Abstract: A carburetor for a multi-cylinder internal combustion engine which has for each cylinder a main combustion chamber defined above the piston in the cylinder and a sub-combustion chamber defined above the main combustion chamber and communicating with the latter through a torch nozzle. The carburetor has a main intake passage and a sub-intake passage for supplying a comparatively lean mixture and a comparatively rich mixture to the main and sub-combustion chambers respectively. The carburetor has a single throttle valve shaft extending across the main and sub-intake passages with a main throttle valve and a sub-throttle valve mounted on the valve shaft and disposed in the main and sub-intake passages respectively.The main and sub-throttle valves are attached to the single throttle valve shaft at the same attaching angle and have respective parallel surfaces and outer peripheral edge surface.

Abstract: A carburetor for a multi-cylinder internal combustion engine which has for each cylinder a main combustion chamber defined above the piston in the cylinder and a sub-combustion chamber defined above the main combustion chamber and communicating with the latter through a torch nozzle. The carburetor has a main intake passage and a sub-intake passage for supplying a comparatively lean mixture and a comparatively rich mixture to the main and sub-combustion chambers respectively. The carburetor has a single throttle valve shaft extending across the main and sub-intake passages with a main throttle valve and a sub-throttle valve mounted on the valve shaft and disposed in the main and sub-intake passages respectively. One of the main and sub-throttle valves has an outside diameter smaller than the inside diameter of the associated intake passage so that the ratio of the open areas of the main and sub-intake passages is not constant as the throttle shaft is operated.

Abstract: A device including a cam member rotatable with the throttle opening and closing operation and a pump-actuating lever operable under the control of the cam member to discharge fuel to an acceleration spray nozzle opening into the intake air passage. The duration of the discharge stroke of the accelerating pump can be extended to any desired extent relative to the throttle opening movement for stable and efficient engine acceleration by selecting an appropriate cam contour.

Abstract: A fast-idle cam apparatus in a carburetor having an opening and closing control for forcibly opening and closing a throttle valve, and a mechanism for moving a choke valve and the throttle valve together during engine starting at low temperature, a spring mechanism being interposed in the mechanism so that closing direction movement of the throttle valve can be absorbed therein.

Abstract: An apparatus for the opening and closing control of a multicarburetor arrangement in which throttle valves of a plurality of carburetors are controlled to be opened and closed by a single common throttle valve operation member. A single drum shaft is inserted through respective carburetor casings and is connected by respective throttle shafts to the throttle valves. The drum shaft is rotatably supported in two bearings in two carburetor casings and the drum shaft is driven in rotation by the common operation member.

Abstract: An acceleration pump apparatus in a carburetor having a pivotable throttle valve operation drum and an acceleration pump, a driving lever for the acceleration pump being pivotally mounted on a supporting shaft which is parallel to the support shaft of the throttle valve operation drum so as to be turnable in the same direction as the throttle valve operation drum. One end of the driving lever is in engagement with a push rod for operating the acceleration pump, and the other end of the lever has a surface facing a pin secured on the throttle valve operation drum, the pin and driving lever being held in engagement with one another by a tension spring.