There are some Four stroke warbirds going fast. here is a blurring video of my Vendetta on a 14x14 prop doing an average of 184.5. just this last weekend with a new carbon fiber prop I did an average of 196.4. I hope to break 200 soon with a four stroke. Engine is a YS115 Warbird Special
https://www.youtube.com/watch?v=cQ66l7nQOls