General information about the carburetor (BMW 5 Series E28)

Early models are equipped with a Solex 2B4 carburetor, while later models are equipped with a Solex 2BE carburetor. Both carburetors are two-chamber, downdraft types. The first chamber is mechanically controlled by the accelerator pedal, while the second is vacuum-controlled.

Each chamber has a separate float chamber, float and needle valve designed to reduce the effects of braking and centrifugal forces.

On the 2B4 model, the first stage air valve is controlled automatically (bimetallic spring with electrical heating) when warming up the engine. Enrichment of the mixture during warming up is also ensured by a thermal valve controlled depending on the coolant temperature and a temperature-controlled air flow valve.

On the 2BE model, automatic control of the carburetor parameters during warm-up and normal engine operating temperature is performed by an electronic control unit. The control unit is located under the instrument panel on the right side.

(You can read the original on the website «BMWMan.ru»)