Locating And Installing The Inboard (Mie) Exhaust System - Mercury MerCruiser D2.8L D-Tronic Service Manual

SERVICE MANUAL NUMBER 22

Locating And Installing The Inboard (MIE) Exhaust System

IMPORTANT: It is the responsibility of the boat manufacturer, or installing dealer, to
properly locate the engine and install the exhaust system. Improper installation may
allow water to enter the exhaust manifolds and combustion chambers and severely
damage the engine. Damage caused by water in the engine will not be covered by
Mercury MerCruiser Warranty, unless this damage is the result of defective part(s).
Determine if an exhaust riser kit or a water lift muffler kit is required, by taking measurements
"a"
"a"
kit must be installed.
Typical Inboard (MIE) Engine
Additional information:
1. If an exhaust riser or a water lift muffler kit is NOT required:
•
The exhaust outlet (for routing exhaust to outside of boat) must be located so that a mini-
mum of 13 mm (1/2 in.) per 305 mm (12 in.) downward pitch (drop) exists in the exhaust
hose or pipe from the engine exhaust elbow to the outlet.
•
A minimum drop of 100 mm (4 in.) overall is required. (This is an American Boat and
Yacht Council recommendation.) The drop must be constant so that a low spot does not
exist at any point in the exhaust hose or pipe.
2. Exhaust outlet must be slightly above the water line with boat at rest in the water and
a full load aboard.
3. Exhaust outlet should be equipped with an internal shutter to prevent seawater from
running back into exhaust system.
4. The use of an exhaust flapper on each outlet also is recommended.
90-860074--1 FEBRUARY 2002
and "b", with boat at rest in the water and maximum load aboard. Subtract
to find "c". If "c" is less than specified in chart, an exhaust riser kit or a water lift muffler
Model
All Models "c" Must Be 279 mm (11 in.) or More
d
a - From Waterline To Top Of Transom
b - From Highest Point On Exhaust Elbow To Top Of Transom
c - From "a" minus "b"
d - Waterline At Rest
MANIFOLDS, ELBOWS AND RISERS
"c" = "a" Minus "b"
b
a
c
c
"b" from
73592
Page 7B-9