The OS 40 LA is a most excellent engine for a trainer. It is light weight, user friendly and good power for basic flying. I have this engine in a WM Sky Raider Mach I trainer and it is an excellent combination. I use an APC 11X5 prop on mine with good success. If you are looking for more than basic flying from your plane, a larger engine, such as any BB 46 will give you a LOT more power. The 40 LA has many virtues, but high power is not one of them.