The high pitch whine is the starter trying to turn over a locked up engine.
Looks like you were a little too late with that oil.
Pull the plug and try to turn over the engine by hand.
Me thinks the engine is siezed.
If this is a Courage single, check the case on the exhaust side for a crack.
If it is cracked , check with Kohler.
here was a recall notice on these engines and according to some in the USA Kohler are replacing these engines .
Check also the 4 bolts that hold down the top plate over the top of the cylinder and to the left side ( looking at it from the front ).
Chances are they will be loose.
I have seen some backed out that far they prevented the flywheel from rotating.