yzf 750 r error codes

Can anybody help me please i have a 1998 yzf 750 r its an american import and im having a few problems with it. I have a constant error code comming up on the tacho at 12,000 rpm ..there is no error code for this exup is fine ,fuel sensor is fine plus usa bikes seem not to of had a tps.Does anyone know a bypass for the error codes i just want my rev counter back. Also running really rough at low revs ,adjuted pilots all over shop cleaned carbs still poo, have been told they may need ultrasonic cleaning anyone had simlar probs...any feed back be cool...Rich oxford uk