Mercury Bravo Three Maintance Manual

OPERATION &
MAINTENANCE MANUAL

7.4L

Bravo Three

1995, Brunswick Corporation 90-805718960 595

CA1

Identification Record

Please Record the Following Information

1.
Engine Model and Horsepower

2.
Engine Serial Number

3.
Transom Assembly Serial Number

4.
Stern Drive Unit Serial Number and Gear Ratio

5.
Propeller Number

6.
Propeller Pitch

7.
Hull Identification Number (HIN) Purchase Date

8.
Boat Manufacturer Boat Model Length

SERIAL NUMBERS

The serial numbers are the manufacturer’s keys to numerous engineering details
which apply to your MerCruiser power package. When contacting your Authorized
MerCruiser Dealer about service, always specify model and serial numbers.

The description and specifications contained herein were in effect at the time this
guide was approved for printing. Mercury Marine, whose policy is one of continuous
improvement, reserves the right to discontinue models at any time, or to change
specifications or designs, without notice and without incurring obligation.

Mercury Marine, Fond du Lac, Wisconsin, U.S.A. Printed in U.S.A.

1995, Brunswick Corporation

The following are registered trademarks of Brunswick Corporation: Auto­blend, Jet-Prop, Mariner, Merc, MerCathode, MerCruiser, Mercury, Mercury
Marine, Quicksilver, Ride-Guide, and Thruster.

0

CB2

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3

ABC12345Z123

7

71350

71348

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71352

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2

1

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4

2

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71773

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-19 48-12345

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1

CB390

Table Of Contents

Page

Welcome! 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Read This Manual Thoroughly 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lanyard Stop Switch 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Safe Boating Suggestions 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Protecting People In The Water 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

High-Speed And High-Performance Boat Operation 11. . . . . . . . . . . . . . .

Conditions Affecting Operation 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Weight Distribution 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bottom Of Boat 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cavitation 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Ventilation 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Propeller Selection 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

How Elevation And Climate Affect Performance 15. . . . . . . . . . . . . . . .

Important Information 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operation And Maintenance 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Freezing Temperature Operation 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Drive Unit Impact Protection 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Attention Required After Submersion 18. . . . . . . . . . . . . . . . . . . . . . . . .

Trailering Boat 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Launching And Boat Operation Care 19. . . . . . . . . . . . . . . . . . . . . . . . . .

Stolen Power Package 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Replacement Service Parts 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Do-It-Yourself Maintenance Suggestions 21. . . . . . . . . . . . . . . . . . . . . .

20-Hour Break-In Period 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

After Break-In Period 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operation 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Instrumentation 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Electrical System Overload Protection 29. . . . . . . . . . . . . . . . . . . . . . . . .

Models With Mercathode System 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Controls (Panel Mounted) 31. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Remote Controls (Console Mounted) 33. . . . . . . . . . . . . . . . . . . . . . . . .

Remote Controls (Two Lever) 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Trim 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Starting, Shifting And Stopping 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Operation Chart 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Specifications 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel Recommendations 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Crankcase Oil 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Engine Specifications 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Tune-Up Specifications 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Capacities 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2

Page

Maintenance 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance Aids 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance Chart 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Checking Fluid Levels 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Changing Fluids 65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Water Separating Fuel Filter 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel Pump Sight Tube Inspection 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Lubrication 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Propeller 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Flushing Cooling System 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Seawater Pump Impeller Inspection 79. . . . . . . . . . . . . . . . . . . . . . . . . .

Cleaning Seawater (Raw Water) Section Of
Heat Exchanger And Oil/Power Steering

Cooler - Closed Cooling Models Only 81. . . . . . . . . . . . . . . . . . . . . . . .

Drive Belts 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Corrosion And Corrosion Protection 85. . . . . . . . . . . . . . . . . . . . . . . . . .

Miscellaneous Maintenance 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Bottom Of Boat 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Inspection And Maintenance 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Cold Weather Or Extended

Storage 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Power Package Lay Up 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Draining Instructions 95. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Battery Winter Storage 102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting 103. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warranty Information 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Owner Warranty Registration 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

International Owner Registration 111. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warranty Policies 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Mercruiser Limited Warranty - Gasoline Engines 112. . . . . . . . . . . . . . .

Mercruiser International Warranty - Gasoline Engines 114. . . . . . . . . .

3 Year Limited Warranty Against

Corrosion Failure 116. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Warranty Coverage 118. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Transferable Warranty 121. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Q-guard Product Protection Plan 122. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Owner Service Assistance 123. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Service Centers 126. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Customer Service Literature 128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Maintenance Parts 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Literature Order Form 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

CA165

Welcome!

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

With proper care and maintenance, you will thoroughly 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 MerCruiser products. We sincerely
hope your boating will be pleasant!

Consumer Affairs Department

4

CA166

Read This Manual Thoroughly

IF YOU DON’T UNDERST AND ANY PORTION, CONTACT YOUR
DEALER FOR A DEMONSTRATION OF ACTUAL STARTING
AND OPERATING PROCEDURES.

NOTICE
Throughout this publication, and on your power package, WARN­INGS and CAUTIONS, accompanied by the International Hazard

Symbol
tions concerning a particular service or operation that may be haz-

ardous if performed incorrectly or carelessly. Observe them care-

fully.

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-Hazards or unsafe practices which could result in
severe personal injury or death.

, may be used to alert the installer/user to special instruc-

!

!

WARNING

!

CAUTION

CAUTION-Hazards or unsafe practices which could result in mi­nor personal injury or product or property damage.

IMPORTANT: - Indicates information or instructions that are
necessary for proper operation and /or maintenance.

!

WARNING

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.

5

CA280

Lanyard Stop Switch

2

1

74608

1 Some boats come equipped with a lanyard stop switch. A lanyard

stop switch can also be installed as an accessory . The purpose of this
switch is to turn off the engine ignition whenever the operator (when
attached to the lanyard) moves far enough away from the operator’s
position to activate the switch.

