Hellow from the hills of West Virginia! The first engin I put in my P-6E was a Zenoha 20cc IE Gas. It flew her but that was all it did. No extra power at all. She could hardly go over the top in a loop! I installed a Zenoha 26cc without the IE and she flys like a charm and sounds great to. She flys like you would expect a P-6E to fly. She stays clean [ no fule and oil ] and I could not be more pleased with it. It really IS a Great Plane! Don't know why they discontinued her. Wish I could find another to stash just in case somthing happens to the one I have. The are a pleasure to watch and fly with the Zenoha 26cc.