Most likely under the left side cover. But the problem with bikes that sit is not adjustment. The old grease has turned to tar. You need to take the clutch actuator (the spiral cam that pushes the clutch rod) apart and clean all the old grease out, regrease and it´ll be fine. Get a YamaLuber and use straight ATF to fill the cables. It´ll make the clutch feel smooth and easy.