class 1 mini build

[Southern_Son91]

hello everyone I am new to this site and I'm about to start my mini build so I'm glad I found this. I am not new to airboats just minis. I recently picked up a Kohler pro 15 hp single cylinder motor and have a few questions. any help will be greatly appreciated. how much power can one of these motors make and I plan on using the arrow prop redrive. so my questions are: what hp can be made and what prop with the 169:1 redrive? and I am also thinking about using the lake buggy design but making it 10x6 with slant nose and grass rake. any advise will be taken into consideration. thank you to everyone and awesome website. P.S. I have thick skin so if you see something wrong or a bad idea please correct me.

[Doozit20]

Hello and welcome to the site. Sounds like you have a pretty good plan on what you are planning. Although a 10x6 hull would be good in my opinion for the displacement in the water. The only thing I would say is to just watch your weight of your hull being made of wood. The redrive will help a lot in adding as much thrust as possible to your 15hp engine. As far as modifying the engine that is not my field of expertise so I will let others hopefully chime in on that subject.

Anyways welcome again to the site
Steve

[Papee]

What prop do you plan on running? I wouldn't run that engine at much more than 3600 rpm or it won't be reliable. 4000 rpm is OK for short bursts but I would not count on running a constant 4000 rpm, it just won't be reliable. The best thing to do is give Don a call and see what he suggests, he's usually right on with his numbers. A single cyl engine is not going to have the torque a twin would have but we build with what we have.