would help if you psted the make/model of the weedie you're talking about, i pretty much explained what's needed for an engine that just has a few threads sticking out past the flywheel.
sounds like you have a long shaft engine (ryobi?) that has the clutch shaft as an integral part of the crank, in this case the prop hub really is just a big spacer. nothing to be afraid of if you have a lathe to use.

dave