Steering with the rudder while under power, the rudder hits the propellor if its put too far to port. Steering with the motor, one is confined to sitting toward the stern within reach of the motor. To solve both problems, I rigged a link from the rudder tiller across to the tiller of our Evinrude, slaving the rudder to the outboard, and visa-versa, so that when I put the boat's tiller over, the motor follows. This results in smooth and responsive steering with the rudder while under power.
I use the same tiller extension I use when under sail, and, because the propellor turns away from the rudder when the helm is pulled up, the prop doesn't hit the rudder when it's kicked up for shoal draft. The rig also permits using the boat hook as an extension of the outboard tiller handle when the rudder is shipped. Different makes of motor will require different solutions for the attachment of the link to the motor. I used a telescoping mop handle ($.50 at a yard sale), cut to the approximate length between the motor handle and the tiller, with a 1/4-inch hole through each end. Attaching the rod to the tiller is easy: drill a 1/4-inch hole through the tiller (top to bottom), place the rod on top the tiller, and secure it with a pin. (I use a trucker's hitch pin.) Behind the twist grip throttle assembly on the motor tiller I secured a 10-inch length of scrap tubing with two large hose clamps over a rubber bushing. Through this tube (top to bottom) I drilled a 1/4-inch hole to which the connecting link attaches with another pin.
The link can be quickly set up or disengaged. The telescoping rod allows alignment of the rudder with the motor for minimum drag. The motor tiller handle on the Evinrude is so shaped that the small tube on the motor handle angles inboard from the axis of the handle. When the rudder is shipped, I slip my boat hook over that tube so that I can steer using the motor while sitting or standing forward in the cockpit or even up by the mast.