I just ran across this thread. The BUSA Ercoupe is one of those planes that I've always wanted to build when I could afford it. The time may this coming year. I'm wondering what engine everyong is using? My wife has given me free reign on this plane and I was thinking I would like to use an OS 3.20 Pegasus if it will fit in the cowl. I don't think I could bring myself to put a 2 stroke in this plane, Anyone know where I can download a copy of the kit manual?