a valve needle of a carburetor of a lawn mower, the carburetor comprising a casing, and a throttle valve disposed on the casing and defining a screw hole, the valve needle being disposed on the throttle valve And comprising a shaft, a regulating seat disposed at one end of the shaft, an oil retaining needle body extending from the other end of the shaft, and a pressing member disposed on the shaft. The shaft includes an outer peripheral surface formed with an external thread and adapted to be locked in the screw hole, and the rod portion forms a receiving hole recessed by the outer circumferential surface. The pressing member is filled in the receiving hole and partially protrudes outside the receiving hole. The valve needle is forced to abut against the throttle valve by the pressing member to increase the friction force, so that the valve needle can be more stably locked on the throttle valve, thereby preventing the valve needle from deviating from the original position due to vibration, thereby improving positioning. The effect of sex.一種割草機之化油器的閥針，該化油器包含一殼體，及一設置於該殼體上且界定出一螺孔的節流閥，該閥針設置於該節流閥上，並包含一軸桿、一設置於該軸桿一端的調控座、一由該軸桿另一端延伸的止油針體，及一設置於該軸桿上的迫緊件。該軸桿包括一外周面形成有外螺紋而適用於鎖設在該螺孔內的桿體部，該桿體部形成一由外周面向內凹陷的容置孔。該迫緊件填塞於該容置孔內且部分凸出於該容置孔外。該閥針透過該迫緊件迫抵該節流閥而增加摩擦力，使該閥針能更穩定地鎖設於該節流閥上，避免該閥針因震動而偏離原位，達到提高定位性之功效。
