Disclosed herein is a carburetor for internal combustion engines having an automatic choke control mechanism including a vacuum diaphragm assembly operatively connected to a choke lever for opening a spring-biased closed choke valve and holding it open at idling and lower engine speeds and a linkage arrangement interconnecting a throttle valve lever and the choke lever for holding the choke valve open at higher engine speeds independently of the vacuum diaphragm assembly. The linkage arrangement includes a spring-biased choke pull-out lever which is held in a locked position during engine idling and lower engine speeds by a link having one end slidably received in a slot in the choke pull-out lever and the other end connected to the throttle lever. As the throttle lever is moved past a predetermined advance speed position, the link is moved to a released position in the choke pull-out lever slot wherein the choke pull-out lever is urged into abutting engagement with the choke lever to hold the choke valve open. As the throttle lever is returned toward the engine idling position past the predetermined advance speed setting, the link returns the choke pull-out lever to the locked position and the choke lever is again controlled by the vacuum diaphragm assembly.