| 摘要 |
PURPOSE:To aim at saving fuel, by providing a solenoid valve and an open degree limiting screw for limiting the open degree of a throttle valve by being abutted against a throttle valve lever upon idle speed, so that the solenoid valve is switchingly controlled in dependence upon loading and noloading conditions, thereby the idle speed is made variable in accordance with the loading condition. CONSTITUTION:A carburettor is provided with a main fuel system comprising a main nozzle 4 opened to a fixed venturi part 17, a main air bleed 3 and a main jet 2, and a low speed fuel system comprising a slow jet 5, a slow air bleed 6, a bypass port 7 and first and second idle ports 8, 10. In this arrangement, there are provided a solenoid valve 13 and an open degree limiting screw 14 for limiting the open degree of a throttle valve upon idle speed, and a solenoid valve 12 for opening and closing the idle port 10. Upon loading or noloading condition the solenoid valve 13 is energized or deenergized so that a plunger 19 is extended or retracted for making the idle speed variable, and as well upon engine stopping the solenoid valve 12 is closed. |