2 The lanyard is a cord usually between 4 and 5 feet (1220 and 1524

mm) in length when stretched out with an element on one end made
to be inserted into the switch and a metal snap on the other end for
attaching to the operator. It is coiled to make its at rest condition as
short as possible so as to minimize the likelihood of lanyard entangle­ment with nearby objects. It is made as long as it is in its stretched
condition to minimize the likelihood of accidental activation should
the operator choose to move around in an area close to the normal
operator’s position. If for any reason it is desired to have a shorter
functional lanyard, this may be accomplished by using up length in
the way the lanyard and clip are attached to the operator (such as
wrapping the lanyard around the operator’s wrist or leg) or by tying
a simple knot in the lanyard.

Read the Safety Warning on this page and the following page
before electing to install, use, or not to use such a switch.

!

WARNING

The following advantages and disadvantages of a lanyard stop
switch should be considered before electing to use, or not to
use, such a switch.

6

ADV ANTAGES: The purpose of a lanyard stop switch is to stop
the engine ignition whenever the operator (when attached to the
lanyard) moves far enough away from the operator’s position to
activate the switch. This would occur if the operator falls or
moves within the boat a sufficient distance from the operator’s
position. This type of accident is most likely in certain types of
boats such as low-sided boats, and high-performance boats,
It is also likely as a result of poor operating practices such as
sitting on the back of the seat at planing speeds, standing at
planing speeds, operating at high speeds in shallow or ob­stacle-infested waters, releasing your grip on a steering wheel
that is pulling in one direction, drinking and driving, or daring,
high-speed boat maneuvers.

DISADVANTAGES: Inadvertent activation of the switch is also
a possibility . This could cause any, or all, of the following poten­tially hazardous situations:

1. Loss of balance and falling forward of unstable boat passen-

gers - a particular concern in bow rider type boats.

2. Loss of power and directional control in heavy seas, strong

current or high winds.

3. Loss of control when docking.

While activation of the lanyard stop switch will result in immedi­ate power shut-down, a boat can continue to coast for some dis­tance depending upon the velocity and degree of any turn at
shut-down. However, the boat will not complete a full circle.
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.

As we cannot possibly know of and advise the boating public
of all conceivable boat/motor types and/or poor operating prac­tices, the final decision of whether to use a lanyard stop switch
rests with you, the owner/driver.

We strongly recommend that other occupants be instructed on
proper starting and operating procedures should they be re­quired to operate the engine and boat in an emergency.

7

CA281

Safe Boating Suggestions

In order to safely enjoy the waterways, familiarize yourself with local
and other governmental boating regulations and restrictions, and
consider the following suggestions.

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

Boat operators should complete a boating safety course. Courses
are offered in the U.S.A. by (1) The U.S. Coast Guard Auxiliary,
(2) The Power Squadron, (3) The Red Cross and (4) your state
or provincial boating law enforcement agency. Inquiries may be
made to the Boating Hotline, 1-800-368-5647 or the Boat U.S.
Foundation information number 1-800-336-BOAT.

We strongly recommend that all powerboat operators attend one of
these courses.

Y ou should also review the NMMA Sources of Waterway Information
booklet. It lists regional sources of safety , cruising and local naviga­tion and is available at no charge by writing to:

Sources of Waterway Information
National Marine Manufacturers Association
410 N. Michigan Avenue
Chicago, IL 60611 U.S.A.

• Perform safety checks and required maintenance. Follow a

regular schedule and ensure that all repairs are properly made.

• Check safety equipment on board. Here are suggestions of the

types of safety equipment to carry when boating:

(1) Approved fire extinguisher(s); paddle or oar.
(2) Signal devices: flashlight, rockets or flares, flag and whistle or

horn.
(3) Spare propeller, thrust hubs and an appropriate wrench.

(4) Tools for necessary minor repairs; first aid kit and book.
(5) Anchor and extra anchor line; water-proof storage containers.
(6) Manual bilge pump and extra drain plugs; compass and map or

chart of area.
(7) Spare operating equipment; batteries, bulbs, fuses, etc.
(8) Transistor radio
(9) Drinking water

8

• Know 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. Just
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, wearable-type life jacket (per­sonal flotation device), correctly sized and readily accessible for
every person on board, 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 on

board 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 capacity
plate). When in doubt, contact your dealer or the boats manufac­turer. Know your boat’s operating and loading limitations.

• Make sure everyone in the boat is properly seated. Don’t allow

anyone to sit or ride on any part of the boat that was not intended
for such use. This includes backs of seats, gunwales, transom,
bow, decks, raised fishing seats, any rotating fishing seat; 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.

• Never be under the influence of alcohol or drugs while boat-

ing (it is the law). They impair your judgment and greatly reduce
your ability to react quickly.

• Know your boating area and avoid hazardous locations.

• Be alert. The operator of the boat is responsible by law to “main-

tain 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 operators view when
operating the boat above idle or planing transition speed. Watch
“the other guy,” the water and your wake.

9

• Never drive your boat directly behind a water skier in case

the skier falls. As an example, your boat traveling at 25 miles per
hour (40 km/hr) in 5 seconds will overtake a fallen skier who was
200 feet in front of you.

• Watch fallen skiers. When using your boat for water skiing or

similar activities, always keep a fallen or down skier on the opera­tor’s side of the boat while returning to attend 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.

10

CA282

Protecting People In The Water

While You Are Cruising

It is very difficult for a person standing or floating in the water to take
quick action to avoid a boat heading in his/her direction even at slow
speed.

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 (coasting) and the drive unit is in neutral
position, 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

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

!

WARNING

Stop your engine immediately whenever anyone in the water is
near your boat. Serious injury to the person in the water is likely
if contacted by a rotating propeller, a moving boat, a moving
gear case, or any solid device rigidly attached to a moving boat
or gear case.

