A governor mechanism for use with a fuel pumping apparatus includes a centrifugal weight mechanism (37, 38) which is coupled to an output member (40) the latter being coupled to a fuel control member so that with increasing speed the quantity of fuel supplied by the apparatus is reduced. A governor spring (43) opposes the movement of the output member but in addition a leaf spring (46) is provided to supplement the action of the governor spring. The leaf spring is formed by one end of a torsion spring (48) which is wound about a cylindrical member (50). The cylindrical member (50) and the torsion spring (48) are axially movable relative to each other to alter the effective number of turns of the torsion spring connected in series with the leaf spring.