Mercury V6 175 Diagnostic Manual page 3

Notice to Users of This Manual
Throughout this publication, safety alerts labeled WARNING and CAUTION (accompanied by the International HAZARD
!
Symbol ) are used to alert the mechanic to special instructions concerning a particular service or operation that may be
hazardous if performed incorrectly or carelessly. Observe these alerts carefully.
These safety alerts alone cannot eliminate the hazards that they signal. Strict compliance to these special instructions when
performing the service, plus common sense operation, are major accident prevention measures.
Indicates a hazardous situation which, if not avoided, could result in death or serious injury.
Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
Additional alerts provide information that requires special attention:
Indicates a situation which, if not avoided, could result in engine or major component failure.
IMPORTANT: Indicates information essential to the successful completion of the task.
NOTE: Indicates information that helps in the understanding of a particular step or action.
This manual has been written and published by the Mercury Marine Service Department to aid our dealers' mechanics and
company service personnel when servicing the products described herein. It is assumed that these personnel are familiar with
marine product servicing procedures. Furthermore, it is assumed that they have been trained in the recommended service
procedures of Mercury Marine power products, including the use of mechanics' common hand tools and the special Mercury
Marine tools or recommended tools from other suppliers.
We could not possibly know of and advise the marine trade of all conceivable procedures and of the possible hazards and
results of each method. Therefore, anyone who uses a service procedure or tool that is not recommended by the manufacturer
must first completely satisfy himself that neither his nor the product's safety will be endangered.
All information, illustrations, and specifications contained in this manual are based on the latest product information available at
the time of publication. As required, revisions to this manual will be sent to all dealers contracted by us to sell or service these
products. We reserve the right to make changes to this manual without prior notification.
Refer to dealer service bulletins, operation and maintenance manuals, and installation manuals for other pertinent information
concerning the products described in this manual.
Precautions
While working on the product, keep in mind that the electrical and ignition systems are capable of violent and damaging short
circuits or severe electrical shocks. When performing any work where electrical terminals could possibly be grounded or
touched by the mechanic, the battery cables should be disconnected at the battery.
Any time the intake or exhaust openings are exposed during service they should be covered to protect against accidental
entrance of foreign material into the cylinders, which could cause extensive internal damage when the engine is started.
During any maintenance procedure, replacement fasteners must have the same measurements and strength as those
removed. Numbers on the heads of the metric bolts and on the surfaces of metric nuts indicate their strength. American bolts
use radial lines for this purpose, while most American nuts do not have strength markings. Mismatched or incorrect fasteners
can result in damage or malfunction, or possibly personal injury. Therefore, fasteners removed should be saved for reuse in the
same locations whenever possible. Where the fasteners are not satisfactory for reuse, care should be taken to select a
replacement that matches the original.
Personnel should not work on or under an engine that is suspended. Engines should be attached to workstands, or lowered to
the ground as soon as possible.
Replacement Parts
Use of parts other than the recommended service replacement parts will void the warranty on those parts that are damaged as
a result.
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WARNING
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CAUTION
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NOTICE
© 2018 Mercury Marine 90-8M0146617 eng JULY 2018