Can i create a home built aircraft with this engine? http://www.chiefaircraft.com/da-100.html
Would this engine work for a homebuilt ultralight aircraft? I am still in the research phase, so i don't know what the weight of the aircraft will be, but I would like to know what a good prop size and max weight that it will be able to fly.
It's a 100cc engine, and it's in the Radio Control section of that web site. It's an engine for model aircraft.

I suppose, technically, that's a home-built aircraft, but you're not going to sit in it!