Cold Weather (Freezing Temperature), Seasonal Storage, And Extended Storage; Cold Weather (Freezing Temperature) Storage; Preparing Your Power Package For Seasonal Or Extended Storage - Mercury MerCruiser Diesel Inboard 2.8L Operation & Maintenance Manual

Section 5 - Storage

Cold Weather (Freezing Temperature), Seasonal Storage, and Extended Storage

IMPORTANT: Mercury Marine strongly recommends that this service be performed by a Mercury Diesel authorized repair
facility. Damage caused by freezing is not covered by the Mercury Marine Limited Warranty.
Water trapped in the seawater section of the cooling system can cause corrosion or freeze damage. Drain the seawater
section of the cooling system immediately after operation or before any length of storage in freezing temperatures. If the boat
is in the water, keep the seacock closed until restarting the engine to prevent water from flowing back into the cooling system.
If the boat is not fitted with a seacock, leave the water inlet hose disconnected and plugged.
NOTE: As a precautionary measure, attach a tag to the key switch or steering wheel of the boat reminding the operator to open
the seacock or unplug and reconnect the water inlet hose before starting the engine.
A boat is considered to be in storage whenever it is not in operation. The amount of time that the power package is not
operated may be for a brief period, such as during a day, overnight, for a season, or for an extended period of time. Certain
precautions and procedures must be observed to protect the power package from freeze damage, corrosion damage, or both
types of damage during storage.
Freeze damage can happen when water trapped in the seawater cooling system freezes. For example, after operating the
boat, exposure to freezing temperatures for even a brief period of time could result in freeze damage.
Corrosion damage is the result of saltwater, polluted water, or water with a high mineral content trapped in the seawater
cooling system. Saltwater should not stay in an engine's cooling system for even a brief storage time; drain and flush the
seawater cooling system after each outing.
Cold weather operation refers to operating the boat whenever the possibility of freezing temperatures exists. Likewise, cold
weather (freezing temperature) storage refers to whenever the boat is not being operated and the possibility of freezing
temperatures exists. In such cases, the seawater section of the cooling system must be completely drained immediately after
operation.
Seasonal storage refers to when the boat is not being operated for one month or more. The length of time varies depending
on the geographic location of the boat in storage. Seasonal storage precautions and procedures include all of the steps for cold
weather (freezing temperature) storage and some additional steps that must be taken when storage will last longer than the
short time of cold weather (freezing temperature) storage.
Extended storage means storage for a period of time that may last for several seasons or longer. Extended storage
precautions and procedures include all of the steps for cold weather (freezing temperature) storage and seasonal storage plus
some additional steps.
Refer to the specific procedures in this section related to the conditions and the length of storage for your application.

Cold Weather (Freezing Temperature) Storage

Water trapped in the seawater section of the cooling system can cause corrosion or freeze damage. Drain the seawater
section of the cooling system immediately after operation or before any length of storage in freezing temperatures. If the boat
is in the water, keep the seacock closed until restarting the engine to prevent water from flowing back into the cooling system.
If the boat is not fitted with a seacock, leave the water inlet hose disconnected and plugged.
NOTE: As a precautionary measure, attach a tag to the key switch or steering wheel of the boat reminding the operator to open
the seacock or unplug and reconnect the water inlet hose before starting the engine.
1. Read all precautions and perform all procedures found in Draining the Seawater System and drain the seawater section
of the cooling system.
2. Place a caution tag at the helm advising the operator to unplug and connect the water inlet hose or open the seacock, if
equipped, before operating the boat.
3. For additional assurance against freezing and corrosion fill the seawater cooling system with a mixture of propylene glycol
antifreeze and tap water. See Seasonal Storage instructions in this section.

Preparing Your Power Package for Seasonal or Extended Storage

Without sufficient cooling water, the engine, the water pump, and other components will overheat and suffer damage. Provide
a sufficient supply of water to the water inlets during operation.
IMPORTANT: If the boat has already been removed from the water, supply water to the water inlet holes before starting the
engine. Follow all warnings and flushing attachment procedures stated in Flushing the Seawater System.
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90-8M0133679 JUNE 2017
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