A fuel tank closure assembly includes an inner cap and an outer cover. The inner cap has a cylindrical side wall and multiple protrusions extending outward from the cylindrical side wall. The protrusions have a height less than a height of the cylindrical side wall. The outer cover has a cylindrical side wall with an inner diameter larger than an outer diameter of the inner cap. The cylindrical side wall has multiple openings and multiple hollows. The openings and the hollows in the outer cover each receive one of the protrusions to secure the cover to the cap and rotatably lock the cover and the cap together.