CA283

High-Speed And High-Performance

Boat Operation

If your boat is considered a high-speed or high-performance boat
with which you are unfamiliar, we recommend that you never operate
it at its high speed capability without first requesting an initial orienta­tion and familiarization demonstration ride with your dealer or an op­erator experienced with your boat. For additional information, obtain
a copy of our “Hi-Performance Boat Operation” booklet (Part Number
90-86168--3) from your dealer, distributor, or Mercury Marine.

11

CA7

Conditions Affecting

Operation

Weight Distribution

Positioning of weight (passengers and gear) inside the boat has the
following effects:

Shifting weight to rear (stern) will:

• Generally increases speed and engine RPM.

• At extremes can cause boat to porpoise.

• Causes bow to bounce in choppy water.

• Increases danger of following wave splashing into boat when

coming off plane.

Shifting weight to front (bow) will:

• Improve ease of planing.

• Improve rough water ride.

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

CA8

Bottom Of Boat

T o maintain maximum speed, the following conditions of the boat bot­tom should be observed.

A. Clean, free of barnacles and marine growth.
B. Free of distortion; nearly flat where it contacts the water.
C. Straight and smooth, fore and aft.
Marine vegetation may accumulate when boat is docked. This

growth must be removed before operation; it may clog water inlets
and cause engine to overheat.

12

CA9

Cavitation

Cavitation occurs when water flow cannot follow the contour of a
fast-moving underwater object, such as a gear housing or propeller.
Cavitation permits the propeller to speed up, but the boat speed to
reduce. Cavitation can seriously erode the surface of the gear hous­ing or propeller. Common causes of cavitation are:

A. Weeds or other debris snagged on propeller or gear housing.
B. Bent propeller blade or damaged gear housing skeg.
C. Raised burrs or sharp edges on propeller or gear housing.

CA10

Ventilation

Ventilation is caused by surface air or exhaust gases which are intro­duced around the propeller resulting in propeller speedup and a re­duction in boat speed. Excessive ventilation is annoying and usually
caused by:

A. Drive unit trimmed out too far.
B. A missing propeller diffuser ring.
C. A damaged propeller or gear housing, which allows exhaust

gases to escape between propeller and gear housing.
D. Drive unit installed too high on transom.

CA294

Propeller Selection

IMPORTANT: Installed propeller must allow engine to run at
its specified maximum wide-open-throttle revolutions per
minute (RPM). Use an accurate service tachometer to verify
engine operating RPM.

It is the responsibility of the boat manufacturer and/or the selling
dealer to equip the power package with the correct propeller(s). Spe­cified engine wide-open-throttle (WOT) and operating RPM range
are listed in “SPECIFICATIONS”.

13

IMPORT ANT : The engines covered in this manual are equipped
with an RPM rev-limiter that is set to an upper (or limited) RPM
amount. This limit is slightly above the normal operating range
of the engine and is designed to help prevent damage from ex­cessive engine RPM. Once the RPM drop into the recommended
operating RPM range normal engine operation resumes.

Select a propeller that will allow the engine power package to operate
at or near the top end of the recommended wide-open-throttle oper­ating RPM range with a normal load. High RPM, caused by an exces­sive trim angle, should not be used in determining correct propeller
selection.

If full throttle operation is below the recommended range, the propel­ler must be changed to prevent loss of performance and possible en­gine damage. On the other hand, operating an engine above the rec­ommended operating RPM range will cause higher than normal wear
and/or damage. Generally , there is a 200-300 RPM change between
propeller pitches.

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.

• Operating in a higher elevation causes an RPM loss.

• Operating with a damaged propeller or dirty boat bottom causes

an RPM loss.

• Operating with increased load ( additional passengers, pulling

skiers, etc.)

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

14

CA12

How Elevation And Climate Affect Performance

Elevation has a very noticeable effect on the wide-open-throttle pow­er of an engine. Since air (containing oxygen) gets thinner as eleva­tion increases, the engine begins to starve for air. Humidity , baromet­ric pressure and temperature do have a noticeable effect on the
density of air. Heat and humidity thin the air. This condition can be­come particularly annoying when the propeller testing was done on
a cool, dry day . Then later; on a hot, sultry day, the boat doesn’t seem
to have the same performance.

Although some performance can be regained by dropping to a lower
pitch propeller, the basic problem still exists. In some cases, a gear
ratio change to more reduction is possible and very beneficial.

Summer conditions of high temperature, low barometric pressure
and high humidity all combine to reduce the engine power. This, in
turn, is reflected in decreased boat speeds, as much as 2 or 3 miles
per hour in some cases. Nothing will regain this speed for the boater,
but the coming of cool, dry weather.

In pointing out the practical consequences of weather effects, an en­gine running on a hot, humid, summer day , may encounter a loss of
as much as 14% of the horsepower it would produce on a dry , brisk
spring or fall day . With the drop in available horsepower , this propel­ler will, in effect, become too large. Consequently, the engine oper­ates at less than its recommended RPM. This will result in further loss
of horsepower at the propeller with another decrease in boat speed.
This secondary loss, however, can be somewhat regained by switch­ing to a lower-pitch propeller that allows the engine to again run at
recommended RPM.

For boaters to realize optimum engine performance under changing
weather conditions, it is essential that the engine be propped to allow
it to operate at or near the top end of the recommended maximum
RPM range at wide-open-throttle with a normal boat load.

Not only does this allow the engine to develop full power, but equally
important is the fact that the engine also will be operating in an RPM
range that discourages damaging detonation. This, of course, en­hances overall reliability and durability of the engine.

15

CA13

Important Information

Operation And Maintenance

OWNER/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 an Authorized Mer­Cruiser Dealer for a periodic checkup.

Normal maintenance service and replacement parts are the respon­sibility of the owner/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 assure op­timum performance and dependability , and will keep your overall op­erating expenses at a minimum. See your Authorized MerCruiser
Dealer for service aids.

CA14

DEALER RESPONSIBILITIES

In general, a dealer’s responsibilities to the customer include prede­livery inspection and preparation such as:

• Make sure that the boat is properly equipped.

• Prior to delivery , make certain that the MerCruiser power package

and other equipment are in proper operating condition.

