I used to have clutches like that on minibikes back in the day. The spring was wrapped around the outside of the clutch seated in a groove. That spring came apart a lot where it was joined. Always tried to fix them but that spring would just not stay put. New one was not in the cards. Make sure this fits your shaft.
Providing direct output to the transmission, the 4-Stroke Clutch Flyweight move and expand when you twist the throttle grip causing the bike to propel forward.