this was my first attempt at this idea. i was looking to get a motor for my little gheenoe and i could not afford to buy a new motor for it so i looked around my town while driving around and i found a 6hp lawn mower that was not running, and a friend of mine had a not running 9.9hp Johnson outboard. so i got both items for free. then it just took a little planning and some faith.
remove both motor from there devices.
lawn mower motor measure the shaft on the outboard motor and then drill the shaft on the mower to the same size
drill a set screw in the mower shaft
build a adapter bracket form the hollow leg of the outboard motor so it can be mounted to the lawn mower motor
bolt it all together and then test it out