Mercury 305 CID User manual

Number 17
Printed in U.S.A. 90-823225--1 1096
1996, Mercury Marine
GM V-8
305 CID (5.0L) / 350 CID (5.7L)
MARINE ENGINES


Book 1 of 2
Sections 1 thru 4

90-823225--1 1096 i
Notice
Throughout this publication, “Dangers,” “Warnings”
and “Cautions”areusedtoalertthemechanictospe-
cial instructions concerning a particular service or
operation that may be hazardous if performed incor-
rectly or carelessly. Observe them carefully!
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- Immediatehazards whichwill resultin
severe personal injury or death.
!WARNING
WARNING - Hazards or unsafe practices which
could result in severe personal injury or death.
!CAUTION
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, of like or
similar products manufactured and marketed by
Mercury Marine, and that they have been trained in
the recommended servicing procedures for these
products which include the use of mechanic’s
common hand tools and the special Mercury
Marine or recommended 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 product’s safety will be endangered by the ser-
vice procedure selected.
All information, illustrations and specifications con-
tained in this manual are based on the latest product
information available at time of publication.
It should be kept in mind, while working on the prod-
uct,that theelectricalsystemandignitionsystemare
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.
It is important to note that, during any mainte-
nance procedure, replacement fasteners must have
the same measurements and strength as those re-
moved, whether metric or customary. Numbers on
the heads of the metric bolts and on surfaces of met-
ric nuts indicate their strength. Customary bolts use
radial lines for this purpose, while most custom-
ary nutsdonot havestrengthmarkings.Mismatched
or incorrect fasteners can result in damage or mal-
function, or possible personal injury. Therefore, fas-
teners removed should be saved for re-use in the
same locations whenever possible. Where the fas-
teners are not satisfactory for re-use, care should be
taken to select a replacement that meets the
same specifications as the original.

90-823225--1 1096ii
Engine Mechanical
Components
Many of the engine mechanical components are de-
signed for marine applications. Unlike automotive
engines, marine engines are subjected to extended
periods of heavy load and wide-open-throttle opera-
tion and, therefore, require heavy-duty components.
Special marine engine parts have design and man-
ufacturing specifications which are required to pro-
vide long life and dependable performance. Marine
enginepartsalsomustbeabletoresistthecorrosive
action of salt or brackish water that will rust or cor-
rode standard automotive parts within a short period
of time.
Failure to use recommended Quicksilver service re-
placement parts can result in poor engine perform-
ance and/or durability, rapid corrosion of parts sub-
jected to salt water and possibly complete failure of
the engine.
Use of parts other than recommended service re-
placement parts,willvoidthewarrantyonthoseparts
which are damaged as a result of the use of other
than recommended replacement parts.
Replacement Parts
!WARNING
Electrical, ignition and fuel system components
on MerCruiser Engines and Stern Drives are de-
signed 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 com-
ponents are properly installed and tightened. If
not, any electrical or ignition component open-
ing would permit sparks to ignite fuel va-
pors from fuel system leaks, if they existed.

90-823225--1 1096 iii
Models Covered in This Manual
MCM Alpha
MODEL SERIAL NUMBER MODEL YEAR
5.0L OD832472 - OF601000
1993 199
5.0LX OD831003 - OF601000 1993 - 1995
5.7L (4 Barrel) OD830700 - OF601000
5.7L (2 Barrel) OF601000 and Above
1996 Th 199
5.7LX OF601957 and Above
1996 Th 199
5.7L EFI OF286830 and Above
1996 Thru 1997
5.7LX EFI OF752400 and Above
1996
Thru
1997
350 Magnum OD830982 and Above
350 Magnum EFI Gen+ OF800500 and Above
MCM Bravo
MODEL SERIAL NUMBER MODEL YEAR
5.0L OD833077 - OF601464
1993
-
1995
5.7L (4 Barrel) OD831826 - OF605335
1993
-
1995
5.7L (2 Barrel) OF605336 and Above
1996 Th 199
5.7LX OF601645 and Above
1996 Th 199
5.7L EFI OF225560 and Above
1996 Thru 1997
5.7LX EFI OF752408 and Above
1996
Thru
1997
350 Magnum OD800300 and Above
350 Magnum EFI Gen+ OF800500 and Above
350 Magnum EFI/MP OF289431 - OF601999 1995
350 Magnum MPI Gen+ OF602000 and Above 1996 Thru 1997

