The Sierra 18-7370N carburetor is a completely new anodized aluminum casting, eliminating the need for remanufacture red castings that are becoming more difficult to rebuild due to the harsh environments marine carburetors are exposed to. Each Sierra carburetor is flow tested throughout the entire throttle range and are preset from the factory ensuring only fine adjustments are needed after installation. All Sierra Carburetors include the base gasket and meet or exceed all OEM specifications for exceptional life and performance.