Mercury 2.8 Diesel, 4.2 Diesel Maintance Manual

2.8 and 4.2 Diesel

Sterndrive Models

OPERATION &

MAINTENANCE

MANUAL

Welcome

You have selected one of the finest marine power packages available. It incorporates numerous design features to
ensure operating ease and durability.

With proper care and maintenance, you will enjoy using this product for many boating seasons. To ensure maximum
performance and carefree use, we ask that you thoroughly read this manual.

The Operation and Maintenance Manual contains specific instructions for using and maintaining your product. We
suggest that this manual remain with the product for ready reference whenever you are on the water.

Thank you for purchasing one of our products. We sincerely hope your boating will be pleasant!
Mercury Marine, Fond du Lac, Wisconsin, U.S.A.

Name / function:

John Pfeifer, President,
Mercury Marine

Read This Manual Thoroughly

IMPORTANT: If you do not understand any portion of this manual, contact your dealer. Your dealer can also provide a
demonstration of actual starting and operating procedures.

Notice

Throughout this publication, and on your power package, warnings, cautions, and notices, accompanied by the

8M0113987 1215 eng

International Hazard Symbol !, may be used to alert the installer and user to special instructions concerning 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 with these special instructions
while performing the service, plus common sense operation, are major accident prevention measures.

WARNING

!

Indicates a hazardous situation which, if not avoided, could result in death or serious injury.

!

CAUTION

Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.

NOTICE

Indicates a situation which, if not avoided, could result in engine or major component failure.

IMPORTANT: Identifies information essential to the successful completion of the task.

NOTE: Indicates information that helps in the understanding of a particular step or action.

IMPORTANT: The operator (driver) is responsible for the correct and safe operation of the boat, the equipment aboard,
and the safety of all occupants aboard. We strongly recommend that the operator read this Operation and Maintenance
Manual and thoroughly understand the operational instructions for the power package and all related accessories before
the boat is used.

WARNING

!

The engine exhaust from this product contains chemicals known to the state of California to cause cancer, birth
defects or other reproductive harm.

2.8 and 4.2 Diesel Sterndrive Models

The serial numbers are the manufacturer’s keys to numerous engineering details that apply to your Mercury Marine
power package. When contacting Mercury Marine about service, always specify model and serial numbers.

Descriptions and specifications contained herein were in effect at the time this was approved for printing. Mercury
Marine, whose policies are based on continuous improvement, reserves the right to discontinue models at any time or to
change specifications or designs without notice and without incurring obligation.

© 2016 Mercury Marine

Warranty Message

The product you have purchased comes with a limited warranty from Mercury Marine; the terms of the warranty are set forth
in the Warranty Manual included with the product. The Warranty Manual contains a description of what is covered, what is not
covered, the duration of coverage, how to best obtain warranty coverage, important disclaimers and limitations of
damages, and other related information. Please review this important information.

Copyright and Trademark Information

© MERCURY MARINE. All rights reserved. Reproduction in whole or in part without permission is prohibited.

Alpha, Axius, Bravo One, Bravo Two, Bravo Three, Circle M with Waves Logo, K‑planes, Mariner, MerCathode, MerCruiser,
Mercury, Mercury with Waves Logo, Mercury Marine, Mercury Precision Parts, Mercury Propellers, Mercury Racing,
MotorGuide, OptiMax, Quicksilver, SeaCore, Skyhook, SmartCraft, Sport‑Jet, Verado, VesselView, Zero Effort, Zeus, #1 On the
Water and We're Driven to Win are registered trademarks of Brunswick Corporation. Pro XS is a trademark of Brunswick
Corporation. Mercury Product Protection is a registered service mark of Brunswick Corporation.

Identification Records

Please record the following applicable information:

MerCruiser

Engine Model and Horsepower Engine Serial Number

Transom Assembly Serial Number (Sterndrive) Gear Ratio Sterndrive Unit Serial Number

Transmission Model (Inboard) Gear Ratio Transmission Serial Number

Propeller Number Pitch Diameter

Hull Identification Number (HIN) Purchase Date

Boat Manufacturer Boat Model Length

Exhaust Gas Emissions Certification Number (Europe Only)

TABLE OF CONTENTS

Section 1 - Getting to Know Your Power Package

Identification............................................................................... 2

Serial Number Decal........................................................... 2

Engine Data Label.............................................................. 2

Bravo Sterndrive Serial Number and Identification............. 3

Bravo Transom Serial Number........................................... 3

Features And Controls............................................................... 4

Audio Warning System....................................................... 4

Switches............................................................................. 4

Lanyard Stop Switch........................................................... 5

Keep the Lanyard Stop Switch and Lanyard Cord in

Good Operating Condition.............................................. 6

Instrumentation................................................................... 6

VesselView..................................................................... 6

SmartCraft Speedometer, Tachometer, and Digital

Gauges........................................................................... 7

System Link Digital Gauges........................................... 7

Emergency Stop Switch...................................................... 8

Section 2 - On the Water

Safe Boating Recommendations............................................. 18

Carbon Monoxide Exposure.................................................... 19

Be Alert To Carbon Monoxide Poisoning........................... 19

Stay Clear of Exhaust Areas.............................................. 19

Good Ventilation ................................................................ 19

Poor Ventilation ................................................................. 20

Important Operation Information.............................................. 20

Launching......................................................................... 20

Duty Cycle Rating Requirements...................................... 20

High‑Output Rating........................................................... 20

Operation Chart................................................................ 21

Freezing Temperature and Cold Weather Operation....... 21

Drain Plug and Bilge Pump............................................... 22

Trailering the Boat............................................................ 22

Starting, Shifting, and Stopping............................................... 22

Before Starting the Engine................................................ 22

Important Information – SmartStart................................... 22

Starting a Cold Engine...................................................... 22

Engine Warm‑Up.............................................................. 23

Starting a Warm Engine.................................................... 23

Shifting.............................................................................. 24

Engine Shut Down (Stopping).......................................... 24

Starting the Engine After Stopped While in Gear............. 24

Protecting People in the Water................................................ 24

While You Are Cruising................................................ 24

Remote Controls................................................................. 8

Panel Mount Features.................................................... 9

Console Mount Features................................................ 9

Power Trim....................................................................... 10

Single‑Engine Trim and Trailer..................................... 11

Dual‑Engine Trim and Trailer....................................... 11

Trim without Key............................................................... 11

Overload Protection—Upper Engine Circuit Breaker

Panel................................................................................. 11

Overload Protection—Port Side Power Distribution

Box.................................................................................... 12

Vessel Integration Panel (VIP) Overload Protection......... 13

Power Trim and MerCathode Overload Protection........... 13

Engine Guardian System.................................................. 14

SeaCore Equipped Drives....................................................... 14

SeaCore Components and Castings................................ 14

Stainless Steel Fasteners................................................. 14

While Boat Is Stationary............................................... 24

High‑Speed and High‑Performance.................................. 25

Passenger Safety In Pontoon Boats and Deck Boats...... 25

Boats Having An Open Front Deck.............................. 25

Boats With Front‑Mounted, Raised Pedestal Fishing

Seats............................................................................ 25

Wave and Wake Jumping........................................................ 25

Impact with Underwater Hazards............................................. 26

Sterndrive Impact Protection.............................................. 26

Conditions Affecting Operation................................................ 27

Weight Distribution (Passengers and Gear) Inside the

Boat.................................................................................. 27

Bottom of Boat.................................................................. 27

Cavitation.......................................................................... 27

Ventilation......................................................................... 27

Elevation and Climate....................................................... 27

Propeller Selection............................................................ 28

Getting Started......................................................................... 28

Initial Break‑In Procedure................................................. 28

Sterndrive 10‑Hour Break‑In Period (New or With

Replacement Gears)......................................................... 28

Engine Break‑In................................................................ 28

20‑Hour Break‑In Period...............................................28

After the 20‑Hour Break‑In Period................................ 29

End of First Season Checkup........................................... 29

Section 3 - Specifications

Fuel Requirements................................................................... 32

Diesel Fuel in Cold Weather.................................................... 32

Antifreeze/Coolant................................................................... 32

Engine Oil................................................................................ 33

Engine Specifications............................................................... 34

90-8M0113987 eng DECEMBER 2015 Page i

Fluid Specifications.................................................................. 34

Engine............................................................................... 34

2.8.................................................................................34

4.2.................................................................................34

Bravo Sterndrive Fluid Specifications—Diesel................. 34

Power‑Assisted Steering and Power Trim Fluids............ 35

Approved Power‑Assisted Steering Fluids.................. 35

Section 4 - Maintenance

Approved Power Trim Fluids....................................... 35

Approved Paints..................................................................... 35

Owner and Operator Responsibilities..................................... 38

Dealer Responsibilities........................................................... 38

Maintenance........................................................................... 38

Do‑It‑Yourself Maintenance Suggestions............................... 38

Inspection............................................................................... 38

Maintenance Schedules......................................................... 39

Routine Maintenance...................................................... 39

Scheduled Maintenance.................................................. 40

Engine Oil............................................................................... 41

Checking......................................................................... 41

Filling............................................................................... 41

Changing Oil and Filter.................................................... 42

Sterndrive Gear Lube............................................................. 43

Checking......................................................................... 44

Filling............................................................................... 44

Changing......................................................................... 45

Power Trim Fluid.................................................................... 47

Checking......................................................................... 47

Filling............................................................................... 48

Changing......................................................................... 49

Power‑Assisted Steering Fluid............................................... 49

Checking......................................................................... 49

Filling............................................................................... 50

Changing......................................................................... 50

Engine Coolant....................................................................... 50

Check Coolant................................................................. 50

Filling............................................................................... 50

Changing......................................................................... 51

2.8 Air Filter............................................................................ 51

Removal.......................................................................... 51

Inspection........................................................................ 52

Installation....................................................................... 52

4.2 Air Filter............................................................................ 53

Removal.......................................................................... 53

Inspection........................................................................ 53

Installation....................................................................... 54

Water‑Separating Fuel Filter.................................................. 54

Draining........................................................................... 55

Replacing........................................................................ 55

Filling............................................................................... 57

Fuel System............................................................................ 58

Priming............................................................................ 58

Filling (Bleeding).............................................................. 58

Fuel Tank Cleaning and Flushing.................................... 59

Seawater System................................................................... 59

Draining the Seawater System........................................ 59

Sterndrive Water Inlets Check......................................... 61

Checking the Seawater Pickups...................................... 62

Cleaning the Seawater Strainer, if Equipped.................. 62

Flushing the Seawater System—Sterndrive Models....... 64

With the Boat out of the Water.................................... 64

With the Boat in the Water.......................................... 66

Engine Seawater Pump Inspection................................. 67

Replacing the Engine Coolant in the Closed‑Cooling

System.................................................................................... 67

Draining the Closed‑Cooling System.............................. 67

Filling the Closed‑Cooling System.................................. 68

Corrosion Protection............................................................... 69

General Information......................................................... 69

Engine Corrosion Protection Components...................... 69

Removal...................................................................... 69

Cleaning and Inspection............................................. 70

Installation................................................................... 71

Sterndrive Corrosion Protection Components................. 72

Continuity Circuit—Bravo Sterndrive............................... 75

MerCathode..................................................................... 77

Boat Bottom Care............................................................ 78

Painting Your Power Package......................................... 78

Sterndrive Surface Care.................................................. 79

Lubrication.............................................................................. 79

Steering System.............................................................. 79

Throttle Cable.................................................................. 81

Shift Cable....................................................................... 81

Transom Assembly.......................................................... 82

Engine Coupler................................................................ 82

Driveshaft Extension Models........................................... 82

Sterndrive, Bellows, and Engine Alignment.................... 83

Maintaining Torques............................................................... 84

Bravo Gimbal Ring U‑bolt Nuts....................................... 84

Engine Mounts................................................................ 85

Propellers............................................................................... 85

Bravo Sterndrive Propeller Removal............................... 85

Bravo One Models...................................................... 86

Bravo Two Models...................................................... 86

Bravo Three Models.................................................... 87

Bravo Sterndrive Propeller Installation............................ 88

Bravo One Models...................................................... 88

Bravo Three................................................................ 89

Drive Belts.............................................................................. 90

Serpentine Belt................................................................ 90

Inspection.................................................................... 90

Replacement............................................................... 91

Power‑Assisted Steering Pump Belt............................... 92

Inspection.................................................................... 92

Adjustment.................................................................. 92

Replacement............................................................... 93

Battery.................................................................................... 94

Battery Precautions for Multiple Engines.......................... 94

Section 5 - Storage

Cold Weather (Freezing Temperature), Seasonal Storage, and

Extended Storage................................................................... 98

Cold Weather (Freezing Temperature) Storage.............. 98

Page ii 90-8M0113987 eng DECEMBER 2015

Preparing Your Power Package for Seasonal or Extended

Storage............................................................................ 98

Seasonal Storage Instructions........................................ 99

Extended Storage Instructions...................................... 100

Battery............................................................................ 100 Recommissioning................................................................... 100

Section 6 - Troubleshooting

Diagnosing Electronically Controlled Fuel System

Problems................................................................................ 104

Troubleshooting Charts.......................................................... 104

Starter Motor Will Not Crank Engine, or Cranks Slow.... 104

Engine Will Not Start, or Is Hard to Start........................ 104

Engine Runs Rough, Misses, or Backfires..................... 104

Poor Performance........................................................... 104

Incorrect Engine Temperature........................................ 105

Low Engine Oil Pressure................................................ 105

Section 7 - Customer Assistance Information

Owner Service Assistance..................................................... 108

Local Repair Service........................................................ 108

Service Away From Home................................................108

Stolen Power Package..................................................... 108

Attention Required After Submersion............................... 108

Replacement Service Parts.............................................. 108

Parts and Accessories Inquiries................................. 108

Resolving a Problem........................................................ 108

Section 8 - Maintenance Log

Battery Will Not Charge.................................................. 105

Remote Control Operates Hard, Binds, Has Excessive

Free‑play, or Makes Unusual Sounds............................ 105

Steering Wheel Turns Hard or Jerky.............................. 106

Power Trim does not Operate (Electric Motor Operates but

Sterndrive does not Move).............................................. 106

Power Trim Does Not Operate (Electric Motor Does Not

Operate).......................................................................... 106

Contact Information for Mercury Marine Customer Service

......................................................................................... 109

Customer Service Literature.................................................. 109

English Language............................................................ 109

Other Languages..............................................................110

Ordering Literature................................................................. 110

United States and Canada............................................... 110

Outside the United States and Canada............................ 110

Scheduled Maintenance Log................................................. 112 Vessel Maintenance Notes.................................................... 113

90-8M0113987 eng DECEMBER 2015 Page iii

Page iv 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

Section 1 - Getting to Know Your Power Package

Table of Contents

Identification........................................................................... 2

Serial Number Decal........................................................2

Engine Data Label........................................................... 2

Bravo Sterndrive Serial Number and Identification.......... 3

Bravo Transom Serial Number........................................ 3

Features And Controls............................................................ 4

Audio Warning System.................................................... 4

Switches.......................................................................... 4

Lanyard Stop Switch........................................................ 5

Keep the Lanyard Stop Switch and Lanyard Cord in

Good Operating Condition ....................................... 6

Instrumentation................................................................ 6

VesselView .............................................................. 6

SmartCraft Speedometer, Tachometer, and Digital

Gauges .................................................................... 7

System Link Digital Gauges .................................... 7

Emergency Stop Switch...................................................8

1

Remote Controls.............................................................. 8

Panel Mount Features ............................................. 9

Console Mount Features ......................................... 9

Power Trim.................................................................... 10

Single‑Engine Trim and Trailer .............................. 11

Dual‑Engine Trim and Trailer ................................ 11

Trim without Key............................................................ 11

Overload Protection—Upper Engine Circuit Breaker

Panel..............................................................................11

Overload Protection—Port Side Power Distribution Box

....................................................................................... 12

Vessel Integration Panel (VIP) Overload Protection...... 13

Power Trim and MerCathode Overload Protection........ 13

Engine Guardian System............................................... 14

SeaCore Equipped Drives.................................................... 14

SeaCore Components and Castings............................. 14

Stainless Steel Fasteners.............................................. 14

90-8M0113987 eng DECEMBER 2015 Page 1

Section 1 - Getting to Know Your Power Package

MODEL..................................................... I4

DISPLACEMENT.................................. 2.8L

ENGINE ROTATION................................LH

MAX. W.O.T. RPM............................... 3800

IDLE RPM IN NEUTRAL...... 700 NON ADJ

Scan for
additional
engine
information

QR CODE

SPECIFICATIONS

BELT ROUTING

COLOR CODES

ENGINE OIL

DRIVE LUBE

COOLANT

PR STR FLUID

ENGINE SERIAL NUMBER

TRANSOM SERIAL NUMBER

DRIVE SERIAL NUMBER

54680

abcde

a

b

c

d

e

b
a

53340

Identification

The serial numbers are the manufacturer's keys to numerous engineering details that apply to your Mercury Marine power
package. When contacting Mercury Marine about service, always specify model and serial numbers.

Serial Number Decal

The serial number decal is located on top of the engine cover.

2.8 shown, 4.2 similar

a - Serial numbers
b - Engine specifications
c - Maintenance color codes
d - Quick reference code
e - Belt routing

Engine Data Label

A tamper‑resistant engine data label is affixed to the engine at the time of manufacture. It contains important information. Note
that the engine data label will not affect the fit, function, or performance of the engine and neither boatbuilders nor dealers may
remove the engine data label or the engine component it is affixed to before sale. If modifications are necessary or the engine
data label is damaged, contact Mercury Marine about the availability of a replacement.

The owner or operator is not to modify the engine in any manner that would alter the horsepower or allow exhaust gas emission
levels to exceed their predetermined factory specifications.

Engine data label example

a - Engine weight
b - Engine power rating
c - Maximum engine speed (RPM)
d - Engine serial number
e - Abbreviated engine description

Page 2 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

33533

44426

Transom Serial No.

53651

Bravo Sterndrive Serial Number and Identification

The Bravo sterndrive serial number, gear ratio, model number, and bar code are embedded in the ground plate on the port side
of the sterndrive.

Bravo sterndrive information on ground plate

The serial number is also stamped on the driveshaft housing behind the back cover. This is used as a permanent reference for
authorized MerCruiser dealers.

Bravo sterndrive serial number stamping

Bravo Transom Serial Number

The Bravo transom serial number is stamped in the transom assembly decal.

90-8M0113987 eng DECEMBER 2015 Page 3

Section 1 - Getting to Know Your Power Package

44425

38160

The serial number is also stamped on the gimbal housing. This is used as a permanent reference for authorized MerCruiser
dealers.

Serial number location on gimbal housing

Features And Controls

Audio Warning System

Your power package is equipped with an audio warning system. The audio warning system monitors critical components and
informs the operator when a malfunction has occurred. The warning system is not capable of protecting the power package
from damage caused by a malfunction.

When an electronic control system detects a recordable malfunction, the audio warning system will sound to alert the operator.
The duration and type of horn sound depend upon the nature of the fault condition. In the case of any horn sounding, the user
should refer to the helm displays to understand the specific situation.

For the operator to view the fault code of the malfunction indicated and any recommended actions, the power package must be
equipped with a gauge package that supports the warning system and can display fault codes.

The following instruments have screens that display fault codes:

• VesselView

• SmartCraft System Tachometer

• SmartCraft System Speedometer

NOTICE

The sound from an audio warning horn indicates that a critical fault malfunction has occurred. Operating a power package
with a critical fault can damage components. If the audio warning horn emits a sound, do not continue operations unless
avoiding a hazardous situation.

If the audio warning sounds, stop the engine immediately if you are not in a hazardous situation. Investigate the cause and
correct it, if possible. If you cannot determine the cause, consult an authorized repair facility.

Switches

Four position key switch

Page 4 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

28082

OFF

ON

38277

c

a

b

53910

OFF

RUN

ATTACH LANYARD

•

"OFF" In the "OFF" position, all electrical circuits are off. The engine will not operate with the key switch in the "OFF"
position.

•

"ACC" In the "ACC" position, any accessory connections to the electrical circuits can be operated. The engine will not
operate with the key switch in the "ACC" position.

