Carburetor appearance:
1 - throttle valve zone heating unit;
2 - engine crankcase ventilation fitting;
3 - cover of the accelerating pump;
4 - electromagnetic shut-off valve;
5 - carburetor cover;
6 - air filter mounting stud;
7 - air damper control lever;
8 - starter cover;
9 - sector of the throttle valve drive lever;
10 - block of wire of the EPHH sensor-screw;
11 - adjusting screw for the amount of the idle mixture;
12 - economizer cover;
13 - carburetor body;
14 - fuel supply union;
15 - fuel outlet fitting;
16 - adjusting screw for the quality of the idle mixture (arrow);
17 - connection for supplying vacuum to the vacuum ignition regulator

For the engine to work, it is necessary to prepare a combustible mixture of air and fuel vapor, which must be homogeneous, that is, well mixed and have a specific composition to ensure the most efficient combustion. The power supply system of a gasoline internal combustion engine with spark ignition is used to prepare a combustible mixture and supply it to the engine cylinders and remove the exhaust gases from the cylinders.
The process of preparing a combustible mixture is called carburetion... For a long time, a unit called a carburetor was used as the main device for preparing a mixture of gasoline and air and supplying it to the engine cylinders.

The principle of operation of the simplest carburetor:
1 - fuel line;
2 - needle valve;
3 - hole in the float chamber cover;
4 - sprayer;
5 - air damper;
6 - diffuser;
7 - throttle valve;
8 - mixing chamber;
9 - fuel jet;
10 - float;
11 - float chamber
In the simplest carburetor, the fuel is kept in a float chamber where the fuel level is kept constant. The float chamber is connected by a channel to the mixing chamber of the carburetor. The mixing chamber contains diffuser - local narrowing of the chamber. The diffuser makes it possible to increase the speed of the air passing through the mixing chamber. In the narrowest part of the diffuser, sprayconnected by a channel to the float chamber. At the bottom of the mixing chamber there is throttle, which turns when the driver presses the gas pedal.
When the engine is running, air flows through the carburetor mixer. In the diffuser, the air speed increases, and a vacuum is formed in front of the atomizer, which leads to the flow of fuel into the mixing chamber, where it mixes with air. Thus, the carburetor, working on the principle of the atomizer, creates fuel-air combustible mixture... Pressing the gas pedal, the driver turns the carburetor throttle, changes the amount of mixture entering the engine cylinders, and consequently, its power and speed.
Due to the fact that gasoline and air have different densities, when you turn the throttle valve, not only the amount of the combustible mixture supplied to the combustion chambers changes, but also the ratio between the amount of fuel and air in it. For complete combustion of the fuel, the mixture must be stoichiometric.
When starting a cold engine, it is necessary to enrich the mixture, since the condensation of fuel on the cold surfaces of the combustion chamber impairs the starting properties of the engine. Some enrichment of the combustible mixture is required when idling, if it is necessary to obtain maximum power, sharp acceleration of the car.
According to the principle of its operation, the simplest carburetor constantly enriches the fuel-air mixture as the throttle valve opens, so it cannot be used for real car engines. For automobile engines, carburetors are used that have several special systems and devices: a starting system (air damper), an idle system, an economizer or econostat, an accelerator pump, etc.
As the requirements for fuel economy and exhaust gas toxicity increased, carburetors became much more complex, and even electronic devices appeared in the latest versions of carburetors.

The main the purpose of the vehicle fuel system are the supply of fuel from the tank, filtration, the formation of a combustible mixture and its supply to the cylinders. There are several types of fuel systems for. The most common in the 20th century was carburetor system fuel mixture supply. The next step was the development of fuel injection using a single nozzle, the so-called mono injection. The use of this system has reduced fuel consumption. Currently, the third fuel supply system is used - injection. In this system, pressurized fuel is supplied directly to the intake manifold. The number of injectors is equal to the number of cylinders.

injection andcarburetor option

Fuel system device

All engine power systems are similardiffer only in the methods of mixture formation. The fuel system includes the following elements:

1. The fuel tank is designed for storing fuel and is a compact container with a fuel intake device (pump) and, in some cases, coarse filtration elements.
2. Fuel lines are a set of fuel pipes, hoses and are designed to transport fuel to the mixing device.
3. Mixing devices ( carburetor, mono injection, injector) Is a mechanism in which fuel and air (emulsion) are combined for further supply to the cylinders at (intake stroke).
4. The control unit for the operation of the mixture formation device (injection power systems) is a complex electronic device for controlling the operation of fuel injectors, cut-off valves, control sensors.
5. A fuel pump, usually a submersible pump, is designed to pump fuel into the fuel line. It is an electric motor connected to a liquid pump in a sealed case. Lubricated directly with fuel and long-term operation with a minimum amount of fuel, leads to engine failure... In some engines, the fuel pump was attached directly to the engine and was driven by rotating the intermediate shaft, or camshaft.
6. Additional coarse and fine filters... Installed filter elements in the fuel supply chain.

