Carburetor K-151: device, adjustment, repair, failure, installation
The K-151 carburetor was often installed on Russian passenger cars and low-tonnage cars. These units are produced by LLC “Pekar”. The manufacturer believes that these are the best and most reliable carburetors of all existing. At the factory, three versions of devices are manufactured for installation on four-cylinder power units ZMZ and UMP of 2.45 liters. Due to the complexity of the device carburetors K-151, adjustment and repair caused some difficulties for the owners.
There are two channels in the body of the device - these are carburetor chambers. At the bottom of each there are mechanically driven dampers. Chambers in the carburetor two. Throttle valves open one after the other as loads increase. The first chamber and its flap operate at low and medium loads. The second camera is valid only at high.
In the middle part of the body there are diffusers. They are designed to create a vacuum, which will then contribute to the intake of gasoline from the carburetor float chamber.
Features of the float mechanism
In the design of the float chamber of the carburetor K-151 on the UAZ there are differences from any similar devices of domestic production. The mechanism together with the locking needle is inside the case. To visually check the status of the camera, you need to remove the top cover. It does not need to disturb the interaction of the float and gasoline. This design is called the bottom float chamber.
The device consists of three separate parts. The top serves as a cover. It has studs through which to install an air filter. In addition, in the cover there are balancing holes for the float chamber, the trigger mechanism parts, screws for attachment to the housing.
In the middle part there is a float chamber of the mechanism, a fuel supply nozzle to which the carburetor K-151 hoses will be connected, as well as a dosing system.
At the bottom are the throttles and their mechanism, as well as a device that provides the engine idle. It is fastened with screws through cardboard and textolite pads. In the device there are other systems, without which the operation of the device will be impossible.
Features of the float mechanism
This mechanism is necessary in order to always have a certain level of fuel in the float chamber. The level of gasoline must be maintained so that the engine can work stably. If there is less fuel, the mixture will become poor, which will affect the fuel consumption. The level is controlled by a float and a special valve. When the level is normal and the float is raised, the valve will be closed and will not allow a new batch of gasoline to enter.
When the fuel level is insufficient, the float will drop down and open the needle valve, thereby providing access to gasoline. As the chamber fills, the float will go up. As a result, the needle valve closes.
Simultaneously with the fact that the fuel consumption is not constant, its supply from the side of the fuel pump also changes.This eliminates the increase in pressure at the inlet of the carburetor. The level in the float chamber is variable and does not persist in different modes of operation of the motor.
SDS - main dosing systems
HDS in the first and second carburetor chambers have the same device. Dosing systems consist of carburetor fuel and air jet nozzles. In K-151, they are installed in the lower part in the float chamber. Under the jets in the two chambers are emulsion tubes.
This is a completely autonomous system for preparing a mixture. It provides intensive spraying of gasoline in the stream of air entering the combustion chambers at idle. Thanks to this system, the motor can operate stably with the throttles closed or covered.
Often, with this system, many have problems. Not knowing the carburetor K-151 device, repairing and adjusting idling can cause a lot of difficulties (especially on dirty, maintenance-free carburetors).
The carburetor is installed on the manifold and bolted. The seat on the cars is designed specifically for this model of the carburetor.
Next you need to connect the hoses, of which there are several, and they are connected in a certain order. So, the main nozzle will connect to the fitting under the float chamber. The return pipe is connected to the lower outlet. Thin hoses come from EMC. One of these connections is connected to the economizer valve XX. The second is connected to the lower fitting located on the other side of the body of the dampers. One more conclusion will be connected to the POP vacuum regulator.
There are not so many faults in carburetors. Knowing the device of the carburetor K-151, repair and adjustment will not cause difficulties even for beginners. Faults are due to incorrect adjustment or improper repair.
So, one of the most important faults, which is very difficult to eliminate, is increased fuel consumption. Also, exhaust gases can be dark or black. Loss of speakers indicates a fault in the power system. Another popular problem is idle. It either disappears altogether, or the engine idling cannot work stably.
Most often, most problems can be solved by cleaning the carburetor jet nozzles K-151.Air and fuel jets can become clogged due to poor-quality gasoline, old hoses, dirty air and gasoline filters.
Another reason for which the engine may be unstable is the overheating of the carburetor. The metal body of the unit is very soft and due to overheating easily deformed. As a result, a gap is formed between the lid and the housing. Excess air is sucked through it, and it is not possible to adjust the carburetor in any way steadily. Often the cause of the failure of the carburetor K-151 may be the wear of components and assemblies. This applies to rubber membranes, springs, jets.
Motor stalls at idle
The most common cause is a clogged idle fuel jet. It is located on the solenoid valve. Also the cause becomes the solenoid valve itself. If the element is working, and there is no idling, then the jet and channel XX should be cleaned. Knowing the device of the carburetor K-151, repair, adjustment and tuning it does not require much time.
What to do if it fills with fuel?
The cause of a large amount of fuel can be a needle valve.If the needle is worn, it can no longer hold the pressure of the fuel, and it enters the float chamber. For repair you need to remove the cover, remove the float axis, unscrew the valve and replace it with a new one.
When you press the gas, the engine does not pick up speed, slows down and can stall - such failures occur most often due to clogged SDS.
This fault is eliminated by cleaning the main dosing system. Also, failures may be due to problems with the accelerator pump. Replace worn parts and clean the duct with compressed air.
Installing the K-151 carburetor instead of the old K-126 will give a significant increase in power and good fuel economy. With regular care, this carburetor does not give the owner extra problems. Repair is the replacement of repair kits.