twin-choke downdraught carburetor Possible demonstrations: throttle butterflies open simultaneously function of choke butterflies, throttle butterflies, float with valve needle, pull-down device, accelerator pump and idle- speed stop description ordernumber 1029 see also: common-Rail high-pressure pump with injector pump tappet of an in-line pump distributor plunger (on a rack) cylinder head – four-valve engine