Adjustment of carburetors K151 and K126. Recommendations for the repair of the K151 carburetor Installation of the carburetor Pekar k 151 t

K-151V carburetors are used to complete UMZ-4178 engines, and K-151U to complete ZMZ-4021.60 engines. The K-126GU carburetor is used to complete the UMZ-417 engines, as an option instead of the K-151V carburetor.

In principle, the K-126GU carburetor is similar to the K-151V carburetor, but has a simpler design in which there is no forced idle economizer system and a float chamber ventilation valve.

K-151V, K-151U and K-126GU carburetors for UMZ-417 and ZMZ-4021.60 engines, device.

Carburettors are vertical, emulsion, two-chamber, with a falling mixture flow and sequential opening of throttle valves. All carburetors include:

- balanced float chamber,
- two main dosing systems - the first and second chambers,
- an autonomous idling system in the primary chamber with a quantitative adjustment of a mixture of constant composition with a forced idling economizer (EPKhK),
— transitional systems of primary and secondary chambers,
- econostat with output to the secondary chamber,
— a diaphragm accelerator pump mechanically driven by the throttle valve roller of the primary chamber and with the atomizer output to the primary chamber,
- semi-automatic system for starting and warming up the engine with manual control,
- in addition, the K-151V and K-151U carburetors are equipped with a float chamber ventilation valve.

Maintenance of carburetors K-151V and K-151U.

It consists in periodically checking the reliability of fastening the carburetor and its individual elements, checking and adjusting the fuel level in the float chamber, adjusting the low speed of the engine crankshaft, cleaning, purging and flushing carburetor parts from resinous deposits, checking the throughput of jets.

Checking the fuel level in the carburetor float chamber.

It is carried out with the engine of the car installed on a horizontal platform and with the carburetor cover removed. The float chamber is filled with fuel using the manual priming lever.

The fuel level should be within 20-23 mm from the plane of the float chamber connector. To check it, it is necessary to screw in a fitting with an M10x1 thread to connect a rubber hose. The fitting is screwed into the float chamber instead of the drain plug. The fuel level is determined through a transparent tube with an inner diameter of at least 9 mm.

The level is adjusted by bending the tongue of the float loop to a size of 10.75 -11.25 mm between the upper part of the float and the plane of the float chamber connector, the float must be raised to its highest position. In the lowest position, the float should not touch the walls of the float chamber, and its tongue should be on stop A. In this case, the stroke of the fuel valve should be equal to 1.5 + 0.5 mm. The stroke of the valve is adjusted by bending the tongue of the float loop.

After adjustment, check the fuel level again and, if necessary, adjust again. If the adjustment does not give the desired result, it is necessary to check the float mechanism. Usually, the causes of an increased or decreased fuel level in the float chamber are the imbalance of the float, its incorrect mass, as well as the fuel valve sticking or leaking.

The tightness of the float is checked by immersing it in water heated to 80-85 degrees with a time delay of at least 30 seconds. The mass of the float assembly with the loop after repair should not exceed 13 grams. If the fuel valve is leaking, the sealing washer must be replaced. After replacing the sealing washer, when assembling the fuel valve with the earring, it must be taken into account that the earring must be installed in such a way that the protrusion of the earring B is directed in the direction opposite to the float.

Adjustment of the minimum speed of the crankshaft in idle mode.

It is carried out on a warm engine at a coolant temperature of at least 70 degrees and in good condition. During vehicle operation, the minimum idle speed is adjusted by turning the service adjustment screw. When the screw is unscrewed, the speed increases, when screwing it decreases.

If it is not possible to achieve stable operation of the engine by turning the operational adjustment screw, unscrew the mixture composition screw to the stop of the restrictive sleeve pressed onto the screw and re-adjust the minimum frequency with the operational adjustment screw.

Full carburetor adjustment.

In full, carburetors K-151V and K-151U are adjusted at a service station using gas analysis equipment and must be carried out under the following conditions: on a warm engine, with adjusted gaps in the mechanism, with serviceable ignition and adjusted ignition timing, with a fully open air damper .

Adjustment sequence:

1. Adjust the operating adjustment screw to the minimum idle speed of 550-650 rpm.
2. Adjust the mixture composition screw with the content of carbon monoxide (CO) within 1.0 -1.5%, having previously removed the restrictive sleeve, the content of hydrocarbons (CH) should not exceed 1000 ppm.
3. Make sure that the selected position of the screws ensures normal operation of the engine during regassing, for which open the throttle and release it sharply, if the engine stops or runs, then you must either increase the minimum speed by unscrewing the operational adjustment screw, or enrich the mixture
screw composition of the mixture, the maximum allowable CO content in this case should be no more than 2%.
4. Increase the rotational speed to 2400 rpm, the content of CO should be no more than 1%, CH - no more than 500 ppm.

After the final adjustment, install a restrictive sleeve on the mixture adjustment screw and mark its position. Warm up the engine to a coolant temperature of 80-85 degrees and check the CO content in the exhaust gases at an idle speed of 550-650 rpm.

Washing carburetor parts.

Carburetors are washed with gasoline followed by compressed air. Do not use metal wire to clean jets and calibrated holes, as this will lead to a violation of their size and throughput.

In order not to confuse the jets during installation, you should pay attention to their marking. Each jet is labeled with the nominal flow rate in ml/min. The marking is applied by impact on the head of the jet from the side of the slot.

The nominal value of the throughput of jets for the K-151V carburetor, ml / min.