90-823225--1 1096iv
MIE Ski
MODEL SERIAL NUMBER MODEL YEAR
5.7L Competition (4 Barrel) OD840220 - OF775199 1993 - 1995
5.7L Competition (2 Barrel) OF775200 and Above 1996 Thru 1997
350 Magnum Tournanment Ski OD840100 and Above 1993 Thru 1997
350 Magnum EFI Tournament Ski OF225157 - OK000000 1994 - 1996
350 Magnum EFI Gen+
Tournament Ski OK040006 and Above 1997
350 Magnum EFI/MP
Tournament Ski OF350583 - OF745536 1995
350 Magnum MPI Tournament Ski OF745537 - OK000000 1996
350 Magnum MPI Gen+
Tournament Ski (Black Scorpion) OF800000 and Above 1996
MIE Inboard
MODEL SERIAL NUMBER MODEL YEAR
5.7L OD84000 and Above 1993 Thru 1997
5.7L EFI Gen+ OK040300 and Above 1997

Important
Information
8
1
2
3
4
5
6
7
9
Removal and
Installation
Engine
Electrical Systems
Fuel System
Cooling System
Exhaust System
Drives
Power Steering
90-823225--1 1096 v
Service Manual Outline
Section 1 - Important Information
A - Specifications
B - Maintenance
C - General Information
Section 2 - Removal and Installation
A - MCM Models - Alpha One Drives
B - MCM Models - Alpha One Drives with Driveshaft Extension
C - MCM Models - Bravo Drives
D - MCM Models - Bravo Drives with Driveshaft Extension
E - MIE Models - Velvet Drive Transmissions
F - MIE Models - Hurth Transmissions
Section 3 - Engine
A - 5.0L / 305 CID / 5.7L /350 CID
Section 4 - Electrical Systems
A - Starting System
B - Ignition System
C - Charging System
D - Instrumentation
E - Electrical Kits
F - Wiring Diagrams
Section 5 - Fuel System
A - Fuel Delivery Systems and Fuel Pumps
B - MerCarb 2 Barrel Carburetor
C - Rochester 4 Barrel Carburetor
D - Weber 4 Barrel Carburetor
E - Electronic Fuel Injection (Throttle Body and Multi-Port)
F - BOS / SAV Emission
Section 6 - Cooling System
A - Seawater Cooled Models
B - Closed Cooled Models
Section 7 - Exhaust System
A - General
B - Manifold and Elbows
C - Risers
D - Collectors
Section 8 - Drives
A - Borg-Warner In-Line Transmission
B - Borg-Warner V-Drive Transmission
C - Hurth Down Angle Transmission
D - Drive Shaft Models/Propeller Shaft
Section 9 - Power Steering
A - Pump

A
1
72000
IMPORTANT INFORMATION
GENERAL INFORMATION

1A-0 –GENERAL INFORMATION 90-823225--1 1096
Table of Contents Page
Introduction 1A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How to Use This Manual 1A-1. . . . . . . . . . . . . . . . . .
Page Numbering 1A-1. . . . . . . . . . . . . . . . . . . . . .
How to Read Parts Manual 1A-2. . . . . . . . . . . . . . . .
Directional References 1A-3. . . . . . . . . . . . . . . . . . . .
Engine Rotation 1A-3. . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Serial Number Locations 1A-3. . . . . . . . . . .
Propeller Information 1A-4. . . . . . . . . . . . . . . . . . . . .
Water Testing New Engines 1A-4. . . . . . . . . . . . . . .
Boat and Engine Performance 1A-4. . . . . . . . . . . . .
Boat Bottom 1A-4. . . . . . . . . . . . . . . . . . . . . . . . . .
Marine Fouling 1A-5. . . . . . . . . . . . . . . . . . . . . . . .
Weight Distribution 1A-6. . . . . . . . . . . . . . . . . . . . .
Water in Boat 1A-6. . . . . . . . . . . . . . . . . . . . . . . . .
Elevation and Climate 1A-7. . . . . . . . . . . . . . . . . .
NOTICE
For information and procedures on
troubleshooting, refer to Section 1C.

