Really an electric motor? You know your are the 2nd person who suggested that. Could you elaborate a bit more? Why would you go electric? At most I will have only two batteries and how far could that take me! Would you carry a generator for re-charging the batteries? I'm assuming you mean like a trolling type motor and if so if it were you appx what size would you be looking for? I should read more carefully. I see you said "Start" motor. Are you referring to a starter motor as used to start a car engine?
Electric start, turn the key instead of pulling the cord.
Not an electric propulsion motor.