It depends on what you want to get out of it. It won't take off in 5 feet and pull out vertically, but do you want that with an LT-40???

I've flown that combo (not my model, I was helping) and it was fine.

I have one under construction that will have 10+ year old OS 48 Surpass four stroke. Not too powerful either, but I also expect it will be fine.