RE: Spinner question
Exactly
I use prop nuts on several four strokes, and have never had a problem. Just don't be scared to get it tight. It has to be real tight, but I've never had one "backfire" and come loose. I also have the saito .56, and trust me--that is one smooth running engine. You will not have one single bit of trouble with it throwing the prop nut--just get it tight to begin with!