How the fuel system works

Let's consider the operation of the entire system as a whole. The fuel from the tank is sucked in by the pump and is fed through the fuel line through the cleaning filters to the mixture formation device. In the carburetor, the fuel enters the float chamber, where it is then fed through the calibrated jets to the mixture formation chamber. Having mixed with air, the mixture enters the intake manifold through the throttle valve. After opening the intake valve, it is fed into the cylinder. IN mono injection system fuel is supplied to the injector, which is controlled by the electronic unit. At the right time, the nozzle opens and the fuel enters the mixture formation chamber, where, as in the carburetor system, it mixes with air. Further, the process is the same as in the carburetor.

IN injection system fuel is supplied to the injectors, which are opened by control signals from the control unit. The injectors are interconnected by a fuel line, which always contains fuel. All fuel systems have a fuel return line, through which excess fuel is drained into the tank.

The power supply system of a diesel engine is similar to a gasoline one. True, fuel is injected directly into the combustion chamber of the cylinder, under high pressure. Mixing takes place in the cylinder. A high pressure pump (high pressure fuel pump) is used to supply fuel under high pressure.

Fuel injection

The era of the carburetor is replaced by the era of the injection engine, the power supply system of which is based on fuel injection. Its main elements are: an electric fuel pump (usually located in the fuel tank), injectors (or a nozzle), an internal combustion engine control unit (so-called "brains").

The principle of operation of the specified power system is reduced to atomization of fuel through nozzles under pressure created by the fuel pump. The quality of the mixture varies depending on the engine operating mode and is monitored by the control unit.
An important component of such a system is the nozzle. The typology of injection engines is based precisely on the number of injectors used and their location.


So, experts tend to highlight the following injector options:

1. with distributed injection;
2. with central injection.

The distributed injection system assumes the use of injectors according to the number of engine cylinders, where each cylinder is serviced by its own injector, which is involved in the preparation of the combustible mixture. The central injection system has only one injector for all cylinders, located in the manifold.

Diesel engine features

The principle of operation, on which the power supply system of a diesel engine is based, stands as it were. Here the fuel is injected directly into the cylinders in atomized form, where the process of mixture formation (mixing with air) takes place, followed by ignition from the compression of the combustible mixture by the piston.
Depending on the fuel injection method, the diesel power unit is presented in three main options:

• direct injection;
• with vortex chamber injection;
• with pre-chamber injection.

The vortex chamber and pre-chamber versions involve the injection of fuel into a special preliminary chamber of the cylinder, where it is partially ignited, and then moves into the main chamber or the cylinder itself. Here the fuel, mixing with air, finally burns out. Direct injection presupposes the delivery of fuel immediately to the combustion chamber, followed by its mixing with air, etc.


Another feature that distinguishes the power supply system of a diesel engine is the principle of ignition of a combustible mixture. This does not come from the spark plug (like in a gasoline engine), but from the pressure created by the cylinder piston, that is, by self-ignition. In other words, there is no need to use spark plugs in this case.

However, a cold engine will not be able to provide the proper temperature level required to ignite the mixture. And the use of glow plugs will allow the necessary heating of the combustion chambers.

Operating modes of the power supply system

Depending on the goals and road conditions, the driver can apply different driving modes. They also correspond to certain operating modes of the power system, each of which has a fuel-air mixture of a special quality.

1. The mixture will be rich when starting a cold engine. At the same time, air consumption is minimal. In this mode, the possibility of movement is categorically excluded. Otherwise, this will lead to increased fuel consumption and wear of parts of the power unit.
2. The composition of the mixture will be enriched when using the "idle" mode, which is used when "coasting" or running the engine in a warm state.
3. The mixture will be lean when driving at partial loads (for example, on a flat road at medium speed in high gear).
4. The mixture will be enriched at full load while driving at high speed.
5. The composition of the mixture will be rich, close to rich, when driving under conditions of sharp acceleration (for example, when overtaking).

The choice of operating conditions for the power supply system, therefore, must be justified by the need for movement in a certain mode.

