G'day Sport Pilot. You have hit the nail on the head. The Kadet Senior is a large airframe with a light wing loading and overpowering it actually makes it less useful as a trainer.

This is why mine have all had small four strokes which have power in the range of a good 40 two stroke.

One of mine has a Saito 72 but only because it was the only engine I had spare. It is about the power of a good 46 two stroke and it very definitely over powers the model.

I trim my Kadets to fly level on about 1/3 to 1/2 full power. Then if I fly faster, I have to hold in quite a bit of down elevator. The main advantage of the larger engine is simply in making very short take off runs possible which makes it possible to take off across our strip if the wind is coming in the wrong direction.

For use as a trainer, I would recommend an OS LA 46 (cheap, simple and long lasting usually), or a small four stroke in the 50 to 61 size range such as the OS Surpass 52, the ASP or Magnum 52 or 61 or the Saito 45, 50 or 56.

Another small point with overpowered models. If you trim the model for full power, you will be dialing in quite a bit of down elevator. Then when you reduce the power to land, the model will put is nose down quite a bit and you will have to hold in lots of up elevator to make a tidy landing.

My oldest Kadet is currently on the operating table having some additional fuel proofing done around the engine bay area. A good coating of epoxy in this area when the model is new will stop a lot of problems later on.