the carburetor cover. The specified cover should be lifted in a strictly horizontal position so as not to cause damage to the floats themselves.
  4. Next, prepare a ruler or vernier caliper. With these tools, you need to measure the distance that is obtained from the fuel in the chamber to the adjacent surface of the carburetor cover. The indicated distance from the cover surface to the fuel surface should be about 2.5 cm. We add that you need to measure the distance in both chambers. This distance may vary, given that the collector is not in a strictly horizontal position. Based on the difference in distance in both cameras, the average value is selected.

If drops of fuel were not noticed, then it remains to re-measure the fuel level in the chamber in a known manner. If the result is positive, this part of the setup can be considered complete. If the level is again different from the norm, then you should adjust the level again. Note that the level setting on the engine turned off during manual pumping is not correct, since after starting the engine the carburetor will still overfill, especially on engines where the “return” was blocked.

Solex carburetor: idle adjustment

The next step after adjusting the fuel level in the carburetor float chamber is to adjust the speed of the twentieth. To set it up, first warm up the motor until it reaches operating temperature. After warming up, shut off the unit.

At the very beginning, it is necessary to find a fuel-air mixture quality screw that rotates with a flat screwdriver. The specified screw is located in the hole, which is made in the lower part of the carburetor.

  1. The quality screw must be tightened fully. The screwdriving is done clockwise, with no need to apply force, as the thread can be damaged. After the screw has rested, you should unscrew it back from the stop position by 4-6 revolutions.
  2. Now the engine should be started, the suction should be removed. Then, set the minimum allowable speed by rotating the number screw. These minimum speeds can be considered an indicator when the engine is running stably and steadily. Also, in the vacuum lead, the vacuum should be minimal. A fairly simple way to determine the vacuum is to shut off the tongue of the tube, which goes into the so-called vacuum stripper. If the twentieth revolutions are in the range from 600-1200, the carburetor is in order.
  3. Next, the quality screw must be tightened slowly until the unit starts to lose stability. As soon as the engine starts to work unstably, you should unscrew the screw back one or one and a half turns, catching the position when the motor is again working stably
  4. Again, we return to the screw of the number by which the idle speed should be set to 800-950 rpm. We set the screw of the number of revolutions XX about 850-900. If the engine stalls when setting such revolutions, then you need to unscrew the quality screw.
  5. The quality and quantity screws are set up until the desired twentieth speed can be set, the vacuum in the front-wheel tube will be minimal, and the internal combustion engine itself will be able to work stably.

There is such a problem for a number of reasons. First of all, a large idle jet can be installed. You should also pay attention to how tightly screwed solenoid valve or plug. In case of a loose landing, excess gasoline can be sucked bypassing the idle jet. Also, possible problems with the jet itself, as well as its seat, should not be ruled out. To more accurately understand the reason, you will need to remove the wire of the solenoid valve on a wound motor that runs at idle. In this case, after removal, the unit should stall quickly. If this happens, then the cause is most likely a large idle jet. The solution will require the installation of a smaller jet.

If, after removing the wire from the valve, the engine does not stall, then this problem may occur as a result of the overflow of gasoline into the float chamber. It is also possible that at a running ICE, fuel bypasses the nozzle or even the entire idle system. First of all, we again check the correctness of the set level in the float chamber. If everything is normal with the level, then the solenoid valve / plug should be unscrewed, after which it is necessary to inspect the nozzle and its installation location. There should be no defects. If any, then a carburetor cap may need to be replaced. In the event that no defects were found, then the nozzle is put on the valve, the o-ring is lubricated with engine oil, after which the key is twisted without effort.

Jets and booster pump

Owners of carburetor cars know that the jets are changing, but they do not always understand why the jets are needed and how their size affects the operation of the carburetor. To begin with, the engine draws in air through a special hole made in a large diffuser. In parallel, a certain amount of fuel is drawn in through the fuel jet. The engine displacement directly affects how much air through the diffuser will tighten the engine for a certain time, as well as the amount of gasoline sucked in parallel with the air.

Now let’s talk about the accelerator pump. The accelerator pump provides an additional amount of fuel at the time of opening the throttle, which allows faster acceleration. The pump is activated using a special cam. On engines with a Solex carburetor installed, the indicated cam of the accelerator pump must be set to the largest.

You should also pay attention to the so-called "nose" of the accelerator pump. During the opening of the dampers, fuel must be supplied in a clear stream, and not drip even with a small opening of the throttle. It is also important what position the nose holds. A stream of gasoline must fall exactly into the area between the wall of the diffuser and the throttle, that is, a fuel stream is fed directly into the manifold. Do not hit the jet on the diffuser or damper. If this happens, then after a sharp press on the accelerator pedal, the car will not accelerate immediately, a failure will occur. Self-completion of the carburetor involves the installation of two nozzles in the camera to get the best return from the engine or only one nozzle in the first carburetor chamber for a more economical mode.

