The one I had flew nice with a TT .91 four stroke. Check the firewall and reenforce it if needed. They may have fixed that issue by now but my firewall broke loose causing a dead stick during the climb out on take off. It stalled and hit hard breaking the main spar. I fixed it but not good enough and lost a wing half on the bottom of a loop and destroyed the plane. That's been a couple years ago and they may have addressed that problem, but I'd check it anyhow.