Shubova, that saito seems to be a good choice for your plane. I Have one of the early G-23's in mine and it does pretty good. The thing about this engine is that it takes a lot to break it in but once it is broken in, it developes it's potential power. It does however fly more scale than if it had a 150 in it. That is where this plane performs best in my opinion. Any plane will fly fast and do all of the doo-dads with excess power. The real challenge is to fly a scale plane scale. But what ever! If you are having a good time with yours like I am with mine, then, that is what counts! Just remember that without the flying wires, you can pull the top wing off! I don't mean the stretchy ones in the box, I mean really putting cables on it and tightening them. Then you will be able to perform safe tough manouvers. The full size is capable of sustaining 12 G's!!!! But, there is no way that you could put a full size in that situation!
My friend and I have been rebuilding a full size for the pase few years. It is a remarkable plane. 1941 vintage.
So long for now buddy. Bird.