The i.c. engine carburettor comprises a main throttle (2) downstream of a venturi (5). The mixture inlet (4) is connected (9) to a mixing duct (10) provided with an air correction orifice (12) and with a fuel jet (13) which controls the fuel supply from a float chamber (23). An upstream eccentric choke disc (8) opens against a spring (17) under the action of the intake air flow. It is coupled (14,15) to a control mechanism, e.g. a valve cone (19) and needle (20) with a seat (25) in the duct (22) leading to needle-controlled orifice (33) and to a further orifice (21). Both orifices are parallel to the fuel jet (13). This mechanism, together with the main throttle-operated (26-28) needle (29), controls parallel fuel contributions to the mixture during engine start-up and heat-up.
展开▼