- Main fuel jet: 1st chamber - 225, 2nd chamber - 330
- Main air jet: 1st chamber - 330, 2nd chamber - 230


- Idling emulsion jet: 1st chamber - 280

The nominal value of the throughput of jets for the K-151U carburetor, ml / min.

- Main fuel jet: 1st chamber - 225, 2nd chamber - 380
- Main air jet: 1st chamber - 330, 2nd chamber - 330
- Block of idle jets:
idle tube: 1st chamber - 95
emulsion tube: 1st chamber - 85
- Air idle jet: 1st chamber - 330
- Idling emulsion jet: 1st chamber - 210
- Jet fuel transition system: 2nd chamber - 150
- Jet air transition system: 2nd chamber - 270

When checking the operation of the K-151V and K-151U carburetors, attention should be paid to the operation of the float chamber ventilation valve, the reliability of the wire connection, the absence of jamming and the tightness of the valve. Valve malfunction leads to increased fuel consumption and difficulty starting a hot engine.

Maintenance of the K-126GU carburetor for the UMZ-417 engine.

Maintenance of the K-126GU carburetor is similar to maintenance. The minimum idle speed is adjusted in the following sequence:

- turn the screw that changes the composition of the mixture to failure, but not tight, and then unscrew it 1.5 turns,
- start the engine and set the throttle stop screw to a stable crankshaft speed of 550-650 rpm,
- the limit value of carbon monoxide is regulated by the screw of the limiter of toxicity.

The nominal value of the throughput of jets for the K-126GU carburetor, ml / min.

- Main fuel jet: 1st chamber - 240 + -3.0, 2nd chamber - 350 + -4.5
— Main air jet: 1st chamber — 280+-3.5, 2nd chamber — 280+-3.5
- Idling fuel jet: 1st chamber - 50 + -1.0, 2nd chamber - 95 + -1.5
- Idle air jet: 1st chamber - 285 + -4.0, 2nd chamber - 285 + -4.0

When experienced motorists casually drop the phrase “before the equipment was exceptionally reliable,” they are right in a certain sense. Indeed, is it worth comparing the level of complexity of a modern car and its analogue of 50-60 years ago? And if the product is simple, then by definition it is more reliable. Owners of the latest generations of machines will certainly agree with this: if major breakdowns at the initial stage of operation are very rare, then minor faults only need to be dealt with in time.

In this aspect, the products of the Leningrad Carburetor Plant can be considered legendary, and the K-151 carburetor, better known under the pseudonym Pekar, is rightfully recognized as its flagship. There are legends about its reliability, it is no coincidence that it is used on cars with ZMZ and UZAM power units, in particular, on the famous domestic UAZ SUV. But, as you know, this device demonstrates the greatest efficiency with the right settings. Today we will show you how to achieve this.

Functions and device of the carburetor

In modern engines, an electronic system operating in pairs is responsible for the preparation of fuel assemblies. The predecessor of this scheme is the carburetor, which is able to prepare a high-quality combustible mixture without any involvement of electronic brains. And since the proportions of the mixture change depending on the mode of operation of the engine, the carburetor must be able to prepare the optimal composition for any load, from idle to maximum crankshaft rotation. And, I must say, he copes well with this task. Even today, K-151 can be found on such domestic cars as the Gazelle with all its modifications, IZH, Volga, and, of course, UAZ.

Although there are many models in the assortment of the Pekar brand, the “one hundred and fifty-first” is given a place of honor, and there are many modifications of this carburetor that differ in the name by a letter after the numerical designation of the model. In particular, GAZ-3302 (or simply Gazelle) cars, as well as GAZ-3102 (Volga) are equipped with a K-151C modification carburetor. The differences between the modifications are jets of different diameters, designed to prepare fuel assemblies for specific power units.

The composition of the carburetor Pekar-151:

• housing with a float chamber;
• the secondary upper housing, in which the throttle valves are installed, which are controlled by a drive cable connected to the accelerator pedal;
• PC cover, which serves as a platform for installing a locking mechanism that prevents the chamber from overflowing with fuel. There is also an air damper used when starting and warming up a cold engine;
• dosing system, which is responsible for the formation of the air-fuel mixture and includes channels of a certain diameter, two air and the same number of fuel jets;
• idle subsystem used when the power unit is operating in idle mode. Includes a bypass channel, one fuel and one air jet each, screws for adjusting the quantity / quality of the combustible mixture, a membrane-type economizer valve;
• an accelerator pump responsible for the uniform dynamics of the engine, without failures with a sharp increase in speed. Includes additional channels passing in the housing with a float chamber, a membrane device, a ball valve and a gasoline sprayer;
• econostat - a part that enriches the mixture when the engine is running on. It includes a system of additional channels designed to supply an unscheduled portion of fuel to the intake manifold at wide open throttle valves;
• a transitional system that is activated at the initial stage of opening the remote sensing located in the secondary chamber and serves for a smooth increase in speed. Includes a pair of jets of both types.

Thus, K-151 belongs to the category of two-chamber carburetors, in which DZs are opened sequentially. A mesh filter is integrated into the inlet fitting. It also has a fuel line designed to drain excess gasoline back into the tank and to protect against excess pressure in the chamber. As you can see, this device cannot be called simple, so considerable experience is required to perform its settings.

