JPS598664B

1530241 Carburetters with accelerator pumps SOC INDUSTRIELLE DE BREVETS ET D'ETUDES 1 Feb 1977 [18 Feb 1976] 04039/77 Heading F1H In order to prevent fuel vapour forming within an accelerator pump chamber 9 of a carburetter, an auxiliary pump 34 is provided to circulate fuel to the carburetter's float chamber 6 (or to a fuel tank supplying the float chamber 6) at least during idling and part-load running of the engine supplied by the carburetter. The pump may be a diaphragm pump 34 operated by vacuum tapped from the engine intake pipe and applied to a control chamber 35. Atmospheric air is intermittently introduced into the control chamber 35 by a ballvalve 46 to effect the pumping action. The ballvalve 46 can be replaced by a slide valve (63 not shown).