1995-1997 Kawasaki 750ZXi-900ZXi Jet Ski Repair Manual., Page 196Get this manual
14-2 STORAGE Preparation for Storage
During the winter, or whenever the watercraft will not be in use for long period of time, proper storage is essentialIt consists of checking and replacing missing or worn parts, lubrication parts to ensure that they do not become rested, and, in general, preparing the watercraft so that when the time comes to use it again, it will be in top condition
Cooling System
Clea the cooling system (see Cooling System Flushing in the Cooling and Bilge Systems chapter)