Hose connection

The complex device K-151 also appears when it is connected to the engine. It provides for the use of a number of hoses, while only two different sizes are used, so it is quite possible to confuse them, while the motor will malfunction in certain modes. The procedure for connecting hoses to the carburetor:

• fuel is supplied through the fuel pipe to the fitting located under the float chamber on the motor side;
• the return hose is put on the lower fitting - it looks away from the power unit and is located below the inlet;
• two small-section hoses are connected to the solenoid valve, the other end of one of them is connected to the economizer valve;
• the second end of a thin hose is put on a fitting located in the lower part of the K-151 on the back of the DZ body (there are two of them standing side by side, we use the lower one);
• on the upper fitting of this pair we pull the hose going to the vacuum ignition advance (it is located on the distributor);
• a large-diameter fitting on the DZ body is used to connect the forced crankcase ventilation pipe, a device usually located on the valve cover;
• a small diameter fitting located in the middle part of the K-151 is used to connect a thermal vacuum switch, however, this branch pipe is used only if the engine has an exhaust gas recirculation system. If such a system is not provided for a specific modification of the motor, a plug is simply installed on this fitting. True, such a precaution is unnecessary - there is no air leakage through this fitting.

In the absence of experience, these connections should be made by referring to the instructions for the device.

XX adjustment on Pekar

On the St. Petersburg carburetor K-151 is of fundamental importance. This is a special mode of engine operation that requires stable operation. This is exactly what is achieved by the correct setting of the XX, which also helps to minimize the amount of carbon dioxide in the car's exhaust, which is important from the point of view of modern environmental requirements.

Over time, as a result of clogging of the filter mesh, the amount of fuel burned in the XX mode increases in excess of the norm, and in this case, the situation can be corrected by appropriate adjustment.

This operation is not particularly difficult:

• first you need to warm up the SA to operating temperature;
• then it is necessary to find the fuel assembly quality screw, located on the rotation shank, and remove the limiter from it. Note that the rotation restriction function is not present on all Pekar modifications. If your car does not have it, just proceed to the next step;
• we adjust the quality screw, for which we are looking for the position of the screw at which the power unit will produce the maximum number of revolutions when operating at idle. This moment should be determined by ear (more accurate methods require the use of special equipment);
• now we move on to the number screw located next to it, by adjusting which it is necessary to increase the speed of rotation of the crankshaft by 100-120 rpm. After that, you need to completely tighten the quality screw, which will lead to a drop in speed by the same amount (within 100-120 rpm).

If during the reverse tightening of the quality screw there was no speed reduction as a result of a slight depletion of the mixture, then this indicates the presence of carburetor malfunctions.

Adjustment of the PU carburetor K-151

The starting device is a node that is the source of a signal informing about the start of the power unit. If the elements of the starting system are faulty, or do not work correctly, you will not be able to start the car. But even with a working starting mechanism, problems are possible that make it difficult to start. To correct them, the K-151 carburetor is being tuned, and such work can be carried out both on a dismantled device and on a working device and installed on the engine.

Adjustment on the dismantled Pekar is carried out in the following order:

• slightly open the DZ and look for the control lever of the PU;
• we turn it to the extreme position and fix it with something suitable (rope, wire);
• we release the DZ to its original position. In this case, the gap between the chamber wall and the damper edge should be within 1.5 ± 0.3 mm;
• we unscrew the lock nut that blocks the rotation of the stop screw located on the DZ lever;
• we turn the screw itself in stages, each time by half a turn. At the same time, we must ensure that when the locknut is tightened, the screw is perpendicular to the cam, otherwise the PU will not work;
• we check the thrust valley, with the help of which the PU cam is connected to the air damper levers. With the PU lever turned to its extreme position and the air intake completely closed, it is necessary to achieve a gap between the levers in the range of 0.2-0.8 millimeters. If this is not the case, the adjustment is made by releasing or tightening the rod head, which allows you to shorten or lengthen the rod itself.

You can adjust the PU of the K-151 carburetor without removing it, while this will not affect the quality of the setting.

Setting algorithm:

• dismantle the car air filter (of course, without removing the box);
• we start the engine at XX;
• by pressing the accelerator pedal, we open the remote control and pull out the lever - the mechanism responsible for controlling the operation of the air damper;
• using a screwdriver with a flat tip, slightly open the air intake, while it is necessary to determine the speed of the shaft of the power unit (reference point - 2600 ± 100 revolutions / minute). If the speed is much higher, we perform a similar operation to the one that was performed on the removed carburetor: we unscrew the lock nut to block the rotation of the adjusting screw of the lever that drives the DZ;
• after unscrewing the locknut, we wrap the crankshaft, if it rotates more slowly than necessary, you screw in the HF;
• tighten the locknut.

After setting up the trigger mechanism, it is necessary to break in the carburetor.

Important! Before carrying out adjustment work, it is necessary to determine and record the fuel consumption during operation in different modes in order to be able to compare with the indicators achieved after adjustment.

Setting the fuel level in the float chamber

An incorrectly set gasoline level in the PC is an imbalance in the operation of the engine. If it is too high, then the mixture will turn out to be enriched, and one of the most tangible consequences of this state of affairs will be. At a level below the norm, the fuel assembly will be lean, which is even worse for the engine, since it can lead to serious breakdowns that require expensive repairs.

Thus, the level of fuel in the float is a critical indicator for any carburetor, regardless of brand and model.

To fine-tune the float in the K-151 chamber, we need a ruler and a drill with a diameter of up to 2 mm.

