Originally Posted by
hsukaria
I didn't know Fox had those, but Norvel (NV Engines) and one of my Irvine 40's has it. It is interesting that I have 2 identical model Irvine 40's, but only one of them has the screw-in prop shaft.
Actually quite a few Fox engines use threaded prop studs on the end of the crankshaft. You can usually tell when you take a look at where the threads end and the crankshaft shoulder starts.