Mercury 565 Manual page 100

COLD WEATHER OR EXTENDED STORAGE
4. After draining seawater cooling system, install drain plugs (Perfect Seal is
not required on wingnut type plugs), reconnect hoses and tighten all hose
clamps securely.
5. Make sure the following passages are open and unobstructed:
a
6. For additional assurance against freezing and rust in the engine seawater
cooling system when storing for winter or long periods of nonuse, perform
the following steps:
IMPORTANT: A nontoxic and environmentally safe ethylene glycol antifreeze
containing a rust inhibitor must be used when preparing the seawater section
of the cooling system for cold weather or extended storage. Be certain to
follow the manufacturer's recommendations.
NOTE: If the boat is in the water during the following procedure, the seawater
shut off valve must be closed and the hose removed from the engine side of
the valve to avoid water entering the boat.
b
a - Speedometer pitot tube
b - Trim tab cavity vent hole
c - Trim tab cavity drain passage
c
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