Well, I watched enough utube videos and read enough about os 40la's. Im not going to try to take off with that engine. Its not that I dont trust my skills, its just matter of gravity versus OS40la plus the weight of the plane just doesnt add up. When I run the engine at full throttle and pick up the plane and hold it in vertical position, I can still feel plane weighs the same. I assume full throttle would at least make the plane feel lighter ( Im not even talking about vertical climb or hovering). Everybody suggested OS46 here, I was thinking about getting a 4 cycle Magnum xl52, what do you guys think about Magnum? Is it a wrong option? I really want to go with a 4 stroke and stay in budget. What do you guys advise?