Adjustment algorithm:

• we install the machine on a flat horizontal platform (this is important, since we will work with liquid);
• dismantle the air filter housing located on the power unit;
• we start the engine, let it run for about 5-7 minutes;
• unscrew and remove the top cover of the carburetor;
• We measure the float chamber in millimeters the fuel level. This operation should be carried out promptly, since gasoline is characterized by a high volatility, especially in the heat, which will also be facilitated by engine heating. By procrastination, we run the risk of distorted results;
• for K-151, measurements should give about 215 millimeters - this is an indicator that is considered normal for the efficient operation of the motor;
• if the level does not correspond to the standard, we perform an adjustment, which consists in changing the position of the float;
• for this we need to use something that allows us to measure the position of the float during adjustment work - the drill proposed at the very beginning, or a piece of wire, or any similar cylindrical object, will come in handy. The main thing is that its diameter does not exceed two millimeters;
• turn the K-151 cover over and put it on a flat horizontal surface - only in this position the measurements will be accurate;
• we measure with a ruler the distance from the carburetor cover (we choose a cardboard gasket as a reference point) to the lower edge of the float. This distance should be no more than two mm;
• if this is not the case, bend the tongue of the float lever in such a way as to achieve the specified clearance.

The same operation can be performed using a caliper, but in this case, you need to measure the distance from the cardboard pad to the top edge of the float. The correct result is 30 millimeters. In case of mismatch, we again bend the tongue of the lever, achieving the required value.

Note that when implementing all the above settings, there is a possibility of errors, especially if an inexperienced car owner is involved in this. Therefore, after making the adjustment, it is necessary to check its correctness. It is done like this:

• cover K-151 move to a vertical position;
• we monitor the tongue, which we folded (or did not touch, if the level was normal);
• if everything is done without errors, the tongue should slightly press and drown the damping ball located on the IR. In this case, the tongue of the lever must be located at a level that runs strictly parallel to the needle valve;
• we also look at the float stamping axis, which should be located at a level coinciding with.

If at least one of these conditions is not met, the procedure for adjusting the fuel level in the PC will have to be repeated. Many drivers limit themselves to two iterations, even if the situation dictates otherwise. We still recommend that you complete the setup properly, regardless of the time spent - the experience gained will definitely come in handy!

This fuel metering device is mechanically driven. In general, it is unpretentious, rarely deteriorates before its operational life. Produced by the domestic Pekar plant (formerly LenKarZ), the K151 carburetor has many varieties. The difference is usually in the size of the jets.

Device and principle of operation

In principle, the device of the K151 carburetor is not much different from Ozone. A two-chamber carburetor consists of three main parts: a cover or upper zone, a body or middle zone and a throttle part, bottom. Each of them has unique parts, systems and components:

• air damper, ventilation valve, start spring, bracket (only for model K-151N), cover gasket and pneumatic corrector assembly;
• inlet valve or ball, float, fuel filter, fitting assembly, atomizer, diffuser and accelerator pump system;
• exhaust gas ventilation fitting, throttle valves, emulsion tubes, textolite gasket and EPHH assembly.

It would also be useful to consider some of the features of this carburetor:

• the air throttle is opened with a stepped lever;
• the standard screw for the quality of the mixture is periodically unscrewed, so it is recommended to put thick rubber on it or coat the head with silicone glue;
• the ball of the suction valve of the acceleration system is a rare commodity in stores, so it is not recommended to lose it - it is located under the restrictive screw;
• The neutral stroke assembly may freeze during operation, especially in winter.

Technical characteristics of the K151 carburetor

See the table for details.

Existing modifications

As mentioned above, the K-151 carburetor has many varieties. The smallest fuel jet is equipped with a K151C carburetor. Otherwise, there is practically no difference between the models, apart from the presence or absence of a special outlet for gases. For example, the K151D model is not equipped with such a fitting.

The difference also concerns the type of chokes. It can be a cable or traction version of the mechanism. Some modifications of the K-151 are equipped with two options for the suction system. There are devices with a plastic-smooth and metal-stepped sector.

For more information about the difference between the modifications, see the table.

Price

The price of K-151 carburetors varies between 7-8 thousand rubles for original products. Analogues can be bought within 3-4 thousand rubles.

It is also worth noting that in the repair kit for Pekar carburetors of all modifications there is often a float chamber needle with a round end. But she's not the best. It is recommended to take a part of the Unicar brand, with a rubber conical end. The seat will also need to be replaced at the same time.

Hose connection diagram

For correct operation, K 151 carburetors must be correctly adjusted according to the hose connection scheme. The performance of the engine depends on this, it becomes possible to increase its power and increase efficiency. There are two connection schemes designed for ZMZ-402 and ZMZ-406 engines. The motors themselves are structurally similar, but the differences affect some fittings and calibration holes.

402 engine

The diagram here should look like this:

• a hose is put on the lower fitting, which, on the other side, is connected to the idle solenoid valve or pneumatic valve;
• a hose from the distributor is put on the upper fitting of the carburetor;
• the return hose located near the fitting for the fuel supply hose - to crankcase gases or to fitting number 8.

2- lower fitting; 3- top fitting of the carburetor; 4- fitting for the crankcase ventilation pipe; 5 - fuel fitting; 6 - return; 7- for the economizer; 8 - for connection with the exhaust gas recirculation valve

406 engine

Almost the same scheme, but the difference, firstly, concerns the crankcase ventilation pipe - it is jammed. Secondly, a hose is put on the lower fitting, which, on the other side, is connected to the idle solenoid valve already through the coil.

The following connection scheme is also possible:

• fitting number 8 is blocked;
• 7 connects to hose 2;
• 4 is covered with a self-tapping screw;
• 3 is connected to the EPHH valve.

