VEB BERLIN SR59, Руководство по эксплуатации

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2.181 maintenance of the carburetor
The main jet can be cleaned without having to take the carburetor apart. All that needs to be
removed for that purpose is the screw plug of the mixing chamber. The main jet sits in the needle
jet. Loosen the clamping screw and turn the carburetor so, that the screw plug can be unsrewed
from the mixing chamber. Now the main jet can be removed using a screwdriver. The jets are
cleand by simply blowing through them or using a horses hair. Never use wire or needles for
cleaning attempts, because it might damage or break the jets alltogether.
The carburetor should be dismounted and disassembled once every 1200 miles. In order to do this,
the silencer needs to be removed along with the fuel line. Afterwards the cap of the mixing chamber
needs to be unscrewed and taken off with the throttle cable and connected throttle slide gate. Next
the carburetor´s clamping screw needs to be loosened and the carburetor pulled off from it´s
socket. After loosening the two screws that are attached to the floater housing, the lid can then be
taken off and the floater with needle removed.
To gain access to the needle jet and the main jet, the screw underneath the mixing chamber needs
to be loosened, using a hexagonical wrench. The needle jet is screwed into the body of the mixing
chamber and should, if possible, not be removed, because this might cause malfunctioning of the
carburetor.
All parts are to be cleansed thoroughly with fuel and then checked for mechanical defects (wear).
Wear and tear of things like loose parts of the carb, worn out floater needle or jet needle, defective
floater, damaged gaskets, bent jet needle or a loose or inclined intake socket are responsible for
poor function of the carburetor. Because one or the other of the above mentioned faults might occur
during regular operation of the scooter, it is advisory to have the carburetor thoroughly checked by
a dealer´s workshop every once in a while.
When assebling the carburetor, it is to be seen, that all the parts are tightened well, that no gaskets
are being damaged and that the needle jet isn´t being bent during installation. The standard setting
of the carburetor must not be changed under any circumstances, because the factory setting is
already optimal regarding gas consumption and performance. Before mounting however, one must
not forget that is is essential to lube the clutch spindle. (Nr. 9 of the lubechart, illustrations 59 and
60)
.
Adjusting idle speed is done by adjusting the idle airflow screw after first cleansing the idle fuel jet.
Unscewing the idle airflow screw in a counterclockwise rotation, leads to more air (a leaner ratio)
and screwing it in results in more fuel being provided, and thus a thicker ratio. Normally, the air/fuel
ratio is correct, when the idle airflow
Illustration 24, Removal of main jet