The loss of the needle valve leakage

In domestic carburetors often encountered such a failure, as wear and tear or loss of tightness of the needle valve in the float chamber. Such damage can happen to import carburetors, but for some reason it happens more often is at home. Determine the loss of tightness of the needle is very easy, looking from the top of the carburetor instigated the motor. At the two-chamber carburetor will be observed leaking gasoline from the nozzle of the second camera. This indicates an increase in leakage of the fuel in the float chamber. With a strong petrol worn needle will follow at the same time and in the first chamber. But first discharge always occurs in the second. An exception is the French two-chambered "Varadzhet." This carburetor gasoline transfusion was observed only in the first chamber. Motor with speed first increases, then gasps and muffled. On the single as the carburetor, "wetting" the needle valve is recognized by the rapid leakage of gasoline from the float chamber vents. Then run the engine will be very difficult because of the excess amount of gasoline in the cylinders. As you know, a very rich mixture does not burn. In this case, the motor is used to start scavenging. Purging is a long rotation starter with the throttle fully depressed. The loss of tightness needles can occur not only from the wear and tear. Any speck of dust stuck between the needle and seat blocks the mobility spines and petrol poured directly into the motor. Loosely twisted saddle or a bad gasket under it also leads to the overflow of gasoline. Spring-loaded ball stuck in the needle (damper) increases the level of fuel. Float, even partially filled with gasoline is no longer performs its function, sinks and the level of gasoline is not controlled. To test the hollow metal or plastic floats to shake their ear. One can hear the splash of gasoline inside. Weight also increases the float when hit into a gas. On carburetors "Solex" and some other dual use of a porous float ebonite. It also can absorb the fuel, but to shake him by the ear is useless. These floats are checked for balance halves. The float is suspended by a thin rod and half, scored the petrol will always be heavier. The next problem, which leads to overflow of gasoline - is sticking float on its axis, or touching them float chamber walls. This fault is eliminated podgibaniem carefully and adjusting the float. Final check tightness of the needle valve should be carried out at a meeting of the carburetor. In the normal position of the carburetor fuel inlet fitting shall be easily purged in the middle. Do not forget to close the finger fitting return line. In the inverted position the carburetor to create a vacuum in the inlet nozzle, checking the tightness of the needle. The last operation is desirable to hold a vacuum pump. Checks must be repeated several times, turning the carburetor. The technical literature contains numerous values ??for different levels of fuel carburetors. But there is one common to all carbs rule. It is as follows. Plastic cover has a float casting seam formed in the manufacture of the plant. By adjusting the fuel level, should be guided by a parallel position to the outlet seam float carburetor top cover. At the same time cover the carburetor to keep upright, the needle is closed, but the vibration damper is not pressed. This is true for almost all models in which the float is attached to the lid carburetor. The exception is Zhigulevsky "Ozone" and some other carbs with round metal float, which when removed the top cover fuel level should be in the middle of the diagonal wall float chamber. Generally parallel to the seam acts and for those carbs that have a float attached to the middle. Parallelism is measured from the middle of the slice. For many Japanese carburetors to control the fuel level is the window. When the car is on level ground, the level of gasoline should be in the middle of this window. There is another reason transfusion of gasoline from the float chamber. This high pressure fuel pump. To control the pressure gauge is used with the maximum of the scale to 1 - 1.5 kg / cm. Normal pressure fuel pump on any carbureted engine does not extend beyond the 0.25 - 0.45 kg / cm. Pressure gauge to the fuel hose to the carburetor through a T-piece. If the pressure exceeds the normal value, even a properly functioning needle valve begins to pass gas. Reduce the pressure can increase the thickness of shims between the pump and its mounting flange. This method of reducing the pressure pump is only suitable for direct-drive shaft. The thickness of the spacers is chosen experimentally, and the pressure is controlled by a manometer. After stopping the engine need to wait for 2-3 minutes, watching the state of the first and second chambers. There should be dry and clean. Disruption is not allowed even one or two drops of gasoline. If the overflow of gasoline occurs periodically, it may be because mote, stuck between the needle and seat. In this case, helps to purge air inlet needle body and the fuel filter.