GENERAL INFORMATION - 1A-190-823225--1 1096
NOTICE
Refer to appropriate Stern Drive Service
Manual for transom assembly and stern
drive unit repair.
Introduction
This comprehensive overhaul and repair manual is
designedasa serviceguideforthe modelsprevious-
ly listed. It provides specific information, including
procedures for disassembly, inspection, assembly
and adjustment to enable dealers and service me-
chanics to repair and tune these engines.
Before attempting repairs or tune-up, it is suggested
thattheprocedurefirstbereadthroughtogainknowl-
edgeofthemethodsand toolsusedandthecautions
and warnings required for safety.
How to Use This Manual
This manual is divided into sections which represent
major components and systems.
Some sections are further divided into parts which
more fully describe the component.
Page Numbering
Two number groups appear at the bottom of each
page. Following is an example and description.
72426

1A-2 –GENERAL INFORMATION 90-823225--1 1096
How to Read Parts Manual
841-81631 1 CYLINDER BLOCK ASSEMBLY 1
N.S.S. 2 PLUG, expansion (1-1/4”) (GM #3738306) 2
22-87238 3 DRAIN COCK, cylinder block 2
19-34270 4 PLUG, expansion - cylinder block (1-5/8” Diameter) 8
17-35465 5 PIN, dowel - block to head (5/16” Diameter) 4
22-72640 6 PLUG, expansion - camshaft bearing hole 1
23-85674 7 BEARING UNIT, camshaft (set) 1
72638 8 LIFTER, hydraulic valve 16
431-5943 9 CAMSHAFT 1
35378 10 CHAIN, camshaft timing 1
43-35338 11 SPROCKET, camshaft timing 1
43-48338 12 SPROCKET, crankshaft timing 1
10-34505 13 BOLT, camshaft timing sprockets (3/4”) 3
12-39167 14 WASHER, camshaft timing sprocket bolt 3
841-8163 Cylinder Block Assembly includes only standard pistons,
piston rings, crankshaft bearings and camshaft bearings.
PART NO. REF.
NO. DESCRIPTION QUAN.
a
A. Part Number: For part ordering - Note N.S.S. for Reference Number 2, Plug, expansion - that means Not Sold Separately by Mercury Marine
however, in this case, the G.M. Part Number (for the plug) is given in the Description Column.
B. Reference Number: For part Shown on exploded parts view.
C. Description: This is the most important column because it gives:
1) Description of Part: Ref. No. 1 is a Cylinder Block Assembly, No. 9 is a Camshaft, etc.
2) What parts are included with a certain part: Notice how the Description of Part, for Ref. Nos. 1 and 8 thru 14, are at the left side of the column.
Description of Part for Ref. Nos. 2 thru 7 are indented under “Cylinder Block Assembly”. If Ref. No. 1 (Cylinder Block Assembly) was ordered,
allindentedparts(Ref.Nos2thru7)wouldcomewiththepart.Ref.Nos.8 thru 14 would not come withRef.No.1andwouldhavetobeordered
separately. If 2Cylinder Blockswere listed, bothcylinder blocks wouldcome with the indented parts.In some cases,an indented partwill have
another part indented under it. The second indented part will come with the first indented part.
3) Serial number break: If serial number information is listed, check product serial number to ensure that correct part is ordered.
4) Specialinformation:Manytimesspecialinformationwillbeshownafterdescriptionsuchas;L.H.Rotation,R.H.Rotation,Filterup,FilterDown,
etc. This will help in selecting the correct part.
D. Quantity: Quantity that has to be ordered.
E. Special Information Block: Additional information, part numbers for gasket sets, etc.
M0033-D8
b
cd
e
CYLINDER BLOCK AND CAMSHAFT

GENERAL INFORMATION - 1A-390-823225--1 1096
Directional References
Front of boat is bow; rear is stern. Starboard side is
right side; port side is left side. In this maintenance
manual, all directional references are given as they
appear when viewing boat from stern looking toward
bow.
72000
STARBOARD
(RIGHT)
PORT
(LEFT)
FORE or BOW
(FRONT)
AFT or STERN
(REAR)
Engine Rotation
Engine rotation is determined by observing flywheel
rotation from the rear (stern end) of the engine look-
ingforward(toward water pump end). Propeller rota-
tion is not necessarily the same as engine rotation.
When ordering replacement engine, short blocks or
parts for engine, be certain to check engine rotation.
Do not rely on propeller rotation in determining en-
gine rotation.
72001
b
a
a - Standard Left Rotation - All MCM Stern Drive Engines,
MIE Inboard, Left Hand Rotation Engines.
b - Opposite Right Hand Rotation - MIE Inboard Right Hand
Rotation Engines.
Engine Serial Number
Locations
72468
b
a
72469
b
a
a - Serial Number
b - Starter Motor

