My local dealer has a 9hp outboard, lower and mid unit. In short, everything I need for an electric motor, except the motor. I've got a 15hp brushless DC motor and as near as I can tell with my trusty micrometer, the same shaft.
So; my ignorance is about to come through. Is there any harm in running a 15hp electric motor on a unit designed for 9hp gas ? I had hoped to find a 25hp lower/mid, but I am not sure what the benefits would be (and the price is right).
I can only speak for OMC because we handled them. Many models from 9.9 - 15 horsepower varied only in tuning and carburetion. The gearboxes were identical.