I use a 5hp 4-stroke 20-inch Nissan on my 1975 M-17 on the transom cutout. It works fine except when using the motor to turn. It does not interfere with the rudder. In one instance in shallow water (sails down) I had to remove the rudder and use the motor to maneuver. All that was necessary was to raise the throttle lever to a vertical position which permitted good clearance and turn the motor using the carry handle. The only problem was that with the motor alone, turning the M-17 in a little wind became really sloppy but I was able to make it to the slip. There's still nothing like the rudder. Bill K M-17 (055)