The main malfunctions of the K151 carburetor

During the operation of these dosing devices, malfunctions are possible, which are detected by signs of a malfunction of the engine.

Doesn't hold idle

This malfunction often occurs due to lean fuel mixture. The reason for this is a failure of the settings for the neutral stroke of the carburetor or a banal clogging of the channels. Another option is that the float is crookedly installed in the chamber.

Carburettors equipped with an electrovalve are regulated as follows:

• slightly loosen the adjustment screw XX;
• check turnover;
• if they have changed, tighten the screw until the speed returns to normal.

In some cases, this bolt even falls out of its place. You can buy it in a repair kit or separately. Before installation, it is recommended to lubricate the hole with sealant or simply wrap the tip of the screw with paper.

Pours (pours)

Not uncommon and overflowarising from the re-enrichment of the gasoline mixture. It is easy to determine this malfunction, just pay attention to the strong smell of fuel and fuel smudges from the atomizers. Also, black smoke can come out of the exhaust pipe.

As a rule, overflow does not allow the motor to start normally. This is especially true on warm engines, which, even after a successful attempt at the plant, are unstable. When the accelerator is activated, dips and jerks begin.

To correct the situation, it is enough to adjust the float chamber. There are several options here on how to proceed:

1. Needle valve damage. It is necessary to check the operation of the needle - a vacuum is applied to it and opening / locking is tested. Read more about valve repair below;
2. Valve stuck. In this case, it is necessary to knock with a hammer lightly on the carburetor cover. This will affect the valve. It is possible that the seal has dried out or the element is not wrapped tightly enough;
3. Valve sticking. This is due to oil getting into the fuel. Impurities can settle in the fuel reservoir and from there, in the form of a sticky solution, penetrate into the dosing device. The malfunction is solved by replacing the entire repair kit, it is possible together with the jets. A less expensive option is to treat the needle with a special paste;
4. Float destruction. A damaged element will simply begin to sink in gasoline, dragging the valve along with it. For this reason, liquid will constantly be pumped into the chamber, which will cause overflow. A leaky float can be identified by the sound of the liquid in it - just remove it and shake it over your ear. In extreme cases, the part is allowed to be soldered;
5. Jamming of the float, touching the walls of the body. This already indicates an incorrect position setting. It is also recommended to check the float stroke with the top of the carburetor placed vertically - naturally, the top must be dismantled before the test.

Freezing system

In autumn, and especially in winter, K-151 can freeze. This happens when driving on roads at high speed. The reason is that the air damper remains constantly open. This situation is a big problem. The ice will block the air holes in the dispenser. The mixture will begin to be enriched, and the spark plugs will become overgrown with soot.

What to do? While driving on the highway, determine by ear that the nature of the internal combustion engine has changed, stop. Remove the top of the air filter, carefully inspect the diffusers. If there are solid drops in this place, wait a bit - the ice will melt, you can continue on your way.

Other causes of carb freezing:

• the solenoid valve XX is damaged;
• clogged or damaged mesh filter;
• the air damper does not close completely;
• sucks air through the connections of the device.

Repair of components

Of course, the K-151 carburetor is far from perfect. For more efficient performance, its individual parts need to be straightened and polished. Speaking of attachment planes:

• top cover, namely in the area of ​​the float chamber;
• the middle part, where the surface is often arched due to the device being pulled towards the manifold.

As for the lower throttle zone, it has normal shapes.

Accelerator Pump Repair

The pump of the accelerator system comes to the attention of the repairman often after the car's dynamics drops. Failures appear, consumption increases - in the initial stages, from time to time.

If the pump test gives such results, it is necessary to start repairing it:

• performance below 8-9 cu. cm;
• the presence of backlash of the pump legs, which explains the delay in the supply of fuel;
• the curved direction of the jet from the nozzle of the atomizer - it hits not into the chamber, but into the diffuser.

Do-it-yourself repair of the K151 carburetor in this case means proper tuning. Naturally, the cover of the device must be removed. The following are helpful tips:

1. You can only test the pump performance with the carburetor removed. It should be filled with gasoline, then set over a funnel with a beaker (a cut off bottom from a plastic bottle will also work if you know how much it fits). Next, open the throttle, hold them for five seconds in the open position. Then close for 1-2 seconds and reopen. Repeat these operations ten times in a row. Check the volume of fuel collected in the beaker;
2. The jet is easy to direct to the right place by cutting through the wall and turning the spray nozzle a couple of millimeters. The mixture should hit directly into the chamber, and not drip there or not fall at all. In the absence of a jet from the sprayer, you need to make sure that the discharge valve is in good condition and the hole is clean. In general, it would be better to disassemble the diaphragm mechanism, rinse its cavity and blow through all the channels with a jet of compressed air. The atomizer hole can be effectively cleaned with a piece of 0.3mm wire;
3. The K-151D/S models are equipped with a double fuel sprayer for the accelerator pump. However, it is not needed in these carburetors, since the second chamber is closed. If this atomizer is installed for any reason (error), it will start pouring fuel into the second chamber as well. When the valve is opened, gasoline will flow into the manifold. This will cause engine failure. Therefore, it is recommended to replace this element with a single one. Or upgrade the carburetor, including the second chamber in the work;
4. When opening the air damper, it must be strictly in a vertical position - 90 degrees! Its slightest blockage will lead to an increase in fuel consumption;
5. The leg is adjustable with a slight bend. It should not have even the slightest free play. A properly adjusted accelerator will begin to respond instantly.

