1991+ Kawasaki 650 SC Factory Service Manual, Page 176Get this manual
14-2 STORAGE Preparation for Storage
During the winter, or whenever the watercrah will not be in use for long period of time, proper storage is essentialIt consists of checking and replacing missing or worn parts; lubricating parts to ensure that they do not become rested; and, in general, preparing the watercrah so that when the time comes to use it again, it will be in top condition
Cooling System
.Clean the cooling system (see Cooling System Flushing in the Cooling and Bilge Systems chapter)