| 摘要 |
PURPOSE:To supplement fuel at warming-up of an engine when mixture is leaned by providing a supplementary fuel nozzle from which fuel is ejected thereat only at a bypass of an intake port wherein a throttle valve is disposed. CONSTITUTION:A bypass 11, bypassing a throttle valve 5, is connected with an intake port 2. A starting fuel nozzle 13 which hangs down to communicate with oil in a float chamber 4 via a starting fuel jet 12 opens to the bypass 11. An opening-and-closing valve 15 is slided inside a valve case 14 which is formed on the way of the bypass 11. A supplementary fuel nozzle 17 opens at the upstream side of the starting fuel nozzle 13 and a secondary opening-and-closing valve 20 which opens or closes a fuel passage 18 is slided inside a valve case 19 thereof. A negative pressure chamber 25 of the opening-and-closing valve 20 is communicated with a negatige pressure detective port 26 disposed at the lower side of the throttle valve 5 and accordingly, opening of the throttle valve 5 for powering an engine may induce reduction in negative pressure which acts in the negative pressure chamber 25, so that the supplementary fuel nozzle 17 is opened if oil ejected from the starting fuel nozzle 13 may be reduced. |
