Several embodiments of steering controls for connection to larger displacement outboard motors that are normally remotely controlled. Each tiller assembly includes at least a throttle control that is connected to the throttle control cable of the outboard motor and a transmission control that is connected to the transmission control cable of the outboard motor. In addition, embodiments of interlocks are depicted that are supported in the tiller assembly and which control the maximum speed of the engine when the transmission is in neutral or reverse and which also prevents shifting into these speeds when the outboard motor is being operated at speeds higher than the those maximum permitted in their respective transmission speeds.