Malfunctions and service

During the operation of the vehicle, the fuel system of the vehicle is under stress, leading to its unstable operation or failure. The following faults are considered the most common.

Insufficient flow (or lack of flow) of fuel into the engine cylinders

Low-quality fuel, long service life, environmental impacts lead to contamination and clogging of fuel lines, tank, filters (air and fuel) and technological openings of the combustible mixture preparation device, as well as damage to the fuel pump. The system will require repair, which will consist in the timely replacement of the filter elements, periodic (every two to three years) cleaning the fuel tank, carburetor or injector nozzles and replacing or repairing the pump.

ICE power loss

A malfunction of the fuel system in this case is determined by a violation of the regulation of the quality and amount of the combustible mixture entering the cylinders. Elimination of the malfunction is associated with the need to diagnose the device for preparing a combustible mixture.

Fuel leak

Fuel leakage is a very dangerous and categorically unacceptable phenomenon. This malfunction is included in the "List of malfunctions ...", with which the movement of the car is prohibited. The causes of the problems lie in the loss of tightness by the components and assemblies of the fuel system. Elimination of the malfunction consists either in replacing damaged system elements, or in tightening the fasteners of the fuel lines.

Thus, the power supply system is an important element of the internal combustion engine of a modern car and is responsible for the timely and uninterrupted supply of fuel to the power unit.

In order for any engine to work like a clock, all its parts must be in perfect condition. Moreover, the systems that ensure its functioning cannot fail. Failure of at least one of them will lead to unstable operation of the device. In the worst case scenario, this can lead to an accident.

One of the most important ICE maintenance systems is the power supply system. It supplies fuel to the interior, where it is ignited and converted into mechanical energy.

There are many ICEs. During the development of the automotive industry, scientists have invented many designs, each of which represented the next round in the development of the industry. Very few of them went into mass production. Nevertheless, over almost a hundred years of continuous evolution, the following basic designs have been identified:

• diesel,
• injection,
• carburetor.

Each of them has its own advantages and disadvantages, moreover, the internal combustion engine power system is different in each design.

Diesel

Diesel internal combustion engine power system

When fuel enters the combustion chamber, the fuel supply system for the diesel internal combustion engine creates the necessary pressure. Also her range of tasks includes:

• fuel dosage;
• injecting the required amount of fuel fluid for a certain time period;
• spraying and distribution;
• filtration of fuel fluid before entering the pump.

To better understand the structure of the diesel engine power system, you need to know what diesel fuel itself is. Its structure is a mixture of kerosene and diesel fuel after special processing. These substances are formed when gasoline is released from oil. In fact, these are leftovers from the main production, which automakers have learned to use effectively.

Diesel fuel circulating in the internal combustion engine system has the following parameters:

• octane number,
• viscosity,
• pour point,
• purity.

Diesel fuel in the internal combustion engine system is divided into three grades, depending on the parameters described above:

• summer,
• winter,
• arctic.

In fact, the classification can occur according to several criteria and be much deeper. Nevertheless, if we take into account the generally accepted standard, then it will be exactly that.

Now let's take a closer look at the structure of the internal combustion engine system, it consists of the following elements:

• fuel tank,
• pump,
• high pressure pump,
• nozzles,
• pipeline with low and high pressure,
• exhaust gas pipeline,
• air filter,
• muffler.

All these elements make up a common power supply system that ensures stable engine operation. If we take into account the design, then it is divided into two subsystems: the one that provides air supply, and the other that implements the fuel supply.

The fuel circulates through two lines.One has low pressure. It stores and filters the fuel fluid, and then goes to the high pressure pump.

Fuel enters the combustion chamber directly through a high-pressure line. It is through it that at a certain moment the fuel substance is injected into the chamber.

Important! The pump has two filters. One provides coarse cleaning and the other fine.

The injection pump supplies power to the injectors. Its operating mode directly depends on the operating mode of the engine cylinders. The fuel pump always has an even number of sections. Moreover, their number directly depends on the number of cylinders. More precisely, one parameter corresponds to another.

The injectors are installed in the cylinder heads. It is they who supply the combustion chamber by spraying the fuel substance inside. But there is one small caveat. The fact is that the pump delivers much more fuel than is needed. Simply put, the amount of food is too large. In addition, air gets inside, which can interfere with all work.

Attention! To avoid malfunctions, there is a drainage pipeline. It is he who is responsible for ensuring that the air is discharged back into the fuel tank.

