Homemade Boat Motor Building A Homemade Boat Motor?

Building a Homemade boat motor? - homemade boat motor

I have a boat for 5 persons, can take the class 3 rapids, and have set up a space for an engine mount. Up to 3 hp motor.
The thing is that I do not want to buy an outboard motor or trolling thanks for this and would just like to waste time in long days.

What you can use to make this thing, the water, in addition to the rowing?
Is a motor of a vacuum cleaner?
one Weedeater?
Air Compressor?
, Etc., etc. .. plz no stupid answers