Replacing the needle valve in the float chamber

As mentioned above, a large amount of fuel consumption may begin due to a faulty needle valve. To replace it, you must perform the following steps:

• dismantle the top of the carburetor;
• pull out the float axle;
• remove the float with a needle;
• unscrew the valve seat;
• install new parts;
• collect everything back.

Complete carburetor replacement

In some cases, repair of the device is impractical. Then you have to completely replace the carburetor.

Removal and installation algorithm:

• dismantle the air filter;
• disconnect hoses - fuel, return and others;
• remove the air damper drive rod;
• unscrew 4 fixing bolts of the device;
• remove the bracket together with the throttle drive rod;
• raise the carburetor with insulating gaskets;
• install new one.

If you want to replace the K-151 with another carburetor model, for example, DAAZ (this is often done on UAZ with 2.5-liter engines), the range of work expands. One of the reasons for the modernization is the conversion of the traction to a cable drive so that the second chamber opens normally.

What is needed for this:

• new dosing device model DAAZ or similar;
• gaskets - textolite and paronite;
• air filter adapter;
• bolts, studs, washers.

Work must be carried out after removing the old carburetor:

• screw in new studs if the old ones are short;
• try on the largest gasket - if the holes do not match, drill new holes by 10 mm;
• also put a thin gasket, preferably turned so that it does not interfere with the movement of the carburetor dampers;
• install the adapter on the air filter - screw it to the carburetor with an M6 bolt;
• install a new device.

Who does not want to connect EPHH can install a plug instead of a valve.

Adjustment instructions: how to adjust the K151 carburetor

The blown and clean K-151 carburetor, which has even planes, can surprise you with high-quality and fine work. On the contrary, a disordered device, which also sucks in air, will not give the motor throttle response and speed stability. Such a carburetor will need adjustment.

The K151 carburetor is adjusted in three main areas:

• XX setting;
• adjusting the position of the air damper and throttle damper;
• adjusting the level of gasoline in the chamber.

Let's start with idle adjustment:

• warm up the engine to 80-90 degrees;
• leave the engine running with the choke open;
• unscrew both screws to the stop (quality and quantity) - the power unit will begin to roar at maximum speed;
• tighten the screws until the speed drops to the minimum possible;
• slightly increase the speed with the quality screw, “catch the hill” or stable operation of the internal combustion engine - it is advisable to screw in as many circles as possible so that the fuel consumption is low;
• tighten the quantity screw, achieving stable engine operation at 700-800 rpm - in this case, it is advisable to screw in as few circles as possible.

Next comes the adjustment of the throttle position using another special screw. The latter often sticks, and it can be impossible to turn it. But there is a slot on it, where you need to insert a flat screwdriver, and then gently tap it several times with a hammer. This will "revive" the screw, it will begin to rotate. So it will be possible to set the most acceptable engine speed with the corrected air supply.

The normal level of gasoline in the float chamber should be 21.5 mm with the valve closed. The distance is measured from the top edge of the chamber to the liquid surface. Obviously, the machine must stand on a flat area, without distortions. By changing the position of the float, it will be possible to lower or increase the fuel level.

Table: technical characteristics of K-151

Table: cost of carburetor and spare parts

Table: varieties of modifications of K-151 carburetors

Carburetor elements

1 - screw-plug of the float axis;
2 - lever on the axis of the air damper;
3 - threaded plug of the fuel jet of the transition system of the secondary chamber;
4 - vacuum extraction fitting to the vacuum regulator of the ignition distributor;
5 - vacuum extraction fitting to the EPHX system valve;
6 - fitting of the crankcase ventilation system;
7 - fuel filter housing with inlet and bypass fittings;
8 - screw for fastening the filter housing;
9 - fitting for vacuum control of the exhaust gas recirculation valve;
10 - threaded plug of the emulsion jet of the idle system;
11 - a hairpin of fastening of the case of the air filter;
12 - threaded plug for draining fuel from the float chamber;
13 - fitting for supplying vacuum to the EPHKh valve;
14 - screw for adjusting the composition of the mixture at idle (screw "quality");
15 - screw-stop of the lever of the damper of the primary chamber;
16, 22 - microswitch of the EPHX system;
17 - screw for adjusting the idle speed of the crankshaft ("quantity" screw);
18 - screw of the two-arm lever of the starting device;
19 - trigger lever;
20 - lever on the axis of the air damper;
21 - air damper drive rod;
23 - coupling spring free travel throttle control lever;
24 - overhead lever of the starting device control cam;
25 - adjusting screw for the position of the air damper drive rod;
26 - opening tendril of the throttle lever of the second chamber;
27 - closing antennae of the throttle lever of the second chamber;
28 - cam starter;
29 - stop screw of the shutter lever of the second chamber;
30 - fuel outlet fitting;
31 - screw fastening the cam of the accelerator pump (option);
32 - fuel supply fitting.

