by attaching throttle levers which are particularly adapted to the given installation conditons etc fig4 to 6 show a few conceivable variations of special types of throttle levers for example fig4 show a throttle lever 4 1 whose axially projecting finger like member 6 is arranged to engage in the upper bore 5 of the basic actuating disc 2 so that the acceleration cable coming from the vehicle accelerator pedal would engage at the downwardly oriented lever arm 14 and would pivot it to the right i e counterclockwise when the accelerator pedal is depressed in fig5 on the other hand however a throttle valve lever 4 2 is shown with its finger like member 6 arranged to engage in the lower recess 5 of the basic actuating disc 2 so that the accelerator cable coming from the accelerator pedal would deflect the upwardly projecting lever arm 14 to the left again counterclockwise when the accelerator pedal is depressed therefore as can easily be seen from a consideration of fig3 the carburetor throttle valve would be displaced in the same direction as that effected by the throttle valve lever 4 1 of fig4 finally fig6 shows a further throttle valve lever 4 3 whose downwardly projecting lever arm 14 39 is composed of the two spaced bars serving as bearing jaws for the bearing shaft of a known accelerator rod assembly for the sake of completeness fig1 also shows that the basic actuating disc 2 or its cylindrical pin 7 can be fastened on the throttle lever shaft 3 with the aid of a washer 12 and a nut 13 fig2 supplements the showing of the connection between the basic actuating disc 2 and the throttle valve lever 4 it is understood that supplementary to the illustrated.