•

"ON" In the "ON" position, all electrical circuits and instrumentation receive power. The engine can be started with an
optional start stop switch.

•

"START" Turn the key to the start position and release to start the engine.

NOTE: The key can only be removed with the key switch in the "OFF" position.

Dual engine start-stop switch

A start‑stop switch is optional equipment. The start‑stop switch works in conjunction with the key switch. There is one start‑stop
switch for each engine. Each button on a multi‑engine start‑stop switch functions independently. The key switch must be in the
run position to start a stopped engine with the the start‑stop switch. Pressing a start‑stop switch button when an engine is
running will shut down the corresponding engine.

Typical bilge blower toggle switch

Operates the bilge blower, if equipped

Lanyard Stop Switch

A lanyard switch is designed to shut down the engine in the event the operator unexpectedly moves away from the helm, as
may happen in an accidental ejection. The lanyard is connected to the operator's personal flotation device or wrist.

A decal near the lanyard stop switch reminds the operator to attach the lanyard to his or her personal flotation device or wrist.

a - Lanyard cord clip
b - Lanyard decal
c - Lanyard stop switch

Accidental ejections, such as falling overboard, are more likely to occur in:

90-8M0113987 eng DECEMBER 2015 Page 5

Section 1 - Getting to Know Your Power Package

• Low‑sided sport boats

• Bass boats

• High‑performance boats
Accidental ejections can also occur from:

• Poor operating practices

• Sitting on the seat or gunwale at planing speeds

• Standing at planing speeds

• Operating at planing speeds in shallow or obstacle‑infested waters

• Releasing your grip on the steering wheel

• Carelessness caused by consuming alcohol or drugs

• High‑speed boating maneuvers
The lanyard is a cord usually between 122 and 152 cm (4 and 5 ft) long when stretched out, with an element on one end made

to be inserted into the switch, and a snap on the other end for attaching to the operator. The lanyard is coiled to make its at‑rest
condition as short as possible to minimize the likelihood of lanyard entanglement with nearby objects. Its stretched‑out length is
made to minimize the likelihood of accidental activation should the operator choose to move around in an area close to the
operator's normal position. The operator can shorten the lanyard by wrapping the lanyard around his wrist, or by tying a knot in
the lanyard.

Activation of the lanyard stop switch will stop the engine immediately, but the boat will continue to coast for some distance,
depending upon its velocity. While the boat is coasting, it can cause injury to anyone in the boat's path as it would under power.

Instruct all passengers on the proper starting and operating procedures should they be required to operate the boat in an
emergency.

WARNING

!

If the operator falls out of the boat, stop the engine immediately to reduce the possibility of serious injury or death from being
struck by the boat. Always properly connect the operator to the stop switch using a lanyard.

Accidental or unintended activation of the switch during normal operation is also a possibility. This could cause any, or all, of
the following potentially hazardous situations:

• Occupants could be thrown forward due to unexpected loss of forward motion, a particular concern for passengers in the
front of the boat who could be ejected over the bow and possibly struck by the propulsion or steering components.

• Loss of power and directional control in heavy seas, strong current, or high winds.

• Loss of control when docking.

WARNING

!

Avoid serious injury or death from deceleration forces resulting from accidental or unintended stop switch activation. The boat
operator should never leave the operator's station without first disconnecting the stop switch lanyard from the operator.

Keep the Lanyard Stop Switch and Lanyard Cord in Good Operating Condition

Before each use, ensure that the lanyard stop switch works properly. Start the engine, and then stop it by pulling the lanyard
cord. If the engine does not stop, have the switch repaired before operating the boat.

Before each use, inspect the lanyard cord to ensure that it is in good working condition and that there are no breaks, cuts, or
wear to the cord. Check that the clips on the ends of the cord are in good condition. Replace any damaged or worn lanyard
cords.

Instrumentation

VesselView

Your power package may be connected to a SmartCraft VesselView display. VesselView 7 is a comprehensive boat
information center that can display information for up to four gasoline or diesel engines. It continuously monitors and reports
basic operating data including detailed information such as seawater temperature and depth, trim status, boat speed and
steering angle, and the status of fuel, oil, water, and waste tanks.

VesselView can be fully integrated with a vessel’s global positioning system (GPS) or other NMEA‑compatible device to provide
up‑to‑the‑minute navigation, speed, and fuel‑to‑destination information.

Page 6 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

52421

a

b

c

c

50400

VesselView 4 and 7 are equipped with a micro SD card port that allows an authorized OEM or dealership to import the
personality configuration. It can also be use by the owner to import pictures or graphics. When more than one VesselView is
used, either as a triple or quad‑engine application for multiple helms, the same mico SD card can be used to download those
configurations.

VesselView

Refer to your VesselView operations manual for detailed instructions on how to operate this display.

SmartCraft Speedometer, Tachometer, and Digital Gauges

The SmartCraft instrument package augments the information provided by VesselView. The instrument package may display:

• Engine RPM

• Boat speed

• Coolant temperature

• Oil pressure

• Battery voltage

• Fuel consumption

• Engine operating hours

SmartCraft tachometer and speedometer

a - Tachometer
b - Speedometer
c - LCD display

The SmartCraft instrument package also aids in identifying the fault codes associated with the engine audio warning system.
The SmartCraft instrument package displays critical engine alarm data and other potential problems on its LCD display.

For basic operation information on the SmartCraft instrument package and for details on the warning functions monitored by the
system, refer to the manual provided with your gauge package.

System Link Digital Gauges

Some instrumentation packages include gauges that augment the information provided by VesselView and the SmartCraft
tachometer and speedometer. The owner and operator should be familiar with all the instruments and their functions on the
boat. Have your boat dealer explain the gauges and normal readings that appear on your boat.

90-8M0113987 eng DECEMBER 2015 Page 7

Section 1 - Getting to Know Your Power Package

abc

d

37925

35308

The following types of digital gauges may be included with your power package.

System Link digital gauges

Item Gauge Indicates
a Oil pressure gauge Engine oil pressure
b Voltmeter Battery voltage
c Water temperature gauge Engine operating temperature
d Fuel gauge Quantity of fuel in tank

Emergency Stop Switch

An emergency stop (E‑stop) switch is used to turn off the engines in an emergency situation, such as a person overboard or a
tangled propeller. When activated, an E‑stop switch interrupts the power supply to the engine and transmission. If the boat is
equipped with an E‑stop switch, the E‑stop switch turns off all of the engines.

Typical E-stop switch

Activation of an E‑stop switch stops the engine, or engines, immediately, but the boat can continue to coast for some distance
depending upon the velocity and degree of any turn at shutdown. While the boat is coasting, it can cause injury to anyone in the
boat's path as seriously as the boat would when under power.

We recommend instructing other occupants on proper starting and operating procedures should they need to operate the
engine in an emergency.

Accidental or unintended activation of the switch during normal operation is also possible, which can cause any or all of the
following potentially hazardous situations:

• Occupants can be thrown forward due to unexpected loss of forward motion, and passengers in the front of the boat could
be ejected over the bow and possibly struck by the propulsion or steering components.

• The operator can lose power and directional control in heavy seas, strong current, or high winds.

• The operator can lose control of the vessel when docking.

Restarting an engine using the key switch or start button after an E‑stop shutdown without first turning the key switch to the off
position for at least 30 seconds will restart the engine but cause fault codes to be set. Unless you are in a potentially hazardous
situation, turn the key switch off and wait at least 30 seconds before restarting the engine or engines. If after restarting, some
fault codes are still being displayed, contact your authorized Mercury Diesel repair facility.

Remote Controls

Your boat may be equipped with Mercury Precision Parts or Quicksilver remote controls. All controls may not have all features
shown. Consult your dealer for a description and/or demonstration of your remote control.

Page 8 90-8M0113987 eng DECEMBER 2015

Panel Mount Features

Section 1 - Getting to Know Your Power Package

a

f

b

e

a - Neutral lock button
b - Throttle‑only button
c - Lanyard stop switch
d - Control handle tension adjustment screw
e - Control handle
f - Trim and tilt button

c

d

mc77019-1

Neutral lock button. Prevents accidental shift and throttle engagement. The neutral lock button must be pushed into move the

control handle out of neutral.
Throttle‑only button. Allows engine throttle advancement without shifting the engine. This is done by disengaging the shift

mechanism from the control handle. The throttle‑only button can be depressed only when the remote control handle is in the
neutral position, and should only be used to assist in starting the engine.

Lanyard stop switch. Turns the ignition off whenever the operator (when attached to the lanyard) moves far enough away
from the operator's position to activate the switch. See Lanyard Stop Switch for information on the use of this switch.

Control handle. The shift and throttle are controlled by the movement of the control handle. Push the control handle forward
from neutral with a quick, firm motion to the first detent for forward gear. Continue pushing forward to increase speed. Pull the
control handle back from neutral with a quick, firm motion to the first detent for reverse gear and continue pushing back to
increase speed.

Control handle tension adjustment screw (not visible). This screw is used to adjust the effort required to move the remote
control handle. Refer to the instructions provided with the remote control for complete adjustment instructions.

Trim (tilt) button. See Power Trim.

Console Mount Features

b

b

c

d

a

a

Throttle‑only button. Allows engine throttle advancement without shifting the engine. This is done by disengaging the shift

mechanism from the control handle. The throttle‑only button can be depressed only when the remote control handle is in the
neutral position.

c

d

mc79503-1

a - Throttle‑only button
b - Control handle
c - Power trim switch
d - Trailer switch

90-8M0113987 eng DECEMBER 2015 Page 9

Section 1 - Getting to Know Your Power Package

Control handles. The shift and throttle are controlled by the movement of the control handle. Push the control handle forward
from neutral with a quick, firm motion to the first detent for forward gear and continue pushing forward to increase speed. Pull
the control handle back from neutral with a quick, firm motion to the first detent for reverse gear and continue pushing back to
increase speed.

Control handle tension adjustment screw (not visible). This screw is used to adjust the effort required to move the remote
control handle. Refer to the instructions provided with the remote control for complete adjustment instructions.

Power trim switch. See the Power Trim section for detailed power trim operating procedures.
Trailer switch. Used to raise the sterndrive for trailering, launching, beaching, or shallow water operation. See Power Trim for

detailed trailer switch operation.

Power Trim

Power trim allows the operator to adjust the sterndrive angle while underway to provide the ideal boat angle for varying load
and water conditions. Also, the trailering feature allows the operator to raise and lower the sterndrive for trailering, beaching,
launching, low‑speed (below 1200 RPM engine speed), and shallow water operation.

WARNING

!

Excessive trim can cause serious injury or death at high speeds, and single‑ram trim systems do not provide a trim‑out
limiting device or trim indicator. Use caution when trimming with a single‑ram trim system and never trim out beyond the unit's
side support flanges while the boat is underway or at engine speeds above 1200 RPM.

For best performance, trim the sterndrive so that the boat bottom is at a 3–5° angle to the water.

3 - 5

mc79528

Trimming the sterndrive up (out) can:

• Generally increase top speed

• Increase clearance over submerged objects or a shallow bottom

• Cause the boat to accelerate and plane off slower

• In excess, cause boat porpoising (bouncing) or propeller ventilation

• Cause engine overheating if trimmed up (out) to a point where any cooling water intake holes are above the water line

mc78529

Trimming the sterndrive down (in) can:

• Help the boat accelerate and plane off quicker

• Generally improve the ride in choppy water

• In most cases, reduce boat speed

Page 10 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

• If excessively trimmed down (in), may lower the bows of some boats to a point at which they begin to plow with their bow in

the water while on plane. This can result in an unexpected turn in either direction called bow steering or over steering if any
turn is attempted or if a significant wave is encountered.

mc79530

Single-Engine Trim and Trailer

Single‑engine applications have a button that can be pressed to trim the sterndrive up (out) or down (in).
To raise the sterndrive for trailering, beaching, launching, low‑speed (below 1200 RPM), and shallow water operation, push the

trim button to raise the sterndrive to the full up (out) position.
Some controls also have a trailer button that trims the sterndrive to a position suitable for trailer purposes only.

NOTE: The Engine Control Module (ECM) limits the extent to which the sterndrive can be trimmed up (out) when engine speed
is above 1200 RPM.

Dual-Engine Trim and Trailer

NOTICE

If using external tie bars, raising or lowering the drives independently of each other can damage the drive and steering
systems. If using an external tie bar, raise and lower all drives together as a unit.

Dual‑engine applications may have a single integral button to operate both sterndrives simultaneously or may have separate
buttons for each sterndrive.

Some controls also have a trailer button that trims the sterndrives to a position suitable for trailer purposes only.

Trim without Key

!

CAUTION

The Trim Without Key mode allows trim operation after the ignition key switch is turned off. To avoid injury or product
damage, do not attempt any engine‑ or sterndrive‑related repairs or maintenance until performing the Wide Open Throttle
Reverse operation to end the Trim Without Key mode.

Trim without key allows trim operation for up to 15 minutes after the ignition key switch is turned off. On multi‑engine
applications, the trim without key time is managed separately for each engine.

The trim without key period may be ended at any time by moving the control handle to Wide Open Throttle Reverse with the
key off.

Overload Protection—Upper Engine Circuit Breaker Panel

If an electrical overload occurs, a fuse will burn out (blow) or a circuit breaker will trip open. Find and correct the cause for the
electrical overload before replacing the fuse or resetting the circuit breaker.

NOTE: In an emergency, when the engine must be operated and the cause for the high current draw cannot be located and
corrected, turn off or disconnect all the accessories connected to the engine and instrumentation wiring. Reset the circuit
breaker. If the breaker remains open, the electrical overload has not been eliminated. Further checks must be made on the
electrical system. Contact your Mercury Diesel authorized repair facility.

90-8M0113987 eng DECEMBER 2015 Page 11

Section 1 - Getting to Know Your Power Package

a

b

c

f

23245

d

e

a

b

Circuit breakers provide protection for the engine electrical system. The circuit breaker panel is located beneath a small access
panel in the engine cover on top of the engine.

Typical engine cover with access panel

a - Engine cover
b - Circuit breakers

After finding and correcting the cause of the overload, reset the circuit breaker by pressing the reset button.

Circuit breakers viewed from the port side of the engine

Reference Circuit breaker rating Protection Location on fuse panel

a 20 A Key unswitched power to helm Lower left
b 10 A Switched power to ECM Upper left
c 10 A Key switch to ECM Middle left
d 15 A Switched power to ECM Middle right
e 15 A ECM switched power to SIM Upper right

f 5 A Power—diagnostic connector Lower right

Overload Protection—Port Side Power Distribution Box

If an electrical overload occurs, a fuse will burn out (blow) or a circuit breaker will trip open. Find and correct the cause for the
electrical overload before replacing the fuse or resetting the circuit breaker.

NOTE: In an emergency, when the engine must be operated and the cause for the high current draw cannot be located and
corrected, turn off or disconnect all the accessories connected to the engine and instrumentation wiring. The circuit breaker
should automatically reset. If the breaker remains open, the electrical overload has not been eliminated. Further checks must
be made on the electrical system. Contact your Mercury Diesel authorized repair facility.

Circuit breakers provide protection for the engine electrical system as indicated. The circuit breaker panel is located within a
power distribution box mounted on the engine control module.

Page 12 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

37254

50465

a

b

c

After finding and correcting the cause of the overload, connect the starting battery and turn the ignition switch to the run
position. The circuit breaker should automatically reset. If a circuit breaker fails to reset, contact your Mercury Diesel authorized
repair facility

Port Side Power Distribution Box

Circuit Protection Circuit Breaker Rating
Key unswitched power to helm 20 A
Switched power to ECM 10 A
Key switch to ECM 10 A
Switched power to ECM 15 A
ECM switched power to SIM 15 A
Power—diagnostic connector 5 A

Vessel Integration Panel (VIP) Overload Protection

A vessel integration panel (VIP) is typically mounted in the engine compartment. The VIP contains three circuit breakers that
help protect system wiring.

a - Helm circuit breaker (10 A)
b - Gear circuit breaker (15 A)
c - SIM/Vessel circuit breaker (10 A)

Power Trim and MerCathode Overload Protection

If an electrical overload on the electrical system occurs, a fuse will open (blow). Find and correct the cause before replacing the
fuse.

NOTE: If you must operate the engine in an emergency, turn off and disconnect all accessories from the engine and
instrumentation wiring in an attempt to isolate the electrical overload or excessive current draw. Replace the fuse. If the fuse
burns out, the electrical overload has not been eliminated and further checks must be made on the electrical system. Contact
your Mercury Diesel authorized repair facility.

90-8M0113987 eng DECEMBER 2015 Page 13

Section 1 - Getting to Know Your Power Package

a

c

50534

b

1. The power trim system is protected from overload by a 110‑amp fuse and a 20‑amp in‑line fuse on the power trim pump.

a - 20‑amp in‑line fuse holder
b - 110‑amp fuse

a

b

2. The MerCathode system has a fuse connected to the positive (+) terminal on the controller. If the fuse is open (blown), the
system will not operate, resulting in a loss of corrosion protection. Replace the fuse with one of the same amp rating.

a - MerCathode
b - Red/purple wire
c - Fuse

9208

Engine Guardian System

The Engine Guardian system monitors the critical sensors on the engine for any early indications of problems. Engine Guardian
is functional whenever your engine is operating, so you never have to be concerned about whether or not you are protected.
The system will respond to a problem by sounding the warning horn for six seconds and/or reducing engine power in order to
provide engine protection.

If Engine Guardian has been activated, reduce the engine speed. The problem will need to be identified and corrected. The
system must be reset before the engine will operate at higher speeds. Moving the throttle lever back to the idle position will
reset the Engine Guardian system. If the Engine Guardian system has determined the reset has not corrected the problem,
Engine Guardian will remain activated, limiting the throttle. The problem must be identified and corrected before Engine
Guardian will allow the engine to reach a normal operating RPM.

SeaCore Equipped Drives

SeaCore Components and Castings

Mercury MerCruiser SeaCore power packages are equipped with additional stainless steel components and particular
aluminum castings with special coatings. Do not replace SeaCore components with non‑SeaCore. Use only the specified
Mercury MerCruiser SeaCore components and castings on these power packages.

Stainless Steel Fasteners

SeaCore models are equipped with additional stainless steel fasteners to maximize corrosion resistance in saltwater
environments.

Page 14 90-8M0113987 eng DECEMBER 2015

Section 1 - Getting to Know Your Power Package

Stainless steel fasteners are subject to galling when installed without lubrication. Galling can result in fastener destruction,
improper clamp loads, or both. Galled fasteners may appear to torque properly, but still have incorrect clamp loads.

Apply lubricant 2‑4‑C with PTFE or an equivalent, on the threads of stainless steel fasteners during installation to avoid galling.
Lubricate at least the first 8 mm (1/4 in.) of the threads before installation.

Tube Ref No. Description Where Used Part No.

