Hope he's got the front wheel, and I notice the rubber roller looks like it's past its use-by date.
I've never seen one dismantled, I gather the large black part opposite the engine is the centrifugal clutch, so there will be concentric shafts (well, a shaft and a tube) with the roller on the outside of the outer tube.
If it has been stored with unfriendly fuel in it, the fuel system could be a wasteland.