1A-4 –GENERAL INFORMATION 90-823225--1 1096
Propeller Information
Refer to the “Propeller” section in appropriate Mer-
CruiserSternDriveServiceManual,ororderpublica-
tion P/N 90-86144, “What You Should Know About
Quicksilver Propellers.”
Changing diameter, pitch or coupling of a propeller
will affect engine RPM and boat performance. The
bladeconfigurationalsowill affectperformance.Two
likepropellers,samepitchanddiameter,fromtwodif-
ferent manufacturers also will perform differently.
Itistheresponsibilityoftheboatmanufacturerand/or
selling dealer to equip the boat with the correct pro-
peller to allow the engine to operate within its speci-
fied RPM range at wide-open-throttle (W.O.T.).
Because of the many variables of boat design and
operation,onlytestingwilldeterminethebestpropel-
ler for the particular application.
Totestforcorrect propeller,operateboat(withanav-
erage load onboard) at W.O.T. and check RPM with
anaccuratetachometer.EngineRPMshouldbenear
top of the specified range so that, under heavy load,
engine speed will not fall below specifications.
If engine exceeds the specified RPM, an increase in
pitch and/or diameter is required.
If engine is below rated RPM, a decrease in pitch
and/or diameter is required.
Normally,achangeofapproximately300to500RPM
willbeachievedforeachsinglepitchchangeofapro-
peller.
!CAUTION
If a propeller is installed that does not allow en-
gine RPM to reach the specified full-throttle RPM
range, the engine will “labor” and will not pro-
duce full power. Operation under this condition
will cause excessive fuel consumption, engine
overheating and possible piston damage (due to
detonation). On the other hand, installation of a
propeller, that allows engine to run above the
specifiedRPMlimit,willcauseexcessivewearon
internalenginepartswhichwillleadtopremature
engine failure.
Water Testing New Engines
Usecareduringthefirst20hoursofoperationonnew
MerCruiser engines or possible engine failure may
occur. If a new engine has to be water-tested at full
throttlebeforethe break-in period is complete, follow
this procedure.
1. Start engine and run at idle RPM until normal op-
erating temperature is reached.
2. Run boat up on plane.
3. Advance engine RPM (in 200 RPM increments)
until engine reaches its maximum rated RPM.
IMPORTANT: Do not run at maximum RPM for
more than 2 minutes.
Boat and Engine
Performance
Boat Bottom
For maximum speed, a boat bottom should be as flat
as possible in a fore-aft direction (longitudinally) for
approximately the last 5 ft. (1.5 m).
72002
a - Critical Boat Area

