The domestic SUV VAZ-2121, also known as the legendary Niva, has been tirelessly traveling around the expanses of our vast homeland and beyond its borders since 1977. Currently, this car not only has not lost its popularity, but on the contrary - the demand of car enthusiasts for this miracle of the automotive industry is only growing every year.
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Why did the Niva become such a popular car? It's simple. The car's high seating position, all-wheel drive, ease of maintenance and relatively cheap prices for spare parts - that's the whole secret. Fishing, hunting, travel, expeditions and even sports racing - all this is the nature of the Niva.
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Since 1994, serial production of the VAZ-21213 model under the name “Taiga” began.
This VAZ model is equipped with a 1.7-liter carburetor gasoline engine, a five-speed manual transmission, and a contactless ignition system. A Solex 21073 carburetor is installed on the Niva. In the modern world, when progress does not stand still, a carburetor under the hood of a car, and even an SUV, looks sad. When buying a used car, most motorists prefer to choose an injection version rather than a carburetor. And today's youth look at the carburetor in surprise, completely not understanding what it is. But if a person has at least a little understanding of technology, then understanding the essence of the Solex 21073 carburetor will not be a problem. It is enough to familiarize yourself with some information.
The design of the Solex 21073 carburetor on the Niva
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This mechanism is a device for mixing the fuel-air mixture. This mechanism is very simplified, unlike the injector. The carburetor consists of only two main parts, one of which is the body and the other is the cover. The carburetor also includes a float chamber, a pump, and an economizer, which is responsible for regulating the fuel supply in order to save it. Inside the housing there are two fuel chambers and diffusers in which a fuel-air mixture is formed. On the carburetor cover there are special fittings for supplying gasoline to the carburetor and studs for attaching the air filter. Also in the cover of the Solex 21073 carburetor there is a needle valve for the float chamber. With the help of these parts the level of fuel consumption is regulated.
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An air damper is installed inside the carburetor, which mechanically regulates the air supply to the chambers. As you can see, the Solex 21073 carburetor on the Niva has a fairly simple design. With proper care, it will not cause problems for the car owner and will not let him down on the road.
Idle system
In some situations, engine operation must be ensured even when the car is in neutral, when the speed is too low. At such a moment, the vacuum is insufficient and fuel will not be able to pass through the main metering chamber. A forced idle system is provided specifically for this purpose.
To do this, air is supplied through the main idle fuel jet into the first chamber. The fuel will then flow to the idle fuel jet. The air also passes through a special jet through a separate channel. This design allows the engine to operate even at low speeds, and when the throttle valve is opened, the power mode economizer begins working, which is considered as a transition system.
However, the system has a number of disadvantages when coasting:
- When the speed decreases by releasing the gas, fuel consumption continues;
- When switching to neutral gear, it increases completely.
Especially for this purpose, the calibration data also includes an EPHH, which turns off the fuel supply when coasting. Its operation continues until the speed drops to 1200 rpm and turns off when the throttle is opened. But when the car is stationary, it does not work.
Operating principle
As already mentioned, the Solex 21073 carburetor on the 1.7 liter Niva mixes gasoline with air and, as a result, the prepared fuel-air mixture enters the engine, where it burns. The driver starts the engine and closes the choke independently. The fuel pump pumps gasoline into the carburetor's float chamber. The amount of gasoline in this case depends on the position of the needle valve. From the float chamber, gasoline enters the nozzle, and then directly into the mixing chamber. At the same time, both cameras will start working only under heavy load on the engine. For example, if the driver sharply increases the speed by pressing the gas pedal. The engine idle mode is maintained by a solenoid valve. Thanks to this, the engine does not stall and fuel is saved at idle.
Setting the level in the float chamber
So, we looked at the Solex device. Adjusting the carburetor will help set the optimal mode when the engine will operate 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 remove the fuel hose and carburetor cover. Then disconnect the suction cable and twist the cover off the device.
It must be removed as smoothly and carefully as possible so as not to damage the float. Then use a ruler or caliper to measure the distance in each chamber. You need to measure from the mating surfaces to the edge of the gasoline. This size should be about 24 mm. If it is larger or smaller, then the parameter is adjusted by bending the float. Then the device is reassembled, the engine is started and it is warmed up.
