Mariner 30 JET 40 (4 CYL) User manual

MODELS
United States 0C159200 and Above. . . . . . .
Belgium 9570305 and Above. . . . . . . . . . .
Canada 0A748269 and Above. . . . . . . . . . . .
With Serial Numbers
SERVICE
MANUAL
30 JET 40 (4 CYL)
Printed in U.S.A. 1996, Mercury Marine 90-814676R1 DECEMBER 1996

90-814676R1 DECEMBER 1996 i
Notice
Throughout this publication, “Dangers”, “Warnings”
and “Cautions” (accompanied by the International
HAZARDSymbol )areusedtoalertthemechanic
tospecialinstructionsconcerningaparticularservice
or operation that may be hazardous if performed in-
correctly or carelessly. OBSERVE THEM CARE-
FULLY!
These“SafetyAlerts”alonecannoteliminatethehaz-
ards that they signal. Strict compliance to these spe-
cial instructions when performing the service, plus
“Common Sense” operation, are major accident pre-
vention 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 injury 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 per-
sonnel when servicing the products described here-
in.
It is assumed that these personnel are familiar with
the servicing procedures of these products, or like or
similar products manufactured and marketed by
Mercury Marine, that they have been trained in the
recommended servicing procedures of these prod-
ucts which includes the use of mechanics’ common
handtools andthe specialMercury Marineor recom-
mended tools from other suppliers.
Wecouldnotpossiblyknowofandadvisetheservice
trade of all conceivable procedures by which a ser-
vice might be performed and of the possible hazards
and/or results of each method. We have not under-
taken 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 con-
tained in this manual are based on the latest product
informationavailableatthetimeofpublication.Asre-
quired,revisionstothismanualwillbesenttoalldeal-
erscontractedbyustoselland/orservicetheseprod-
ucts.
It should be kept in mind, while working on the prod-
uct,thattheelectricalsystemandignitionsystemare
capable of violent and damaging short circuits or se-
vere 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.
Anytimetheintakeorexhaustopeningsareexposed
during service they should be covered to protect
againstaccidentalentranceofforeignmaterialwhich
could enter the cylinders and cause extensive inter-
nal damage when the engine is started.
Itisimportanttonote,duringanymaintenanceproce-
dure replacement fasteners must have the same
measurements and strength as those removed.
Numbers on the heads of the metric bolts and on the
surfacesofmetricnutsindicatetheirstrength.Ameri-
canboltsuse radial linesforthis purpose,whilemost
American nuts do not have strength markings. Mis-
matched or incorrect fasteners can result in damage
or malfunction, or possibly personal injury. There-
fore,fasteners removedshould besaved forreuse in
the same locations whenever possible. Where the
fasteners are not satisfactory for re-use, care should
be taken to select a replacement that matches the
original.

90-814676R1 DECEMBER 1996ii
Cleanliness and Care of
Outboard Motor
A marine power product is a combination of many
machined,honed,polishedandlappedsurfaceswith
tolerancesthat aremeasured inthe tenthousands of
an inch./mm. When any product component is serv-
iced,careandcleanlinessareimportant.Throughout
this manual, it should be understood that proper
cleaning, and protection of machined surfaces and
friction areas is a part of the repair procedure. This is
consideredstandardshoppracticeevenifnotspecif-
ically stated.
Whenever components are removed for service,
they should be retained in order. At the time of instal-
lation, they should be installed in the same locations
and with the same mating surfaces as when re-
moved.
Personnel should not work on or under an outboard
which is suspended. Outboards should be attached
toworkstands,orlowered togroundassoonas pos-
sible.
Wereserve the righttomake changes tothismanual
without prior notification.
Refertodealerservicebulletinsforotherpertinentin-
formation concerning the products described in this
manual.

Important
Information
Electrical & Ignition
Fuel System &
Carburetion
Powerhead
Mid-Section
Lower Unit
Outboard Motor
Installation/
Attachments
Oil Injection System 8
1
2
3
4
5
6
7
90-814676R1 DECEMBER 1996 iii
Service Manual Outline
Section 1 - Important Information
Section 2 - Electrical & Ignition
A - Ignition System
B - Battery, Charging System & Starting System
C - Timing, Synchronizing & Adjustment
D - Wiring Diagrams
Section 3 - Fuel System & Carburetion
Section 4 - Powerhead
Section 5 - Mid-Section
A - Clamp/Swivel Bracket & Drive Shaft Housing
B - Power Trim (Design I)
C - Power Trim (Design II)
D - Power Trim (Design III)
E - Power Trim (Design IV)
F - Manual Tilt System (Design I, II, III)
G - Manual Tilt System (Design IV)
Section 6 - Lower Unit
A - Lower Unit
B - Jet Drive
Section 7 - Outboard Motor Installation/Attachments
A - Outboard Motor Installation/Attachments
B - Tiller Handle and Co-Pilot
C - Rewind Starter
Section 8 - Oil Injection System

1
50332
IMPORTANT
INFORMATION
GENERAL INFORMATION and
SPECIFICATIONS