Join Date: Aug 2017
Model: Shadow Spirit VT1100C A
Location: Milford, Michigan
The rear cylinder which is burning the oil is the same one that was running in your words "realllly rich" previously. If this condition lasted long wnough, there's always the possibility that the excess fuel was washing the oil off the cylinder and scored the walls themselves.
I'm just trying to brain-storm here and not trying to diagnose it at this point.