95

2-4-C with PTFE Threads of stainless steel fasteners 92-802859A 1

90-8M0113987 eng DECEMBER 2015 Page 15

Section 1 - Getting to Know Your Power Package

Notes:

Page 16 90-8M0113987 eng DECEMBER 2015

Table of Contents

Section 2 - On the Water

Section 2 - On the Water

Safe Boating Recommendations.......................................... 18

Carbon Monoxide Exposure................................................. 19

Be Alert To Carbon Monoxide Poisoning ..................... 19

Stay Clear of Exhaust Areas ........................................ 19

Good Ventilation .......................................................... 19

Poor Ventilation ........................................................... 20

Important Operation Information........................................... 20

Launching...................................................................... 20

Duty Cycle Rating Requirements...................................20

High‑Output Rating........................................................ 20

Operation Chart............................................................. 21

Freezing Temperature and Cold Weather Operation.... 21

Drain Plug and Bilge Pump............................................22

Trailering the Boat......................................................... 22

Starting, Shifting, and Stopping............................................ 22

Before Starting the Engine.............................................22

Important Information – SmartStart................................22

Starting a Cold Engine................................................... 22

Engine Warm‑Up........................................................... 23

Starting a Warm Engine.................................................23

Shifting........................................................................... 24

Engine Shut Down (Stopping)....................................... 24

Starting the Engine After Stopped While in Gear.......... 24

Protecting People in the Water............................................. 24

While You Are Cruising ......................................... 24

While Boat Is Stationary ........................................ 24

High‑Speed and High‑Performance...............................25

Passenger Safety In Pontoon Boats and Deck Boats... 25

Boats Having An Open Front Deck ....................... 25

Boats With Front‑Mounted, Raised Pedestal Fishing

Seats ..................................................................... 25

Wave and Wake Jumping..................................................... 25

Impact with Underwater Hazards......................................... 26

Sterndrive Impact Protection ........................................ 26

Conditions Affecting Operation............................................. 27

Weight Distribution (Passengers and Gear) Inside the

Boat............................................................................... 27

Bottom of Boat............................................................... 27

Cavitation....................................................................... 27

Ventilation...................................................................... 27

Elevation and Climate.................................................... 27

Propeller Selection.........................................................28

Getting Started..................................................................... 28

Initial Break‑In Procedure.............................................. 28

Sterndrive 10‑Hour Break‑In Period (New or With

Replacement Gears)......................................................28

Engine Break‑In............................................................. 28

20‑Hour Break‑In Period ....................................... 28

After the 20‑Hour Break‑In Period ......................... 29

End of First Season Checkup........................................ 29

2

90-8M0113987 eng DECEMBER 2015 Page 17

Section 2 - On the Water

Safe Boating Recommendations

To safely enjoy the waterways, familiarize yourself with local and all other governmental boating regulations and restrictions
and consider the following suggestions.

Know and obey all nautical rules and laws of the waterways.

• We recommend that all powerboat operators complete a boating safety course. In the U.S., the U.S. Coast Guard Auxiliary,
the Power Squadron, the Red Cross, and your state or provincial boating law enforcement agency provide courses. For
more information in the U.S., call the Boat U.S. Foundation at 1‑800‑336‑BOAT (2628).

Perform safety checks and required maintenance.

• Follow a regular schedule and ensure that all repairs are properly made.

Check safety equipment onboard.

• Here are some suggestions of the types of safety equipment to carry when boating:

Approved fire extinguishers

Signal devices: flashlight, rockets or flares, flag, and whistle or horn

Tools necessary for minor repairs

Anchor and extra anchor line

Manual bilge pump and extra drain plugs

Drinking water

Radio

Paddle or oar

Spare propeller, thrust hubs, and an appropriate wrench

First aid kit and instructions

Waterproof storage containers

Spare operating equipment, batteries, bulbs, and fuses

Compass and map or chart of the area

Personal flotation device (one per person onboard)

Watch for signs of weather change and avoid foul weather and rough‑sea boating.

Tell someone where you are going and when you expect to return.

Passenger boarding.

• Stop the engine whenever passengers are boarding, unloading, or are near the back (stern) of the boat. Shifting the drive
unit into neutral is not sufficient.

Use personal flotation devices.

• Federal law requires that there be a U.S. Coast Guard‑approved life jacket (personal flotation device), correctly sized and
readily accessible for every person onboard, plus a throwable cushion or ring. We strongly advise that everyone wear a life
jacket at all times while in the boat.

Prepare other boat operators.

• Instruct at least one person onboard in the basics of starting and operating the engine and boat handling in case the driver
becomes disabled or falls overboard.

Do not overload your boat.

• Most boats are rated and certified for maximum load (weight) capacities (refer to your boat's capacity plate). Know your
boat's operating and loading limitations. Know if your boat will float if it is full of water. When in doubt, contact your
authorized Mercury Marine dealer or the boat manufacturer.

Ensure that everyone in the boat is properly seated.

• Do not allow anyone to sit or ride on any part of the boat that was not intended for such use. This includes the backs of
seats, gunwales, transom, bow, decks, raised fishing seats, and any rotating fishing seat. Passengers should not sit or ride
anywhere that sudden unexpected acceleration, sudden stopping, unexpected loss of boat control, or sudden boat
movement could cause a person to be thrown overboard or into the boat. Ensure that all passengers have a proper seat
and are in it before any boat movement.

Never operate a boat while under the influence of alcohol or drugs. It is the law.

• Alcohol or drugs can impair your judgment and greatly reduce your ability to react quickly.

Know your boating area and avoid hazardous locations.

Page 18 90-8M0113987 eng DECEMBER 2015

Section 2 - On the Water

43367

Be alert.

• The operator of the boat is responsible by law to maintain a proper lookout by sight and hearing. The operator must have

an unobstructed view particularly to the front. No passengers, load, or fishing seats should block the operator's view when
the boat is above idle or planing transition speed. Watch out for others, the water, and your wake.

Never drive your boat directly behind a water skier.

• Your boat traveling at 40 km/h (25 mph) will overtake a fallen skier who is 61 m (200 ft) in front of you in five seconds.

Watch fallen skiers.

• When using your boat for waterskiing or similar activities, always keep a fallen or down skier on the operator's side of the

boat while returning to attend to the skier. The operator should always have the down skier in sight and never back up to
the skier or anyone in the water.

Report accidents.

• Boat operators are required by law to file a boating accident report with their state boating law enforcement agency when

their boat is involved in certain boating accidents. A boating accident must be reported if 1) there is loss of life or probable
loss of life, 2) there is personal injury requiring medical treatment beyond first aid, 3) there is damage to boats or other
property where the damage value exceeds $500.00, or 4) there is complete loss of the boat. Seek further assistance from
local law enforcement.

Carbon Monoxide Exposure

Be Alert To Carbon Monoxide Poisoning

Carbon monoxide (CO) is a deadly gas that is present in the exhaust fumes of all internal combustion engines, including the
engines that propel boats, and the generators that power boat accessories. By itself, CO is odorless, colorless, and tasteless,
but if you can smell or taste engine exhaust, you are inhaling CO.

Early symptoms of carbon monoxide poisoning, which are similar to the symptoms of seasickness and intoxication, include
headache, dizziness, drowsiness, and nausea.

WARNING

!

Inhaling engine exhaust gases can result in carbon monoxide poisoning, which can lead to unconsciousness, brain damage,
or death. Avoid exposure to carbon monoxide.

Stay clear from exhaust areas when engine is running. Keep the boat well‑ventilated while at rest or underway.

Stay Clear of Exhaust Areas

Engine exhaust gases contain harmful carbon monoxide. Avoid areas of concentrated engine exhaust gases. When engines
are running, keep swimmers away from the boat, and do not sit, lie, or stand on swim platforms or boarding ladders. While
underway, do not allow passengers to be positioned immediately behind the boat (platform dragging, teak/body surfing). This
dangerous practice not only places a person in an area of high engine exhaust concentration, but also subjects them to the
possibility of injury from the boat propeller.

Good Ventilation

Ventilate the passenger area, open side curtains or forward hatches to remove fumes.
Example of desired air flow through the boat:

90-8M0113987 eng DECEMBER 2015 Page 19

Section 2 - On the Water

21626

a

b

a

b

43368

Poor Ventilation

Under certain running or wind conditions, permanently enclosed or canvas enclosed cabins or cockpits with insufficient
ventilation may draw in carbon monoxide. Install one or more carbon monoxide detectors in your boat.

Although the occurrence is rare, on a very calm day, swimmers and passengers in an open area of a stationary boat that
contains or is near a running engine may be exposed to a hazardous level of carbon monoxide.

1. Examples of poor ventilation while the boat is stationary:

a - Operating the engine when the boat

is moored in a confined space

b - Mooring close to another boat that

has its engine operating

2. Examples of poor ventilation while the boat is moving:

a - Operating the boat with the

trim angle of the bow too
high

b - Operating the boat with no

forward hatches open
(station wagon effect)

Important Operation Information

Launching

IMPORTANT: Install the bilge drain plug before launching the boat.

Duty Cycle Rating Requirements

IMPORTANT: Damage caused by incorrect application or failure to operate the power package within the specified operating
parameters will not be covered by the Mercury Marine Limited Warranty.

Mercury Diesel engines must be used in applications that meet the operation specifications indicated by a Mercury Diesel
product application engineer. The power package must be equipped with a gear ratio and propeller that allows the engine to
operate at wide open throttle (WOT) at the engine's rated speed (RPM). Use of Mercury Diesel engines in applications that do
not meet specified operational parameters is not approved.

High‑Output Rating

A High‑output rating applies to pleasure (nonrevenue generating) applications that operate 500 hours or less per year, where
full power is limited to one (1) hour out of every eight (8) hours of operation. Reduced power operation must be at or below
cruise speed (RPM). Cruise speed is dependant on the engine's maximum rated speed (RPM).

Page 20 90-8M0113987 eng DECEMBER 2015

Section 2 - On the Water

Operation Chart

Starting Procedure After Starting While Underway Stopping and Shut Down

Open the engine hatch. Air
out the bilge completely.

Turn the battery switch on, if
equipped.

Turn on and run the engine
compartment bilge blower, if
equipped, for five minutes.

Check for leaks: fuel, oil,
water, fluid, etc.

Open the fuel shut‑off valve,
if equipped.

Open the seacock, if
equipped.

Prime the fuel injection
system, if necessary.

Turn the key switch to
"START" position. Release
the key when the engine
starts.

Warm‑up the engine at a
fast idle‑RPM for several
minutes.

Observe all instrumentation to
monitor the condition of the
engine. If not normal, stop the
engine.

Check for fuel, oil, water, fluid,
and exhaust leaks, etc.

Check shift and throttle control
operation.

Check steering operation.

Frequently review all
instrumentation to monitor
engine condition.

Listen for the audio alarm.

Shift the remote control lever
to the neutral position.

Run the engine at idle‑RPM
for several minutes to allow
the turbocharger and engine
to cool.

Turn the key switch to "OFF"
position.

Turn the battery switch off, if
equipped.

Close the fuel shut‑off valve, if
equipped.

Close the seacock, if
equipped.

Flush the seawater cooling
circuit, if operating in
saltwater, brackish water, or
polluted water.

Freezing Temperature and Cold Weather Operation

IMPORTANT: If the boat is operated during periods of freezing temperature, take precautions to prevent freezing damage to
the power package. Damage caused by freezing is not covered by the Mercury Marine Limited Warranty.

NOTICE

Water trapped in the seawater section of the cooling system can cause corrosion or freeze damage. Drain the seawater
section of the cooling system immediately after operation or before any length of storage in freezing temperatures. If the boat
is in the water, keep the seacock closed until restarting the engine to prevent water from flowing back into the cooling system.
If the boat is not fitted with a seacock, leave the water inlet hose disconnected and plugged.

NOTE:
the seacock or unplug and connect the water inlet hose before starting the engine.

In order to operate the engine in temperatures of 0° C (32° F) or lower, observe the following instructions:

• At the end of each daily operation, completely drain the seawater section of the cooling system to protect against damage

• At the end of each daily operation, drain the water from the water separator, if equipped. Fill the fuel tank at the end of daily

• Use the required permanent‑type antifreeze solution to protect components against damage by freezing.

• Use proper cold weather lubrication oil; ensure that the crankcase contains a sufficient amount.

• Make certain that the battery is of sufficient size and is fully charged. Check that all other electrical equipment is in

• At temperatures of –20° C (–4° F) and below, use a coolant heater to improve cold starting.

• If operating in arctic temperatures of –29° C (–20° F) or lower, consult your Mercury Diesel authorized repair facility for

Refer to Section 6 for cold weather or extended storage related information.

As a precautionary measure, attach a tag to the key switch or steering wheel of the boat reminding the operator to open

by freezing.

operation to prevent condensation.

optimum condition.

information about special cold weather equipment and precautions.

90-8M0113987 eng DECEMBER 2015 Page 21

Section 2 - On the Water

Drain Plug and Bilge Pump

The engine compartment in your boat is a natural place for water to collect. For this reason, boats are normally equipped with a
drain plug or a bilge pump. It is important to check these items on a regular basis to ensure that the water level does not come
into contact with your power package. Components on your engine will be damaged if submerged. Damage caused by
submersion is not covered by the Mercury Marine Limited Warranty.

Trailering the Boat

Your boat can be trailered with the sterndrive in the up (out) or down (in) position. Adequate clearance is required between the
road and sterndrive when transporting.

If adequate road clearance is a problem, place the sterndrive in full trailer position and support it with an optional trailer kit,
which is available from your Mercury Marine authorized repair facility.

Starting, Shifting, and Stopping

WARNING

!

Vapors can ignite and cause an explosion, resulting in engine damage or severe personal injury. Do not use volatile starting
aids such as ether, propane, or gasoline in the engine air intake system.

WARNING

!

Fuel vapors trapped in the engine compartment may be an irritant, cause difficulty breathing, or may ignite resulting in a fire
or explosion. Always ventilate the engine compartment before servicing the power package.

Before Starting the Engine

NOTICE

Without sufficient cooling water, the engine, the water pump, and other components will overheat and suffer damage. Provide
a sufficient supply of water to the water inlets during operation.

IMPORTANT: Observe the following before starting:

• If running the engine with the boat out of the water, provide water to both the engine and sterndrive seawater pickup
pumps. Refer to Section 5—Flushing the Seawater System.

• Trim the sterndrive to the full down (in) position.

•

Ensure that the engine crankcase is filled to the correct level with the specified engine oil. Refer to Section 4:
Specifications—Engine Oil.

• Ensure all electrical connections are secure.

•

Check all items listed in Section 5—Maintenance Schedules and the Operation Chart.

• Perform any other necessary procedures as indicated by your dealer or Mercury Diesel authorized repair facility.

Important Information – SmartStart

IMPORTANT: This power package is equipped with SmartStart. SmartStart performs all appropriate starting operations upon
initial start switch actuation. To begin the SmartStart sequence, turn the ignition key switch to the "START" position and
release, or turn the ignition key switch to the run position and press and release the start/stop switch, if equipped.

SmartStart controls the starting process automatically. When the start switch is actuated, the system signals the engine's
electronic controller to start the engine. The starter will receive power until the engine starts and will time out after a few
seconds, or when the engine reaches 400 RPM. Attempting to start the engine with the engine running will turn the engine off.

Starting a Cold Engine

WARNING

!

A spinning propeller, a moving boat, or any solid device attached to the boat can cause serious injury or death to swimmers.
Stop the engine immediately whenever anyone in the water is near your boat.

NOTE: Check the fluid levels before starting the engine. Refer to

IMPORTANT: Mercury Marine DTS and Axius models are equipped with SmartStart. SmartStart features push and release
starting. The PCM completely controls the starting process after it receives a start command from the ignition key or start
button. The starting process will time‑out if the engine does not start after a few seconds or when cranking speed reaches 400
RPM. Attempting to start the engine with the engine already running will turn the engine off.

1. Turn on and run the engine compartment bilge blower (if equipped) for five minutes. Or, open the engine hatch to air out
the bilge before attempting to start the engine.

Page 22 90-8M0113987 eng DECEMBER 2015

Section 5—Maintenance Schedule

.

Section 2 - On the Water

2. Place the control handle in neutral.

NOTE: If the engine has not been run for a period of time and will not readily start with the standard starting procedure, use
the fuel primer located on the fuel filter header. Cycle the primer plunger up and down four or five strokes then attempt to
start the engine.

3. Turn the ignition key to the "RUN" position.

4. Turn the ignition key switch to the "START" position then release, or press the start/stop button and release. If the engine

is cold, allow the engine to operate at idle for 6–10 minutes or until the engine reaches normal operating temperature.
IMPORTANT: Engine oil pressure should exceed 69 kPa (10 psi) within seconds of starting the engine. Stop the engine if
the engine oil pressure does not meet this specification. Locate and correct the problem. If you are unable to correct the
problem, see a Mercury Diesel authorized repair facility.

5. Ensure all instrumentation is functioning properly and indicating normal readings.

Engine Warm‑Up

NOTICE

Engine wear caused by increased friction and limited oil flow is greatest when an engine is cold. Decrease engine wear by
allowing the engine coolant temperature to reach normal operating range before hard acceleration or applying full throttle.

1. After starting, ensure that all instrumentation is functioning properly.

2. Operate the engine at 1,000 to 1,200 RPM until the engine temperature is within the normal operating range. It is very

important that any engine be warmed up before applying full load. The warm‑up period provides time for the lubricating oil
to establish a film between moving parts.

NOTE: Engine warm‑up time during cold weather can be reduced by operating the vessel at a reduced engine speed.
Begin normal vessel operation when systems reach operating temperatures.

3. After the engine has reached operating temperature:

a.

The oil pressure should be within the range specified. Refer to Section 4: Specifications—Engine Specifications.

Stop the engine if the oil pressure is not within the range specified.
b. Check the fuel system for leakage from the injection pump, fuel pipes, fuel filter, or fuel lines.
c. Check for oil leakage. Check the engine and the sterndrive for oil leakage. Especially check the oil filter, oil lines, oil

line connectors, and oil pan.
d. Check for coolant leaks. Check the coolant hoses and connection pipes of the heat exchanger, fluid coolers,

aftercooler, water pump, and drain fittings.

4. Locate and correct any problems, or see your Mercury Diesel authorized repair facility if you are unable to determine the
problem.

Starting a Warm Engine

WARNING

!

A spinning propeller, a moving boat, or any solid device attached to the boat can cause serious injury or death to swimmers.
Stop the engine immediately whenever anyone in the water is near your boat.

NOTE: Check the fluid levels before starting the engine. Refer to

IMPORTANT: Mercury Marine SmartCraft equipped models feature push and release starting. The PCM completely controls
the starting process after it receives a start command from the ignition key or start button. The starting process will time‑out if
the engine does not start after a few seconds or when cranking speed reaches 400 RPM. Attempting to start the engine with
the engine already running will turn the engine off.

1. Turn on and run the engine compartment bilge blower (if equipped) for 5 minutes. Or, open the engine hatch to air out the
bilge before attempting to start the engine.

2. Place the control handle in neutral.

3. Turn the ignition key to the "RUN" position.

4. Turn the ignition key switch to the "START" position then release, or depress the start/stop button and release.
IMPORTANT: Stop the engine if the oil pressure does not exceed 69 kPa (10 psi) within seconds of starting the engine.
Stop the engine if the engine oil pressure does not meet this specification. Locate and correct the problem. If you are
unable to correct the problem, see a Mercury Diesel authorized repair facility.

5. Ensure that all instrumentation is functioning properly and indicating normal readings.

Section 5—Maintenance Schedule

.

90-8M0113987 eng DECEMBER 2015 Page 23

Section 2 - On the Water

21604

Shifting

NOTICE

Shifting into gear at engine speeds above idle will damage the drive system. Shift the drive into gear only when the engine is
operating at idle.

NOTICE

Failure to rotate the propeller shaft when shifting gears or forcing the shift mechanism while the engine is not operating can
result in product damage. If you must shift gears with the engine off, manually rotate the propeller shaft in the appropriate
direction.

1. Ensure that the remote control shift lever is in neutral.

2. To shift the sterndrive, move the remote control shift lever with a firm, quick motion forward to shift to forward gear, or
backward to shift to reverse.

3. After shifting the sterndrive, advance the throttle to the desired setting.
IMPORTANT: Avoid stopping the engine if the sterndrive is in gear. If the engine does stop with the sterndrive in gear,
Refer to the following procedure:

a. Push and pull repeatedly on the remote control handle until the handle returns to the neutral detent position. This may

take several tries if the power package was operating above idle RPM when the engine stopped.

b. After the handle returns to the neutral detent position, resume normal starting procedures.

Engine Shut Down (Stopping)

1. Place the remote control lever in neutral.

NOTICE

Immediately stopping the engine after high load operation can damage the turbocharger bearings. Idle the engine for several
minutes before shutdown.

2. Operate the engine at idle speed for several minutes to allow the turbocharger and engine to cool.

3. Turn the key switch to the "OFF" position or press the start‑stop switch button if equipped.

Starting the Engine After Stopped While in Gear

IMPORTANT: Avoid stopping the engine if the sterndrive is in gear. If the engine does stop with the sterndrive in gear, see the
following procedure:

1. Push and pull repeatedly on the remote control handle until the handle returns to the neutral detent position. This may take
several tries if the power package was operating above idle RPM when the engine stopped.

