A fan won't flip the boat or weigh it down. Just collecting all of the required items, can be difficult. I had what I needed for it. 2" aluminum pipe, 2 2/8 flange bearings, a bender for the shroud, a 13 hp engine, a teleflex throttle cable, some small pulleys, 3" and 4" aluminum pipe to make two steering drums, some stainless cable, a long turnbuckle, some cable clamps, and we had made a drunk chicken cooker, I used for the motor mount. I bought a 2 3/8" press fit bearing for the bottom, and cut some 6" aluminum pipe to shell the bearing. The six inch pipe also fit the flange bearing. A good hole saw set, and someone with a small lathe, and a welder. A sawzall will cut aluminum just fine. Then there is the expensive part, the prop. Of course I had to remove the muffler, and flange mount a 1" pipe muffler, out to the side. The teleflex cable has to be stiff enough to stay out of the prop. I have never had a problem with mine.
As always,,,, should you disagree feel free to comment.