Because of variations in models, it is not possible to include this information for all of our products on this website. We recommend that you have this procedure completed by an authorized dealer.
The raw water section of the cooling system must be COMPLETELY drained for winter storage, or immediately after cold weather use, if the possibility of freezing temperatures exists. As manual multi-point drain systems can have as few as three blue drain plugs and as many as seven, MerCruiser recommends referring to your Operation, Maintenance & Warranty manual or Service manual for the type of drain system you have.
Draining of the seawater section of your engine does not mean it is winterized, MerCruiser requires that propylene glycol antifreeze be used in the seawater section to insure protection from freeze damage. Failure to do this may result in trapped water causing freeze and/or corrosion damage to the engine.
Damage caused by freezing or improper winterization IS NOT covered by the MerCruiser limited warranty.