MIE (Inboard) Engines
Exhaust Hose Connection
When designing and installing exhaust system, it is
very important that the following additional points be
taken into consideration:
1. Exhaust hoses must be connected to exhaust el-
bows so that they do not restrict the flow of dis-
charge water from the elbow. If hoses are con-
nected incorrectly, a hot spot in the hose can
occur, and can eventually burn through.
1.
System layout and construction must prevent
cooling system discharge water from flowing
back into engine and also must prevent seawater
from entering engine via exhaust at any point.
2.
3.
The exhaust hoses and pipes must not be higher
than exhaust elbows at any point.
a
The exhaust outlet (for routing exhaust to outside
of boat) must be located so that a minimum of 1/2
in. (13 mm) per foot (305 mm) downward pitch
(drop) exists in the exhaust hose or pipe from the
engine exhaust elbow to the outlet, with a mini-
mum drop of 4 in. (102 mm) overall. (This is an
American Boat & Yacht Council recommenda-
tion.) The drop must be constant so that a low
spot does not exist at any point in the exhaust
hose or pipe.
b
4.
5.
Exhaust outlet must be slightly above the water-
line with boat at rest in the water and full load
aboard. Exhaust outlet should be equipped with
an internal shutter to prevent seawater from run-
ning back into exhaust system. The use of an ex-
haust flapper on each outlet also is recom-
mended.
72538
a - Correct Connection
b - Incorrect Connection
2.
Exhaust hoses must be secured at each connec-
tion with two hose clamps.
System must not cause excessive back pres-
sure. Back pressure MUST NOT exceed 4 in.
(102
mm) of mercury when measured with a mer-
cury manometer at exhaust elbow outlets. Mini-
mum exhaust hose sizes are given in chart.
Minimum Hose Size
Model
Single Outlet
Dual Outlet
All (Except
Magnums)
5
in. (127 mm) 4 in. (102 mm)
Index
7A-2 - GENERAL
90-823224--2 796
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
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This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
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