ORIGINAL: skelrad
I do have a question regarding the "Sturdy Birdy" mentioned. On Tower's website it says it can take up to a .40 engine, but in the manual it says not to exceed .30 due to weight. Better to go with a different model, like the Duraplane Trainer that is built for a .40 size engine, or do you think the Sturdy Birdy would be okay with the bigger engine? By the way, I'm at 9000 feet, so as far as power goes, the bigger engine the better.
It depends upon which .40 you have.
If you have the .40 LA then it will work fine on the Sturdy Birdy as the .40 is more like a .25 FX in weight and power.
If you have the .40 FX, then yeah go with something else.