Carburetor transient setting

While the engine is idling, the throttle valves are closed. A vacuum (vacuum) is generated under the dampers. Thanks to the specified vacuum, gasoline is exhausted through a small idle channel and nozzle, and the engine runs idle smoothly. If you open the damper sharply, then the vacuum also weakens. over, this vacuum is not enough for the normal operation of the GDS (main dosing system) in the first chamber, and the idle system and accelerator pump are not yet able to normalize the operation of the motor. In other words, with a sharp pressure on the gas after idling, a delay in the reaction to pressing the accelerator pedal is noted.

In order to minimize or completely remove the indicated failure in the carburetor device, a transition system is used. This diagram is a hole-slot made over the throttle in the first chamber. At the moment of pressing the gas pedal, the slit-like hole is in the zone of high vacuum, due to which there is an intensive suction of fuel in parallel with its supply through the idle jet.

Back to the settings. After the carburetor has been installed, a failure occurs when starting off on many cars, reactions to pressing the gas pedal are slowed down, the engine may start shooting at the carburetor or stall. In such a situation, the transition system may be to blame. In order to normalize the operation of the carburetor, it is necessary to correctly select the cross section of the “nose” of the accelerator pump and the size of the idle nozzle.

It is important to know that the nozzles in the first chamber do not need to be touched, and the indicated dips should not be attempted to be eliminated by replacing the nozzles of the main dosing system. To solve the problem, it is necessary to correctly select the idle nozzle and the nozzle of the accelerator pump on the previously tuned carburetor. The selection must be carried out after the internal combustion engine has warmed up; the suction should be removed.

In practice, it looks like this:

The level in the float chamber was previously set, idle adjusted. The warmed-up engine runs normally at idle without choking. A stream of gasoline from the nozzle of the accelerator pump hits exactly the collector. Now you can sharply press the gas pedal. What is needed is the sharpness of the depression, and not how much the pedal has been depressed (to the floor, halfway, or ¼). Normally, the motor should immediately respond and spin, that is, a set of revolutions occurs without delays or failures. In the event that the reaction to a sharp press on the accelerator is slowed down or there is a noticeable pause before the increase in speed, then go to the settings.

To accurately determine the cause, the gas pedal must be pressed again, but smoothly, and not abruptly. If in this case there is an even set of revolutions (without pauses, dips and delays), then you should pay attention to the idler nozzle and the pump nozzle, since the main dosing system is not related to the failure. If, by smoothly pressing the gas, the engine spins up poorly, the unit itself starts to run jerkyly, buzzes, vibrates violently, etc., then the problem lies in the selection of the nozzles of the first chamber. In other words, excessive enrichment or depletion of the mixture occurs after the carburetor enters the power mode after pressing the accelerator. An indirect sign of a too "rich" mixture during operation in transition mode is that the engine smokes black smoke, the smell of gasoline comes from the exhaust system. The specified smoke and smell appear after a sharp throttling.

To remove the failure, it is necessary to carefully select the idle nozzles under the pump nozzle or vice versa. This is done until the delay disappears when you sharply press the accelerator pedal. In parallel with this, a re-adjustment of the idle speed may be necessary, since replacing the XX nozzle will make its changes to the idle system. We add that if the mixture remains lean and there is a failure, and the idle nozzle is too large and it is not possible to adjust the idle speed, then you can put a twin pump nozzle, after which both tubes are bent into the first float chamber.

Adjustment of the second Solex carburetor chamber

To begin with, when setting up a carburetor, the second camera is usually not affected, since often standard jets will be enough. Also in the carburetor device there is an econostat, which is able to correct possible nuances. Econostat is a tube, which is located in the second chamber at a slight slope.

The task of the econostat is that when the throttle is fully open, the discharge in the carburetor allows fuel to be sucked through the econostat. Econostat is activated when the engine is running at high speeds and allows you to enrich the fuel-air mixture. To refine the second chamber, which allows you to implement a "pickup", set nozzles to enrich the mixture. The selection of nozzles in this case is no different from the selection for the first camera.

To summarize

The steps to adjust and adjust the Solex carburetor described above are basic. In other words, if you wish, you can adjust the carburetor with your own hands, based on this information. Note that the accuracy of the settings can be further checked on the gas analyzer, after which you can make the necessary adjustments yourself instead of constantly contacting specialists. Finally, we add that the metering device of this type lends itself to various types of tuning, all kinds of improvements and improvements. For this reason, when choosing a carburetor on a VAZ, many motorists not in vain prefer Solex.

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