Mercury MERCRUISER, Service Manual, Page: 14 / 566

Protecting the Emissions System
Running Out of Fuel
NOTICE
Running out of fuel can damage catalyst components. Do not allow the fuel tanks to become empty during operation.
When the engine runs out of fuel, the temperature of the exhaust gases rises dramatically, reaching temperatures above
850° C (1500° F). These high temperatures can destroy catalysts rapidly. Never allow the engine to run out of fuel.
35104
Catalyst damage due to running out of fuel
Preventing Contamination of the Emissions Control System
Catalyst and oxygen sensors can become contaminated, leading to component failure.
Phosphorus, found in some marine‑grade oils, and other compounds will damage or destroy a catalyst's ability to clean the
exhaust. Catalyst‑friendly oil, such as Mercury MerCruiser Synthetic Blend Engine Oil, prevents this damage. Approved oils
must be used in MerCruiser engines with Emissions Control Technology (ECT), except in special circumstances. Refer to
Section 1A
‑
Engine Oil
for additional information.
NOTICE
Acetoxy silicone sealants and other compounds can damage oxygen sensors and catalysts. Use only compounds and
sealants approved by Mercury Marine for use on catalyzed engines, such as Loctite 587 High Performance Blue.
Fiberglass is a silica‑based material that can contaminate the catalyst and the oxygen sensors. To reduce the possibility that
the engine will ingest harmful fiberglass and poison the emission control components, protect the engine from fiberglass dust
and debris during construction and clean‑up.
Fuel system and engine cleaners in the form of an aerosol sprayed near or into the intake of an operating engine can
contaminate the catalyst and the oxygen sensors. The use of spray cleaners could cause irreversible damage to the catalytic
converter leading to component failure.
NOTICE
Aerosol fuel system and engine cleaners sprayed near or into the intake of an operating engine can damage the catalyst and
the oxygen sensors. Do not spray aerosol cleaners near or into the intake of an operating engine. Use only approved fuel
system additives.
The recommended method for fuel system and engine cleaning on an operational engine equipped with ECT is to use
approved cleaners added to the fuel system. The cleaners approved by Mercury MerCruiser include Quickare, Quickleen, and
Quickstor. Refer to the manufacturer's instructions for proper use.
Emissions Control
Page 1B-2 © 2016 Mercury Marine 90-8M0099748 eng DECEMBER 2015