The nozzles in the structure responsible for supplying the internal combustion engine can be closed and open. In the first case, the holes are closed due to the shut-off needle. To make this possible, the internal cavity of the parts is connected to the combustion chamber. That's just happening this is when injecting liquid.

The main element in the nozzle design is the atomizer. It can have one or several nozzle holes. Thanks to them, the internal combustion engine power structure creates a kind of torch.

To increase power, a turbine is added to the internal combustion engine power system. It allows the car to gain momentum much faster. By the way, earlier such devices were installed only on racing and trucks. But modern technologies made it possible not only to make the product several times cheaper, but also significantly reduced the dimensions of the structure.

The turbine is capable of supplying air through the internal combustion engine power system inside the cylinders. The turbocharger is responsible for charging. He uses waste gases for his work. Air enters the combustion chamber under a pressure of 0.14 to 0.21 MPa.

The role of the turbocharger is to fill the cylinders with the volume of air required for operation. If we talk about power characteristics, then this element in the internal combustion engine power system allows achieving an increase of up to 25-30 percent.

Important! The turbine increases the load on the parts.

Possible malfunctions

Despite a number of visible advantages of the internal combustion engine power system, it still has a number of significant disadvantages that can result in a number of malfunctions, the most common ones being:

1. The engine does not want to start. Typically, such a malfunction indicates a problem with the fuel priming pump. But other options are also possible, for example, improper condition of injectors, ignition system, plunger pairs or discharge valve.
2. Uneven engine operation indicates a problem with individual injectors. A leak in the valve can lead to the same results. Also, during the operation of the car, there may be a weakening of the plunger fastening.
3. The engine does not provide the power declared by the manufacturer. Most often, this defect is associated with the fuel priming pump. Nozzles and nozzle breakage can lead to the same result.
4. Knocking when the engine is running, smoke from under the hood... This happens when the fuel is fed into the system too early, or it does not have a cetane number that does not correspond to the standards declared by manufacturers.
5. Soft claps. The reason for such a malfunction in the internal combustion engine power system lies in the air leak.
6. Clutch knock. This happens if the parts of the device are too worn out and there is a strong shrinkage of the springs.

As you can see, there can be more than enough malfunctions in the internal combustion engine system. That is why, in order to determine exactly what is the matter, it is necessary to conduct a comprehensive diagnosis. Moreover, some manipulations require special equipment.

Almost all of the faults described above can be corrected. A complete replacement of the internal combustion engine power system is needed only in extreme cases. Moreover, even a simple adjustment can completely restore the functionality of the automotive unit.

Methods for the restoration of a diesel engine

To restore the operation of the device, it is necessary to clean the blow-out windows from carbon deposits, if present there. Check if there is enough lubricant inside the coupling. If the amount of lubricant is minimal, add it to an acceptable amount

Most often, the engine knocks and smokes in those cases when the fuel you fill in has a low cetane number. Fortunately, the recipe for getting out of this situation is pretty simple. It is enough to change the fuel fluid to one in which this indicator will be more than 40.

Injection engine

Injection engine power supply system

Injection power systems began to be used at the beginning of the 80s of the last century. They replaced carburetor designs. In a device working with an injector, each cylinder has its own injector.

The injectors are attached to the fuel rail. Inside this structure, the fuel fluid is under pressure, which is provided by the pump. The longer the period of time the injector is open, the more fuel is injected inside.

The period that the injectors are in the open position is controlled by the electronic controller. This is a kind of control unit with a clearly built control algorithm. It matches the opening moment with the sensor readings. The electronic filling does not stop for a second. This ensures a stable fuel supply.

Important! A special sensor is responsible for the air flow. It is on the basis of the cycles that the cylinder filling is calculated.

A separate sensor detects the throttle load. More precisely, he makes calculations. After that, it sends the data to the controller, where verification takes place and adjustments are made if necessary.

If we talk about the fuel injection system of the internal combustion engine, then it almost completely works due to the indicators of many sensors. The most important sensors are those responsible for the following parameters:

• temperature,
• crankshaft position,
• oxygen concentration,
• control of detonation during ignition.

Moreover, these are only basic sensors. In fact, there are much more of them in the internal combustion engine power system.

Malfunctions

As mentioned above, the internal combustion engine power system is almost entirely based on the operation of sensors. The greatest harm can be caused by a breakdown of the sensor responsible for the crankshaft. If this happens, then you will not even reach the garage. The same will happen if the fuel pump fails.

Important! If you are going on a long trip, take a spare gas pump with you. This is the second heart of your car.

