Everything Jestr said. Most of the time my four strokes only have one nut on them, usually just the spinner adapter nut. I only use wood props on my gas engines in larger sizes, APCs on my glow engines. I loosen the spinner and prop nut on my gassers because the wood props compress and get loose, by loosening things myself at the end of the day I have to tighten everything up before every flying session. I do it this way because I tend to forget to re-tighten the prop before use. I never have had an APC just come loose like a wood prop.