Mercury MCM Series Important Information Manual page 27

9. Insert a small wire (repeatedly) to make sure that
speedometer pitot tube, trim tab cavity vent hole,
and trim tab cavity drain passage are unob-
structed and drained.
a
Typical Bravo Drive Unit
a - Speedometer Pitot Tube
b - Trim Tab Cavity Vent Hole
c - Trim Tab Cavity Drain Passage
a. Crank engine over slightly with starter motor
to purge any water trapped in seawater pick-
up pump. DO NOT ALLOW ENGINE TO
START.
b. After cooling system has been drained com-
pletely, coat threads of drain plugs with
Quicksilver Perfect Seal. Install all drain
plugs and tighten securely. Reconnect all
hoses and tighten all hose clamps securely.
Index
90-823224--2 796
IMPORTANT: MerCruiser recommends that pro-
pylene glycol antifreeze (nontoxic and biode-
gradable, which makes it friendly to lakes and riv-
ers) be used in sea-water section of the cooling
system for cold weather or extended storage.
Make sure that the propylene glycol antifreeze
contains a rust inhibitor and is recommended for
use in marine engines. Be certain to follow the
propylene glycol manufacturer's recommenda-
tions.
b
10. For additional assurance against freezing and
rust, remove the thermostat cover and thermo-
stat. Fill the engine seawater cooling system with
a mixture of antifreeze and tap water mixed to
manufacturer's recommendation to protect en-
gine to the lowest temperature to which it will be
exposed during cold weather or extended stor-
age. Using a new gasket, reinstall thermostat and
c
cover. Tighten cover bolts to 30 lb. ft. (41 N·m).
NOTE: Hoses shown removed only to indicate flow.
Do not remove hoses.
71217
a - Cover
b - Gasket
c - Spacer
d - Thermostat
e - O-Ring
f - Housing
g - Fill Here
a
b
c
f
MAINTENANCE - 1B-25
d
e
g
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