Re: "Those engines are supposed to be tuned right out of the box"< thats what they say but in practice there a lot of threads of the low speed needle valve being completely closed from the factory! Mine was just the opposite. The low speed idle was open so much that fuel was sputtering out the top of carb at idle. If you have some experienced flyers around, ask them if they wouldn't mind checking the settings on the engine. They may be way out! I agree with the others on the fuel. High nito fuel is usually used for very small engines. I think your engine will overheat and die with that fuel so that doesn't help your engine. I would switch to 10% or 15% at the most. I only buy fuel that has 10% because I have some engines that don't like to run over that. [8D]