• Make all necessary adjustments for maximum efficiency.

• Familiarize the customer with the on-board equipment.

• Explain and demonstrate the operation of the power package and

boat.

• At the time of delivery , the dealer should provide you with a copy

of a Predelivery Inspection Checklist.

• Your selling dealer should fill out the Warranty Registration Card

completely and mail it to the factory immediately upon sale of the
new product.

16

CA15

Freezing Temperature Operation

IMPORT ANT : It boat is operated during periods of freezing tem­perature, precautions must be taken to prevent freezing dam­age to power package. Refer to “COLD WEATHER or EX­TENDED STORAGE” for draining instructions.

CA17

Drive Unit Impact Protection

The Power Trim hydraulic system is designed to provide impact pro­tection for drive unit. If a submerged object is struck while boat is
moving forward, the hydraulic system will cushion the kickup of drive
unit as it clears the object, reducing damage to unit. After drive unit
has cleared object, the hydraulic system allows drive unit to return
to 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. Use extreme care to pre­vent striking submerged object while operating in REVERSE. No im­pact protection is provided in REVERSE.

If drive unit should strike a submerged object, stop engine as soon
as possible and inspect drive unit for damage. If damage is present
or suspected, boat should be taken to an Authorized MerCruiser
Dealer for thorough inspection and necessary repair. Operating a
damaged drive unit could cause additional damage to other parts of
drive unit, or could affect control of boat. If continued running is nec­essary, do so at greatly reduced speeds.

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

17

CA18

Attention Required After Submersion

• Before recovery, contact a MerCruiser Dealer.

• After recovery, immediate service by an Authorized MerCruiser

Dealer is required to prevent serious damage to power package.

CA19

Trailering Boat

Boat can be trailered with drive unit in “up” or “down” position. Ade­quate road clearance is required between road and gear housing
skeg when trailering with drive unit in “down” position.

If adequate road clearance is a problem, place drive unit in full trailer
position and support with an optional trailer kit which is available from
your Authorized MerCruiser Dealer.

18

CA20

Launching And Boat Operation Care

!

CAUTION

During launching from a trailer , if the unloading ramp is steep
or the trailer bed must be tilted, the boat may enter the water rap­idly and at a steep angle. This may force water through the ex­haust system into the cylinders. The more weight on the tran­som, the more likely this is to occur.

Slowing down rapidly or stopping suddenly may cause a follow­ing wave to “swamp” the transom. In this instance, water may
enter the cylinders through the exhaust system.

When backing up rapidly, the same situation may occur as
stated in the preceding paragraph.

In any of these situations, water entering the engine could cause se­vere damage to internal parts. Refer to “Attention Required After
Submersion”.

CA21

Stolen Power Package

If your power package is stolen, immediately advise the local authori­ties and Mercury Marine of the model and serial number(s) and to
whom the recovery is to be reported. This “Stolen Motor” information
is placed into a file at Mercury Marine to aid authorities and dealers
in recovery of stolen motors.

19

CA22

Replacement Service Parts

!

WARNING

Electrical, ignition and fuel system components on MerCruiser
gasoline power packages are designed and manufactured to
comply with U.S. Coast Guard rules and regulations to minimize
risks of fire or explosion.

Use of replacement electrical, ignition or fuel system compo­nents, which do not comply to these rules and regulations,
could result in a fire or explosion hazard and should be avoided.

When servicing the electrical, ignition and fuel systems, it is ex­tremely important that all components are properly installed
and tightened. If not, any electrical or ignition component would
permit sparks to ignite fuel vapors from fuel system leaks, if
they existed.

Marine engines are expected to operate at or near full–throttle for
most of their life. They are also expected to operate in both fresh and
saltwater environments. These conditions require numerous special
parts. Care should be exercised when replacing marine engine parts
as specifications are quite different from those of the standard auto­motive engine.

For example, one of the most important, and probably the least sus­pected special replacement part, is the cylinder head gasket. Since
saltwater is highly corrosive, the steel-type automotive head gasket
cannot be used. A marine engine head gasket uses special materials
to resist corrosive action.

Since marine engines must be capable of running at or near maxi­mum RPM much of the time, special valve springs, valve lifters, pis­tons, bearings, camshafts and other heavy-duty moving parts are re­quired for long life and peak performance.

These are but a few of the many special modifications that are re­quired in MerCruiser marine engines to provide long life and depend­able performance.

20

CA23

Do-It-Yourself Maintenance Suggestions

If you are one of those persons who likes to do-it-yourself, here are
some suggestions for you.

• Present-day marine equipment, such as your MerCruiser power

package, are highly technical pieces of machinery . Electronic ig­nition and special carburetion provide greater fuel economies, but
also are more complex for the untrained mechanic.

• Do not attempt any repairs which are not covered in this manual

unless you are aware of the precautions (“Cautions” and “Warn­ings”) and procedures required. Your safety is of our concern.

• If you attempt to service the product yourself, we suggest you or-

der the service manual for that model. The service manual out­lines the correct procedures to follow. It is written for the trained
mechanic, so there may be procedures you don’t understand. Do
not attempt repairs if you do not understand the procedures.

• There are special tools and equipment that are required to per-

form some repairs. Do not attempt these repairs unless you have
these special tools and/or equipment. You can cause damage to
the product in excess of the cost a dealer would charge you.

• Also, if you partially disassemble an engine or drive assembly and

are unable to repair it, the dealer’s mechanic must reassemble the
components and test to determine the problem. This will cost you
more than taking it to the dealer immediately upon having a prob­lem. It may be a very simple adjustment to correct the problem.

• Do not telephone the dealer, service office or the factory to at-

tempt for them to diagnose a problem or request the repair proce­dure. It is difficult for them to diagnose a problem over the tele­phone. A doctor can’t and won’t diagnose your illness by
telephone; he must examine you personally, just as a mechanic
must examine your power package.

• Your Authorized Dealer is there to service your power package.

He has qualified factory-trained mechanics.

