An inhibit lock arrangement for a marine engine controller including a valve-operating shaft axially movable by an operator's handle, when set in a "start" position, for opening a valve whereby a fluid pressure signal is transmitted to the engine to start the engine. Axial movement of the shaft may be blocked by a piston rod actuated by a cylinder when the cylinder is pressurized by a pressure signal indicating an undesirable engine operating or malfunctioning condition. A pair of pivotable latches disposed on each side of the operator's handle for retaining the handle in a neutral position until a release piston is actuated by the operator for releasing the latches and permitting the handle to be moved through a slot but not into the "start" positions until the undesirable condition has been eliminated.