GENERAL INFORMATION - 1A-590-823225--1 1096
For best speed and minimum spray, the corner be-
tween the bottom and the transom should be sharp.
72003
a - Flat
b - Sharp Corner
The bottom is referred to as having a “hook” if it is
concave in the fore-and-aft direction. A hook causes
more lift on the bottom near the transom and forces
the bow to drop. This increases wetted surface and
reducesboatspeed.Ahook,however,aidsinplaning
and reduces any porpoising (rhythmical bouncing)
tendency. A slight hook is often built in by the man-
ufacturer. A hook also can be caused by incorrect
trailering or storing the boat with support directly un-
der the transom.
72004
a - Hook
A “rocker” is the reverse of a hook. The bottom is convex
orbulgedinthefore-and-aftdirection.Itcancausetheboat
to porpoise.
72005
a - Rocker
Any hook, rocker or surface roughness on the bot-
tom,particularlyintheall-importantcenter-aftportion
will have a negative effect on speed, often several
miles per hour on a fast boat.
Marine Fouling
Foulingisanunwantedbuild-up(usuallyanimal-veg-
etable-derived) occurring on the boat’s bottom and
drive unit. Fouling adds up to drag, which reduces
boatperformance.Infreshwater,foulingresultsfrom
dirt, vegetable matter, algae or slime, chemicals,
minerals and other pollutants. In salt water, bar-
nacles,mossandothermarine growthoftenproduce
dramatic build-up of material quickly. Therefore, it is
important to keep the hull as clean as possible in all
water conditions to maximize boat performance.
Antifouling paint, if required, may be applied to boat
hull observing the following precautions.
IMPORTANT: DO NOT paint anodes or MerCa-
thode System reference electrode and anode, as
this will render them ineffective as galvanic cor-
rosion inhibitors.
!CAUTION
Avoid corrosion damage. Do not apply antifoul-
ing paint to MerCruiser drive unit or transom as-
sembly.
IMPORTANT:Ifantifoulingprotection isrequired,
Tri-Butyl-Tin-Adipate (TBTA) base antifouling
paints are recommended on MerCruiser boating
applications. In areas where Tri-Butyl-Tin-Adi-
pate base paints are prohibited by law, copper
base paints can be used on boat hull and boat
transom.Corrosion damagethatresultsfromthe
improper application of antifouling paint will not
be covered by the limited warranty. Observe the
following:

1A-6 –GENERAL INFORMATION 90-823225--1 1096
Avoid an electrical interconnection between the
MerCruiser Product, Anodic Blocks, or MerCa-
thode System and the paint by allowing a mini-
mum of 1 in. (26mm) UNPAINTED area on tran-
som of the boat around these items.
71176
b
a
a - Antifouling Paint
b - MINIMUM 1 Inch (25.4 mm) UNPAINTED Area
Weight Distribution
Weight distribution is extremely important; it affects
aboat’srunningangleorattitude.Forbesttopspeed,
all movable weight - cargo and passengers - should
be as far aft as possible to allow the bow to come up
toamoreefficientangle(3to5degrees).Ontheneg-
ative side of this approach is the problem that, as
weight is moved aft, some boats will begin an unac-
ceptable porpoise.
Secondly, as weight is moved aft, getting on plane
becomes more difficult.
Finally, the ride in choppy water becomes more un-
comfortable as the weight goes aft. With these fac-
tors in mind, each boater should seek out what
weight locations best suit his/her needs.
Weight and passenger loading placed well forward
increases the “wetted area” of the boat bottom and,
in some cases, virtually destroys the good perform-
anceandhandlingcharacteristicsoftheboat.Opera-
tion in this configuration can produce an extremely
wet ride, from wind-blown spray, and could even be
unsafe in certain weather conditions or where bow
steering may occur.
Weight distribution is not confined strictly to fore and
aft locations, but also applies to lateral weight distri-
bution. Uneven weight concentration to port or star-
boardofthelongitudinalcenterlinecanproducease-
vere listing attitude that can adversely affect the
boat’s performance, handling ability and riding com-
fort. In extreme rough water conditions, the safety of
the boat and passengers may be in jeopardy.
Water in Boat
When a boat loses performance, check bilge for wa-
ter. Water can add considerable weight to the boat,
thereby decreasing the performance and handling.
Make certain that all drain passages are open for
complete draining.

GENERAL INFORMATION - 1A-790-823225--1 1096
Elevation and Climate
Elevation has a very noticeable effect on the
wide-open- throttle power of an engine. Since air
(containing oxygen) gets thinner as elevation in-
creases,theenginebeginstostarveforair.Humidity,
barometric pressure and temperature do have a no-
ticeableeffectonthedensityofair.Heatandhumidity
thin the air. This phenomenon can become particu-
larly annoying when an engine is propped out on a
cool dry day in spring and later, on a hot, sultry day
in August, doesn’t have its old zip. (See chart.)
Although some performance can be regained by
droppingto alowerpitchpropeller,thebasicproblem
still exists. The propeller is too large in diameter for
the reduced power output. The experienced marine
dealer or a Quicksilver Propeller Repair Station can
determinehowmuchdiametertoremovefrom alow-
er-pitch propeller for specific high-elevation loca-
tions.Insomecases,agear-ratiochangetothedrive
unittomorereductionispossibleandverybeneficial.
It is a known fact that weather conditions exert a pro-
found effect on power output of internal combustion
engines. Therefore, established horsepower ratings
refer to the power that the engine will produce at its
rated RPM under a specific combination of weather
conditions.
72006

