Installation - Mercury MerCruiser MCM 454 Mag MPI Service Manual

CLOSED COOLED (FRESH WATER) MODELS

Installation

Avoid seawater pickup pump impeller damage. DO NOT operate engine without
cooling water being supplied to seawater pickup pump.
1. Remove thermostat housing and gaskets. Discard gaskets.
2. Clean gasket surfaces on thermostat cover, thermostat housing and intake manifold.
3. Position gasket on intake manifold. Place thermostat housing on gasket.
IMPORTANT: If gasket has continuity rivets, do not coat with Quicksilver Perfect Seal,
or audio warning temperature switch may not work properly.
4. Install thermostat, as previously shown, into thermostat housing.
5. Position gasket on thermostat and reinstall thermostat cover. Torque bolts to 30 lb-ft
(41 Nm).
6. Connect hoses to thermostat cover. Tighten hose clamps securely.
7. With boat in the water and/or cooling water properly supplied to seawater pickup pump,
start engine and inspect for leaks.
Index
Page 6B-12
Downloaded from https://needmanual.com/
a - Thermostat Housing
b - Thermostat
c - Gasket
d - Thermostat Housing Cover
CAUTION
a
b
c
d
SERVICE MANUAL NUMBER 23
75746
90-861326--1 MARCH 1999