2. After the handle returns to the neutral detent position, resume normal starting procedures.

Protecting People in the Water

While You Are Cruising

It is very difficult for a person in the water to take quick action to avoid a boat heading in their direction, even at slow speeds.

Always slow down and exercise extreme caution any time you are boating in an area where there might be people in the water.
Whenever a boat is moving (even coasting) and the gear shift is in neutral, there is sufficient force by the water on the propeller

to cause the propeller to rotate. This neutral propeller rotation can cause serious injury.

While Boat Is Stationary

WARNING

!

A spinning propeller, a moving boat, or any solid device attached to the boat can cause serious injury or death to swimmers.
Stop the engine immediately whenever anyone in the water is near your boat.

Page 24 90-8M0113987 eng DECEMBER 2015

Section 2 - On the Water

Shift into neutral and shut off the engine before allowing people to swim or be in the water near your boat.

High‑Speed and High‑Performance

If your boat is considered a high‑speed or high‑performance boat, we recommend that you never operate it at its high‑speed
capability without first requesting an initial orientation and demonstration ride with your dealer or an operator experienced with
your boat. For additional information, refer to the Hi‑Performance Boat Operation booklet from your Mercury Diesel
authorized repair facility.

Passenger Safety In Pontoon Boats and Deck Boats

Whenever the boat is in motion, observe the location of all passengers. Do not allow any passengers to stand or use seats
other than those designated for traveling faster than idle speed. A sudden reduction in boat speed, such as plunging into a
large wave or wake, a sudden throttle reduction, or a sharp change of boat direction, could throw them over the front of boat.
Falling over the front of the boat between the two pontoons will position them to be run over.

Boats Having An Open Front Deck

No one should ever be on the deck in front of the rail while the boat is in motion. Keep all passengers behind the front rail or
enclosure.

Persons on the front deck could easily be thrown overboard or persons dangling their feet over the front edge could get their
legs caught by a wave and pulled into the water.

mc79555-1

WARNING

!

Sitting or standing in an area of the boat not designed for passengers at speeds above idle can cause serious injury or death.
Stay back from the front end of deck boats or raised platforms and remain seated while the boat is in motion.

Boats With Front-Mounted, Raised Pedestal Fishing Seats

Elevated fishing seats are not intended for use when the boat is traveling faster than idle or trolling speed. Sit only in seats
designated for traveling at faster speeds.

Any unexpected, sudden reduction in boat speed could result in the elevated passenger falling over the front of the boat.

mc79557-1

Wave and Wake Jumping

WARNING

!

Wave or wake jumping can cause serious injury or death from occupants being thrown within or out of the boat. Avoid wave
or wake jumping whenever possible.

mc79680-1

90-8M0113987 eng DECEMBER 2015 Page 25

Section 2 - On the Water

Operating recreational boats over waves and wakes is a natural part of boating. However, when this activity is done with
enough speed to force the boat hull partially or completely out of the water, certain hazards arise, particularly when the boat
reenters the water.

The primary concern is the boat changing direction while in the midst of the jump. In such cases the landing may cause the
boat to violently veer in a new direction. Such a sharp change in direction or turn can cause occupants to be thrown out of their
seats or out of the boat.

There is another less common hazardous result from allowing your boat to launch off of a wave or wake. If the bow of your boat
pitches down far enough while airborne, upon water contact it may penetrate under the water surface and submarine for an
instant. This will bring the boat nearly to a stop in an instant and can send the occupants flying forward. The boat may also veer
sharply to one side.

Impact with Underwater Hazards

Reduce speed and proceed with caution whenever you're driving a boat in shallow water or in areas where the waters are
suspected of having underwater obstacles that could be struck by the underwater drive components, rudder, or the boat
bottom.

mc79679-1

IMPORTANT: The most important thing you can do to help reduce injury or impact damage from striking a floating or
underwater object is control the boat speed. Under these conditions, boat speed should be kept to a maximum speed of
24 to 40 km/h (15 to 25 mph).

The following demonstrate some, but not all, examples of what can happen if the boat strikes an object:

• The boat could move suddenly in a new direction. Such a sharp change in direction or turn can throw occupants out of their
seats or out of the boat.

• A rapid reduction in speed. This will cause occupants to be thrown forward, even out of the boat.

• Impact damage to the underwater drive components, rudder, or boat.

Keep in mind that one of the most important things you can do to help reduce injury or impact damage in these situations is
control the boat speed. Boat speed should be kept to a minimum planing speed when driving in waters known to have
underwater obstacles.

After striking a submerged object, stop the engine as soon as possible and inspect the drive system for any broken or loose
parts. If damage is present or suspected, the power package should be taken to an authorized Mercury Diesel repair facility for
a thorough inspection and any necessary repair.

The boat should be checked for hull fractures, transom fractures, and water leaks.
Operating with damaged underwater drive components, rudder, or boat bottom could cause additional damage to other parts of

the power package, or could affect control of the boat. If continued operation is necessary, do so at greatly reduced speeds.

WARNING

!

Operating a boat or engine with impact damage can result in product damage, serious injury, or death. If the vessel
experiences any form of impact, have an authorized Mercury Marine dealer inspect and repair the vessel or power package.

Sterndrive Impact Protection

The power trim hydraulic system is designed to provide impact protection for the sterndrive. If a submerged object is struck
while the boat is moving forward, the hydraulic system will cushion the kickup of the sterndrive as it clears the object, reducing
damage to the sterndrive. After the sterndrive has cleared the object, the hydraulic system allows the sterndrive to return to its
original operating position, preventing loss of steering control and engine overspeed.

Use extreme caution when operating in shallow water or where underwater objects are known to be present. No impact
protection is provided in reverse; use extreme care to prevent striking submerged objects while operating in reverse.

IMPORTANT: Impact protection system cannot be designed to ensure total protection from impact damage under all
conditions.

Page 26 90-8M0113987 eng DECEMBER 2015

Section 2 - On the Water

Conditions Affecting Operation

Weight Distribution (Passengers and Gear) Inside the Boat

Shifting weight to rear (stern):

• Generally increases speed and engine RPM

• Causes bow to bounce in choppy water

• Increases danger of following wave splashing into the boat when coming off plane

• At extremes, can cause the boat to porpoise

Shifting weight to front (bow):

• Improves ease of planing

• Improves rough water ride

• At extremes, can cause the boat to veer back and forth (bow steer)

Bottom of Boat

To maintain maximum speed, ensure that the boat bottom is:

• Clean, free of barnacles and marine growth.

• Free of distortion, nearly flat where it contacts water.

• Straight and smooth, fore and aft.
Marine vegetation may accumulate when the boat is docked. This growth must be removed before operation; it may clog water

inlets and cause the engine to overheat.

Cavitation

Cavitation occurs when water flow cannot follow the contour of a fast‑moving underwater object, such as a gear housing or a
propeller. Cavitation increases propeller speed while reducing boat speed. Cavitation can seriously erode the surface of the
gear housing or the propeller. Common causes of cavitation are:

• Weeds or other debris snagged on the propeller

• Bent propeller blade

• Raised burrs or sharp edges on the propeller

Ventilation

Ventilation is caused by surface air or exhaust gases that are introduced around the propeller resulting in propeller speed‑up
and a reduction in boat speed. Air bubbles strike the propeller blade and cause erosion of the blade surface. If allowed to
continue, eventual blade failure (breakage) will occur. Excessive ventilation is usually caused by:

• Drive unit trimmed out too far

• A missing propeller diffuser ring

• A damaged propeller or gear housing, which allows exhaust gases to escape between propeller and gear housing

• Drive unit installed too high on transom

Elevation and Climate

NOTE: Engines equipped with an Engine Control Module (ECM) reduce the effects of changes in elevation and climate by
automatically adjusting fuel flow for weather conditions and elevation. ECM controlled engines, however, do not compensate for
increased loading or hull conditions.

Elevation and climate changes affect the performance of your power package. Loss of performance can be caused by:

• High elevations

• High temperatures

• Low barometric pressures

• High humidity
For optimum engine performance under changing weather conditions and high elevation, use a propeller that allows the engine

to operate at rated RPM at wide open throttle (WOT) with a maximum boat load during your normal boating.
In most cases, the rated RPM at WOT can be achieved by changing to a lower pitch propeller.

90-8M0113987 eng DECEMBER 2015 Page 27

Section 2 - On the Water

Propeller Selection

NOTICE

Operating the engine with the wrong propeller installed can limit power, increase fuel consumption, overheat the engine, or
cause internal powerhead damage. Choose a propeller that allows the engine to operate at the specified wide open throttle
RPM.

The boat manufacturer and the selling dealer are responsible for equipping the power package with the correct propellers.
IMPORTANT: The engines covered in this manual are equipped with an ECM that limits engine RPM. Be sure that the propeller

being used does not allow the engine to run against the limiter, as a significant loss in performance will result.

NOTE: Use an accurate service tachometer to verify RPM.

Select a propeller that will allow the engine power package to operate at the rated engine RPM with a maximum load.
If full throttle operation is below the engine rated RPM, the propeller must be changed to prevent loss of performance and

possible engine damage. On the other hand, operating an engine above the rated engine RPM will cause higher than normal
wear or damage.

After initial propeller selection, the following common problems may require that the propeller be changed to a lower pitch:

• Warmer weather and greater humidity cause an RPM loss (not as significant on these models).

• Operating in a higher elevation causes an RPM loss (not as significant on these models).

• Operating with a damaged propeller or dirty boat bottom causes an RPM loss.

• Operating with increased load (additional passengers, pulling skiers).

For better acceleration, such as is needed for water skiing, use the next lower pitch propeller. Do not operate at full throttle
when using the lower pitch propeller but not pulling skiers.

Getting Started

Initial Break‑In Procedure

It is important to follow this procedure to properly break in the engine.
IMPORTANT: Mercury Marine recommends that the boat not be accelerated hard until this procedure has been completed.

IMPORTANT: Never operate the starter motor longer than 15 seconds at a time to avoid overheating the starter motor. If the
engine does not start, wait one minute to allow the starter motor to cool; then, repeat the starting procedure.

1.

Refer to the appropriate Starting, Shifting, and Stopping section and start the engine.

2. Operate the engine at a fast idle until it has reached normal operating temperature.

3. Operate the engine in gear for three minutes at each of the following: 1200 RPM, 2400 RPM, and 3000 RPM.

4. Operate the engine in gear for three minutes at each of the following: 1500 RPM, 2800 RPM, and 3400 RPM.

5. Operate the engine in gear for three minutes at each of the following: 1800 RPM, 3000 RPM, and maximum rated full
throttle RPM.

Sterndrive 10‑Hour Break‑In Period (New or With Replacement Gears)

It is important that the following procedure be used on new sterndrives and rebuilt sterndrives with new replacement gears. This
break‑in procedure allows the proper seating of the sterndrive gears and related components, which greatly reduces the
likelihood of problems.

• Avoid full throttle starts.

• Do not operate at any one constant speed for extended periods of time.

• Do not exceed 75% of full throttle during the first 5 hours. During the next 5 hours, operate at intermittent full throttle.

• The sterndrive should be shifted into forward gear a minimum of 10 times during break‑in, with run‑in time at moderate
RPM after each shift.

Engine Break‑In

20-Hour Break-In Period

IMPORTANT: The first 20 hours of operation are considered to be the engine break‑in period. Correct break‑in is essential to
obtain minimum oil consumption and maximum engine performance. During this break‑in period, observe the following rules:

• Do not operate below 1500 RPM for extended periods of time for the first 10 hours. Shift into gear as soon as possible after
starting, and advance the throttle above 1500 RPM if conditions permit safe operation.

• Do not operate at one constant speed for extended periods.

• Do not exceed 3/4 throttle during the first 10 hours. During the next 10 hours, occasional operation at full throttle is
permissible (five minutes at a time maximum).

Page 28 90-8M0113987 eng DECEMBER 2015

Section 2 - On the Water

• Avoid full‑throttle acceleration from idle speed.

• Do not operate at full throttle until the engine reaches normal operating temperature.

• Check the engine oil level frequently. Add oil as needed. High oil consumption is normal during the break‑in period.

After the 20-Hour Break-In Period

To help extend the life of your power package, Mercury Marine recommends the following:

•

Change the engine oil and filter and the transmission fluid at the interval indicated in the Maintenance Schedule. Refer to
Specifications and Maintenance.

• Use a propeller that allows the engine to operate at the rated engine RPM when at full throttle with a fully loaded boat.

Refer to Specifications and Maintenance.

• Operation at 3/4 throttle setting or lower is recommended. Refrain from prolonged operation at wide‑open throttle RPM.

End of First Season Checkup

At the end of the first season of operation, contact an authorized repair facility to discuss or perform scheduled maintenance
items. If you are in an area where the product is operated continuously, year‑round, you should contact your dealer at the end
of the first 100 hours of operation or once yearly, whichever occurs first.

90-8M0113987 eng DECEMBER 2015 Page 29

Section 2 - On the Water

Notes:

Page 30 90-8M0113987 eng DECEMBER 2015

Table of Contents

Section 3 - Specifications

Section 3 - Specifications

Fuel Requirements............................................................... 32

Diesel Fuel in Cold Weather................................................. 32

Antifreeze/Coolant................................................................ 32

Engine Oil............................................................................. 33

Engine Specifications........................................................... 34

Fluid Specifications............................................................... 34

Engine............................................................................34

2.8 ......................................................................... 34

4.2 ......................................................................... 34

Bravo Sterndrive Fluid Specifications—Diesel.............. 34

Power‑Assisted Steering and Power Trim Fluids.......... 35

Approved Power‑Assisted Steering Fluids ............ 35

Approved Power Trim Fluids ................................. 35

Approved Paints................................................................... 35

3

90-8M0113987 eng DECEMBER 2015 Page 31

Section 3 - Specifications

Fuel Requirements

WARNING

!

Failure to comply with regulations can result in injury from fire or explosion. Electrical system components on this engine are
not rated as external ignition–protected (EIP). Do not store or use gasoline on boats equipped with these engines, unless
provisions have been made to exclude gasoline vapors from the engine compartment (REF: 33 CFR).

WARNING

!

Fuel leakage is a fire or explosion hazard, which can cause serious injury or death. Periodically inspect all fuel system
components for leaks, softening, hardening, swelling, or corrosion, particularly after storage. Any sign of leakage or
deterioration requires replacement before further engine operation.

WARNING

!

This engine requires diesel fuel. Mixing gasoline, gasohol, or alcohol and diesel fuel can cause serious injury or death due to
fire or explosion. Never mix gasoline, gasohol, or alcohol with diesel fuel.

IMPORTANT: Use of improper or water‑contaminated diesel fuel can seriously damage your engine. Use of improper fuel is
considered misuse of the engine, and damage caused thereby will not be covered by the warranty.

Mercury diesels are required to use grade 2–D ULSD (ultra‑low sulphur diesel) fuel meeting ASTM Standards D975 (or fuel
rated Diesel DIN EN 590), and having a minimum cetane rating of 51.

BIODIESEL: The blend of diesel fuel used may not contain more than 7% biodiesel fuel. Use of LSD or blends of ULSD fuel
containing more than 7% biodiesel fuel may result in fuel system degradation, injection nozzle clogging, hard starting,
increased oil change intervals, or excessive exhaust smoke.

The cetane number is a measure of the ignition quality of diesel fuel. Increasing the cetane number will not improve overall
engine performance, but it may be necessary to raise the cetane rating for low‑temperature or high‑altitude use. A lower cetane
number could cause hard starting and slower warm‑up, and could increase engine noise and exhaust emissions.

NOTE: If your engine suddenly becomes noisy after a fill‑up, you possibly received substandard fuel with a low cetane rating.

On engines that use high sulphur content diesel fuel, this will greatly increase:

• Corrosion on metal parts

• Deterioration of elastomer and plastic parts

• Excessive wear of internal engine parts, particularly bearings, and corrosion and extensive damage to other engine parts

• Difficulty starting and operating the engine

Diesel Fuel in Cold Weather

Unaltered diesel fuels thicken and gel in cold temperatures unless treated. Virtually all diesel fuels are climatized to allow their
use in the particular region for that time of the year. If it becomes necessary to further treat diesel fuel, it is the owner/operator's
responsibility to add a commercial standard brand of antigel diesel fuel additive, following that product's directions.

Antifreeze/Coolant

NOTICE

Using propylene glycol antifreeze in the closed cooling system can damage the cooling system or the engine. Fill the closed
cooling system with an ethylene glycol antifreeze solution suitable to the lowest temperature to which the engine will be
exposed.

Diesel engines are high‑compression engines that operate at higher temperatures than typical internal combustion engines.
Therefore, the closed‑cooling system and engine, including related cooling passages, must remain as clean as possible to
provide adequate engine cooling. To ensure proper cooling, we recommend filling the closed‑cooling section of the cooling
system with a low silicate formula of ethylene glycol antifreeze in a solution with deionized water. Common tap water or
softened water contains unwanted minerals that can leave large deposits in the system that restrict the cooling system
efficiency. A low silicate formula prevents the antifreeze from separating and forming a silicate gelatin. This gelatin can block
passages in the engine and heat exchanger, causing the engine to overheat.

Only premixed coolant should be added to the closed‑cooling system. Additives and inhibitors introduced into acceptable
coolant solutions will form a protective film on the internal passages and provide protection against internal cooling system
erosion.

Page 32 90-8M0113987 eng DECEMBER 2015

Section 3 - Specifications

Do not drain the closed‑cooling section for storage. The closed‑cooling section should be kept filled year‑round with an
acceptable antifreeze/coolant solution to avoid rust forming on the internal surfaces. If the engine will be exposed to freezing
temperatures, ensure that the closed‑cooling section is filled with a properly mixed antifreeze/coolant solution to protect the
engine and closed‑cooling system to the lowest temperature to which they will be exposed.

NOTE: It is recommended that a 50/50 solution of coolant (antifreeze) and deionized, purified water be used. A 50/50 solution
will provide freeze protection to –35° C (–31° F). Decreasing the solution to 40/60 will provide freeze protection to –25° C
(–13° F). Even in the warmest climates, never decrease the solution below 40/60. Increasing the solution to 60/40 will provide
freeze protection to –50° C (–58° F).

IMPORTANT: The antifreeze/coolant used in these marine engines must be a low silicate ethylene glycol, containing special
additives, and deionized, purified water. Using other types of engine coolant may cause fouling of the heat exchangers and
overheating of the engine. Do not combine different types of coolants without knowing that they are compatible. Refer to the
coolant manufacturer's instructions.

The acceptable antifreeze/coolants is listed in the following table. Refer to Section 5 ‑ Maintenance for respective change
intervals.

Tube Ref No. Description Where Used Part No.

122

Extended Life Antifreeze/Coolant Closed-cooling system 92-877770K1

Engine Oil

NOTICE

Discharge of oil, coolant, or other engine/drive fluids into the environment is restricted by law. Use caution not to spill oil,
coolant, or other fluids into the environment when using or servicing your boat. Be aware of the local restrictions governing
the disposal or recycling of waste, and contain and dispose of fluids as required.

To help obtain optimum engine performance and to provide maximum protection, the engine requires engine oil with a rating of
HD‑SAE‑API CG‑4 and CH‑4.

We strongly recommend the use of:

Tube Ref No.

121

15W-40 4-Cycle Diesel Engine Oil Engine crankcase 92-858042K01

Description Where Used Part No.

This oil is a specially blended 15W‑40 oil with marine additives for all‑temperature operation. It exceeds requirements for API
CF‑2, CF‑4, CG‑4, and CH‑4 oils.

Other recommended oils:

Description

Where Used Part Number
Shell Myrina
Mopar
Texaco Ursa Super TD
Wintershall Multi‑Rekord

Engine crankcase Obtain Locally

Veedol Turbostar
Wintershall VIiva 1

These oils are approved by Mercury Marine and Marine Power Europe. For all temperature operation use 15W‑40 oil.