B
1
IMPORTANT INFORMATION
MAINTENANCE

1B-0 - MAINTENANCE 90-823225--1 1096
Table of Contents Page
Maintenance Schedules 1B-1. . . . . . . . . . . . . . . . . . .
Maintenance Intervals 1B-1. . . . . . . . . . . . . . . . . .
Alpha Models 1B-1. . . . . . . . . . . . . . . . . . . . . . . . .
Bravo Models 1B-4. . . . . . . . . . . . . . . . . . . . . . . . .
Tune-Up Specifications 1B-7. . . . . . . . . . . . . . . . . . .
Tune-Up Specifications
(Gen + Engines Only) 1B-10. . . . . . . . . . . . . . . . . . .
Fluid Capacities 1B-11. . . . . . . . . . . . . . . . . . . . . . . . .
All Models 1B-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20-Hour Break-In Period 1B-12. . . . . . . . . . . . . . .
After Break-In Period 1B-12. . . . . . . . . . . . . . . . . .
Fuel, Oil, Fluid, and Coolant Specifications 1B-12.
Fuel 1B-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase Oil 1B-14. . . . . . . . . . . . . . . . . . . . . . . .
Power Steering Fluid 1B-14. . . . . . . . . . . . . . . . . .
Transmission Fluid 1B-14. . . . . . . . . . . . . . . . . . . .
Coolant for Closed Cooling System 1B-15. . . . .
Maintaining Crankcase Oil Level 1B-15. . . . . . . . . .
Overfilled Engine Crankcase 1B-15. . . . . . . . . . .
Checking Engine Oil Level/Filling 1B-15. . . . . . .
Changing Oil and Filter 1B-15. . . . . . . . . . . . . . . . . . .
Maintaining Power Steering Pump
Fluid Level 1B-16. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
With Engine Warm 1B-16. . . . . . . . . . . . . . . . . . . .
With Engine Cold 1B-16. . . . . . . . . . . . . . . . . . . . .
Filling and Bleeding Power Steering System 1B-17
Maintaining Closed Cooling Coolant Level 1B-17. .
Flushing Cooling System 1B-17. . . . . . . . . . . . . . . . .
MCM Stern Drive 1B-18. . . . . . . . . . . . . . . . . . . . .
MIE Inboard 1B-19. . . . . . . . . . . . . . . . . . . . . . . . .
Maintaining Transmission Fluid Level 1B-20. . . . . .
Lubrication 1B-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Throttle Cable 1B-21. . . . . . . . . . . . . . . . . . . . . . . .
Shift Cable 1B-23. . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Coupler/U-Joint Shaft Splines 1B-24. . .
Drive Shaft Extension Models 1B-24. . . . . . . . . .
Starter Motor (MIE Models) 1B-25. . . . . . . . . . . .
Audio Warning System 1B-25. . . . . . . . . . . . . . . . . . .
Maintenance 1B-25. . . . . . . . . . . . . . . . . . . . . . . . .
Cold Weather or Extended Storage 1B-25. . . . . . . .
Precautions 1B-25. . . . . . . . . . . . . . . . . . . . . . . . . .
Layup 1B-26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Draining Instructions 1B-28. . . . . . . . . . . . . . . . . .
Recommissioning 1B-39. . . . . . . . . . . . . . . . . . . . .