Float mechanism
On Niva, the float chamber in the carburetor consists of two sections located on the sides of the chambers for preparing the fuel-air mixture. In general, the float mechanism consists of two floats made of hard rubber, mounted on a special lever, which looms on an axis pressed into the cover of the Solex 21073 carburetor. The essence of the float mechanism is to regulate the fuel supply.
Advantages and disadvantages of tuning
The Solex carburetor is assembled from standard parts and assemblies from various manufacturers and is not subject to individual adjustment. But the cast body, made of aluminum alloy, diffusers, damper jets, as well as fasteners have unprocessed burrs, protrusions, and roughness. The task of tuning is to remove all obstacles to the movement of the air-fuel mixture by grinding, polishing channels and parts with which the fuel flow comes into contact, as well as modifying diffusers and adjusting jets in accordance with the individual requirements of the car enthusiast.
To perform the above work, it is necessary to remove the carburetor from the engine intake manifold and remove the cover. It is necessary to achieve complete alignment of all holes of adjacent removable parts. This is done using a scraper or file.
You need to remove the air damper and replace its round head screws with flat head screws. Then drill out the holes a little to “recess” the protruding parts of the fasteners. This will reduce hydrodynamic resistance during the passage of the air-fuel mixture. It is advisable to replace the needle valve with a valve with a rubber tip to prevent gasoline overflow.
All carburetor diffusers need to be polished, the technological ebbs on the bridges must be cut down and given a more streamlined shape. The flow rate of the fuel mixture in the mixing chamber reaches 120 meters per second, and any roughness will impede the flow of air.
Tuning the carburetor not only affects the throttle response of the engine, increases its power, but also significantly increases fuel consumption. Before assembling the mechanism after modification, it is recommended to wash all its parts with a special liquid for cleaning the carburetor, and then blow out the holes with compressed air.
The Solex carburetor is one of the best engineering developments successfully used on Russian Niva SUVs. Carburetor engines are repairable, easy to maintain and reliable. Tuning can significantly improve engine performance and increase its efficiency.
Operating principle of the main dosing chamber
During the combustion of the fuel-air mixture in the engine cylinders, air enters the chambers through the air filter. As the air flow increases, pressure is exerted on the nozzles. As a result, fuel rises from the wells into the atomizer. At the same time, air is fed through an air jet from above into the emulsion tube. In the chamber, the fuel is mixed with air and goes into the carburetor channels, where it is directed further into the engine under high pressure. This is the operating principle of almost all Solex carburetors.
What brands and models of cars were installed on?
C were installed not only on VAZs. Other automakers also actively used them for their cars.
Table: modifications and applicability of Solex carburetors
| Modification | Applicability | Engine volume, cm3 | Notes |
| DAAZ-2108–1107010 | VAZ 2108, 2109 | 1,3 | |
| DAAZ-21081–1107010 | VAZ 21081, 21091, ZAZ 1102 | 1,1 | |
| DAAZ-21083–1107010 | VAZ 21083, 21093, 21099 | 1,5 | |
| DAAZ-21083–1107010–31 | VAZ 2108, 2109, 2110, 2111 | 1,5 | Has a semi-automatic starting device |
| DAAZ-21083–1107010–35 | VAZ 2108, 2109, 2110, 2111 | 1,5 | Has a two-level semi-automatic starting device (winter/summer) |
| DAAZ-21083–1107010–62 | VAZ 2109, 2115 | 1,5 | Has an electronic device for controlling the composition of the combustible mixture |
| DAAZ-21083–1107010–05 | VAZ 2109 | 1,5 | |
| DAAZ-21412–1107010, DAAZ-21412–1107010–30 | AZLK 2141, 2141–23 | 1,5/1,8 | |
| DAAZ-1111–1107010 | VAZ 1111, 11113 "Oka" | 0,65/0,75 | |
| DAAZ-21051–1107010 | VAZ 2103, 2105 | 1,5 | |
| DAAZ-21053–1107010 | VAZ 21074, 21061 | 1,6 | |
| DAAZ-21051–1107010–30 | VAZ 2104, 2105 | 1,3 | |
| DAAZ-21053–1107010–62 | VAZ 2107, 21072, 21074 | 1,3/1,5/1,6 | |
| DAAZ-21073–1107010 | VAZ 2121, 21213 "Niva" | 1,6/1,7 |
Diagnostics of malfunctions of the Solex 21073 carburetor on a Niva
Any mechanism is subject to physical wear and tear during its operation. Likewise, the Solex 21073 carburetor on the Niva requires periodic inspection and maintenance. If any malfunction is detected, it is first necessary to carry out diagnostics. The causes of carburetor malfunction can be different. This includes refueling with low-quality gasoline and a dirty air filter. As a result, small particles of dirt enter the carburetor chamber. This results in problems in the system in the form of increased fuel consumption and poor operation of the mechanism as a whole. There is no need to rush to replace the carburetor with a new one. Simple cleaning and adjustment will help eliminate these symptoms.
