I believe it will separate after a few really good whacks. If not I
suspect your going to find something out of the ordinary that’s
keeping it from separating, possibly making both the crankshaft
and flywheel unusable. Its more likely that it just on there tighter
than normal, but what ever the case, I suggest you use this method
to its maximum potential before moving on to more drastic measures.
Tubs.
A "Boathouse Repair" is one thats done without having tools or the skills to do it properly.