| 摘要 |
PURPOSE:To prevent the excessive increase of an air-fuel ratio due to the outflow from an acceleration pump during the acceleration-to-deceleration transitional period by providing an electromagnetic switch valve, which opens to air at the time of deceleration, in a passageway through which a supercharged air is led into the float chamber of a carburetor. CONSTITUTION:A supercharged air upstream of a carburetor is led, via a pipe 23, into a float chamber 14 of the carburetor which has an acceleration pump 18 linked with a throttle valve 13, supplying an amount of fuel well fit for an amount of supercharged air. An electromagnetic switch valve 24 provided in the pipe 23, when not energized, closes an open-to-air hole 25 and opens the pipe 23. And, during a regular operation the supercharged air is led in, and at the time of acceleration the fuel is jetted out from a nozzle 15 by the acceleration pump 18. At the time of deceleration, the negative pressure of an intake pipe closes a switch 27 through a pipe 26, and makes the electromagnetic switch valve work to lead air into the float chamber. In this way, the float chamber decreases its inside pressure, leading to no jet of the fuel from the nozzle 15 through the acceleration pump 18. |
