In the picture, nothing is tight. The washer is not even making full contact with the prop. The nuts in the picture are the standard nuts that come with Magnum/ASP four strokes.

The crankshaft does look pretty long. My brother and I have several Magnum 91s and the crankshaft length varies quite a bit. I am guessing they have multiple vendors for crankshafts but that is only a guess.