90-8M0113987 eng DECEMBER 2015 Page 33

Section 3 - Specifications

Engine Specifications

Description

Engine type In‑line 4‑cylinder diesel In‑line 6‑cylinder diesel
Displacement 2.8 L (169 cid) 4.2 L (254 cid)
Firing order 1 ‑ 3 ‑ 4 ‑ 2 1 ‑ 5 ‑ 3 ‑ 6 ‑ 2 ‑ 4
Bore 94 mm (3.700 in.)
Stroke 100 mm (3.937 in.)
Rated engine RPM (refer to Conditions Affecting Operation

‑ Propeller Selection for additional information)
Idle RPM in neutral (engine at normal operating temperature) 700 600
Oil pressure @ idle 2.4 bar [240 kPa] (35 psi) 2.1 bar [210 kPa] (30 psi)
Oil pressure @ 3800 RPM 6.2 bar [620 kPa] (87 psi) 6.6 bar [660 kPa] (93 psi)
Thermostat (water) 83° C (181° F) 89° C (192° F)
Thermostat (oil) 95° C (203° F) 87° C (187° F)
Coolant temperature 80–85° C (176–185° F)
Electrical system 12‑volt negative (–) ground
Alternator rating 1540W, 14V, 110 A
Recommended battery rating 750 CCA, 950 MCA, or 180 Ahm

2.8 4.2

Specifications

3800

Fluid Specifications

IMPORTANT: All capacities are approximate fluid measures.

Engine

IMPORTANT: You may need to adjust oil levels depending on the installation angle and cooling systems (heat exchanger and
fluid lines).

Always use the dipstick to determine the exact quantity of oil or fluid required.

2.8

All models Capacity liters (US qt) Fluid Type Part Number

Engine oil (with filter) 8.9 (9.4) 15W40 4‑cycle Diesel Engine Oil 92‑858042K01
Closed cooling system 11 (11.6) Mercury Extended Life Antifreeze 92‑877770K1

4.2

All models Capacity liters (US qt) Fluid Type Part Number

Engine oil (with filter) 13.8 (14.6) 15W40 4‑cycle Diesel Engine Oil 92‑858042K01
Closed cooling system 17.25 (18.2) Mercury Extended Life Antifreeze 92‑877770K1

Bravo Sterndrive Fluid Specifications—Diesel

Fluid Capacity includes the

Sterndrive Model

Bravo One X Diesel
Bravo One XR

Bravo Three X Diesel
Bravo Three XR

Sterndrive and the

Gearlube Monitor

2736 ml (92‑1/2 oz.)

2972 ml (100‑1/2 oz.)

Fluid Type Fluid Part Number

High Performance Gear

Lubricant

92‑858064K01Bravo Two X Diesel 3209 ml (108‑1/2 oz.)

Page 34 90-8M0113987 eng DECEMBER 2015

Section 3 - Specifications

Power‑Assisted Steering and Power Trim Fluids

Approved Power-Assisted Steering Fluids

Description Part Number
Power Trim and Steering Fluid 92‑858074K01

Approved Power Trim Fluids

Description Part Number
Power Trim and Steering Fluid 92‑858074K01
SAE Engine Oil 10W‑30
SAE Engine Oil 10W‑40

Obtain locally

Approved Paints

Description
Mercury Diesel White 8M0108939
Mercury Light Gray Primer 92‑80287852
Mercury Phantom Black 92‑802878Q1

Part Number

90-8M0113987 eng DECEMBER 2015 Page 35

Section 3 - Specifications

Notes:

Page 36 90-8M0113987 eng DECEMBER 2015

Table of Contents

Section 4 - Maintenance

Section 4 - Maintenance

Owner and Operator Responsibilities................................... 38

Dealer Responsibilities......................................................... 38

Maintenance......................................................................... 38

Do‑It‑Yourself Maintenance Suggestions............................. 38

Inspection............................................................................. 38

Maintenance Schedules....................................................... 39

Routine Maintenance..................................................... 39

Scheduled Maintenance................................................ 40

Engine Oil............................................................................. 41

Checking........................................................................ 41

Filling............................................................................. 41

Changing Oil and Filter.................................................. 42

Sterndrive Gear Lube........................................................... 43

Checking........................................................................ 44

Filling............................................................................. 44

Changing....................................................................... 45

Power Trim Fluid.................................................................. 47

Checking........................................................................ 47

Filling............................................................................. 48

Changing....................................................................... 49

Power‑Assisted Steering Fluid............................................. 49

Checking........................................................................ 49

Filling............................................................................. 50

Changing....................................................................... 50

Engine Coolant..................................................................... 50

Check Coolant............................................................... 50

Filling............................................................................. 50

Changing....................................................................... 51

2.8 Air Filter.......................................................................... 51

Removal.........................................................................51

Inspection...................................................................... 52

Installation......................................................................52

4.2 Air Filter.......................................................................... 53

Removal.........................................................................53

Inspection...................................................................... 53

Installation......................................................................54

Water‑Separating Fuel Filter................................................ 54

Draining......................................................................... 55

Replacing....................................................................... 55

Filling............................................................................. 57

Fuel System.......................................................................... 58

Priming...........................................................................58

Filling (Bleeding)............................................................ 58

Fuel Tank Cleaning and Flushing.................................. 59

Seawater System................................................................. 59

Draining the Seawater System...................................... 59

Sterndrive Water Inlets Check....................................... 61

Checking the Seawater Pickups.................................... 62

Cleaning the Seawater Strainer, if Equipped................. 62

Flushing the Seawater System—Sterndrive Models..... 64

With the Boat out of the Water .............................. 64

With the Boat in the Water .................................... 66

Engine Seawater Pump Inspection................................67

Replacing the Engine Coolant in the Closed‑Cooling System

.............................................................................................. 67

Draining the Closed‑Cooling System............................. 67

Filling the Closed‑Cooling System................................. 68

Corrosion Protection............................................................. 69

General Information....................................................... 69

Engine Corrosion Protection Components.................... 69

Removal ................................................................ 69

Cleaning and Inspection ........................................ 70

Installation ............................................................. 71

Sterndrive Corrosion Protection Components............... 72

Continuity Circuit—Bravo Sterndrive............................. 75

MerCathode................................................................... 77

Boat Bottom Care.......................................................... 78

Painting Your Power Package....................................... 78

Sterndrive Surface Care................................................ 79

Lubrication............................................................................ 79

Steering System............................................................ 79

Throttle Cable................................................................ 81

Shift Cable..................................................................... 81

Transom Assembly........................................................ 82

Engine Coupler.............................................................. 82

Driveshaft Extension Models......................................... 82

Sterndrive, Bellows, and Engine Alignment................... 83

Maintaining Torques............................................................. 84

Bravo Gimbal Ring U‑bolt Nuts......................................84

Engine Mounts............................................................... 85

Propellers............................................................................. 85

Bravo Sterndrive Propeller Removal............................. 85

Bravo One Models ................................................. 86

Bravo Two Models ................................................. 86

Bravo Three Models .............................................. 87

Bravo Sterndrive Propeller Installation.......................... 88

Bravo One Models ................................................. 88

Bravo Three ........................................................... 89

Drive Belts............................................................................ 90

Serpentine Belt.............................................................. 90

Inspection .............................................................. 90

Replacement ......................................................... 91

Power‑Assisted Steering Pump Belt.............................. 92

Inspection .............................................................. 92

Adjustment ............................................................ 92

Replacement ......................................................... 93

Battery.................................................................................. 94

Battery Precautions for Multiple Engines ...................... 94

4

90-8M0113987 eng DECEMBER 2015 Page 37

Section 4 - Maintenance

Owner and Operator Responsibilities

It is the operator's responsibility to perform all safety checks, to ensure that all lubrication and maintenance instructions are
complied with for safe operation, and to return the unit to a Mercury Diesel authorized repair facility for a periodic checkup.

Normal maintenance service and replacement parts are the responsibility of the owner or operator and, as such, are not
considered defects in workmanship or material within the terms of the warranty. Individual operating habits and usage
contribute to the need for maintenance service.

Proper maintenance and care of your power package will ensure optimum performance and dependability and will keep your
overall operating expenses at a minimum. See your Mercury Diesel authorized repair facility for service aids.

Dealer Responsibilities

It is the dealer's responsibility to provide predelivery inspection and preparation:

• Before delivery, making certain that the Mercury power package is in proper operating condition.

• Making all necessary adjustments for maximum efficiency.

• Explaining and demonstrating the operation of the power package and the boat.

• Providing a copy of the Predelivery Inspection Checklist.

• Completing the warranty registration and immediately submitting it to Mercury Marine via MercNET, e‑mail, or mail. All
power packages must be registered for warranty purposes.

Maintenance

WARNING

!

Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.

WARNING

!

Fuel vapors trapped in the engine compartment may be an irritant, cause difficulty breathing, or may ignite resulting in a fire
or explosion. Always ventilate the engine compartment before servicing the power package.

IMPORTANT: Refer to Maintenance Schedule for a complete listing of all scheduled maintenance to be performed. Some
listings can be done by the owner or operator, while others should be performed by a Mercury Diesel authorized repair facility.
Before attempting maintenance or repair procedures not covered in this manual, we recommended that you purchase the
appropriate Mercury or Mercury MerCruiser Service Manual and read thoroughly.

NOTE: Maintenance points are color coded for ease of identification. Refer to the decal on the engine for identification.

• Blue—Coolant

• Yellow—Engine oil

• Orange—Transmission fluid

• Black—Gear lube oil

Do‑It‑Yourself Maintenance Suggestions

Mercury power packages are highly technical, complex pieces of machinery. Only qualified personnel using the proper tools
should attempt major repair.

• Your safety is our concern. Always read and understand the Cautions, Warnings, Important Notices, and Notes.

• Do not attempt repairs unless specifically trained in that procedure.

• Reference the correct service manual for the product. Do not attempt repairs unless qualified.

• Special tools and equipment are required to perform certain repairs. Failure to use the correct special tools and equipment
can result in severe damage to the product.

• Always have a Mercury Diesel authorized repair facility service your power package and do periodic maintenance
inspections to help provide safe and trouble‑free boating.

Inspection

Inspect your power package often and at regular intervals to help maintain its top operating performance and correct potential
problems before they occur. The entire power package should be checked carefully, including all accessible engine parts.

1. Check for loose, damaged, or missing parts, hoses and clamps; tighten or replace as necessary.

2. Check electrical connections and leads for damage.

Page 38 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

24522

a

b

a

b

3. Remove and inspect the propeller. If badly nicked, bent, or cracked, contact your Mercury Diesel authorized repair facility.

4. Repair nicks and corrosion damage on power package exterior finish. Contact your Mercury Diesel authorized repair

facility.

It may be necessary to remove the engine cover during some maintenance inspections and procedures. To remove the engine
cover:

NOTE: The engine cover contains an access panel which can be used to access the engine circuit breakers and the oil fill cap
and dipstick without removing the entire engine cover.

1. Lift and detach the engine cover from the mounts.

Typical engine cover Engine cover with access panel showing

a - Engine cover
b - Engine cover access panel location

2. Set the engine cover over the mounts and press the cover down in the mount areas to reattach the engine cover.

Maintenance Schedules

Routine Maintenance

IMPORTANT: Some procedures can be done by the owner or operator, while others should be performed by a Mercury Diesel
authorized repair facility. Before attempting maintenance or repair procedures not covered in this manual we recommended
that you purchase the appropriate Mercury Service Manual, and read it thoroughly.

NOTE: Only perform maintenance that applies to your particular power package.

Task Interval

• Check the engine oil level. This task interval can be extended based on operator experience
with the product.

Each day start

Each day end

Weekly

• Check the engine coolant level.

• Check the power‑assisted steering fluid level.

• Check the sterndrive gear lube level in the gear lube monitor.

• If operating in saltwater, brackish water, or polluted water, flush the seawater section of the
cooling system after each use.

• Drain any water from the primary fuel filter after each use. Drain any water from both fuel
filters if operating in freezing temperatures.

• Drain any water from the fuel filters.

• Check the trim pump fluid level.

• Check the seawater inlets for debris or marine growth.

• Check and clean the seawater strainer.

• Inspect the sterndrive anodes and replace if eroded 50% or more.

Maintenance to Be Performed

90-8M0113987 eng DECEMBER 2015 Page 39

Section 4 - Maintenance

Task Interval Maintenance to Be Performed

Every two months

Scheduled Maintenance

• Check the battery connections and fluid level.

• Lubricate the propeller shaft and tighten the propeller nut to the specified torque. If operating
in only freshwater, this maintenance may be extended to every four months.

• Treat the engine surfaces with Corrosion Guard if operating in saltwater, brackish, or polluted
waters.

• Inspect the air filter every two months or every 50 hours, whichever occurs first.

• Inspect the engine anodes and replace if 50% or more eroded.

• Ensure that the gauges and the wiring connections are secure. Clean the gauges every two
months or every 50 hours, whichever occurs first. If operating in saltwater, the interval is
reduced to every 25 hours or 30 days whichever occurs first.

Task Interval

Annually • Touch up the power package with paint and spray with Corrosion Guard.

Every 100 hours or

annually

(whichever occurs first)

Every 200 hours or

annually

(whichever occurs first)

Every 2 years

Every 700 hours or 3

years (whichever occurs

first)

Every 1000 hours or 5

years (whichever occurs

first)

Maintenance to Be Performed

• Change the sterndrive gear lube.

• Torque the gimbal ring U‑bolt locknuts.

• Check the steering system and the remote control for loose, missing, or damaged parts.
Lubricate the cables and linkages.

• Inspect and lubricate the sterndrive U‑joint splines. Inspect the bellows, the exhaust tube, and
check the clamps.

• Lubricate the engine coupler (lubricate the engine coupler every 50 hours if operated at idle
for prolonged periods of time).

• Check the continuity circuit for loose or damaged connections. If the boat is equipped with a
MerCathode system, test the unit's output.

• Check the engine alignment.

• Torque the engine mounts.

• Check the electrical system for loose, damaged, or corroded terminals.

• On driveshaft extension models, lubricate the driveshaft U‑joints, transom end (tailstock)
bearings, and engine end (output) bearings.

• Inspect the cooling system and the exhaust system for damage or leaks. Check both systems
hose clamps for tightness.

• Change the engine oil and filter.

• Replace the fuel filters.

• Replace the air filter.

• Inspect the condition and tension of the engine accessory drive belts.

• Disassemble and inspect the engine seawater pump and replace worn components.

• Check the seawater pump drive belt.

• Clean the seawater section of the closed‑cooling system. Clean, inspect, and test the
pressure cap. Check the anodes and replace if eroded by 50% or more.

• Check the closed‑cooling fluid level and level of protection.

• Clean the seawater strainer.

• Check the run history for faults.

• Check the engine timing belt.

• Replace the engine coolant.

• Replace the power‑assisted steering pump drive belt.

• Replace the engine timing belt.

• Clean the fuel tank.

• Clean the aftercooler core.

Page 40 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

b

c

d

37285

a

b

c

d

37281

Engine Oil

NOTICE

Discharge of oil, coolant, or other engine/drive fluids into the environment is restricted by law. Use caution not to spill oil,
coolant, or other fluids into the environment when using or servicing your boat. Be aware of the local restrictions governing
the disposal or recycling of waste, and contain and dispose of fluids as required.

Checking

IMPORTANT: Check the engine oil at the intervals specified by the maintenance schedule. It is normal for an engine to use a
small amount of oil during operation. The amount of oil consumed depends upon engine speed. Oil consumption is the highest
at wide open throttle and decreases substantially as engine speed is reduced.

NOTICE

With the engine running, the crankshaft journals or rod journals may strike and break the dipstick, resulting in damage to
internal engine components. Stop the engine completely before removing or inserting the dipstick.

1. To check the engine oil level during operation, stop the engine and allow five minutes for the oil to drain into the pan.

2. Remove the dipstick, wipe clean, and reinstall.

3. Remove the dipstick and observe the oil level. The oil level must be between the marks on the dipstick. If necessary, add
oil. Refer to Filling.

Typical

a - Oil fill cap
b - Dipstick
c - Maximum mark
d - Minimum mark

Filling

IMPORTANT: Do not overfill the engine with oil.

1. Remove the oil fill cap.

Typical

a - Engine cover
b - Oil fill cap
c - Access panel removed
d - Engine oil dipstick

2. Add the specified oil to bring the oil level up to, but not over, the maximum mark on the dipstick.

90-8M0113987 eng DECEMBER 2015 Page 41

Section 4 - Maintenance

11591

23306

a

b

c

a

b

2.8 Capacity Fluid Type
Engine oil (with filter) 8.9 L (9.4 U.S. qt) 4‑Cycle 15W40 Marine Engine Oil

4.2 Capacity Fluid Type
Engine oil (with filter) 13.8 L (14.6 U.S. qt) 4‑Cycle 15W40 Marine Engine Oil

IMPORTANT: Always use the dipstick to determine the amount of oil required to refill the engine oil.

3. Install the oil fill cap.

Changing Oil and Filter

See the Maintenance Schedule for the change interval. You should change the engine oil before placing the boat in storage.
IMPORTANT: Change the engine oil when the engine is warm from operation. Warm oil flows more freely, carrying away more

impurities. Use only recommended engine oil. See Specifications.

1. Start the engine and allow it to warm up to normal operating temperature.

2. Stop the engine and allow some time for the oil to drain into the oil pan (approximately five minutes).

3. Remove the fitting from the end of crankcase oil drain hose.

4. Install the crankcase oil pump (order separately) onto the threaded fitting of the oil drain hose.

Typical

a - Threaded fitting
b - Oil drain hose
c - Crankcase oil pump

Crankcase oil pump 91‑90265A 5

Aids in the removal of engine oil without draining the crankcase.

5. Pump the oil out of the crankcase into the drain pan.

6. Contain and dispose of the oil or oil waste as directed by local authorities.

7. Remove the crankcase oil pump and install the crankcase oil drain hose fitting when the crankcase is empty. Tighten
securely.

8. Install the oil dipstick.

9. Place a suitable container under the oil filter housing to contain any oil leakage that may occur. Use an appropriate socket
to loosen the oil filter top piece.

10. Remove the top piece and cartridge type oil filter.

Page 42 90-8M0113987 eng DECEMBER 2015

11. Disconnect and discard the old filter element. Discard the old O‑ring from the top piece.

23195

a

b

Section 4 - Maintenance

a

Typical

a - Top piece
b - O‑ring
c - Filter element

b

c

16603

12. Install the new O‑ring. Apply lubricant to the O‑ring.

Tube Ref No. Description Where Used Part No.

121

13. Push the filter element onto the top piece until it is locked. Listen for a click.

14. Install the top piece with the new filter element into the oil filter housing.
IMPORTANT: Overtightening the top piece will cause deformation resulting in oil leakage.

15. Turn the oil filter top piece until the sealing surface contacts the housing. Torque the top piece using an appropriate socket.

15W40 4-cycle Diesel Engine Oil Oil filter O-rings 92-858042K01

a - Top piece
b - Oil filter housing

Description Nm lb. in. lb. ft.
Oil filter top piece 25 18

16.

Remove the oil fill cap and refill the engine with new oil. See Filling.
IMPORTANT: When refilling the engine with oil, always use the dipstick to determine how much oil is required.

17. Start the engine and check for leaks.

Sterndrive Gear Lube

Discharge of oil, coolant, or other engine/drive fluids into the environment is restricted by law. Use caution not to spill oil,
coolant, or other fluids into the environment when using or servicing your boat. Be aware of the local restrictions governing
the disposal or recycling of waste, and contain and dispose of fluids as required.

NOTICE

90-8M0113987 eng DECEMBER 2015 Page 43

Section 4 - Maintenance

Checking

NOTE: The gear lube level will fluctuate during operation. The gear lube level should be checked with the engine cold, before
starting.

1. Check the gear lube monitor to determine the gear lube level. Keep the gear lube level within the recommended operating
range. Refer to Filling.

Gear lube level shown is at the correct operating range

a - "ADD" mark

b

b - "OPERATING RANGE" mark

a

19948

IMPORTANT: If any water is visible at the bottom of the gear lube monitor or appears at the fill and drain plug hole, or if the
gear lube appears discolored, contact your Mercury Diesel authorized repair facility immediately. Both conditions may
indicate a water leak in the sterndrive.

