Well, you are going to have to look for a new torque driver, not clutch. That is the back half. A quick look on the googler doesn't bring one up, but they must be available OEM, as that 250 motor was used on several models.
If buying new from Kymco, also get new pins, o-rings, spring, as well as the nut. Maybe you can buy a whole new torque driver.
Finding a socket to fit the nut can also be a challenge. I have found that some large sockets can be found at the discount tool sellers, but they need to be modified. As the nut is thin, the chamfers in the socket keep the nut from seating. Take the socket to a belt sander and spend some time with it to flatten it out until the chamfer is gone.
You can also look up "fork cap nut" sockets for one that may fit. Good luck.