I have the same Eindecker 90 from Balsa USA. I have a 23.6 CC Echo engine on it. Also have all my engines on CH systems. My Echo engine weighs at least 1.5 pounds less than you are getting and mine balanced perfect. Radio gear in the middle right under the wing. Batteries and all. Ignition box is right behind the firewall. I did add another firewall but only to meet my requirements and I wanted a solid ring to mount the cowl to instead of the screw blocks. Flying is a dream, 7300 with a MA 16/6. In anything else it may be under powered but not in this. Only thing you may want to watch is your ignition battery. Had a 700ma in there and maybe 3 flights. But the flights are 20 minutes then I get tired of standing there flying slow. Even then there is still a third of a tank left out of a 14 ounce tank. Need to fly at at least 3/4 throttle so the system uses a third of the juice per flight. Using 1500ma now and no problem. Tried other prop sizes but this one works best for me. By the way I am using the Syncrospark with Bosch cap, but, you can easily use the standard ignition from them or Ralph. Less $$$ too!