If we talk about the safest malfunctions of the internal combustion engine power system, then this is, of course, a breakdown of the phase sensor. This defect will cause the least damage to the car. In addition, repairs will take a minimum of time.

Important! The phase sensor malfunction is indicated by the unstable operation of the injectors. This is usually evidenced by a sharp jump in gasoline consumption.

Carburetor engines

Supply system

The first carbureted engine was created in the last century by Gottlieb Daimler. The power supply system of a carburetor engine is not particularly complex and consists of such elements as:

• fuel tank,
• pump,
• fuel line,
• filters,
• carburetor.

The capacity of the tank is usually about 40-80 liters in cars with carburetor ICE power systems. This device is in most cases mounted at the rear of the machine for greater safety.

From the fuel tank, gasoline flows into the carburetor. A fuel line connects these two devices. It runs under the bottom of the vehicle. During transportation, the fuel passes through several filters. The pump is responsible for the flow.

Malfunctions

The design is the oldest of the three. Despite this, its simplicity helps to significantly reduce the risk of any breakdown. Unfortunately, not a single internal combustion engine power supply system, including a carburetor one, is immune from malfunctions; the following defects can occur with it:

• leaning the fuel mixture,
• fuel cut-off,
• gasoline leak.

Leaks are easily seen with the naked eye. Stopping the fuel supply will prevent the car from moving. If the carburetor sneezes, then the fuel mixture is lean.

Outcome

Over the years of development of the automotive industry, many ICE power systems have been created. The first was the carburetor. She is the most simple and unpretentious. Its successors are diesel and injection.

The main elements, which are nozzles.

The power supply system of the carburetor engine includes: fuel tank, sump filter, fuel lines, fuel pump, fine fuel filter, air cleaner, intake pipe, exhaust pipe, intake pipes, muffler, fuel level control devices.

Work power system

When the engine is running the fuel pump sucks fuel from the fuel tank and feeds it through the filters into the carburetor float chamber. During the intake stroke, a vacuum is created in the engine cylinder and the air, passing through the air cleaner, enters the carburetor, where it mixes with fuel vapors and is fed into the cylinder in the form of a combustible mixture, and there, mixing with the remaining exhaust gases, a working mixture is formed. After completing the working stroke, the exhaust gases are pushed out by the piston into the exhaust pipe and through the intake pipes through the muffler into the environment.

Power supply and exhaust systems of the car engine:

1 - channel for supplying air to the air filter; 2 - air filter; 3 - carburetor; 4 - handle for manual control of the air damper; 5 - handle for manual control of the throttle valves; 6 - throttle valve control pedal; 7 - fuel wires; 8 - filter-settler; 9 - muffler; 10 - receiving pipes; 11 - outlet pipeline; 12 - fine fuel filter; 13 - fuel pump; 14 - fuel level indicator; 15 - fuel level indicator sensor; 16 - fuel tank; 17 - fuel tank filler cap; 18 - crane; 19 - exhaust pipe of the muffler.

Fuel. Gasoline, which is obtained from oil refining, is usually used as fuel in carburetor engines.

Automobile gasolines, depending on the amount of easily evaporating fractions, are divided into summer and winter.

For automobile carburetor engines, gasolines A-76, AI-92, AI-98, etc. are produced. The letter "A" denotes that gasoline is automobile, the number is the lowest octane number that characterizes the detonation resistance of gasoline. Isooctane has the highest detonation resistance (its resistance is taken as 100), the least is n-heptane (its resistance is 0). The octane number, which characterizes the detonation resistance of benzene, is the percentage of isooctane in such a mixture with n-heptane, which in terms of detonation resistance is equivalent to the test fuel. For example, the test fuel detonates in the same way as a mixture of 76% iso-octane and 24% n-heptane. The octane number of this fuel is 76. The octane number is determined by two methods: motor and research. When determining the octane number by the second method, the letter "I" is added in the marking of gasoline. The octane number determines the allowable compression ratio.

Fuel tank. One or more fuel tanks are installed on the car. The volume of the fuel tank should provide 400-600 km of the vehicle's run without refueling. The fuel tank consists of two welded halves, stamped from leaded steel. There are partitions inside the tank, which give rigidity to the structure and prevent the formation of waves in the fuel. A filler neck is welded in the upper part of the tank, which is closed with a stopper. Sometimes, for the convenience of filling the tank with fuel, a retractable neck with a mesh filter is used. The fuel level indicator sensor and fuel intake pipe with a mesh filter are mounted on the top wall of the tank. There is a threaded hole in the bottom of the tank for draining sediment and removing mechanical impurities, which is closed with a plug. The filler neck of the tank is closed tightly with a plug, in the body of which there are two valves - steam and air. The steam valve opens when the pressure in the tank rises and releases steam to the environment. The air valve opens when fuel is consumed and vacuum is generated.

