A temperature compensated carburetor having a fuel metering system including a variable restriction needle gate valve (42) for varying the effective flow cross-sectional area of the main and/or idle fuel supply duct to modulate the flow rate of fuel to the carburetor venturi mixing passage (16). The needle gate valve (42) is made of plastic material having a much greater coefficient of expansion than the aluminum carburetor body (12) in which it is adjustably mounted such that differential linear expansion and contraction of the needle valve (42) relative to the carburetor body (12) in response to ambient temperature changes varies the flow-controlling cross-sectional area of the fuel duct inversely relative to ambient temperature changes. The needle valve (42) is a rod-like body with a threaded cylindrical mounting portion (60) at one end threadably secured in a threaded bore in the carburetor body (12). A reduced diameter extension of the needle body extends axially away from the mounting end of the needle body and has cylindrical stem portion (70) slidable in another bore (52) of the carburetor body (12). The needle body is unrestrained linearly from the free end of the stem portion (70) to the needle body mounting portion. The free end of the stem is movable in a jet fuel feeding passageway (28, 30) of the fuel duct to thus vary the flow controlling cross-section thereof.