I'm using a YS110. It's an excellent choice. But the way the plane is built you can easily move the servo for the rudder to the tail (already a mount there, and in the fuse, cool) so you can use a heavier engine as well. I think a Saito 150 or even 180 would be good choices. Not24 has an OS160 in his but I think that's way>>>overkill. I think that new OS120 2 stroke looks very interesting. or even a YS140 Sport would work well. I wouldn't go with the OS46LA but that's just me.

It really is that good. And flexible. All of the above engines would work and I'm sure a few others too.

Thanks
Barry