Filling

IMPORTANT: If more than 59 ml (2 fl. oz.) of High Performance Gear Lube is required to fill the gear lube monitor, a seal may
be leaking. Damage to the sterndrive may occur due to lack of lubrication. Contact your Mercury Diesel authorized repair
facility.

1. If the gear lube level is below or near the "ADD" mark, the specified gear lube must be added.

2. Remove the gear lube monitor cap.

3. Fill the gear lube monitor with the specified gear lube so that the gear lube level is in the operating range. Do not overfill.

c

b

Gear lube monitor

a - Gear lube level at the "ADD" mark
b - Gear lube level at the "OPERATING RANGE" mark
c - Gear lube monitor cap

a

19947

Tube Ref No. Description Where Used Part No.

87

4. Ensure that the rubber gasket is inside the gear lube monitor cap and install the cap. Do not overtighten.

a

NOTE: When filling the entire sterndrive, Refer to

High Performance Gear Lube Gear lube monitor 92-858064K01

Gear lube monitor cap

a -

19962

Changing

.

Page 44 90-8M0113987 eng DECEMBER 2015

Changing

mc79506-1

a

b

1. Remove the gear lube monitor from the bracket.

Section 4 - Maintenance

a

b

a - Gear lube monitor bracket
b - Gear lube monitor and cap
c - Retaining strap

c

5500

2. Empty the contents of the gear lube monitor into a suitable container.

3. Install the gear lube monitor in the bracket.

4.

Remove the propeller. Refer to Propellers.

5.

Bravo One Models:

a. Lower the sterndrive to the full down (in) position.
b. Remove the gear lube fill and drain plug and sealing washer.
c. Drain the gear lube into a suitable container

a - Fill and drain plug
b - Sealing washer

6.

Bravo Two models and Bravo Three models:

a. Place the sterndrive in full trim limit out (up) position.
b. Remove the fill and drain plug and sealing washer.
c. Drain the gear lube into a suitable container.

b

a

19777

Bravo Two

a - Fill and drain plug
b - Sealing washer

b

a

14621

Bravo Three

90-8M0113987 eng DECEMBER 2015 Page 45

Section 4 - Maintenance

7. Remove the vent plug and sealing washer. Allow the gear lube to drain completely.

a - Vent plug
b - Sealing washer

b

a

19066

IMPORTANT: If any water drains from the fill and drain plug hole, or if the gear lube appears milky, the sterndrive is
leaking and should be checked immediately by your Mercury Diesel authorized repair facility.

8. Lower the sterndrive so that the propeller shaft is level.

9. Fill the sterndrive through the fill and drain plug hole with the specified gear lube until an air‑free stream of lube flows from
the vent plug hole.

Tube Ref No. Description Where Used Part No.

87

IMPORTANT: Use only Mercury/Quicksilver High Performance Gear Lube in the sterndrive.

10. Install the vent plug and sealing washer.

11. Continue to pump gear lube into the drive through the fill and drain plug hole until the gear lube appears in the gear lube
monitor.

12. Fill the gear lube monitor so that the gear lube level is in the operating range. Do not overfill.

High Performance Gear Lube Sterndrive unit 92-858064K01

c

b

Gear lube monitor

a - Gear lube level at the "ADD" mark
b - Gear lube level at the "OPERATING RANGE" mark
c - Gear lube monitor cap

a

19947

Fluid Capacity includes

Sterndrive Model

Bravo One X Diesel
Bravo One XR

Bravo Three X Diesel
Bravo Three XR

13. Ensure that the rubber gasket is inside the gear lube monitor cap and install. Do not overtighten.

a

the Sterndrive and the

Gear lube Monitor

2736 ml (92‑1/2 oz.)

2972 ml (100‑1/2 oz.)

Gear lube monitor cap

a -

Fluid Type Fluid Part Number

High Performance Gear

Lube

92‑802854A1Bravo Two X Diesel 3209 ml (108‑1/2 oz.)

19962

Page 46 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

mc79506-1

a

b

14. Remove the pump from the sterndrive fill and drain plug hole.

15. Quickly install the sealing washer and the fill and drain plug. Torque to the following specifications.

b

a

14621

All Bravo Models Shown

a - Fill and drain plug
b - Sealing washer

b

a

19777

Description Nm lb. in. lb. ft.
Fill and drain plug 6.8 60

16.

Install the sterndrive propeller. Refer to Propellers.

17.

Recheck the gear lube level at the gear lube monitor after the first use. Refer to Checking.
IMPORTANT: The gear lube level in the gear lube monitor will rise and fall during sterndrive operation; always check the gear
lube level when the sterndrive is cool and the engine is shut down.

Power Trim Fluid

Checking

IMPORTANT: Check the fluid level with the sterndrive in the full down (in) position only.

1. Place the sterndrive in full down (in) position.

90-8M0113987 eng DECEMBER 2015 Page 47

Section 4 - Maintenance

7701

b

a

2. Observe the fluid level. The fluid level must be between the "MIN" and "MAX" lines on the reservoir.

a

a - Reservoir
b - "MIN" and "MAX" lines

3.

Fill as necessary with the specified fluid. See Filling.

Tube Ref No. Description Where Used Part No.

114

Power Trim and Steering Fluid Power trim pump 92-858074K01

b

7876

Filling

1. If the fluid level is below the "MIN" line, the specified fluid must be added.

2. Remove the fill cap from the reservoir.

NOTE: The fill cap is vented.

Power trim pump reservoir shows the

fluid level is below "MIN" line

a - Fill cap assembly
b - Fill cap installed

Page 48 90-8M0113987 eng DECEMBER 2015

3. Add the specified fluid to bring the fluid level to within the "MIN" and "MAX" lines on the reservoir.

a

b

c

d

Section 4 - Maintenance

a

a - Reservoir
b - "MIN" and "MAX" lines

Tube Ref No. Description Where Used Part No.

114

4. Install the fill cap.

Power Trim and Steering Fluid Power trim pump 92-858074K01

b

7876

Changing

Power trim fluid does not require changing unless it becomes contaminated with water or debris. Contact your Mercury Diesel
authorized repair facility.

Power‑Assisted Steering Fluid

IMPORTANT: Use only Quicksilver Power Trim and Steering Fluid or Dexron III automatic transmission fluid (ATF) in the
power‑assisted steering system.
IMPORTANT: Running the pump dry will damage the pump. Always check steering fluid levels before operating the boat.

Checking

1. Center the sterndrive and stop the engine.

2. Remove the fill cap and dipstick from the fluid reservoir and observe the level.
a. The proper fluid level with the engine cold should be between the full cold mark and the end of the dipstick.
b. With the engine at normal operating temperature, the fluid level should be between the full hot and full cold marks.

Typical

a - Fill cap and dipstick
b - Full hot mark
c - Full cold mark
d - Fluid reservoir

13064

90-8M0113987 eng DECEMBER 2015 Page 49

Section 4 - Maintenance

37255

a

b

c

IMPORTANT: If fluid is not visible in the fluid reservoir, see your Mercury Diesel authorized repair facility.

Filling

1. Remove the fill cap and dipstick and observe the fluid level.

2. Add the specified fluid to bring the fluid level up to the proper level.

Tube Ref No. Description Where Used Part No.

114

28

3. Install the fill cap and dipstick.

Power Trim and Steering Fluid Power-assisted steering system 92-858074K01

Dexron III Automatic
Transmission Fluid

Power-assisted steering system Obtain Locally

Changing

Power‑assisted steering fluid does not require changing unless it becomes contaminated. See your Mercury Diesel authorized
repair facility.

Engine Coolant

!

CAUTION

A sudden loss of pressure can cause hot coolant to boil and discharge violently resulting in serious injury from burns. Allow
the engine to cool down before removing the coolant pressure cap.

Check Coolant

IMPORTANT: When possible, check the engine coolant before starting the engine.

1. Allow the engine to cool.

2. Remove the pressure cap from the coolant expansion tank.

3. The coolant level in the coolant expansion tank should be above the coolant level indicator attached to the bottom of the
coolant cap.

a - Filler neck
b - Coolant cap
c - Level indicator

4. If the coolant level is low:

a. Inspect the coolant recovery system for leaks.
b. Inspect the gasket in the pressure cap for damage and replace if necessary.
c. The pressure cap maintains pressure on the cooling system and may not be holding pressure properly. To have the

5. If the coolant level is correct, install the pressure cap and tighten.

cap tested, contact your Mercury Diesel authorized repair facility.

d.

Add the specified coolant as necessary. Refer to Add Coolant.

IMPORTANT: Tighten the pressure cap to prevent coolant loss.

Filling

1. Allow the engine to cool.

2. Remove the pressure cap from the coolant expansion tank.

Page 50 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

b

23248

e

e

d

c

a

b

26147

3. If the coolant is low in the coolant expansion tank, add the specified coolant as necessary to bring the level to within 25 mm

(1 in.) of the bottom of the fill neck or between the upper and lower marks, if applicable.

a - Pressure cap
b - Bottom of fill neck

Description Where Used Part Number
Mercury Extended Life Antifreeze Closed‑cooling system 92‑877770K1

IMPORTANT: When installing the pressure cap, be sure to tighten it securely to prevent coolant loss.

4. Install the pressure cap. Tighten securely.

Changing

Change (replace) the engine coolant at the prescribed interval. See Replacing the Engine Coolant in the Closed‑Cooling
System.

2.8 Air Filter

Removal

IMPORTANT: Keep gear lube monitor bottle in an upright position to prevent fluid from spilling.

NOTE: It is not necessary to drain the gear lube monitor to perform this procedure.

1. Remove the gear lube monitor retaining strap and remove the gear lube monitor from the bracket and set aside.

2. Remove the air filter cover retaining nut from the gear lube monitor bracket on the air filter.

3. Remove the gear lube monitor bracket.

a - Gear lube monitor
b - Gear lube monitor retaining

strap

c - Gear lube monitor bracket
d - Air filter cover retaining nut
e - Gear lube monitor bracket

retaining bolts

4. Remove the air filter cover.

NOTE: It is not necessary to remove the air filter bracket mounted on the turbocharger inlet.

90-8M0113987 eng DECEMBER 2015 Page 51

Section 4 - Maintenance

a

b

ee

d

c

a

b

26147

5. Remove the air filter cartridge from the air filter bracket mounted on the turbocharger inlet.

Shown removed from the engine for clarity only

a - Air filter cartridge
b - Air filter bracket

12618

Inspection

1. The air filter cannot be cleaned. Replace the air filter if it is dirty or contaminated.

2. Replace the air filter if the foam element is deteriorated or torn.

3.

Replace the air filter at the recommended interval. See Maintenance Schedules for the replacement interval under normal
conditions.

Installation

IMPORTANT: Treatment such as partial oil saturation is not required and is not recommended on the foam element before use.
The foam element must be clean and dry for proper filtration.

1. Install the air filter cartridge onto the air filter bracket.

2. Install the air filter cover, gear lube monitor bracket, and nuts.

3. Torque the air filter cover retaining nut and gear lube monitor bracket nuts.

Description
Air filter cover retaining nut 10.8 95
Gear lube monitor bracket nuts 11 8

4. Install the gear lube monitor in the bracket and hold in place with the retaining strap.

Nm lb. in. lb. ft.

a - Gear lube monitor
b - Gear lube monitor retaining

strap

c - Gear lube monitor bracket
d - Air filter cover retaining nut
e - Gear lube monitor bracket

retaining bolts

Page 52 90-8M0113987 eng DECEMBER 2015

4.2 Air Filter

a

b

c

d

d

25881

25893

a

b

Removal

1. Loosen the clamp and remove the oil separator vent hose.

2. Loosen the clamp and remove the air filter housing from the turbocharger inlet.

a - Oil separator vent hose
b - Air filter housing
c - Turbocharger
d - Clamp

3. Remove the air filter element from the air filter housing

Section 4 - Maintenance

a - Air filter housing
b - Air filter element

Inspection

1. The air filter cannot be cleaned. Replace the air filter if it is dirty or contaminated.

2. Replace the air filter if the foam element is deteriorated or torn.

3.

Replace the air filter at the recommended interval. See Maintenance Schedules for the replacement interval under normal
conditions.

90-8M0113987 eng DECEMBER 2015 Page 53

Section 4 - Maintenance

25893

a

b

a

b

c

d

d

25881

Installation

1. Slide the filter element into the air filter housing. Ensure that the element is seated fully into the air filter housing.

a - Air filter housing
b - Air filter element

NOTE: The warning labels on the air filter housing must be visible after the air filter housing is installed.

2. Install the air filter housing on to the turbocharger inlet.

3. Torque the air filter housing clamp.

Description
Air filter housing clamp 3.4–6.8 30–60

4. Install the oil separator vent house. Tighten the oil separator vent hose clamp securely.

a - Oil separator vent hose
b - Air filter housing
c - Turbocharger
d - Clamp

Nm lb. in. lb. ft.

Water‑Separating Fuel Filter

WARNING

!

Fuel is flammable and explosive. Ensure that the key switch is off and the lanyard is positioned so that the engine cannot
start. Do not smoke or allow sources of spark or open flame in the area while servicing. Keep the work area well ventilated
and avoid prolonged exposure to vapors. Always check for leaks before attempting to start the engine, and wipe up any
spilled fuel immediately.

Water entering the fuel injection system will cause corrosion and rusting of the injectors and other components, disabling the
fuel injection system. Check daily for water in the water‑separating fuel filter and have the engine inspected immediately if
there is evidence of water in the fuel system.

NOTICE

IMPORTANT: Use a suitable container to collect fuel. Clean up any spills immediately and dispose of fuel in a safe manner in
accordance with all local, federal, and international regulations.

Page 54 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

c

b

23318

The engine‑mounted water‑separating fuel filter is equipped with a water‑in‑fuel (WIF) sensor that should alert the operator
when water is present in the filter. This fuel filter needs to be replaced at specified intervals or whenever water is detected in
the fuel, whichever comes first.

The operator may be alerted that the WIF sensor has detected water in the fuel, depending upon the boat instrumentation
package and if equipped:

• A message may be displayed on an instrument

• An indicator lamp may be illuminated
See Instrumentation.
Drain or replace the remote mounted primary filter (such as a Racor® filter) at specified intervals, or whenever water is

detected in the engine‑mounted fuel filter.

Draining

The engine‑mounted water‑separating fuel filter can be drained of water and small dirt particles by opening the drain cap on the
bottom of the filter.

NOTE: To ensure complete draining in warm weather, drain the filter before starting daily operations. In cold weather, where
there is a possibility that the condensed water will freeze, drain the filter shortly after the end of daily operations.

NOTE: Place a suitable container under the fuel filter to catch contaminated fuel or water. Dispose of properly.

1. Place a container under the drain cap on the filter.

2. Open the drain by turning the drain cap counterclockwise (as viewed from the bottom of the filter) until fuel starts draining.
Do not remove the drain cap.

Typical water-separating fuel filter

a - WIF sensor wire connection
b - Filter
c - Drain cap

3. Drain until the fuel is clear in appearance.

4. Close the drain cap by turning clockwise. Tighten securely.

5.

Fill the fuel filter. See Filling.

Replacing

WARNING

!

Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.

IMPORTANT: The element cannot be cleaned and reused. It must be replaced.

1. Disconnect both battery cables from the battery.

2. Disconnect the WIF sensor wires, if equipped.

90-8M0113987 eng DECEMBER 2015 Page 55

Section 4 - Maintenance

a

23459

a

a

b

24566

a

a

b

24568

3. Remove the water‑separating fuel filter and sealing ring from the mounting bracket. Do not use a filter wrench.

Typical

a - Water‑separating fuel filter

NOTE: It may be necessary to keep the existing drain cap and use it on the new filter. Be sure to replace the O‑ring on the
drain cap.

4. Remove the drain cap and O‑ring seal from the bottom of the existing fuel filter. Note the position of the O‑ring seal.

Typical

a - Drain cap
b - O‑ring seal

5. Discard the used filter and O‑ring seal as defined by local authorities.

6. Install the O‑ring and drain cap on the new water‑separating fuel filter.

Typical

a - Drain cap
b - O‑ring seal

Page 56 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

24569

a

bb

a

23460

7. Lubricate the fuel filter seals.

Typical

a - Water‑separating fuel filter
b - Seals

Tube Ref No. Description Where Used Part No.

80

8. Align the filter to the bracket. Twist the filter by hand to secure the filter to the bracket. Do not use a filter wrench.

SAE Engine Oil 30W Water-separating fuel filter sealing ring Obtain Locally

Typical

a - Water‑separating fuel filter

9. Ensure that the drain cap is securely tightened.

10. Connect the WIF sensor wires, if equipped.

11.

Fill the water‑separating fuel filter with fuel. Refer to Filling.

12. Check the filter and drain cap for fuel leaks.

13. Connect the battery cables.

14. Start and operate the engine. Check the filter connection for fuel leaks. If leaks exist, recheck filter installation. If leaks
continue, stop the engine immediately and contact your Mercury Diesel authorized repair facility.

Filling

A type of hand pump and primer plunger is located on the fuel filter bracket and is used to

• Refill the fuel filter when draining or changing the filter.

• Refill the fuel system on the engine if the system was run dry.

• Prime the fuel system if the engine has not been run for an extended period.

IMPORTANT: Only fill the fuel filter with the hand pump and primer plunger to ensure that unfiltered fuel does not get into the
fuel system.

NOTE: Follow this procedure after installing a new filter or if the fuel has been drained from the filter checking for water.

90-8M0113987 eng DECEMBER 2015 Page 57

Section 4 - Maintenance

23469

a

b

23468

a

23469

a

1. Loosen the air vent (bleed) screw on the fuel filter bracket.

Typical

a - Air vent screw

2. Move the primer plunger up and down repeatedly. The filter is full when an air‑free stream of fuel flows from the air vent
screw.

Typical

a - Air vent screw
b - Primer plunger

3. Securely tighten the air vent screw.

Typical

a - Air vent screw

Fuel System

Priming

Prime the engine if it has not been run for an extended period or if the engine will not start.

1. Move the hand pump and primer plunger up and down several times as previously outlined.

2. Attempt to start the engine.

Filling (Bleeding)

NOTE: Follow this procedure if the fuel system was run dry or if part of the fuel system was drained for a service function.

1.

See Water Separating Fuel Filter ‑ Filling and fill the fuel filter.

2. Check the filter and drain cap for fuel leaks. Ensure that the bleed screw on the fuel filter bracket is closed.

Page 58 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

23710

b

Fuel Tank Cleaning and Flushing

IMPORTANT: Diesel fuel should not be left in the tank during winter storage, as an accumulation of rust, sludge, and wax
residue will form.

Refer to the boat manufacturer's instructions and clean the fuel tank at specified intervals. Unless specified otherwise, flush and
clean the diesel fuel tank every 1000 hours or five years, whichever occurs first.

Seawater System

Draining the Seawater System

!

CAUTION

Water can enter the bilge when the drain system is open, damaging the engine or causing the boat to sink. Remove the boat
from the water or close the seacock, disconnect and plug the seawater inlet hose, and ensure the bilge pump is operational
before draining. Do not operate the engine with the drain system open.

IMPORTANT: The engine must be as level as possible to ensure complete draining of the cooling system.
Drain the seawater system of the power package before cold weather (freezing temperature), seasonal storage, or extended

storage.
IMPORTANT: The boat must not be operating during this procedure.

!

CAUTION

Water can enter the bilge when the drain system is open, damaging the engine or causing the boat to sink. Remove the boat
from the water or close the seacock, disconnect and plug the seawater inlet hose, and ensure the bilge pump is operational
before draining. Do not operate the engine with the drain system open.

1. Remove the boat from the water if possible.

2.

If the boat is to remain in the water, turn on the bilge pump, close the seacock (if equipped), or disconnect and plug the
seawater inlet hose.

3. Make the engine as level as possible to ensure complete draining of the seawater system.

NOTE: The anode assembly on the back of the fluid cooler can be used as a drain plug.

