A walk behind mower includes an engine-driven transmission for driving a pair of wheels at rate that varies according to the position of a transmission setting control selected by an operator. The transmission setting control positions a member that has a stop surface proximate to a transmission speed input on the transmission. The transmission speed input is adjusted by one or more levers on a handle of the mower. The transmission setting control is adjusted to define a home position of the stop surface relative to the transmission speed input and define a range of travel of the transmission speed input before it contacts the stop surface. The member is spring biased toward the home position but is moveable away from the home position. The position of the transmission speed input when it contacts the stop surface defines a first rate of travel of the transmission. An operator applies a first amount of force to the lever until the transmission speed input contacts the stop surface. The operator can apply a second greater amount of force to the lever that exceeds the spring biasing force on the member to further move the transmission speed input to define a second higher rate of travel of the transmission.