LF has a point. I often use engines on the small end of the scale, but I build light, and I think that's the key. I pay especially close attention to the extremities...tail and wing tips, because that's what gives crisp handling. People tend to beef up kits and add accessories when they use large engines and their planes are often on the heavy side. With a light airframe you can use a low pitch, large diameter prop to get the vertical. You don't need a lot of speed for a scale model, unless that's the way you like to fly.

The 55AX is a great engine, and more powerful than a lot of older 60s, which is what the plane was designed for many years ago. And if you don't like it, do what LF says and put on a bigger engine later.

Jim