4. Remove the drain plug from the aft end cover of the fluid cooler.

Typical engine

a - Anode assembly drain

plug

b - Fluid cooler

90-8M0113987 eng DECEMBER 2015 Page 59

Section 4 - Maintenance

a

b

23295

a

b

23480

c

a

b

c

b

a

23649

5. Remove the drain plug, or fitting (if equipped), from the aft end cover of the engine oil cooler.

Typical engine

a - Engine oil cooler
b - Drain plug, or fitting if equipped

NOTE: In the following steps, the hoses may require lowering or bending to allow seawater to drain completely.

6. Disconnect the seawater inlet hose from the connector on the seawater pump hose and drain.

2.8

a - Seawater inlet hose
b - Connector
c - Seawater pump hose

7. Repeatedly clean out the drain holes using a stiff piece of wire until the seawater section is completely drained.

8.

On models equipped with a seawater strainer:

a. Remove the drain plug and washer if equipped.
b. Remove both hoses from the seawater strainer and drain them completely.
c. Drain and empty the seawater strainer.
d. Connect the hoses and tighten the hose clamps.

4.2

Page 60 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

37290

a

b

22495

e. Install the sealing washer and drain plug, if equipped.

Typical

9. After the seawater has completely drained, apply sealant to the threads of the drain plugs or fittings (if equipped). Install
and tighten the drain plugs or fittings.

Tube Ref No. Description Where Used Part No.

19

10. Connect all hoses. Tighten the hose clamps.

Perfect Seal Drain plug or fitting threads 92-34227Q02

Sterndrive Water Inlets Check

1. Obtain a piece of wire the appropriate size to insert into the water inlets holes.

2. Insert the wire in and out of the sterndrive water inlets to ensure that they are open and to remove debris or marine growth.
Do not scrape the sterndrive paint.

3. Remove the wire from the sterndrive and retain for periodic water inlet checks.

a - Dual water pickup water inlets
b - Side pickup water inlets

90-8M0113987 eng DECEMBER 2015 Page 61

Section 4 - Maintenance

Checking the Seawater Pickups

1. Ensure that the water inlet holes for the seawater pickup are clean and not obstructed.

a

a

16776

Typical through-hull seawater pickup Typical through-transom seawater pickup

a - Water inlet holes

Cleaning the Seawater Strainer, if Equipped

NOTICE

An open seawater strainer or seacock during some service or maintenance procedures can introduce water into the boat,
causing damage or sinking the boat. Always close the water supply from the seawater pump, water inlet, or seacock when
performing service or maintenance on the cooling system.

1. With the engine off, close the seacock, if equipped, or remove and plug the seawater inlet hose.

2. For metal seawater strainers:
a. Remove the screws, washers, and cover.
b. Remove the strainer, drain plug, and sealing washer.
c. Clean any debris from the strainer housing.
d. Flush both the strainer and housing with clean water.
e. Inspect the cover gasket and replace if damaged.

a

b

f

a - Screws and washers
b - Cover with glass
c - Strainer
d - Housing
e - Drain plug and sealing washer
f - Seal

c

d

e

12863

3. For plastic seawater strainers:
a. Remove the cover.
b. Remove the strainer.

Page 62 90-8M0113987 eng DECEMBER 2015

c. Clean any debris from the strainer housing.

37287

a

b

c

d. Flush both the strainer and housing with clean water.
e. Inspect the cover gasket and replace if damaged.

Section 4 - Maintenance

a - Strainer cove
b - Strainer basket
c - Seal

4.

Seawater leaking from the seawater strainer could cause excess water in the bilge, damaging the engine or causing the boat
to sink. Do not overtighten the cover screws, or the cover may warp and introduce seawater into the bilge.

5. For metal seawater strainers:
a. Install the strainer, drain plug, and sealing washer.
b. Install the strainer basket.
c. Assemble the cover.
d. Tighten the cover screws. Do not overtighten.

a

b

f

!

CAUTION

a - Screws and washers
b - Cover with glass
c - Strainer
d - Housing
e - Drain plug and sealing washer
f - Seal

c

d

e

12863

6. For plastic seawater strainers:
a. Insert the plastic strainer basket.
b. Check the cover seal installation.

90-8M0113987 eng DECEMBER 2015 Page 63

Section 4 - Maintenance

37287

a

b

c

c. Screw the strainer cover on.

a - Strainer cove
b - Strainer basket
c - Seal

7. Open the seacock, if equipped, or remove the plug and reconnect the seawater inlet hose.

8. Upon first starting the engine, check for leaks or air in the system that would indicate an external leak.

Flushing the Seawater System—Sterndrive Models

Flushing the seawater system with fresh water is needed only for applications operating in saltwater, brackish water, polluted
water, or water with a high mineral content to avoid salt or silt buildup. For best results we recommend flushing the seawater
system after each outing. After each operation in saltwater and before storage, the seawater cooling system must be flushed.

With the Boat out of the Water

1. Lower the sterndrive to the full down (in) position.

WARNING

!

Rotating propellers can cause serious injury or death. Never operate the boat out of the water with a propeller installed.
Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the
engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate.

2.

Remove the propeller. See Propellers.

3. Install the appropriate flushing attachment over the water inlet holes in the gear housing.

21081

Dual water pickup

Side pickup

Page 64 90-8M0113987 eng DECEMBER 2015

Flushing Device 91‑44357Q 2

9192

9194

a

b

23450

c

b

a

d

Attaches to the water intakes; provides a fresh water connection when flushing the cooling system
or operating the engine.

Dual Water Pick‑up Flush Gearcase Seal Kit 91‑881150K 1

Blocks off the front water inlet holes on the dual water inlet gearcases.

4. Connect a flushing hose from a water tap to the flushing attachment.

Typical

a - Flushing attachment
b - Hose

Section 4 - Maintenance

12374

IMPORTANT: Engines with the sterndrive water inlet blocked off at the gimbal housing and using a through‑hull or
through‑transom water inlet need a supply of cooling water available to both the sterndrive and to the engine during
operation.

5.

If your power package uses a through‑hull or through‑transom pickup, connect a second flushing hose from a water
tap to the seawater inlet hose connected to the seawater pump inlet using an appropriate adapter.

2.8 shown, 4.2 similar

a - Adapter
b - Flushing hose
c - Water tap
d - Seawater inlet hose

6. Partially open the water source to about 1/2 maximum. Do not use full water pressure.

90-8M0113987 eng DECEMBER 2015 Page 65

Section 4 - Maintenance

23450

c

b

a

d

7. Place the remote control in neutral, idle speed position and start the engine.

NOTICE

Operating the engine out of the water at high speeds creates suction, which can collapse the water supply hose and overheat
the engine. Do not operate the engine above 1400 RPM out of the water and without sufficient cooling water supply.

8. Operate the engine at idle speed in neutral for about ten minutes or until the discharge water is clear.

9. Observe the water temperature gauge to ensure that the engine is operating in the normal range.

10. Stop the engine.

11. Shut off the water tap.

12. Remove the sterndrive flushing attachment.

13.

If your power package uses a through‑hull pickup,

a. Remove the adapter from the seawater pump inlet hose connection.
b. Reconnect the seawater inlet hose. Tighten the hose clamps securely.

With the Boat in the Water

NOTICE

Disconnecting the seawater inlet hose will cause water to enter the bilge resulting in engine damage. Close the seacock
before disconnecting the seawater inlet hose. Plug the seawater inlet hose immediately after disconnecting it.

1. Close the seacock, if equipped, or disconnect and plug the seawater inlet hose.

a

b

c

13171

Typical

a - Seacock
b - Seawater inlet hose
c - Plug

2. Using an appropriate adapter, connect a flushing hose from a water tap to the seawater inlet hose connected to the

seawater pump inlet.

2.8 shown, 4.2 similar

a - Adapter
b - Flushing hose
c - Water tap
d - Seawater inlet hose

3. Lower the sterndrive to the full down (in) position.

4. Partially open the water source to about 1/2 maximum. Do not use full water pressure.

Page 66 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

5. Place the remote control in neutral, idle speed position and start the engine.

NOTICE

Operating the engine out of the water at high speeds creates suction, which can collapse the water supply hose and overheat
the engine. Do not operate the engine above 1400 RPM out of the water and without sufficient cooling water supply.

6. Operate the engine at idle speed in neutral for about ten minutes or until the discharge water is clear.

7. Observe the water temperature gauge to ensure that the engine is operating in the normal range.

8. Stop the engine.

9. Shut off the water tap.

10. Remove the adapter from the seawater pump inlet hose connection.

11. Do not open the seacock or reconnect the water inlet hose at this time to prevent water from siphoning into the boat or
engine.

12. Place an appropriate tag on the key switch stating that the seacock must be opened or the seawater inlet hose must be
reconnected before operating the engine.

Engine Seawater Pump Inspection

IMPORTANT: Mercury strongly recommends that this service be performed by a Mercury Diesel authorized repair facility.
Remove and inspect the engine seawater pump at the interval specified in the Maintenance Schedule. See your Mercury

Diesel authorized repair facility.

Replacing the Engine Coolant in the Closed‑Cooling System

Draining the Closed‑Cooling System

NOTICE

Discharge of oil, coolant, or other engine/drive fluids into the environment is restricted by law. Use caution not to spill oil,
coolant, or other fluids into the environment when using or servicing your boat. Be aware of the local restrictions governing
the disposal or recycling of waste, and contain and dispose of fluids as required.

NOTE: For instructions on draining the seawater section, refer to

IMPORTANT: Observe the following points.

• Ensure that the engine is as level as possible to promote complete draining of the cooling system.

• The closed‑cooling section must be filled year‑round with the required coolant. If the engine will be exposed to freezing
temperatures, ensure that the closed‑cooling section is filled with a solution of ethylene glycol antifreeze and water properly
mixed to protect the engine to the lowest temperature to which it will be exposed.

• Do not use propylene glycol antifreeze in the closed‑cooling section of the engine.

A sudden loss of pressure can cause hot coolant to boil and discharge violently resulting in serious injury from burns. Allow
the engine to cool down before removing the coolant pressure cap.

1. Allow the engine to cool.

2. Remove the pressure cap from the expansion tank and coolant reservoir.

Draining the Seawater System

!

CAUTION

in this section.

NOTE: Drain coolant into a suitable container. Dispose of old coolant properly.

3. Remove the intake and exhaust manifold drain plug.

90-8M0113987 eng DECEMBER 2015 Page 67

Section 4 - Maintenance

a

b

23631

24552

a

a

b

23302

4. Remove the heat exchanger drain plug.

5. Open the engine block drain plug.

4.2 shown, 2.8 similar

a - Intake and exhaust manifold drain plug
b - Fluid cooler drain plug

4.2 shown, 2.8 similar

a - Engine block drain plug

6. After the coolant has drained completely, install the intake and exhaust manifold drain plug, the heat exchanger drain plug,
and the engine block drain plug. Tighten all drain plugs securely.

7. If required, clean the closed‑cooling system. See your local Mercury Diesel authorized repair facility.

8.

Fill the system with the specified coolant. Refer to Filling the Closed Cooling System.

Filling the Closed‑Cooling System

1. Remove the pressure cap.

Pressure cap

a ­b - Coolant expansion tank

Page 68 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

IMPORTANT: Use only the specified coolant.

2. If the coolant is being replaced or the level is low, slowly add the specified coolant to the level indicated in the table.

Coolant level in expansion tank
All models Within 25 mm (1 in.) of the bottom of the filler neck, or between the upper and lower marks, if marked

Description Where Used Part Number
Mercury Extended Life Antifreeze Closed‑cooling system 92‑877770K1

NOTICE

Without sufficient cooling water, the engine, the water pump, and other components will overheat and suffer damage. Provide
a sufficient supply of water to the water inlets during operation.

3. Ensure that the seawater pickup pump is supplied cooling water.

4. Do not install the pressure cap. Start and operate the engine at fast idle (1500–1800 RPM). Add coolant if necessary to

maintain the coolant at the level specified previously.
IMPORTANT: When installing the pressure cap, be sure to tighten it securely to avoid coolant loss.

5. Install the pressure cap after the engine has reached normal operating temperature (with the thermostat fully open) and the

coolant level remains constant.

6. Test the engine operation. Observe the temperature gauge and check the engine for coolant leaks. If the temperature

gauge indicates excessive temperature or if the coolant is leaking, stop the engine immediately and inspect for the cause.

7. After the first operation, allow the engine to cool.

8. Remove the pressure cap and add the specified coolant to the level indicated in the table.

Coolant level in expansion tank
All models Within 25 mm (1 in.) of the bottom of the filler neck, or between the upper and lower marks, if marked

9. Install and securely tighten the pressure cap.

Corrosion Protection

General Information

Whenever two or more dissimilar metals (such as those found on this power package) are submerged in a conductive solution
such as saltwater, polluted water, or water with a high mineral content, a chemical reaction takes place causing electrical
current to flow between metals. The electrical current flow causes the metal that is most chemically active, or anodic, to erode.
This erosion is known as
package components exposed to water.

To help control the effects of galvanic corrosion, Mercury power packages come with several sacrificial anodes and other
corrosion protection devices. For a more comprehensive explanation of corrosion and corrosion protection refer to the Marine
Corrosion Protection Guide.

IMPORTANT: Replace sacrificial anodes if eroded 50% or more. Mercury strongly recommends avoiding the use of anodes
from other manufacturers. Refer to your Mercury Diesel authorized repair facility for additional information.

Engine Corrosion Protection Components

The engine is equipped with a sacrificial anode located on top of the aftercooler end cover to assist in protecting the engine and
the seawater cooling system from corrosion. 4.2 models contain a second sacrificial anode assembly on the stern end of the
fluid cooler.

Removal

1. Allow the engine to cool.

galvanic corrosion

and, if it is not controlled, it will eventually cause the need for replacement of power

NOTICE

Failure to close the seawater inlet or seacock when removing or replacing the anode plugs can lead to water damage. Close
the seacock or remove and plug the seawater inlet hose to prevent water from entering the anode plug holes.

2. With the engine off, close the seacock, if equipped, or remove and plug the seawater inlet hose.

3.

Drain the seawater system. See Draining the Seawater System .

90-8M0113987 eng DECEMBER 2015 Page 69

Section 4 - Maintenance

a

b

23266

a

23710

b

abcde

4. Remove the anode assembly (anode plug and the sacrificial anode) from the top of the aftercooler end cover.

a - Aftercooler end cover
b - Anode assembly

5.

On 4.2 models, remove the anode assembly (anode plug and the sacrificial anode) from the aft end of the fluid cooler.

4.2

a - Anode assembly
b - Fluid cooler

Cleaning and Inspection

Inspection and replacement interval will vary according to the condition of the seawater and the mode of engine operation.

NOTE: Using sandpaper, fiber brush, or cleaning pad, remove the deposits from the surface of the anode before trying to
determine the amount of erosion. Do not use a mild steel brush, which might leave deposits that could accelerate corrosion.

1. Remove the deposits.

2. Inspect and measure the anode. Compare the measurements to the specifications for a new sacrificial anode and replace
the anode assembly when deteriorated 50%.

NOTE: Sacrificial anodes are available only as an assembly. Replace both the plug and anode as a unit.

Anode assembly

a - Anode plug
b - Sacrificial anode
c - Length
d - Diameter
e - Sealing washer

19226

Page 70 90-8M0113987 eng DECEMBER 2015

Sacrificial anode measurements (new)

a

b

a

b

23266

a

23710

b

Length 19 mm ( 3/4 in.)
Diameter 16 mm ( 5/8 in.)

3. Discard the sealing washer.

Installation

1. Install a new sealing washer on the anode assembly (anode plug with the sacrificial anode).

a - Anode assembly
b - Sealing washer

19227

2. Install the anode assembly and washer into the aftercooler end cover. Tighten securely.

a - Aftercooler end cover
b - Anode assembly

Section 4 - Maintenance

3.

On 4.2 models, install the anode assembly and washer into the aft end of the fluid cooler. Tighten securely.

4.2

a - Anode assembly
b - Fluid cooler

4. Unplug and connect the seawater inlet hose, or open the seacock if equipped.

90-8M0113987 eng DECEMBER 2015 Page 71

Section 4 - Maintenance

a

c

d

e

b

35214

f

f

a

a

c

c

d

d

e

e

b

b

35213

NOTICE

Without sufficient cooling water, the engine, the water pump, and other components will overheat and suffer damage. Provide
a sufficient supply of water to the water inlets during operation.

5. Ensure that the seawater pickup pump is supplied cooling water.

6. Start the engine and check for leaks

Sterndrive Corrosion Protection Components

To help control the effects of galvanic corrosion, sterndrives come with several sacrificial anodes and other corrosion protection
devices. For a more comprehensive explanation of corrosion and corrosion protection, refer to the Marine Corrosion
Protection Guide.

Typical single sterndrive

a - Anode (Alpha models), MerCathode (Bravo models)
b - Ventilation plate anode
c - Trim cylinder anodes
d - Bearing carrier anodes
e - Gearcase anodic plate
f - Anode kit on lower hull

Dual sterndrive

a - Anode (Alpha models), MerCathode (Bravo models)
b - Ventilation plate anode
c - Trim cylinder anodes
d - Bearing carrier anodes
e - Gearcase anodic plate
f - Anode kit on lower hull

NOTICE

Washing the MerCathode assembly can damage components and lead to rapid corrosion. Do not use any cleaning
equipment such as brushes or high‑pressure washers to clean the MerCathode assembly.

Page 72 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

6211

c

b

a

Do not pressure‑wash the MerCathode assembly, if equipped. Doing so will damage the coating on the reference electrode
wire and decrease the corrosion protection.

MerCathode mounted to the underside of
the gimbal housing, if equipped

a - MerCathode reference electrode, if

equipped

b - Do not paint
c - Do not pressure wash

IMPORTANT: Replace sacrificial anodes if eroded 50% or more.
The following sacrificial anodes are installed at different locations on your power package. These anodes help protect against

galvanic corrosion by sacrificing its metal to be slowly eroded instead of the metal components on the power package.
MerCathode System—The electrode assembly, if equipped, replaces the anode block. The system should be tested to ensure

adequate output. Perform the test when the boat is moored, using a Quicksilver reference electrode and test meter. Contact
your Mercury Diesel authorized repair facility.

90-8M0113987 eng DECEMBER 2015 Page 73

Section 4 - Maintenance

22405

53380

Description Location Figure

Alpha sterndrive

gearcase anodic plate

Alpha sterndrive

gimbal housing anode

Bravo sterndrive

gearcase anode plate

Alpha and Bravo sterndrive

ventilation plate anode

Mounted on the underside of the lower gearcase.

Mounted on the underside of the gimbal housing.

Mounted on the underside of the lower gearcase.

20336

Mounted on the front of the gearcase.

20338

Alpha and Bravo sterndrive

trim cylinder anodes

Alpha and Bravo sterndrive

bearing carrier anode

Mounted on each of the trim cylinders.

Located in front of the propeller, between the front
side of the propeller and the gear housing.

The MerCathode electrode, if equipped, is mounted
to the underside of the gimbal housing. The

MerCathode System

MerCathode controller is mounted on the engine or
on the boat transom. The controller harness
connects to the electrode harness.

Anode kit (if equipped) Mounted to the boat transom.

20342

20343

20340

20341

In addition to the corrosion protection devices, take the following steps to inhibit corrosion:

Page 74 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

27282

a

27283

1. Paint the power package.

2. Annually spray the power package components on the inside of the boat with Corrosion Guard to protect the finish from
dulling and corrosion. You may also spray external power package components.

3. Keep all lubrication points, especially the steering system, shift, and throttle linkages, well lubricated.

4. Flush the cooling system periodically, preferably after each use.

Continuity Circuit—Bravo Sterndrive

The transom assembly and sterndrive have ground‑circuit wires to ensure good electrical continuity between the engine,
transom assembly, and sterndrive components. Good continuity to a ground is essential for the anode and MerCathode system
to function effectively.

1. Inspect the steering lever ground wire for loose connections, broken connectors, or frayed wiring.

2. Inspect the inner transom plate ground wire for loose connections, broken connectors, or frayed wiring.

Steering lever continuity wire

a - Continuity wire

3. Inspect the flywheel housing grounding stud and ground wire, and the inner transom plate grounding screw for loose
connections, broken connectors, or frayed wiring.

