Abstract: A package that contains component parts of a carburetor tune-up kit is formed in a box-like configuration with a plastic overwrap that protects the component parts contained in the package from the environment outside the plastic. The package is configured to serve as a parts tray for the parts of the kit when the plastic overwrap has been removed. Four interconnected flanges at the top of the package together form a border around an access opening into the interior of the package. First and second members of an adjustable carburetor float gauge are formed integrally in two of the flanges. The first and second members are denoted in the flanges by perforated lines forming their boundaries. The perforated boundaries of the gauge members permit the members to be removed from the package and assembled into an adjustable carburetor float gauge shaped as a T square with a cross piece and linear rule, where the cross piece is mounted for sliding movement across the linear rule.