Connections and grounds need checked. The ground on the engine, near the clutch lever is a common hassle.
It can look good, and not be good.

Another ground strap from the motor to the frame may keep your lights shinning bright ,but is not doing anything for your starter,which is your heavy electrical draw.The power to the starter must return from the motor case to the neg. side of the battery(the neg. wire being the same size as the pos. cable you replaced)or you could have future problems,trace the neg. cable back to the right side of the bike and clean it! IT's not rocket science!