I have a VE4 [20 HP] that had a clutch, it is not part of the crankshaft on that one. I guess it all boils down to which is less work & money, changing the cylinder on the engine, or changing the engine on the welder. If You change the whole engine You don't need any rings or gaskets, but if the crankshaft end is different You have no choice but to swap the cylinder. I think I would start by removing the clutch on the MVF4 and seperating the engine from the generator, as that involves no new parts.