Maintenance Instructions; Installation Diagrams; Cast Iron Elbows With 3 Inch Riser - Mercury MerCruiser MCM 454 Mag MPI Service Manual

SERVICE MANUAL NUMBER 23

Maintenance Instructions

Maintenance inspection is owner's responsibility and must be performed at intervals speci-
fied in owner's "Operation and Maintenance Manual".
1. Check to ensure exhaust elbow and manifold fasteners are adequately tightened.
2. Check to ensure hose clamps are adequately tightened.
3. Check area around exhaust elbows, manifolds and riser gaskets for leakage. Replace
Water must be completely drained from exhaust elbow riser during freezing temper-
atures. Failure to perform draining procedures can cause severe damage.

Installation Diagrams

Cast Iron Elbows With 3 Inch Riser

NOTE: Later models will have an open gasket (four slots) instead of a restrictor gasket (two
slots and two holes). If replacing gaskets, it is acceptable to replace the old gaskets with the
open gaskets. Be sure that the same type of gasket is used on both manifolds.
Index
90-861326--1 MARCH 1999
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gaskets, if necessary.
a - Exhaust Elbow
b - Separator Gasket
c - 3 Inch (76 mm) Exhaust Riser
d - Open Gasket
e - Restrictor Gasket
f - Nut (8)
g - Stud (8) 9-3/8 Inch (238 mm)
h - Stud (8) 10-3/8 Inch (264 mm) Used With Remote Oil Filter
i - Washer (8)
j - Exhaust Manifold
k - Refer To Note Following
CAUTION
i
f
a
e
k
c
d
g
h
j
RISERS
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