I have an Echo 23.6 in a Balsa USA Eindecker, just finished making all the parts and test running a 25cc Toro with CH Ignition and will be switching to that. Also finished a 21cc Echo on CH for my two boys' Seagull Models 60 size Edge. You can put these little brutes in about anything you want. By the time you are done you will find the cost of the motors to be a little less than glow. That is with the $100.00 for the ignition. Best of all a 12 ounce tank of gas lasts about 20 minutes or so. Try one and have fun.