Mercury FourStroke 2.5, Service Manual, Page: 78 / 205

Emissions
90-8M0065421 NOVEMBER 2012 Page 3B-3
Outboard Hydrocarbon Emissions Reduction
0
20
40
60
80
100
120
96 97 98 99 2000 01 02 03 04 05 06 07 08
22523
8-1/3% change per year over 9 model years
Emissions Information
Manufacturer's Responsibility
Beginning with 1998 model year engines, manufacturers of all marine propulsion engines must determine the exhaust emission
levels for each engine horsepower family and certify these engines with the United States Environmental Protection Agency
(EPA). A certification decal/emissions control information label, showing emission levels and engine specifications directly
related to emissions,
must
be placed on each engine at the time of manufacture.
Dealer Responsibility
When performing service on all 1998 and newer outboards that carry a certification, attention must be given to any adjustments
that are made that affect emission levels.
Adjustments must be kept within published factory specifications.
Replacement or repair of any emission related component must be executed in a manner that maintains emission levels within
the prescribed certification standards.
Dealers are
not
to modify the engine in any manner that would alter the horsepower or allow emission levels to exceed their
predetermined factory specifications.
Exceptions include manufacturer's prescribed changes, such as that for altitude adjustments.
Owner Responsibility
The owner/operator is required to have engine maintenance performed to maintain emission levels within prescribed
certification standards.
The owner/operator is
not
to modify the engine in any manner that would alter the horsepower or allow emissions levels to
exceed their predetermined factory specifications.
Exceptions
• Carburetor jets may be changed for high altitude use in accordance with factory recommendations.
• Single engine exceptions may be allowed with permission from the EPA for racing and testing.
EPA Emission Regulations
All 1998 and newer outboards manufactured by Mercury Marine are certified to the United States Environmental Protection
Agency as conforming to the requirements of the regulations for the control of air pollution from new outboard motors. This
certification is contingent on certain adjustments being set to factory standards. For this reason, the factory procedure for
servicing the product must be strictly followed and, whenever practicable, returned to the original intent of the design.