It is recommended you have the dealer do periodic maintenance
checks on your power package. Have him winterize it in the fall and
service it before the boating season. This will reduce the possibility
of any problems occurring during your boating season when you
want trouble-free boating pleasure.

21

CA24

20-Hour Break-In Period

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

• Do not operate below 1500 RPM for extended periods of time for

first 10 hours. Shift into gear as soon as possible after starting and
advance throttle above 1500 RPM if conditions permit safe op-

eration.

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

• Do not exceed 3/4 throttle during first 10 hours. During next 10

hours, occasional operation at full throttle is permissible (5 min­utes at a time maximum).

• Avoid full throttle acceleration from IDLE speed.

• Do not operate at full throttle until engine reaches normal operat-

ing temperature.

• Frequently check crankcase oil level. Add oil if needed. It is nor-

mal for oil consumption to be high during break-in period.

• After 20-hour break-in period, drain crankcase oil and replace oil

filter (see MAINTENANCE). Fill crankcase with correct oil (see
SPECIFICATIONS).

CA211

After Break-In Period

T o help extend the life of your MerCruiser power package, the follow­ing recommendations should be considered;

• Use a propeller that allows the engine to operate at or near the top

of the maximum RPM range (See “Specifications” section) when
at full throttle with a normal boat load.

• Operation at 3/4 throttle setting or lower is recommended. Refrain

from prolonged operation at maximum (full throttle) RPM.

22

CB270

20-Hour Checkup

After first 20 hours of operation, an Authorized MerCruiser Dealer
should be contacted for the following maintenance. The boat owner
is responsible for any charges.

• Change crankcase oil and filter.

• Retorque intake manifold to

35 lb.ft. (48 N·m).

• Check all fluid levels.

• Cooling System: Inspect all hoses for damage and deterioration;

check all hose clamps for adequate tightness.

• Check carburetor adjustment.

• Inspect ignition system and timing.

• Check for loose, missing or damaged parts.

• Check shift and throttle cable adjustments, and lubricate and in-

spect for loose, damaged or missing parts.

• Steering System: Lubricate and inspect for loose, damaged or

missing parts.

• Inspect all drive belts.

• Check engine alignment. Include proper lubrication of U-joint and

splined shaft.

• Inspect Complete Engine Exhaust System (Externally) for dam-

age and deterioration; check all hose clamps for adequate tight­ness.

• Retorque gimbal ring clamping screws to 50-55 lb. ft. (67-74 N⋅m).

• Check that both front engine mount locknuts are tightened se-

curely. Then, check to ensure that tab washers are bent down
over adjusting nuts.

• Check that rear engine mounts are torqued to

35-40 lb.ft. (47-54 N

⋅m).

23

CA26

1

10

9

70514

70523

70522

2

70515

3

4

5

70516

70517

70518

8

24

70521

7

70520

6

70519

CA27

Operation

Instrumentation

The following is a brief explanation of instrumentation typically found
on some boats. The owner/operator should be familiar with all instru­ments and their functions on the boat. Because of the large variety
of instrumentation and manufacturers, you should have your boat
dealer explain the particular gauges and normal readings that will ap­pear on your style gauges.

1 Speedometer: Indicates boat speed.
2 Tachometer: Indicates engine RPM.
3 Oil Pressure Gauge: Indicates engine oil pressure.
4 Battery Meter: Indicates battery voltage.
5 Water Temperature Gauge: Indicates engine operating tempera-

ture.

6 Fuel Gauge: Indicates fuel tank volume.
7 Power Trim Gauge: Indicates drive unit angle (trim up/out and

down/in).

8 Hour Meter: Records engine running time.
9 Bilge Blower Switch: Must be operated for five minutes before

starting engine, to ventilate bilge.

10Ignition Switch: Allows operator to start and stop engine.

25

CB218

705161A

26

1B

1C

70518

71987

CB200

Audio Warning System

Y our MerCruiser power package is equipped with an Audio W arning
System.

1 The audio warning system buzzer will sound if one of the following

occur:

A Insufficient Oil Pressure
B Excessive Engine Temperature
C Insufficient Drive Lubricant

NOTE: To provide a test of the system, the audio warning buzzer will

sound when the ignition switch is first turned to the run position, prior
to cranking the engine. Once the engine starts, the buzzer should
stop.

!

CAUTION

Avoid engine damage. Do not operate engine once the buzzer
has sounded EXCEPT TO AVOID A HAZARDOUS SITUATION.
The Audio Warning System will not protect the engine from
damage. It is designed to warn the operator that a problem has
occurred.

When the buzzer sounds with the engine running, stop engine im­mediately . Investigate cause and correct it, if possible. If cause can­not be determined, consult your Authorized MerCruiser Dealer.

27

CB125

1

71466

4

2

70525

70527

28

71773

5

70528

3

70526

CA30

Electrical System Overload Protection

If an electrical overload occurs, a fuse will blow or the circuit breaker
will trip open. The cause must be found and corrected before replac­ing fuse or resetting circuit breaker.

1 A circuit breaker provides protection for engine wiring harness

and instrumentation power lead. Reset by pushing RESET button.
In an emergency , when engine must be operated and cause for high

current draw cannot be located and corrected, turn OFF or discon­nect all accessories connected to engine and instrumentation wiring.

Reset circuit breaker. If breaker will not reset, electrical overload has
not been eliminated. Further checks must be made on electrical sys­tem.

2 A 20 amp fuse may be located in ignition switch “I” terminal lead

to protect electrical system. Check for blown fuse if key Is turned to
START and nothing happens (and circuit breaker is not tripped).

3 The Power Trim System is protected from overload by 110 amp

fuse and a 20 amp in-line fuse on Power Trim pump.

4 Quicksilver Three-Button Power Trim Control Panel is further pro-

tected by a 20 amp in-line fuse.

CA31

Models With Mercathode System

5 A 20 amp in-line fuse is in wire which connects to positive (+) ter-

minal on controller. If fuse is blown, system will not operate. (For ad­ditional information see “Corrosion and Corrosion Protection” sec­tion.)

