The Homie 25cc makes about as much power as the older single-ring Ryobi 31cc. The newer twin-ring Ryobi shown in the pics above makes quite a bit more power. I will only recommend the Ryobi if you cut the firewall so that the carb and muffler are recessed behind the firewall. I personally don't like the idea of extending the cowl. It will cause balancing problems, especially if you keep the magneto. And it screws up the nice clean lines of the Rascal, which is why I bought in in the first place.

I've got a Homie 30cc, which is almost identical to the 25cc, in a Super Decathlon. It is physically even larger than the 25cc Echo in the above pics, so you'll have to cut the cowl even more.

I am thinking about gutting the 21.1cc engine out of my Echo blower. It's the same as the FPE 21cc shown in the Rascal 110 manual, so it should fit a lot better. I've been wanting a blower with more power anyway (insert Tim "the tool man" Taylor grunt here).