What is the difference between modifications 21081 and 21083
If you compare the two main modifications of Solex carburetors (21081 and 21083), used on front-wheel drive Sputniks and Samaras, then visually you will not find any differences between them. The difference exists only in the operating parameters of some of their elements.
Table: comparison of basic calibration data for Solex carburetors 21081 and 21083
| 21081 | 21083 | |||
| For 1st camera | For 2nd camera | For 1st camera | For 2nd camera | |
| Mixing chamber diameter, mm | 32 | 32 | ||
| Diffuser diameter, mm | 21 | 23 | 21 | 23 |
| Air jet of the main dosing system | 165 | 135 | 155 | 125 |
| Fuel jet of the main metering system | 95 | 97,5 | 95 | 97,5 |
| Idle air jet | 170 | 170 | ||
| Idle fuel jet | 39–44 | 39–44 | ||
| Air jet of the second chamber transition system | 120 | 120 | ||
| Fuel nozzle of the second chamber transition system | 50 | 50 | ||
| Economizer fuel jet | 40 | 40 | ||
| Accelerator pump cam number (size) | 4 | 7 | ||
| Throttle valve starting gap, mm | 1,0 | 1,1 | ||
| Air damper starting gap, mm | 2,7±0,2 | 2,5±0,2 | ||
| Needle valve hole diameter, mm | 1,8 | 1,8 | ||
| Vacuum regulator hole diameter, mm | 1,2 | 1,2 |
How to restore carburetor operation?
To clean or adjust the Solex 21073 carburetor on the Niva, it must be removed. We remove the air filter housing and remove all the tubes and wires that interfere with getting the mechanism to the surface. Unscrew the nuts and remove the carburetor.
It is best to disassemble it on a table in a well-lit and ventilated area. There are many small parts in the carburetor, therefore, in order not to get confused about what and where, it is recommended to put all the parts in order. You may have to purchase a Solex 21073 carburetor repair kit for the Niva at an auto parts store. It will help you quickly fix the breakdown, and besides, it is inexpensive. Wash the carburetor with special means or regular gasoline.
Adjusting the Solex 21073 carburetor on a Niva
Adjust the carburetor on site after washing and installing it. At the bottom of the Solex 21073 carburetor there is a screw that controls the fuel supply level. Using a flat-head screwdriver, turn this screw until it stops with the engine off. Then unscrew the screw five turns back and start the engine. Next, the screw must be tightened and unscrewed until engine operation becomes uniform. After the engine speed is normalized within 900, the screw is set one turn all the way.
Washing machine inlet valve
The filling valve of the washing machine allows you to draw in water, preparing the equipment for washing. The valve can be in 2 functional positions: open and closed. More often it is closed. When current is applied to the valve coil, an electromagnetic field is generated, creating optimal conditions for its opening. When the rod is tightened, the membrane opens. Having gained access to the dispenser hopper, the incoming water washes away the washing powder, which will later be poured into the washing machine tank.
As soon as the required amount of water is collected, the supply of electricity to the coil stops, and along with it the water supply stops.