Typical

a - Flywheel housing screw or grounding stud
b - Continuity circuit (ground) wire

c

c - Inner transom plate grounding screw

Transom plate continuity wires

a

b

7782

90-8M0113987 eng DECEMBER 2015 Page 75

Section 4 - Maintenance

27285

a

27263

a

4. Inspect the driveshaft housing‑to‑gear housing ground plate inside the anode cavity for a loose or faulty connection.

Sterndrive anodic plate cavity

a - Ground plate (inside anode cavity)

5. Inspect the gimbal housing ground wires for loose connections, broken connectors, or frayed wiring.

a - Gimbal housing‑to‑gimbal ring ground wire

b

b - Gimbal housing‑to‑trim cylinder ground wires

a

7006

6. Inspect the gimbal ring ground wire for loose connections, broken connectors, or frayed wiring.

a - Gimbal ring‑to‑bell housing ground wire

Page 76 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

9188

a

27264

a

9957

a

19627

7. Inspect the sterndrive ground plate for loose or broken connections.

a - Sterndrive‑to‑bell housing ground plate

8. Inspect the continuity washers under the hydraulic manifold block fasteners for a loose or faulty connection.

a - Continuity washers

9. Inspect the sterndrive U‑joint bellows ground clips and exhaust tube ground clip for loose or faulty connections.

Exhaust tube ground clip shown, U-joint bellows ground clips similar

a - Exhaust tube ground clip

MerCathode

If the boat is equipped with a MerCathode system, the system should be tested to ensure that it is providing adequate output to
protect the underwater metal parts on the boat. The test should be made where the boat is moored, using a Reference
Electrode and Test Meter.

Reference Electrode

91‑76675T 1

Senses and electrical current in the water when testing the MerCathode system. Use to check hull
potential.

90-8M0113987 eng DECEMBER 2015 Page 77

Section 4 - Maintenance

Refer to the appropriate Mercury MerCruiser sterndrive service manual for testing procedures.

Boat Bottom Care

To achieve maximum performance and fuel economy, the boat bottom must be kept clean. Accumulation of marine growth or
other foreign matter can greatly reduce boat speed and increase fuel consumption. To ensure best performance and efficiency,
periodically clean the boat bottom in accordance with manufacturer's recommendations.

In some areas, it may be advisable to paint the bottom to help prevent marine growth. Refer to the following information for
special notes about the use of antifouling paints.

Painting Your Power Package

IMPORTANT: Corrosion damage that results from the improper application of anti‑fouling paint will not be covered by the
limited warranty.

1.

Painting the boat hull or transom: you may apply anti‑fouling paint to the boat hull and transom. However, observe the
following:
IMPORTANT: Do not paint anodes or MerCathode System reference electrode and anode. Paint will render them
ineffective as inhibitors of galvanic corrosion.
IMPORTANT: If anti‑fouling protection is required for the boat hull or transom, you can use copper‑based or tin‑based
paints where not prohibited by law. If using copper‑based or tin‑based anti‑fouling paints, observe the following:

• Avoid any electrical interconnection between the paint and the Mercury MerCruiser product, anodic blocks, or
MerCathode system by allowing a minimum of 40 mm (1‑1/2 in.) unpainted area on the transom of the boat around
these items.

a - Painted boat transom
b - Unpainted area on transom

a

b

5578

2.

Painting the sterndrive unit or transom assembly: The sterndrive unit and transom assembly should be painted with a
good‑quality marine paint or an anti‑fouling paint that does not contain copper, tin, or any other material that could conduct
electrical current. Do not paint drain holes, anodes, MerCathode system, or items specified by the boat manufacturer.

Page 78 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

21083

a

b

c

d

e

f

g

Sterndrive Surface Care

Standard Bravo sterndrive

a - Sacrificial trim cylinder anode
b - Sacrificial anodic plate
c - Steering lever ground wire
d - Ground wire between the gimbal ring and bell housing
e - Stainless steel hoses
f - Ground wire between the gimbal housing and trim cylinder
g - Ground wire between the gimbal ring and gimbal housing

We recommend the following maintenance items to help keep your sterndrive corrosion‑free:

• Maintain a complete paint covering on the sterndrive.

• Check the finish regularly. Prime and paint nicks and scratches using Mercury enamel paint and touch up paint. Use only
tin‑based antifouling paint or its equivalent on or near aluminum surfaces below the waterline.

• If bare metal is showing, apply two coats of paint.

• Spray all electrical connections with sealant.

• Inspect the sacrificial trim tab or anode plate if equipped, at regular intervals and replace it before it is half gone. If a

• Inspect the propeller shaft for fishing line, which can cause corrosion on a stainless steel shaft.

• Remove the propeller at least every 60 days and lubricate the propeller shaft.

• Do not use lubricants containing graphite on or near the aluminum in saltwater.

• Do not paint trim tabs or the mounting surface.

Lubrication

Steering System

Incorrect cable lubrication can cause hydraulic lock, leading to serious injury or death from loss of boat control. Completely
retract the end of the steering cable before applying lubricant.

NOTE: If the steering cable does not have a grease fitting, the inner wire of the cable cannot be greased.

Description
Mercury Phantom Black Bare metal 92‑ 802878‑1

Tube Ref No.

25

stainless steel propeller is installed, additional anodes or a MerCathode system will be required.

Liquid Neoprene All electrical connections 92- 25711 3

Description Where Used Part No.

WARNING

!

Where used Part number

90-8M0113987 eng DECEMBER 2015 Page 79

Section 4 - Maintenance

1.

If the steering cable has grease fittings, turn the steering wheel until the steering cable is fully retracted into the cable
housing. Apply approximately three pumps of grease from a typical hand‑operated grease gun.

a - Steering cable grease fitting

a

6221

Tube Ref No. Description Where Used Part No.

95

2-4-C with PTFE Steering cable grease fitting 92-802859A 1

2. Turn the steering wheel until the steering cable is fully extended. Lightly lubricate the exposed part of the cable.

a - Extended steering cable

a

6222

Tube Ref No. Description Where Used Part No.

95

2-4-C with PTFE Steering cable 92-802859A 1

3. Lubricate the steering pin.

a - Steering pin

a

mc71904-1

Tube Ref. No. Description Where Used Part No.

Synthetic Blend MerCruiser Engine Oil
SAE25W‑40

4. On dual engine boats: Lubricate the tie bar pivot points.

Steering pin 8M0078630

Page 80 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

aa

b

23643

Tube Ref. No. Description Where Used Part No.

Synthetic Blend MerCruiser Engine Oil
SAE25W‑40

5. Upon first starting the engine, turn the steering wheel several times to starboard and then port to ensure that the steering
system operates properly before getting underway.

Tie bar pivot points 8M0078630

Throttle Cable

1. Lubricate the pivot points and guide contact surfaces.

a - Pivot points
b - Guide contact surfaces

Tube Ref No. Description Where Used Part No.

80

SAE Engine Oil 30W Throttle cable pivot points and guide contact surfaces Obtain Locally

Shift Cable

Lubricate the pivot points and guide contact surfaces.

Typical sterndrive model shift cable

a - Pivot points
b - Guide contact surface

a

a

a

20261

b

Tube Ref No. Description Where Used Part No.

80

90-8M0113987 eng DECEMBER 2015 Page 81

SAE Engine Oil 30W Shift cable pivot points and guide contact surfaces Obtain Locally

Section 4 - Maintenance

a

b

23500

Transom Assembly

Lubricate the gimbal bearing by applying approximately 8‑10 pumps of grease from a typical hand‑operated grease gun.

a - Gimbal bearing grease insert

a

19979

Tube Ref No. Description Where Used Part No.

Extreme Grease Gimbal bearing grease insert 8M0071842

Engine Coupler

IMPORTANT: These engines are equipped with a sealed engine coupler. The sealed coupler and the shaft splines can be
lubricated without removing the sterndrive.

Lubricate the engine coupler splines through the grease fitting on the coupler by applying approximately 8–10 pumps of
Extreme Grease from a typical hand‑operated grease gun.

NOTE: If the boat is operated at idle for prolonged periods of time, the coupler should be lubricated on Bravo models every 50
hours.

a - Grease fitting
b - Coupler splines

Tube Ref No. Description Where Used Part No.

Extreme Grease Engine coupler and shaft splines 8M0071842

Driveshaft Extension Models

1. Lubricate the transom end grease fitting and engine end grease fitting by applying approximately 10–12 pumps of grease
from a typical hand‑operated grease gun.

Page 82 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

a

b

a

c

17014

2. Lubricate the driveshaft grease fittings by applying approximately 3–4 pumps of grease from a typical hand‑operated

grease gun.

a - Driveshaft grease fittings
b - Transom end grease fitting
c - Engine end grease fitting

Tube Ref No. Description Where Used Part No.

Extreme Grease

Transom end grease fitting, engine end grease fitting, driveshaft grease

fittings

8M0071842

Sterndrive, Bellows, and Engine Alignment

IMPORTANT: Have your Mercury Diesel authorized repair facility perform the maintenance procedures listed, or refer to the
appropriate Mercury MerCruiser Bravo Sterndrive Service Manual.

1. Lubricate the U‑joint shaft splines and the O‑rings.

a - U‑joint shaft splines

b

b - U‑joint shaft O‑rings

a

19867

Tube Ref No. Description Where Used Part No.

Extreme Grease U-joint shaft splines and O-rings 8M0071842

2. Inspect the U‑joint bellows for cracks or other signs of deterioration. Ensure that the bellows clamps are tight.

90-8M0113987 eng DECEMBER 2015 Page 83

Section 4 - Maintenance

3. Rotate the bell housing in the upward and side‑to‑side directions to inspect the exhaust tube, shift cable bellows, and
clamps.

e

a - U‑joint bellow
b - Exhaust tube
c - Bell housing

a

c

d - Gimbal ring
e - Gimbal housing
f - Shift cable bellows

f

b

d

4. Check the engine alignment.

22189

b

a

a - Alignment tool
b - End of alignment tool to insert through gimbal housing assembly
c - Gimbal bearing
d - Engine coupler

d

c

a

7936

Maintaining Torques

Bravo Gimbal Ring U‑bolt Nuts

NOTE: The gimbal ring is a component of the transom assembly.

Page 84 90-8M0113987 eng DECEMBER 2015

Section 4 - Maintenance

Tighten the gimbal ring U‑bolt nuts to the specified torque.

a - Transom assembly
b - Gimbal ring U‑bolt nuts

b

a

19624

Description Nm lb‑in. lb‑ft
Gimbal ring U‑bolt nuts for 7/16 in. U‑bolt 95 – 70

Engine Mounts

Loosen the rear engine mount bolts 1 to 1‑1/2 turns. Retorque the rear engine mount bolts.

a - Rear engine mount
b - Transom plate mount
c - Rear engine mount bolt

a

b

Description Nm lb. in. lb. ft.
Rear engine mounts 47 35

c

19622

Propellers

Bravo Sterndrive Propeller Removal

WARNING

!

Rotating propellers can cause serious injury or death. Never operate the boat out of the water with a propeller installed.
Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the
engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate.

90-8M0113987 eng DECEMBER 2015 Page 85

Section 4 - Maintenance

a

b

c

d

e

4750

a

b

c

d

e

g

f

5301

a

b

c

d

e

4750

Bravo One Models

1. Straighten the bent tabs of the tab washer on the propeller shaft.

a - Propeller
b - Tab washer
c - Drive sleeve adapter
d - Tab bent down
e - Propeller nut

2. Place a block of wood between the propeller blade and the sterndrive's anti‑ventilation plate.

a - Wood block
b - Propeller
c - Propeller nut under socket

3. Turn the propeller shaft nut counterclockwise and remove the nut.

4. Slide the propeller and the attaching hardware from the propeller shaft.

Bravo One models

a - Propeller shaft splines
b - Forward thrust hub
c - Flo‑Torque II drive hub
d - Propeller
e - Drive sleeve adapter
f - Tab washer
g - Propeller nut

Bravo Two Models

1. Straighten the bent tabs of the tab washer on the propeller shaft.

Propeller

a ­b - Tab washer
c - Drive sleeve adapter
d - Tab bent down
e - Propeller nut

Page 86 90-8M0113987 eng DECEMBER 2015

2. Place a block of wood between the propeller blade and the sterndrive's anti‑ventilation plate.

10677

a - Wood block
b - Propeller
c - Propeller nut under socket

3. Turn the propeller shaft nut counterclockwise to remove the nut.

4. Slide the propeller and attaching hardware from the propeller shaft.

Section 4 - Maintenance

c

d

f

a

b

8566

e

Bravo Two

a - Propeller shaft splines
b - Forward thrust hub
c - Propeller
d - Spline washer
e - Tab washer
f - Propeller nut

Bravo Three Models

1. Place a block of wood between the propeller blade and the sterndrive's anti‑ventilation plate.

2. Remove the bolt and washers securing the propeller shaft anode.

3. Remove the propeller shaft anode.

a - Propeller
b - Propeller shaft nut
c - Propeller shaft anode
d - Propeller shaft anode screw
e - Flat washer

a

b

f - Star washer

c

d

f

e

4. Turn the aft propeller shaft nut counterclockwise to remove the nut.

5. Slide the propeller and thrust hub off of the propeller shaft.

6. Using the propeller nut tool, turn the front propeller shaft nut counterclockwise and remove the nut.

Propeller Nut Tool

Aids in the removal and installation of the front propeller nut.

90-8M0113987 eng DECEMBER 2015 Page 87

19058

91‑805457T 1

Section 4 - Maintenance

a

b

c

d

e

g

f

5301

7. Slide the propeller and the thrust hub off the propeller shaft.

e

f

b

d

c

a

i

j

g

h

5304

Bravo Three

a - Aft propeller nut
b - Aft propeller
c - Aft propeller thrust hub
d - Front propeller nut
e - Front propeller
f - Front propeller thrust hub
g - Propeller shaft anode screw
h - Flat washer
i - Star washer
j - Propeller shaft anode

Bravo Sterndrive Propeller Installation

WARNING

!

Rotating propellers can cause serious injury or death. Never operate the boat out of the water with a propeller installed.
Before installing or removing a propeller, place the drive unit in neutral and engage the lanyard stop switch to prevent the
engine from starting. Place a block of wood between the propeller blade and the anti‑ventilation plate.

a - Wood block
b - Propeller
c - Propeller nut under socket

Bravo One Models

IMPORTANT: Use the correct rotation propeller. The propeller rotation must match the direction of rotation of the propeller
shaft.

1. Liberally coat the propeller shaft spline with one of the following lubricants.

Tube Ref No.

95

2. Install the propeller with the attaching hardware as shown.

3. Tighten the propeller nut to the specified torque.

2-4-C with PTFE Propeller shaft splines 92-802859A 1

Extreme Grease Propeller shaft splines 8M0071842

Description Where Used Part No.

Typical Bravo One models

a - Propeller shaft splines
b - Forward thrust hub
c - Flo‑Torque II drive hub
d - Propeller
e - Drive sleeve adapter
f - Tab washer
g - Propeller nut

Page 88 90-8M0113987 eng DECEMBER 2015

NOTE: The propeller torque stated is a minimum torque value.

10677

a

b

c

d

e

4750

Description Nm lb‑in. lb‑ft

Bravo One propeller nut

4.

Models equipped with the tab washer: Continue to tighten the propeller nut until the three tabs on the tab washer align
with the grooves on the spline washer.

5. Bend the three tabs down into the grooves.

a - Propeller
b - Tab washer
c - Drive sleeve adapter
d - Tab bent down
e - Propeller nut

Bravo Three

1. Liberally coat the propeller shaft spline with one of the following lubricants.

Section 4 - Maintenance

75 – 55

Then align tabs with grooves

Tube Ref No.

95

2-4-C with PTFE Propeller shaft splines 92-802859A 1

Extreme Grease Propeller shaft splines 8M0071842

Description Where Used Part No.

2. Slide the forward thrust hub onto the propeller shaft with the tapered side toward the propeller hub.

3. Align splines and place front propeller on propeller shaft.

4. Install the front propeller locknut and tighten to the specified torque using the propeller nut tool.

Propeller Nut Tool

Aids in the removal and installation of the front propeller nut.

91‑805457T 1

Description Nm lb‑in. lb‑ft
Bravo Three front propeller nut 136 – 100

5. Slide the aft thrust hub onto the propeller shaft with the tapered side toward the propeller hub.

6. Align the splines and install the aft propeller.

7. Install the propeller nut and torque.

NOTE: The propeller torque stated is a minimum torque value.

Description

Nm lb‑in. lb‑ft

Bravo Three rear propeller nut 81 – 60

90-8M0113987 eng DECEMBER 2015 Page 89

Section 4 - Maintenance

a

b

c

d

e

f

h

g

i

23313

8. Install the propeller shaft anode and secure with the screw. Tighten the screw to the specified torque.

e

f

b

d

c

a

i

j

g

h

5304

Description Nm lb‑in. lb‑ft
Propeller shaft anode screw 19 168 –

Bravo Three

a - Rear propeller nut
b - Rear propeller
c - Rear propeller thrust hub
d - Front propeller nut
e - Front propeller
f - Front propeller thrust hub
g - Propeller shaft anode screw
h - Flat washer
i - Star washer
j - Propeller shaft anode

Drive Belts

All drive belts must be periodically inspected for tension and condition, such as excessive wear, cracks, fraying, or glazed
surfaces.

WARNING

!

Inspecting the belts with the engine running may cause serious injury or death. Turn off the engine and remove the ignition
key before adjusting tension or inspecting belts.

Serpentine Belt

Inspection

1. Inspect the belt for proper tension and for the following:

2.8 shown, 4.2 similar

a - Water circulating pump pulley
b - Alternator pulley
c - Idler
d - Automatic tensioner
e - Crankshaft pulley
f - Seawater pump pulley
g - Power assisted steering pulley
h - Power assisted steering belt
i - Serpentine belt

• Excessive wear

• Cracks

NOTE: Minor, transverse cracks (across the belt width) may be acceptable. Longitudinal cracks (in the direction of
belt length) that join transverse cracks are not acceptable.

• Fraying

Page 90 90-8M0113987 eng DECEMBER 2015

• Glazed surfaces

21062

23256

b

a

b

a

23258

2. Check the operation of the automatic tensioner and associated components.
a. Position a suitable tool in the automatic tensioner release slot.
b. Rotate the automatic tensioner in the direction of the arrow.

a - Automatic tensioner
b - Release slot

Section 4 - Maintenance

c. Release the automatic tensioner and allow it to glide back slowly.
d. The automatic tensioner must return to the initial position and hold tension on the serpentine belt.

Replacement

IMPORTANT: If a belt is to be reused, it should be installed in the same direction of rotation as when first used.

1. Position a suitable tool in the automatic tensioner release slot.

2. Rotate the automatic tensioner in the direction of the arrow to remove the tension on the serpentine belt.

a - Serpentine belt
b - Release slot

3. Remove the serpentine belt.

4. Replace the serpentine belt.

5. Carefully release the automatic tensioner with the breaker bar, ensuring that the belt stays positioned properly.

90-8M0113987 eng DECEMBER 2015 Page 91

Section 4 - Maintenance

a

23632

23767

aa

23650

aa

b

Power‑Assisted Steering Pump Belt

Inspection

1. Inspect the belt for proper tension and for the following:

• Excessive wear

• Cracks

• Fraying

• Glazed surfaces

2.

Replace the belt if worn or damaged. See Replacement.

3. Check belt tension by depressing the upper strand of the belt, with moderate hand pressure, at the point shown. The belt
must correspond to the specifications in the following table.

2.8 shown, 4.2 similar

a - Power steering pump belt

Power‑assisted steering drive belt tension
Belt deflection, with moderate hand pressure 5 mm (3/16 in.)

4.

Adjust the tension if necessary. See Adjustment.

Adjustment

1. Loosen the power‑assisted steering pump mounting bolts.

2.8 shown, 4.2 similar

a - Mounting bolts

2. Use the adjustment screw to move the power‑assisted steering pump to tension the power‑assisted steering belt.

Mounting bolts

a ­b - Adjustment screw

Page 92 90-8M0113987 eng DECEMBER 2015