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Fuel system

Carburetor cleaning adjustment should be carried out by an authorized BMW workshop.
In an emergency, the carburetors can be detached and all fuel and air passages, and also float needle valve 5, main jet 4 and idle jet 3 blown through and the float chamber cleaned. It is inadvisable to alter the setting of throttle slide (throttle stop) screw 1. When assembling, tighten idle air (idle mixture) regulating screw 2 fully, but without using force Slacken it oft again by app. 1 turn to obtain the correct basic setting. Fig. 66

Insert the vacuum slide with diaphragm in a dry condition; press the locating peg of the diaphragm into the cutout provided in the sealing groove on the upper part of the carburetor body so that the two pressure equalizing passages in the vacuum slide are on the throttle butterfly side.
Mount and tighten down the vacuum housing cover so that the wire cable adjusting screws are on the same side as the choke and throttle levers. If correctly assembled, the vacuum slide should move by its own weight between the two limit positions in the guide passage.