29

CB181

3

1

7

2

30

5

6

4

CB182

Remote Controls (Panel Mounted)

Your boat may be equipped with one of many Quicksilver remote
controls available. All controls feature an integral safety switch that
allows starting engine in NEUTRAL only. Also, all controls may not
have all features shown. If boat is equipped with a remote control oth­er than shown, consult your dealer for a description and/or demon­stration of the control.

1 Neutral Lock Bar - Prevents accidental shift and throttle engage-

ment. Neutral lock bar must be pulled “Up” to move the control handle
out of neutral.

2 Throttle Only Button - Allows engine throttle advancement with-

out 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.

3 Power Trim Switch - See “Power Trim” for detailed power trim

operating procedures.

4 Trailer Switch - Used to raise drive unit for trailering, launching,

breaching or shallow water operation. See “Power Trim” for detailed
trailer switch operation.

5 Lanyard Stop Switch - Turns ignition “Off” whenever the opera-

tor (when attached to the lanyard) moves far enough away from the
operator’s position to activate the switch. See “Lanyard Stop Switch”
at the front of this manual for safety warning on the use of this switch.

6 Control Handle T ension Adjustment Screw - This screw can be

adjusted to “Increase” or “Decrease” the tension on the control han­dle. This will help prevent “Creep” of the remote control handle. Turn
screw “Clockwise” to increase tension and “Counterclockwise” to
decrease tension. Adjust to tension desired.

7 Control Handle - Operation of 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. Continue pushing back to increase speed.

31

CB183

4

1

3

5

2

1

4

32

5

3

6

2

6

CB184

Remote Controls (Console Mounted)

1 Control Handle(s) - Operation of the 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. Continue pushing back to
increase speed.

2 Throttle Only Button - Allows engine throttle advancement with-

out 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.

3 Control Handle T ension Adjustment Screw - This screw can be

adjusted to “Increase” or “Decrease” the tension on the control han­dle (cover must be removed to adjust). This will help prevent “Creep”
of the remote control handle. Turn screw “Clockwise” to increase ten­sion and “Counterclockwise” to decrease tension. Adjust to tension
desired.

4 Power Trim Switch - See “Power T rim” section for detailed power

trim operating procedures.

5 Trailer Switch - Used to raise drive unit for trailering, launching,

breaching or shallow water operation. See “Power Trim” for detailed
trailer switch operation.

6 Power Trim Adjustment Switches (Used on Three Button

Trim Control Only) - See “Power Trim” section for detailed power

trim operating procedures.

33

CB185

1

2

71339

4

34

3

70537

CB186

Remote Controls (Two Lever)

1 Shift Lever - shifts unit into gear with full lever movement. Move

lever forward to shift to FORWARD gear. Move lever backward to
shift to REVERSE gear. Lever in full vertical position shifts to NEU­TRAL.

!

CAUTION

Never shift unit into or out of gear unless throttle lever is a idle
RPM.

2 Throttle Lever - allows engine RPM to be increased or decreased.
3 FRICTION Screw - adjusts control handle friction so motor speed

can be set and driver does not have to hold handle.
Turn screw clockwise to increase friction. Do not thread screw all the

way out.

4 DETENT Screw - controls the effort needed to move control han-

dle out of NEUTRAL. To increase tension, turn screw clockwise; to
decrease, turn screw counterclockwise. Do not thread screw all the
way out.

IMPORTANT: Boats equipped with dual power packages may
have both shift levers on one control and both throttle levers on
the other control.

35

CA34

3° - 5°

36

1

71338

CA284

Power Trim

Power Trim allows the operator to adjust the drive angle, while under­way , to provide the ideal boat angle for varying load and water condi­tions. Also, the Power Trim system “T railering” feature allows the op­erator to raise and lower the drive unit for trailering, beaching,
launching and low speed (below 1200 RPM engine speed), shallow
water operation.

!

CAUTION

Never trim the drive unit UP/OUT using TRAILER switch while
boat is underway at engine speeds above 1200 RPM. Use ex­treme caution when operating with drive unit raised. Severe
damage to the drive unit may result if unit is raised beyond the
gimbal ring support flanges at engine speeds above 1200 RPM.

1 In most cases, best overall performance is obtained with the drive

unit adjusted so the boat bottom will run at a 3° to 5°angle to the wa­ter.

Trimming Drive Unit UP/OUT Can:

• Lower the bow.

• Generally increase top speed.

• Increase clearance over submerged objects or a shallow bottom.

• Cause boat to accelerate and plane off slower.

• In excess, cause boat “porpoising” (bouncing) or propeller ventila-

tion.

• Cause engine overheating if trimmed UP/OUT to a point where

any cooling water intake holes are above the water line.

Trimming Drive Unit DOWN/IN Can:

• Help the boat accelerate and plane off quicker.

• Generally improve the ride in choppy water.

• In most cases, reduce boat speed.

• If in excess, lower the bow 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.

37

CB187

2
3

1

73976

5

6

38

4

73977

CB188

POWER TRIM OPERATION - PANEL MOUNT
REMOTE CONTROL

IMPORTANT: If TRAILER button is held depressed after drive
unit reaches end of upward travel, an internal circuit breaker will
open and pump will stop. Should this happen, release button
and allow motor to cool for about one minute. Circuit breaker
will reset and Power Trim operation may be resumed.

1 Trailer Position: Press button until drive unit reaches desired

height.

2 Trim Up/Out: Press UP on T rim switch until drive unit reaches de-

sired trim position.

3 Lower Drive Unit: Press DOWN on Trim switch until drive unit

reaches desired position.

CB189

POWER TRIM OPERATION - CONSOLE MOUNT
REMOTE CONTROL (SINGLE ENGINE VERSION)

4 Trailer Position: Press button until drive unit reaches desired

height.

5 Trim Up/Out: Press UP on T rim switch until drive unit reaches de-

sired trim position.

6 Lower Drive Unit: Press DOWN on Trim switch until drive unit

reaches desired position.

