same problem, different plane, different engine.

saito 100 with the ryan sta-m spinner that came with the bird and an apc prop. I'm left with just under 1/4" for the saito adapter to act as the locknut. Others have told me that its because of the very thick prop hub that creates lack of room to have more space at the locking end.

I've run it so far (virgin engine) without the spinner/adapter, just the backplate/prop/washer/nut/locking nut. no room for more than that.

It'll be interesting when I switch the locking nut for the adapter.