JPS57165648A - Carburetor with machine for cold time excess fuel - Google Patents

Abstract

PURPOSE:To obtain adequate mixture ratio in accordance with a status of operation, in a carburetor feeding a rich mixture at cold time of an engine, by opening and closing a solenoid mechanism in an excess fuel bypass passage through an engine temperature detector switch. CONSTITUTION:At starting, an intake passage 2 is closed by a choke valve 10, if started here, the intake passage 2 also becomes negative pressure by negative pressure of a combustion chamber 4, and fuel is fed from a slow line port 19. In this case, because the valve 10 is closed, an air amount is decreased to obtain a relatively rich mixture, further fuel is also fed from a bypass passage 23 due to the negative pressure, then a mixture becomes excessively rich, thus starting can be surely performed even at cold time. On the other hand, when an engine is warmed up, a water temperature sensor 34 turns off a solenoid 30, and a plunger 29 is pressed by a spring 31 and lowered to close a valve hole 27 and close the bypass passage 23. At this time, normal fuel is fed into the passage 2 from the slow line port 19, 20 or main port 17.