new to airboats need help

[gonefishing]

A few years ago my father crashed his powered parachute and decided he didnt want to fly anymore.He gave me what was left of the unit and said do what you want with it. The motor runs perfect and the aluminum cage it is mounted to survived but the prop and parachute didnt make it. It sat in my back yard collecting dust until the other day when I came accross your site. I would love to build a mini airboat out of this unit to fish the rivers and creeks where I live but wonder what size and weight of hull would I be limited to. The engine is a Bombardier 503 rotax aprox 50hp ( http://www.leadingedge-airfoils.com/503dual.htm )that could easily bumped up to 65 or 70hp. Would it be possible to build a two seater with this engine. Last but not least prop selection, are airboat specific props required or can I use the same prop used for flying. Two of the three blades are cracked but replacable and the adjustable hub is in working condition. Any help with this project would be greatly appreciated.

[papajack]

The rotax will work in an airboat. The prop will not. With some hulls a two seater is very doable, depending on what you expect to do with the boat and water conditions where you run. I would suggest that you look through the threads on two cycle engines and study that first. Many of the questions and answers have been discussed here without the bashing that occurs on some sites. The time that you spend on these threads will save you time and $$$$$$$$$$$$$$$$$$. Good luck with your project.

[Flathead]

There is also a wealth of information online in the ultralight aircraft community concerning rotax motors and prop selection. Save me a lot of time and trouble.

Flathead