If you call Scotsman tech line they will help you out if your stuck, the guys they have in house are great. Does this unit have a hot gas defrost on the evaporator? I have had those things let refrigerant leak by. Water temp is very critical to these units. Another thing I would check is the position of the sensing bulb for the power head, and if the sensing bulb is insulated. TXV should also be insulated. All of these items will influence the system
Don't all ice machines have hot gas defrost? And, on a CM cuber, incoming water temp has no effect on the refrigeration cycle, other than warm incoming water extends the cycle time slightly, of course.