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Carburetor "Solex 21073": characteristics, adjustment

Carburetor "Solex 21073": characteristics, adjustment
Carburetor "Solex 21073": characteristics, adjustment

The power systems of modern cars are becoming more complex every year, but a simple, affordable and reliable carburetor will serve the owners of old cars for a long time to come. Now carbureted cars have not been produced for a long time. But this does not eliminate the need for maintenance of such machines. For example, the Solex 21073 carburetor manufactured by the Dimitrovsky Auto-Aggregate Plant is still being manufactured and successfully operates in the power systems of engines of classic VAZ models, as well as front-wheel drive VAZ 2108, 2109. It can also be found on early models of the “tenth family”.

Despite its simplicity, this element is in demand and popular among motorists. Solex 21073 was installed not only on the Niva. The reviews about it are positive, which means you need to learn more about it and learn how to set it up.

Solex carburetor: modifications

The basic design of these devices was developed by engineers from the French company Soleks.

solex 21073

At the Dimitrovgrad plant, they later received a license for production, and that's allother modifications were made by specialists here. At DAAZ, the popular Solex 21073 was developed. Reviews about him are only positive. The mechanism is easy to adjust and highly reliable. DAAZ-2108 is designed to work with a 1.3 liter engine for the VAZ 2108 and 2109. Solex 21083 has been modified for 1.5-liter power units. The same mechanisms were equipped with models from the first batches of the VAZ 2110 with a microprocessor-based ignition system. On classic VAZ models, Solex 21053-1107010 was installed. The VAZ Niva models were equipped with the Solex mechanism 21073-1107010. Now it has been replaced by an injector.


Carburetor "Solex" 21073 refers to the type of emulsion. Its modifications were originally installed on motors with contactless ignition. The device is distinguished by the presence of two chambers equipped with throttle valves, as well as dosing systems. The device also has transitional systems for the first and second cameras. There is an idle system, but only for the first chamber.

solex 21073 reviews

The mechanism consists of two halves. Lower - more massive - and upper. This half is the body of the device itself, and the upper part is a cover for the carburetor. At the bottom of each of the chambers there are rotary-type dampers with a mechanical type of drive. At the top in the first chamber of the carburetor is a damper for air supply. It is necessary to start the still unheated power unit. This part is actuated by a cable, whichgoes into the salon and is connected to the lever responsible for the suction and with the starting vacuum system.

Operation principle

Solex 21073 works as follows. Gasoline enters the float chamber using the inlet fitting - the fuel also passes through the filter mesh, where it is cleaned, and goes through the needle valve. The chamber with a float is two-section, and the sections are interconnected. They will have the same amount of gasoline. This design can significantly reduce the effect of body tilt on the fuel level in this chamber.

solex adjustment

This ensures more stable engine operation. As the chamber fills, the float, pressing part of the needle valve, blocks the access of fuel to the chamber. This maintains a constant level of gasoline in the mechanism. Further, from the float chamber, gasoline through the jets enters the mixing wells. Air enters the same wells through special holes in the emulsion tubes or air jets. Further, gasoline and air are mixed in them. As a result, a fuel mixture is formed. It will fall into the small as well as the large diffusers of the device. This is the main dosing chamber. Depending on the mode of operation of the engine, certain mechanisms and systems can be started in the carburetor. When the owner tries to start the engine "cold" to enrich the fuel mixture, the starting device comes into play. His driver launches from the passenger compartment - this is a suction.

carburetor 21073

When the handle is pulled out to the maximum, the choke is the firstchambers are completely closed. At the same time, the throttle valve in the first chamber opens to the distance of the starting gap. It is adjusted using the adjusting screw on the Solex carburetor. Adjusting the gap will allow you to adjust the idle speed.

Launching system

This mechanism is a special cavity that connects to the intake manifold. The device also has a diaphragm and a stem that is connected to the air damper. After the engine is started, a vacuum occurs in the intake manifold. It acts on the diaphragm rod, thereby opening the air damper. If the choke handle is returned to its normal position, this will lead to a decrease in starting gaps.

Solex on the field

Gap parameters depend on the geometric characteristics of the lever and are not adjustable in any way. As for the throttle valve of the second chamber, when the choke is pulled out, it is in a locked state.

Idling system

This assembly is necessary in order to supply the combustion chambers with a combustible mixture at the lowest speed. Thanks to this system, the power unit will not stall when there is no load. Fuel enters the system through the main jet into the first chamber. Through the jet XX, where it is then mixed with oxygen, the fuel enters the system through the air valve. This mechanism allows you to ensure stable operation of the engine at idle without load.

Further, the combustible mixture will enter the first chamber through a special channel located under the throttledamper. The fuel mechanism leading to the outlet XX is closed with a quality screw. This is an adjusting screw with which you can adjust and change the characteristics of the carburetor. The operation of the motor in idle mode on the Solex 21073 mechanism is also adjusted by this element. Due to it, the value of the throttle gap of the first chamber in the XX mode is determined.

Other carburetor components

Also in the device of the mechanism there is an accelerating pump and an economizer. These units are designed for the fuel mixture of the engine when it is running in loaded modes.

Setting the level in the float chamber

So, we have considered the Solex device. Adjusting the carburetor will help you set the optimum mode when the engine will work as efficiently as possible and at the same time fuel consumption will not be too high. First you need to start and warm up the engine a little. Then dismantle the fuel hose and carburetor cover. After that, the suction cable is disconnected and the cover is twisted from the device.

solex 21073 1107010

It must be removed as evenly and carefully as possible so as not to damage the float. Then, with a ruler or caliper, measure the distance in each of the chambers. You need to measure from the mating planes to the edge of the gasoline. This size should be about 24 mm. If it is more or less, then the parameter is adjusted by bending the float. Then the device is assembled again, start the engine and warm it up.

Idling setting

Many car owners, namely beginners, most oftenbuy old cars and don't know how to tune the carburetor correctly. The result is power loss, high fuel consumption, floating speed and other problems. After the level adjustment is successfully completed, adjust the idle. Before doing this, it is recommended to turn off the engine. To work, you need a flat-blade screwdriver and time. There is a hole on the sole of the mechanism. It contains a screw that is responsible for the quality of the mixture. It is screwed in all the way. However, do not be too zealous.

how to set up a carburetor

Then, from the most extreme position, the screw is unscrewed five turns. Next, the engine is started without suction. The quality screw is unscrewed - the carburetor 21073 will regulate the engine speed. Then the element is screwed again. It is necessary to rotate until the operation of the power unit becomes as stable as possible. Turn the screw slowly. When the operation of the motor becomes calmer, it is unscrewed by no more than one revolution. As a result, the idle speed will be about 900. But if the engine stalls, they are slightly increased.


These are the most important rules on how to set up the Solex carburetor (it goes to the Niva or the Seven, it doesn’t matter). The setting allows you to improve the operation of the motor, stabilize idle speed. This carburetor is good because it can be adjusted with a minimum set of tools in any conditions. But as time goes on, there are fewer and fewer cars with this type of power system.

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