Carburetor diagram

1 - cover;
2 - float;
3 - air jet of the transition system of the second chamber;
4 - fuel jet of the transition system of the second chamber;
5 - threaded screw-holder of the econostat atomizer;
6 - main air jet of the second chamber;
7 - econostat atomizer;
8 - emulsion tube of the main dosing system of the second chamber;
9 - small diffuser of the first chamber with a spray;
10 - accelerator pump atomizer holder with discharge valve;
11* - accelerator pump sprayers;
12 - air damper;
13 - small diffuser of the second chamber with atomizer;
14 - main air jet of the first chamber;
15 - emulsion tube of the main dosing system of the first chamber;
16 - block of fuel and air idle jets with an emulsion tube;
17 - emulsion jet of the idle system;
18 - second idle air jet;
19 - adjusting needle on the jet of the drainage channel of the accelerator pump;
20 - stroke limiter of the suction ball valve of the accelerator pump;
21 - carburetor body;
22 - bypass (drainage) jet of the accelerator pump;
23 - ball of the suction valve of the accelerator pump;
24 - suction stroke spring of the accelerator pump diaphragm;
25 - accelerator pump diaphragm;
26 - accelerator pump diaphragm cover;
27 - accelerator pump drive lever;
28 - main fuel jet of the first chamber;
29 - EPHX valve fitting;
30 - EPHX valve diaphragm;
31 - shut-off valve EPHKh;
32 - plug-in plastic stop screw "quality";
33 - screw for adjusting the composition of the mixture ("quality screw") at idle;
34 - unloading subdiaphragmatic hole in the EPHX valve body;
35 - forced idle economizer housing (idling unit);
36 - valve seat of the idle system;
37 - screw for adjusting the idle speed of the crankshaft;
38 - laying of the idling unit;
39 - additional screw for adjusting the composition of the mixture on the main idling fuel supply branch (only on early modifications of carburetors);
40 - transitional slotted hole of the idle system;
41 - throttle valve of the first chamber;
42 - accelerator pump lever drive cam;
43 - accelerator pump lever roller;
44 - inlet window of the air channel of the idle system;
45 - throttle valve of the second chamber;
46 - heat-insulating type-setting gasket of the carburetor body;
47 - throttle body;
48 - vacuum extraction fitting to the EPHKh solenoid control valve;
49 - vacuum extraction fitting to the vacuum ignition timing controller;
50 - main fuel jet of the second chamber;
51 - vacuum extraction fitting to the exhaust gas recirculation valve;
52 - power circuit of the EPHX control unit;
53 - microswitch circuit of the EPHX system;
54 - filter on the vent fitting of the EPHX solenoid control valve;
55 - solenoid valve of the EPHX system;
56 - screw for fastening the fuel filter housing;
57 - fuel filter;
58 - fuel fitting;
59 - plug on the wall of the float chamber;
60 - shut-off valve of the float mechanism;
61 - locking needle earring;
62 - float tongue.

* For carburetors installed on the ZMZ-402 engine, the sprayer has one nozzle directed to the first chamber.
Design features

K-151 carburetors are devices for precise dosing of fuel in an air stream, formation of a combustible mixture from fuel and air and regulation of its supply to the engine.

The carburetor has two side-by-side vertical air passages, each with a rotary throttle valve at the bottom of each. Each of the channels is called a carburetor chamber. Since there are two such channels-cameras, and the throttle actuator is designed so that as you press the accelerator pedal, one and then the other damper opens first, this type of carburetor is called two-chamber with sequential opening of the chambers. The chamber in which the throttle valve opens earlier is called the first, the other - the second.

In the middle part of each of the main air channels there are cone-shaped constrictions-diffusers, by means of which a vacuum is created in the air flow, which is necessary for sucking fuel from a special container located in the carburetor body - a float chamber. The fuel level in the float chamber, necessary for the normal operation of the carburetor, is maintained constant (more precisely, almost constant) using a mechanism with a float and a locking needle.

The fundamental difference between the float mechanism of the K-151 carburetor and the similar device of all other domestic carburetors: it is completely, together with a needle and a float, located in the carburetor body and is available for control after removing the cover, without disturbing its operation.

The carburetor consists of three main parts:

Upper - covers with a flange and air filter mounting studs, with a float chamber ventilation device and starting device details. With seven screws, the cover is attached to the carburetor body through a cardboard gasket;
medium - carburetor housing with a float chamber and a float mechanism, a fuel supply fitting and fuel metering systems;
lower - throttle bodies, with throttle valves and their drive mechanism, as well as an idle device. The throttle body is attached to the carburetor body from below with two screws through gaskets: two thin cardboard and one thick plastic.

The carburetor has the following systems, devices and mechanisms:

float mechanism;
fuel dosing systems;
main dosing systems of the first and second chambers;
idle system;
transitional system of the second chamber;
econostat;
accelerator pump;
starting device;
valve-economizer for shutting off fuel supply in forced idle mode;
forced crankcase ventilation system;
float chamber ventilation system;
throttle control mechanism.

Idling system - with adjustment of the amount and composition of the mixture (autonomous idling system).

The second chamber of the carburetor has a transitional system with fuel supply directly from the float chamber. The system comes into operation at the moment the throttle valve of the second chamber is opened.

Diaphragm type accelerator pump. To enrich the combustible mixture at full load, an econostat is provided in the second chamber.

The starting device is of a semi-automatic type, it consists of a pneumatic corrector, a system of levers and an air damper, which is closed by the driver using a manual drive before starting a cold engine. At the moment of starting the engine, the pneumatic corrector, using the vacuum that occurs under the carburetor, automatically opens the air damper to the required angle, ensuring stable operation of the engine when warmed up.

ATTENTION
When pulling out the choke knob, press the accelerator pedal.

The K-151D and K-151T carburetors differ from the K-151 carburetor by the accelerator pump sprayer with two nozzles and flow sections of the dosing elements.

The K-151D carburetor fuel cut-off system consists of a solenoid valve controlled by an ignition controller and a forced idle economizer (EPKhK). EPHH is located on the carburetor, the solenoid valve and the ignition controller are under the hood, on the front panel of the car.

