RE: Goldberg Yak 54 Engine choice
If I was going to stay with a glow engine, I would go with the Saito 220 4 stroke, or the Moki 2.10 2 stroke. But, by the time you pay for the big Saito, you could by a nice gas motor for it. The Moki is probably the best bang for the buck. I'd definitely consider a gasser on this plane, though.