The trimmer engines can be OK. I have done a few Poulan engines, 42cc down to 25 I think. The 42 was from a Craftsman saw. Decent power but the trimmer engine was not too good. It would do OK in your plane but may be a little low on power due to the wing area I am thinking. I have done many saw engines and the Echos so far are my favorite. Echo blowers have almost the same power for the ones I have done. I have a 23.6 in an Eindecker 90 and it does very well. The Toro 25 is a screamer but the plug sticks straight down and may be an issue for you. Search for Echo and see from there. Also search for Homelite Powerstroke. I know someone who did one of those saw engines and it is very strong.