If your ground wire is getting hot then it is passing more than enough current. My thinking is to start with he starter motor, If it is slow and drawing excessive current then I would be getting that looked at. Suspect brushes or armature needs to be regrooved or possible shorted turn in the motor..

2002 Sporty , Ironman 2.5" spring, 2" body, 15 x 7 ROH wheels, K&N, 15 x 10.5 Simex Centipedes, Powerchip 91.

"Never argue with an idiot. They will bring you down to their level then beat you with experience!"