OK,

I got it that the fox needs castor oil for the lube instead of synthetic. My .46, in the eagle, likes synthetic better. And it's even finickey about the brand it likes.

Other than needing castor oil (you said, I need a good understanding about "Why it's different") why is it different?

The .19 won't fly a plane the size of the eagle, so it'll have to go in some small sport plane. I'll need more flying experience to handle that.

Will the fox need a long break-in time? There's no paperwork with the engine. AND no muffler. I won't like that.

freeDeal