39

CB190

2A

1

2B

73979

4

40

1

73978

3

CA285

POWER TRIM OPERATION - DUAL ENGINE CONSOLE
MOUNT REMOTE CONTROL (TWO BUTTON AND THREE
BUTTON VERSIONS)

IMPORTANT: If TRAILER button is held depressed after drive
unit reaches end of upward travel, an internal circuit breaker will
open and pump will stop. Should this happen, release button
and allow motor to cool for about one minute. Circuit breaker
will reset and Power Trim operation may be resumed.

!

CAUTION

When lowering or raising stern drives equipped with a dual
engine tie bar kit; in the trailering position, stern drives must be
lowered evenly to prevent tie bar from becoming twisted. Fail­ure to lower stern drives evenly may result in tie bar or stern
drive(s) damage.

1 Trailer Button (Both V ersions) - Press button until drive unit reach-

es desired height for trailering drive units.

2 Two Button Trim Control (Dual Buttons in Handle) - used to

contol both drive units from the handle. Press UP on button(s) to trim
drive unit UP/OUT . Press down on button(s) to trim drive unit DOWN/
IN.

A Forward Trim Button - Used to trim the port drive unit.
B Rear Trim Button - Used to trim the starboard drive unit.

3 Three Button Trim Control (Trim Adjustment Switch’s) - With

a single integral trim button in the handle to control two drive units
simultaneously, these two switches control the “Fine Tune” adjust­ment of each drive unit. Using these “Fine Tune Switches”, set each
drive unit to the desired trim angle. Then use the single trim switch
in the handle to control the trim of both drive units simultaneously.

4 Three Button Trim Control (Single Trim Switch in Handle) -

used to trim both drives simultaneously after drives have been fine­tuned as described above.

41

CB192

1

70540

42

2

70540

3

70540

CB193

POWER TRIM OPERATION - THREE BUTTON TRIM PANEL
(USED ON MODELS WITHTWO-LEVER CONTROL)

IMPORTANT: If TRAILER button is held depressed after drive
unit reaches end of upward travel, an internal circuit breaker will
open and pump will stop. Should this happen, release button(s)
and allow motor to cool for about one minute. Circuit breaker
will reset and Power Trim operation may be resumed.

1 Trailer Position: Simultaneously press the UP button (top) along

with the UP/OUT button (center) until drive unit reaches desired trail­er position.

2 Trim Drive Unit UP/OUT: Press center UP/OUT button until drive

unit reaches desired trim position.

3 Trim Drive Unit IN/DOWN: Press IN button until drive unit reaches

desired trim position.

43

CA40

Starting, Shifting And Stopping

!

WARNING

Before starting engine, operate bilge blower for at least five min­utes to remove any explosive fumes from engine compartment.
If boat is not equipped with a bilge blower, open engine hatch
and leave open while starting engine.

IMPORTANT: Observe the following:

• Do not start engine without water being supplied to seawater

pickup pump (to prevent pump or engine damage).

• Do not operate starter motor continuously for more than 30

seconds.

• When engine starts, quickly reduce throttle setting to avoid

exceeding 1500 RPM.

• Never shift drive unit unless engine is at Idle RPM.

1 Perform the following as appropriate:

A Check all items listed in OPERATION CHART.
B Perform any other necessary checks, as indicated by your dealer ,

or specified in your boat owner’s manual.

C Place drive unit in full down/in position.
D Place control handle in NEUTRAL.
E Position throttle setting as follows: COLD ENGINE - Move control/

throttle lever to full throttle, then return to about 1/4 throttle. In ex­treme cold it may be necessary to pump lever more than once.

WARM ENGINE - Move control/throttle lever to 1/4 throttle position.

44

FLOODED ENGINE - Move control/throttle lever to full throttle. Be
prepared to decrease engine speed to 1000-1500 RPM as soon as
engine starts.

F Turn ignition key to START Release key when engine starts and

allow switch to return to RUN position. Move control/ throttle lever
back to decrease engine RPM to 1000-1500 RPM if necessary.

G Check oil pressure gauge immediately after engine starts If oil

pressure is not within specified range (see SPECIFICATIONS),
stop engine immediately and determine cause.

H If engine is cold, run engine for 1 or 2 minutes at fast idle

(1000-1500 RPM).

I After engine has warmed up, check water temperature gauge to

ensure that engine temperature is not abnormally high. If it is, stop
engine immediately and determine cause.

J Be sure charging system is functioning correctly.
K Observe power package for fuel, oil, water and exhaust leaks.
L T o shift drive unit, return control/throttle lever to NEUTRAL. Move

control/shift lever with a firm, quick motion forward to shift to FOR­WARD gear , or backward to shift to REVERSE. After shifting drive
unit, advance throttle to desired setting.

M Move control/shift lever to NEUTRAL and allow engine to drop to

IDLE speed. If engine has been run at high speed for a long period
of time, allow engine to cool by running at IDLE speed for 3 to 5
minutes.

N Turn ignition key to OFF.

CB13

IMPORTANT: Starting procedure if engine is shut-off or stops
with drive unit in gear. 1. Pull/push remote control handle to
neutral-lock position (it will be necessary to exert force to move
handle).

2. T urn key to start position, momentarily, to release clutch from

gear.

3. Resume normal starting procedure.

45

CA41

Operation Chart

BEFORE

STARTING

Open engine
hatch.

Turn battery
switch ON, if so
equipped.

Operate bilge
blowers, if so
equipped.

Open fuel
shutoff valve.

AFTER

STARTING

Observe all
gauges to
check
condition of
engine. If not
normal, stop
engine.

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

Check shift
and throttle
control op­eration.

Check
steering
operation

WHILE

UNDERWAY

Observe all
gauges to
monitor
engine
condition.

AFTER

STOPPING

Turn ignition
key OFF.

Turn bat­tery switch
OFF, if so
equipped.

Close fuel
valve.

Close sea­cock, if so
equipped.

Open
seacock, if so
equipped.

Place drive
unit in full
down/in
position.

