Hey guys need some help here. Just bought a nexstar for my son. Put a saito 72 on it cause we had it laying around. From a Funtana Re-kitting on me.

I had a nexstar a few years back an i flew it with an O.S. 46 an it was great with a 11x5 prop. I could fly around at half throttle or a little higher without it being to fast.

Now with this saito i now its a little slower reving engine, i am also limited in prop length. I have a 11x6 an 12x8 prop. Which would be a good starting point. Thanks