MAINTENANCE - 1B-190-823225--1 1096
Maintenance Schedules
Maintenance Intervals
Maintenance intervals and the tasks to be performed, as shown in this current schedule, or as found in a
previously printed schedules, are generally based on an average boating application and environment.
However, individual operating habits and personal maintenance preferences can have an impact on the
suggestedintervals.Inconsiderationofthesefactors,MerCruiserhasadjustedsomemaintenanceintervalsand
corresponding tasks to be performed. In some cases, this may allow for more individual tasks to be performed
inasinglevisittotheservingdealer,rather thanmultiplevisits.Therefore,itisveryimportantthattheboatowner
andservicingdealerdiscussthecurrentMaintenanceSchedule anddevelopappropriate maintenanceintervals
to coincide with the individual operating habits, environment, and maintenance requirements.
Alpha Models
SCHEDULED MAINTENANCE THAT CAN BE PERFORMED BY OWNER/OPERATOR
NOTE: Only perform maintenance which applies to your particular power package.
Task Interval
Engine Crankcase Oil - Check level
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Closed Cooling Coolant - Check level
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Power Steering Fluid - Check level
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Stern Drive Unit Oil - Check level
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Battery - Check level and inspect for damage
Weekly
Fuel Pump Sight Tube (If so Equipped) - Check that
no fuel is present
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ee
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y
Power Trim Pump Oil - Check level
Anodes - Inspect for erosion
Gear Housing Water Pickups - Check for marine
growth or debris
Drive Belt(s) - Inspect condition and check tension Every 100 hours of operation or 120 days.
Whichever occurs first.
Propeller Shaft - Lubricate Saltwater Use: Every 50 hours of operation or 60
days Whichever occurs first
Power Package - Exterior Surfaces - Spray with rust
preventative
days
,
Whichever
occurs
first
.
Freshwater Use: Every 100 hours of operation or
120 days, Whichever occurs first.
Power Package Exterior Surfaces - Clean and paint Once a year
Cooling System - Flush seawater section Saltwater Use: After every use.

1B-2 - MAINTENANCE 90-823225--1 1096
SCHEDULED MAINTENANCE THAT CAN BE PERFORMED BY DEALER
NOTE: Only perform maintenance which applies to your particular power package.
Task Interval
Seawater Pickup Pump - Disassemble and inspect Whenever insufficient seawater flow is suspected.
(If operating temperature exceeds normal range.)
Crankcase Oil and Filter Change
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Ignition system - Clean and Inspect condition.
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Flame Arrestor and Crankcase Ventilation Hose -
Clean and Inspect.
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Positive Crankcase Ventilation (PCV) Valve
(If Equipped) - Change
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Stern Drive unit Oil - Change
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Gimbal Ring Clamping Screws
Retorque to 50-55 ft. lb. (67-74 N·m)
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Rear Engine Mounts
Check torque to 30-40 ft. lb. (47-54 N·m)
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Gimbal Bearing - Lubricate
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Cooling System - Clean and Inspect
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Steering System - Lubricate and inspect for loose,
damage or missing parts. End of first boating season and thereafter, every 100 hours of operation or once yearly, whichever occurs
first
Electrical System - Check for loose or damaged
wiring. first.
Closed Cooling System Pressure Cap - Clean,
inspect and test.
Cooling System Hoses and Clamps - Inspect for
damage and deterioration. Check clamps for
tightness.
Continuity Circuit - Check components for loose
connections, broken or frayed wires.
Shift and Throttle Cable and Linkage - Lubricate and
inspect for loose, damaged or missing parts.
Engine Exhaust System - Inspect externally for
damage, deterioration and restrictions. Check for
tightness.
IgnitionSystem-Check Timingandadjustas needed.

MAINTENANCE - 1B-390-823225--1 1096
SCHEDULED MAINTENANCE THAT CAN BE PERFORMED BY DEALER (CONTINUED)
NOTE: Only perform maintenance which applies to your particular power package.
Task Interval
Steering Head and Remote Control - Inspect and
lubricate. End of first boating season and thereafter, every 100
hours of operation or once yearly whichever occurs
Carburetor (If Equipped) - Inspect and adjust. hours of operation or once yearly, whichever occurs
fir
s
t.
Throttle Body (EFI Models) - Inspect.
first
.
Fuel Filters - Replace.
OY
Quicksilver Mercathode System - Test output.
OY
Closed Cooling Coolant - Test for Alkalinity. Once a Year
Heat Exchanger - Clean seawater section.
Drive Unit Bellows and Clamps - Inspect.
Engine Alignment - Check. End of first boating season and thereafter,
Saltwater Use: Every 300 hours of operation or once
Engine Coupling Universal Joint Shaft Splines -
Lubricate.
S
altwater Use: Every 300 hours of operation or once
yearly, whichever occurs first.
Freshwater Use: Ever
y
300 hours of o
p
eration or
Universal Joint Cross Bearings- Inspect.
Freshwater
Use:
Every
300
hours
of
operation
or
once every two years, whichever occurs first.
Closed Cooling Coolant - Replace. Every Two Years