1st post here. Just got a used Motovox MBX 10 minibike and was going though it before letting my son ride it. Removed the clutch assembly because i found some slop in the fit of the clutch key/key fit. After removing the clutch, the shaft if broken where the key sits in the shaft. What are the easiest/best options for repair. I'm not an engine guy but I am an Industrial Maintenance tech and work on equipment.