Abstract: In a carburetor for an internal combustion engine having a primary air passage with an air valve therein and a fuel inlet port, an improvement comprising, a valve needle member having a portion extending into the fuel inlet port to a selected extent for varying the flow of fuel through the fuel inlet port and into the primary air passage. A secondary air passage is defined within the valve needle member to provide a secondary flow of air into the primary air passage. The secondary flow of air enhances mixture of the fuel and further regulates the flow of air in the primary air passage. A secondary air passage regulating body is resiliently held within the secondary air passage to selectively restrict the flow of air within the secondary air passage depending upon the position of the air valve in the primary air passage to at all times provide the proper flow of air within the primary air passage to induce full combustion of the fuel entering through the fuel inlet port.