You can change the number
            of joints or influence objects that can influence a skin object’s
            points. In general, you set the initial Max influences value
            in the Smooth Bind Options when you
            bind skin. 
         
         To edit maximum influences
         
         
            - Select the skin object(s) whose maximum
               influences you want to edit.
            
- Select 
                        Skin > Edit Smooth Skin > Set Max Influences.
            
- In the Set
                  Max Influences window, set Max Influences.
            
- Click Apply to
               set the new value.