It is possible that maybe you have it too lean and just richening the mixture a little would solve it. If that gets you nowhere then replace the fuel lines and shorten them as much as possible. You can get a small pinch clip like is used to clip office papers together to put on your fuel line to prevent the flooding while the plane is sitting. Your prop doesn't seem to be what is normally used in 3D and hovering. The 3D flyers at my field prefer the longer less pitched props. Yours is typically a high speed prop. I would try something like a 14x4 or 15x4 if you can to see how they help out, but whatever you like best is what I would suggest you stick with.