The ignition controller controls the solenoid valve depending on the engine speed and vacuum in the intake pipe.

The fuel cut-off system works as follows. When the throttle actuator pedal is released and the engine crankshaft speed is more than 1650 min-1, the controller does not supply voltage to the solenoid valve, as a result, atmospheric air enters the EPHH through the channels of the solenoid valve, the valve of which closes the idling channel.

Calibration data for carburetors K-151 (ZMZ-402), K-151D (ZMZ-406), K-151T (UMZ-4215)

About the book: Management. Edition 2003.
Book format: pdf file in zip archive
Pages : 76
Language: Russian
Size: 9.3 mb.
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Carburetor K-151. Device, adjustment, repair.

The book discusses the features of the design and operation of automobile carburetors of the K-151 family manufactured by PEKAR OJSC. The main characteristics and parameters of carburetor units and systems are given. The features of the operation and maintenance of carburetors and related systems of a car - an economizer of forced idling and a decrease in toxicity are outlined.

Recommendations for the detection and elimination of typical faults are given. Instructions for disassembly, assembly, diagnostics, adjustment and repair of carburetor units and systems are given. Color illustrations contribute to a better understanding of the material.

Carburettors of the K-151 series are made according to general standard schemes, but in design they radically differ from the widespread carburetors of the Weber, Ozone and Solex types and practically have no common parts with them. The need to create carburetors of the K-151 series is caused by the expansion of the model range of the Gorky and Ulyanovsk Automobile Plants, whose cars are equipped with engines from the Zavolzhsky Motor Plant (ZMZ).

The design of the K-126 and K-131 carburetor series, which were previously installed on these engines, was outdated and did not provide the required performance characteristics of the engines of the 402 family of Gazelle GAZ-3302, 31022, Volga GAZ-3102, 31022, 3110, engines mod. 4063 Sobol GAZ-2752, 2217 and 22171 cars, as well as UAZ-3153, 33036, 39094 and 39095 cars.

Modifications of carburetors of the K-151 series, depending on the model of the car for which they are intended, differ in the parameters of some metering elements (diffusers, jets, emulsion tubes), as well as in the design and dimensions of individual components, for example, the presence of an electrically driven float chamber ventilation valve in the carburetor and a fuel return fitting for the carburetor of the Sobol GAZ-2752 car, etc.

Compared to the previous models of carburetors by PECAR OJSC, carburetors of the K-151 series provide better mixture formation and accurate fuel dosing in all operating modes, which sufficiently meets the requirements of existing and future exhaust gas toxicity and fuel efficiency standards.

JSC "PECAR" produces the basic carburetor of the K-151 series and seven of its modifications - K-151V, 151G, 151E, 151I, 151D, 151P and 151N, designed for installation on four-cylinder GAZ, UMZ - UAZ cars and UZAM - Izh cars.

All modifications of carburetors of this family are of the same type: two-chamber two-diffuser with a falling flow of a combustible mixture and pneumatic braking of fuel, a balanced float chamber, elements of a closed crankcase ventilation system and sequential opening of throttle valves. They differ mainly in calibration data and sets of complete sets with additional elements.

K-151 series carburetors are equipped with a single-section float chamber with a hollow brass float; autonomous idling system (ACXH); main dosing systems in the primary and secondary chambers, secondary chamber transition system; control vacuum selection systems for the vacuum corrector of the ignition distributor and the exhaust gas recirculation valve (not on all modifications); valve for shutting off the fuel supply in the forced idle mode (PHX); mechanical drive of the throttle valve of the secondary chamber; diaphragm mechanism for starting and warming up a cold engine with a manual air damper; econostat; diaphragm accelerator pump.

The base carburetor K-151 is installed on engines of the ZMZ-402 family with a working volume of 2.45 liters. cars Volga GAZ-24-10, 31029, 3102. 3110 and Gazelle GAZ-33021, 33023, 33027, 330273, 2705, 27057.

Modifications K-151V and K-151G are designed for engines of the UMZ-417.10 family with a working volume of 2.45 liters. , 31514, 3741, 3962, 2206, 3303, 3909. They differ from the base carburetor, and from all other modifications of the family, by calibration data, the presence of an electrically driven float chamber imbalance valve, the absence of fuel return fittings and the selection of a control vacuum for the recirculation system valve exhaust gases.

Both modifications have the same calibration data and differ only in the design of the throttle actuator: in the K-151V modification, a lever is installed on the axis of the throttle valve of the primary chamber for connecting to the accelerator pedal using a linkage system, in the K-151G, instead of a lever, a sector is mounted for connecting a flexible cable.

For engines of increased power UMZ-4218.10 with a working volume of 2.89 liters. UAZ-3153, 33036, 39094 and 39095 vehicles install the K-151E modification, which is identical in design to the K-151V modification, but differs significantly from it in the calibration data of the dosing elements of the idle system.

Modification K-151I was developed for a family of high-power engines ZMZ-410.10 with a working volume of 2.9 liters. cars Volga GAZ-31029 and Gazelle GAZ-3302. It differs from the base carburetor in the diameter of the large diffuser of the secondary chamber, the throughput of the emulsion jet of the idle system and the supply of the accelerator pump.

For a family of new generation engines ZMZ-406 with a working volume of 2.3 liters. Volga GAZ-3110, Sobol GAZ-2752, 2217, 22171 and Gazelle cars of all modifications, except for GAZ-33021, a modification of the K-151D has been developed, which, like the base carburetor, has a fuel return fitting, but differs from it in the calibration data of the main systems dosing and idle code.