SERVICE
MANUAL
Number 25
MARINE ENGINES
GM V-6
262 CID (4.3L)
Printed in U.S.A. 1999, Mercury Marine 90-861328--1 1199
,MerCruiser #25 GM V-6 90-861328--1
262 CID (4.3L)
i
MerCruiser #25 GM V-6 90-861328--1
262 CID (4.3L)
90-
,Notice
Throughout this publication, “Dangers,” “Warnings” and “Cautions” (accompanied by the In-
ternational HAZARD Symbol ) are used to alert the mechanic to special instructions con-
cerning a particular service or operation that may be hazardous if performed incorrectly or
carelessly. OBSERVE THEM 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.
DANGER
DANGER - Immediate hazards which WILL result in severe personal injury or death.
WARNING
WARNING - Hazards or unsafe practices which COULD result in severe personal in-
jury or death.
CAUTION
Hazards or unsafe practices which could result in minor personal injury or product
or property damage.
Notice to Users of This Manual
This service manual has been written and published by the Service Department of Mercury
Marine to aid our dealers’ mechanics and company service personnel when servicing the
products described herein.
It is assumed that these personnel are familiar with the servicing procedures of these prod-
ucts, or like or similar products manufactured and marketed by Mercury Marine, that they
have been trained in the recommended servicing procedures of these products which in-
cludes the use of mechanics’ common hand tools and the special Mercury Marine or recom-
mended tools from other suppliers.
We could not possibly know of and advise the service trade of all conceivable procedures
by which a service might be performed and of the possible hazards and/or results of each
method. We have not undertaken any such wide evaluation. Therefore, anyone who uses
a service procedure and/or tool, which is not recommended by the manufacturer, first must
completely satisfy himself that neither his nor the products safety will be endangered by the
service procedure selected.
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 and/or service these products.
It should be kept in mind, while working on the product, that the electrical system and ignition
system 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 which could enter the cylinders and
cause extensive internal damage when the engine is started.
90-861328--1 NOVEMBER 1999 Page i
, It is important to note, during any maintenance procedure replacement fasteners must have
the same measurements and strength as those removed. Numbers on the heads of the met-
ric 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. Mis-
matched 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 when-
ever possible. Where the fasteners are not satisfactory for re-use, care should be taken to
select a replacement that matches the original.
We reserve the right to make changes to this manual without prior notification.
Refer to dealer service bulletins for other pertinent information concerning the products
described in this manual.
Engine Mechanical Components
Many of the engine mechanical components are designed for marine applications. Unlike
automotive engines, marine engines are subjected to extended periods of heavy load
and wide-open-throttle operation and, therefore, require heavy-duty components. Special
marine engine parts have design and manufacturing specifications which are required to
provide long life and dependable performance. Marine engine parts also must be able to
resist the corrosive action of salt or brackish water that will rust or corrode standard automo-
tive parts within a short period of time.
Failure to use recommended Quicksilver service replacement parts can result in poor en-
gine performance and/or durability, rapid corrosion of parts subjected to salt water and
possibly complete failure of the engine.
Use of parts other than recommended service replacement parts, will void the warranty on
those parts which are damaged as a result of the use of other than recommended replace-
ment parts.
Replacement Parts
WARNING
Electrical, ignition and fuel system components on MerCruiser Engines and Stern-
drives are designed and manufactured to comply with U.S. Coast Guard Rules
and Regulations to minimize risks of fire or explosion.
Use of replacement electrical, ignition or fuel system components, which do not
comply to these rules and regulations, could result in a fire or explosion hazard and
should be avoided.
When servicing the electrical, ignition and fuel systems, it is extremely important
that all components are properly installed and tightened. If not, any electrical or ig-
nition component opening would permit sparks to ignite fuel vapors from fuel sys-
tem leaks, if they existed.
Page ii 90-861328--1 NOVEMBER 1999
MANUAL
Number 25
MARINE ENGINES
GM V-6
262 CID (4.3L)
Printed in U.S.A. 1999, Mercury Marine 90-861328--1 1199
,MerCruiser #25 GM V-6 90-861328--1
262 CID (4.3L)
i
MerCruiser #25 GM V-6 90-861328--1
262 CID (4.3L)
90-
,Notice
Throughout this publication, “Dangers,” “Warnings” and “Cautions” (accompanied by the In-
ternational HAZARD Symbol ) are used to alert the mechanic to special instructions con-
cerning a particular service or operation that may be hazardous if performed incorrectly or
carelessly. OBSERVE THEM 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.
DANGER
DANGER - Immediate hazards which WILL result in severe personal injury or death.
WARNING
WARNING - Hazards or unsafe practices which COULD result in severe personal in-
jury or death.
CAUTION
Hazards or unsafe practices which could result in minor personal injury or product
or property damage.
Notice to Users of This Manual
This service manual has been written and published by the Service Department of Mercury
Marine to aid our dealers’ mechanics and company service personnel when servicing the
products described herein.
It is assumed that these personnel are familiar with the servicing procedures of these prod-
ucts, or like or similar products manufactured and marketed by Mercury Marine, that they
have been trained in the recommended servicing procedures of these products which in-
cludes the use of mechanics’ common hand tools and the special Mercury Marine or recom-
mended tools from other suppliers.
We could not possibly know of and advise the service trade of all conceivable procedures
by which a service might be performed and of the possible hazards and/or results of each
method. We have not undertaken any such wide evaluation. Therefore, anyone who uses
a service procedure and/or tool, which is not recommended by the manufacturer, first must
completely satisfy himself that neither his nor the products safety will be endangered by the
service procedure selected.
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 and/or service these products.
It should be kept in mind, while working on the product, that the electrical system and ignition
system 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 which could enter the cylinders and
cause extensive internal damage when the engine is started.
90-861328--1 NOVEMBER 1999 Page i
, It is important to note, during any maintenance procedure replacement fasteners must have
the same measurements and strength as those removed. Numbers on the heads of the met-
ric 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. Mis-
matched 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 when-
ever possible. Where the fasteners are not satisfactory for re-use, care should be taken to
select a replacement that matches the original.
We reserve the right to make changes to this manual without prior notification.
Refer to dealer service bulletins for other pertinent information concerning the products
described in this manual.
Engine Mechanical Components
Many of the engine mechanical components are designed for marine applications. Unlike
automotive engines, marine engines are subjected to extended periods of heavy load
and wide-open-throttle operation and, therefore, require heavy-duty components. Special
marine engine parts have design and manufacturing specifications which are required to
provide long life and dependable performance. Marine engine parts also must be able to
resist the corrosive action of salt or brackish water that will rust or corrode standard automo-
tive parts within a short period of time.
Failure to use recommended Quicksilver service replacement parts can result in poor en-
gine performance and/or durability, rapid corrosion of parts subjected to salt water and
possibly complete failure of the engine.
Use of parts other than recommended service replacement parts, will void the warranty on
those parts which are damaged as a result of the use of other than recommended replace-
ment parts.
Replacement Parts
WARNING
Electrical, ignition and fuel system components on MerCruiser Engines and Stern-
drives are designed and manufactured to comply with U.S. Coast Guard Rules
and Regulations to minimize risks of fire or explosion.
Use of replacement electrical, ignition or fuel system components, which do not
comply to these rules and regulations, could result in a fire or explosion hazard and
should be avoided.
When servicing the electrical, ignition and fuel systems, it is extremely important
that all components are properly installed and tightened. If not, any electrical or ig-
nition component opening would permit sparks to ignite fuel vapors from fuel sys-
tem leaks, if they existed.
Page ii 90-861328--1 NOVEMBER 1999