Fuel filters. Coarse and fine filters are used to clean fuel from mechanical impurities. A coarse filter settler separates the fuel from water and large mechanical impurities. The filter-sump consists of a body, a sump and a filter element, which is assembled from plates with a thickness of 0.14 mm. The plates have holes and projections with a height of 0.05 mm. The plate pack is installed on a rod and is pressed against the body by a spring. When assembled, there are slots between the plates through which the fuel passes. Large mechanical impurities and water are collected at the bottom of the sump and are periodically removed through the plug hole in the bottom.

Fuel tank (a) and operation of outlet (b) and inlet (c) valves: 1 - filter-sump; 2 - tank mounting bracket; 3 - tank fastening clamp; 4 - fuel level indicator sensor in the tank; 5 - fuel tank; 6 - crane; 7 - tank plug; 8 - neck; 9 - cork lining; 10 - rubber gasket; P - plug body; 12 - outlet valve; 13 - exhaust valve spring; 14 - inlet valve; 15 - tank plug lever; 16 - inlet valve spring.

Sump filter: 1 - fuel line to the fuel pump; 2 - body gasket; 3 - case-cover; 4 - fuel wire from the fuel tank; 5 - gasket of the filter element; 6 - filter element; 7 - stand; 8 - sump; 9 - drain plug; 10 - rod of the filtering element; 11 - spring; 12 - filter element plate; 13 - hole in the plate for the passage of cleaned fuel; 14 - projections on the plate; 15 - hole in the plate for racks; 16 - plug; 17 - bolt for fastening the body-cover.

Fine fuel filters with filter elements: a - mesh; b - ceramic; 1 - body; 2 - inlet; 3 - gasket; 4 - filter element; 5 - removable sump bowl; 6 - spring; 7 — screw for fastening the glass; 8 — channel for fuel removal.

Fine filter. To clean fuel from small mechanical impurities, fine filters are used, which consist of a housing, a settling glass and a filtering mesh or ceramic element. The ceramic filter element is a porous material that provides labyrinthine fuel movement. The filter is held in place by a bracket and a screw.
Fuel wires connect the fuel system devices and are made of copper, brass and steel pipes.

Fuel pump system

The fuel pump is used to supply fuel through filters from the tank to the carburetor float chamber. The diaphragm type pumps are used, driven by the camshaft eccentric. The pump consists of a body in which the drive is mounted - a two-armed lever with a spring, a head, where inlet and discharge valves with springs are located, and a cover. The edges of the diaphragm are clamped between the body and the head. The diaphragm stem is pivotally attached to the actuator arm, which allows the diaphragm to operate with variable stroke.
When the two-armed lever (rocker arm) lowers the diaphragm down, a vacuum is created in the cavity above the diaphragm, due to which the intake valve opens and the above-diaphragm cavity is filled with fuel. When the lever (pusher) escapes from the eccentric, the diaphragm rises upward under the action of the return spring. Above the diaphragm, the fuel pressure rises, the intake valve closes, the discharge valve opens, and fuel flows through a fine filter into the carburetor float chamber. When changing filters, the float chamber is filled with fuel using a manual pumping device. In the event of a diaphragm failure (crack, breakthrough, etc.), fuel enters the lower part of the body and flows out through the control hole.

Air filter serves to clean the air entering the carburetor from dust. The dust contains tiny crystals of quartz, which, when deposited on the lubricated surfaces of parts, causes them to wear out.

Requirements for filters:

... efficiency of air cleaning from dust;
... low hydraulic resistance;
... sufficient dust holding capacity:
... reliability;
... ease of maintenance;
... manufacturability of the design.

According to the method of air purification, filters are divided into inertial oil and dry.
Inertial oil filter consists of a housing with an oil bath, a cover, an air intake and a filter element made of synthetic material.
When the engine is running, the air passing through the annular slot inside the housing and contacting the oil surface sharply changes the direction of movement. As a result, large airborne dust particles adhere to the oil surface. Then the air passes through the filter element, is cleaned of fine dust particles and enters the carburetor. Thus, the air is purified in two stages. If clogged, the filter is washed.
Dry type air filter consists of a housing, a cover, an air intake and a filtering element made of porous cardboard. Change the filter element if necessary.