ORIGINAL: chocorrol
and what about the engine? do you still think the TT 75 would be a good choice if I only want to do sport flying? I saw somewhere on the internet about a 60 size trainer and the specs stated a 70 four strokes engine would fit, that's why I metioned those engines at the begining
Trainers have much less wing loading and the flat bottom wing makes the plane 'floaty' so they don't need as much power. With 3 years of experience I think you will appreciate a .90 four stroke. You don't have to use all the throttle, and you can use the engine down the road in a bigger plane if you wish. It stinks to have a plane, buy a new engine, and wish you had more power and wanted a different engine.
This is a hobby, so do what makes you happy. If you want the minimum amount of power, get the .70. If you want a little extra, get the .90.