SECTION - 3 EXHAUST SYSTEM
90-899883183 DECEMBER 2007 Page 3 / 12
1. Example of desired air flow through the boat.
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Poor Ventilation
Under certain conditions, permanently enclosed or canvas enclosed cabins or cockpits with
insufficient ventilation may draw in carbon monoxide. Install 1 or more carbon monoxide detectors
in your boat.
Although the occurrence is rare, on a very calm day, swimmers and passengers in an open area
of a stationary boat that contains or is near an operating engine may be exposed to a hazardous
level of carbon monoxide.
1. Examples of poor ventilation while a boat is stationary:
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a
b
a - Operating the engine when the boat
is moored in a confined space.
b - Mooring close to another boat with its
engine operating.
2. Examples of poor ventilation while a boat is moving:
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a
b
a - Operating the boat with the trim angle
of the bow too high.
b - Operating the boat with no forward
hatches open (station wagon effect).
Measuring Exhaust Elbow Height
General Information
The height of the exhaust elbows must be within the dimensions specified to prevent water
intrusion problems. Exhaust elbow risers must be installed, if needed, to obtain the proper exhaust
elbow height and exhaust angle. Take measurements with the boat in the water. Load the boat as
outlined to simulate the maximum loading conditions likely to be encountered in normal operation.
IMPORTANT: Exhaust elbow height is measured to the waterline inside of the water lift muffler
(instead of the water line outside of the boat) on applications so equipped. Refer to Water Lift
Muffler.
IMPORTANT: Load distribution recommendations are the responsibility of the boat manufacturer.
Any load distribution conditions that will affect the exhaust system must be clearly communicated
to the operator in the owner's manual. For example, the number of people that can be located on
the swim platform simultaneously should be included in the manual if this could pose a problem.
Measurements under all loading conditions must be within the following specifications.
Minimum Exhaust Elbow Height
Model Specifications
3.0 MPI 279 mm (11in.)