| 摘要 |
PURPOSE:To prevent air-fuel mixture from getting too lean by the air drawn from a low-speed fuel system to a main fuel system at the time of high-load operation of an engine, by providing a check valve at the portion where th low- speed fuel system is branched from the main fuel system. CONSTITUTION:Fuel from a float chamber 1 is drawn from a main nozzle 6 to a venturi portion via a main jet 2 and a main fuel system 3-5. On the other hand, a low-speed fuel system is branched from the main fuel system and communicated with an idle port and a low-speed port via a low-speed jet 8, a check valve 12 and a passage 7. At the time of high-load operation of an engine, air tends to flow into the main nozzle via passages of the low-speed fuel system by the function of a high negative pressure at the main nozzle 6 and the atmospheric pressure at the low-speed port, but intrusion of air into the main nozzle via passages of the low-speed fuel system is prevented by the check valve 12. Therefore, it is enabled to prevent air-fuel mixture from getting too lean. |
