Do a full blown tuned exhaust on the puppy and lets see how it does!
Wait a minute, did you say 27% Yak? Somewhere around 76" span? and you are putting a 58cc engine in it? Yikes!
So far AI is the only place other than palces like Macs to get exhaust flanges for BME.
Andy should have Keiths stock of mufflers by now and the 50ccBME exhaust will fit right to it. Kinda loud, kinda power robbing and guarranteed to blow exhaust slime all over your nice new plane but easy to install.