| 摘要 |
PURPOSE:To improve especially a low temperature starting characteristic, by extensibly providing a relatively removable control needle to a suction hole in a bore wall face of a carburetor at a a face-to-face position to the suction hole drilled in a head of a suction piston. CONSTITUTION:The captioned carburetor is provided with a suction piston 4', which opens and closes a Venturi part 7 in accordance with an intake air amount on the basis of opening of a throttle valve 3, and said piston 4' is stopped in a stationary state in a position in which suction negative pressure generated in a negative pressure chamber 16 through a suction hole 15' and atmospheric pressure of an atmospheric pressure chamber 19 and tension of a damper spring 21 are balanced. Here a tapered control needle 28 of circular section is embedded to the part of a barrel 5 at a face-to-face position to the hole 15' in a head 8' of said piston 4', and the total protrusive amount of said needle 28 is movably inserted concentrically to the hole 15'. In this way, a rich mixture necessary at starting can be generaged to improve a starting characteristic. |
