het werkplaatshandboek: inhoudsopgave


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das Werkstattbuch: Inhaltsverzeignnis



Cleaning and maintenance of the carburetor


Abb.1The most frequent break downs come from the pollution of the carburetor by dirt from the fuel or from sucked in air. Depending the environment, in which the motorcycle is driven, the time schedule is to be selected, in which the carburetor is cleaned. Other disturbances do not arise with the carburetor. If the throttle valve should wobble, then it became loose and must be replaced against a new one. If the throttle valve abrasive itself in, the mixing chamber must be honed. Usually with to strong pressure on the needle perforated floats must be replaced or after drying soldered. The leakage of the float needle in its seat in the float frame cover is eliminated by grinding in with abrasive paste or by replacement of the components. Cleaning the carburetor must be done off the machine, for which the two door halves of the front lining must be opened (fig. 1).Vergaser 2914 Hz

Carburetor JIKOV 2914 Hz (fig. 2); ( parts catalog carburetor ).
This type is used with the machine Jawa 50, type 555. The Fuel valve is locked off and the fuel rubber hose is removed. By opening the fuel valve is the control that the fuel inlet from the tank is not clogged. If this is the case, the valve must dismantled and the fuel strainer cleaned. The nut of the mixing chamber (20) and the guide screw (23) are loosened and the fuel valve (16) is taken out including the nozzle needle (17) adjusted according to work regulation by means of the safety device (18) in the second needle cut from above. Then the screw (26) is loosened and the carburetor is removed from the motor. With the same screw the filter is fastened as well, always the filter is to be cleaned in gasoline. Take care that always first the carburetor parts are rinsed in the gasoline and then the dirty filters, whose efficiency  can be increased by rinsing it with a thin oil film. The needle jet (6) is accessible after loosening of the screw (4). The correct caliper of the nozzle is the number 65. The two screws (24) are unscrewed and the float house cover (14) is removed, whereby damage of the seal is to be avoided (15). After removal of the float (l1) the entrance to its needle (12) secured by the safety device (13) is free. If the fuel valve (16) must be dismantled, the spring(19) is slightly pressed in and the gas cable is taken out of its cut. The assembly takes place in reverse.

Carburetor Jikov 2912 (fig. 3)
This carburetor was used with the Jawa 50, type 550.  Vergaser 2912
After separating the fuel hose from the tank and after control of the fuel streaming, proceed as follows: The nut of the mixing chamber (25) and the guide screw (8) are loosened and the fuel valve (18) is taken out. The carburetor is dismantled from the motor. The noise damping air filter is removed likewise and cleaned after shifting the clamp spring (30). The fuel flush mouthpiece  onto the floating chamber (7) is also cleaned, after loosening of the nut. The strainer is to be flushed as well. The floating chamber is dismantled after loosening the two screws (19), its cover (22) and seal (17) is removed and the floater including the needle (20) is taken out. After unscrewing the screw (19) provided with the seal (15) the entrance to the main jet (19) is free. All components are rinsed and the assembly of the carburetor and the filter is accomplished in reversed order. The gas cable is taken from the cut in the throttle lever after pressing the spring slightly. The cable play is adjusted by the screw (4) and the locknut (5).  By assembling the carburetor on the motor may not be forgotten to install the the seal.

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