I did about 3 searches and can't find anything on my question. Went out today and put my electric starter on the spinner to start it up. Off comes the backplate and spinner. Retightened nut, with some serious torque...same thing...doesn't make for a very safe situation. I'm thinking that it may have something to do with the way the prop is positioned on the backplate, but I could be mistaken. The instructions with my Tower Trainer say when putting the prop on the backplate, to rotate the prop counter-clockwise unitl it hits the SMALLEST pin. The problem is this APC prop won't fit between the larger and smaller pins which, as I see it, is the only way to have it against the smaller pin. The only way I can get it to work is to rotate the prop counter-clockwise til it's against the LARGER pin. As you can see from the pic, when I do that, the spinner doesn't line up.
Any help/suggestions would be greatly appreciated.