Perform all
other checks
specified by
your dealer
and\or boat
builder.

46

Flush cool­ing system
if in saltwa­ter area.

CA261

Specifications

Fuel Recommendations

IMPORTANT: Use of improper gasoline can damage your en­gine seriously. Engine damage resulting from use of improper
gasoline is considered misuse of engine, and damage caused
thereby will not be covered under the limited warranty.

FUEL RATINGS

MerCruiser engines will operate satisfactorily when using a major
brand of unleaded gasoline as follows:

USA and Canada

- having a posted pump Octane Rating of
87 (R+M)/2 minimum. Premium gasoline [92 (R+M)/2 Octane] is
also acceptable. DO NOT use leaded gasoline.

Outside USA and Canada

- having a posted pump Octane Rating
of 90 RON minimum. Premium gasoline (98 RON) is also accept­able. If unleaded gasoline is not available, use a major brand of
leaded gasoline.

CA291

USING REFORMULATED (OXYGENATED) GASOLINES
(USA ONLY)

This type of gasoline is required in certain areas of the USA. The two
types of “oxygenates” used in these fuels is Alcohol (Ethanol) or
Ether (MTBE or ETBE). If Ethanol is the “oxygenate” that is used in
the gasoline in your area, refer to “Gasolines Containing Alcohol”
also.

These “Reformulated Gasolines” are acceptable for use in your Mer­Cruiser engine.

CA277

GASOLINES CONTAINING ALCOHOL

If the gasoline in your area contains either “methanol” (methyl alco­hol) or “ethanol” (ethyl alcohol), you should be aware of certain ad­verse effects that can occur . These adverse effects are more severe
with “methanol”. Increasing the percentage of alcohol in the fuel can
also worsen these adverse effects.

Some of these adverse effects are caused because the alcohol in the
gasoline can absorb moisture from the air, resulting in a separation
of the water/alcohol from the gasoline in the fuel tank.

47

The fuel system components on your MerCruiser engine will with­stand up to 10% alcohol content in the gasoline. We do not know
what percentage your boat’s fuel system will withstand. Contact your
boat manufacturer for specific recommendations on the boats fuel
system components (fuel tanks,fuel lines, and fittings). Be aware that
gasolines containing alcohol may cause increased:

• Corrosion of metal parts.

• Deterioration of rubber or plastic parts.

• Fuel permeation through rubber fuel lines.

• Starting and operating difficulties.

!

WARNING

FIRE AND EXPLOSION HAZARD: Fuel leakage from any part of
fuel system can be a fire and explosion hazard which can cause
serious bodily injury or death. Careful periodic inspection of en­tire fuel system is mandatory , particularly after storage. All fuel
components including fuel tanks, whether plastic metal or fi­berglass, fuel lines, fittings, fuel filters and carburetors/fuel in­jection components should be inspected for leakage, soften­ing, hardening, swelling or corrosion. Any sign of leakage or
deterioration requires replacement before further engine oper­ation.

Because of possible adverse effects of alcohol in gasoline, it is rec­ommended that only alcohol-free gasoline be used where possible.
If only fuel containing alcohol is available, or if the presence of alco­hol is unknown, increased inspection frequency for leaks and abnor­malities is required.

IMPORT ANT : When operating a MerCruiser engine on gasoline
containing alcohol, storage of gasoline in the fuel tank for long
periods should be avoided. Long periods of storage, common
to boats, create unique problems. In cars alcohol-blend fuels
normally are consumed before they can absorb enough mois­ture to cause trouble, but boats often sit idle long enough for
phase separation to take place. In addition, internal corrosion
may take place during storage if alcohol has washed protective
oil films from internal components.

48

Quicksilver Gasoline Stabilizer for Marine Engines (92-817529A12)
is highly recommended for addition during storage periods. See
“Cold Weather or Extended Storage” later in this manual.

CA43

Crankcase Oil

To help obtain optimum engine performance and to provide maxi­mum protection, we strongly recommend the use of Quicksilver
4-Cycle Marine Engine Oil. If not available, a good grade, straight
weight, detergent automotive oil of correct viscosity, with an API clas­sification of CD or SG, may be used.

The chart below is a guide to crankcase oil selection. Oil filter should
always be changed with oil.

In those areas where recommended straight weight oil is not avail­able, a multiviscosity 20W-40 (SG or CD) or, as a second but less
preferable choice, 20W-50 (SG or CD) may be used.

IMPORTANT: The use of non-detergent oils, multi-viscosity
oils (other than 20W-40 or 20W-50), low quality oils or oils which
contain solid additives, are specifically not recommended.

Quicksilver 4-Cycle Marine Engine Oil

SAE 20W, SG or CD

SAE 30W, SG or CD

32

° F

° C

0

AIR TEMPERATURE

SAE 40W, SG or CD

° F

50

° C

10

70534

49

CB175

Engine Specifications

MODEL

Propshaft Horsepower
Propshaft Kilowatts

1

Displacement
Engine Type
Bore

Stroke

Compression Ratio
Compression Pressure

Maximum RPM @
WOT

Idle RPM in
Forward Gear

Fuel Pump Pressure

7.4L Bravo Three

1

300

224

454 C.I.D.

(7.4 L)

V8

4.25 in.

(108mm)

4.00 in.

(101.6mm)

8.6:1

150 psi

(1035 kPa)

4200-4600 RPM

650 RPM

2

3-7 psi (21-48 kPa)

Oil Pressure @
2000 RPM

Min. Oil Pressure

30-70 psi

(207-483 kPa)

4 psi (28 kPa)

@ Idle

160

Thermostat

1

Power Rated in Accordance with NMMA procedure using Marine Engine Rating Code

SAE J1228 (Technically Identical to ISO 3046 and ICOMIA 28-83).

2

A special procedure must be followed for adjusting idle RPM in Neutral. Consult your Autho-

rized MerCruiser Dealer before adjusting idle speed.

50

° F (71° C)

CB391

Tune-Up Specifications

MODEL

Spark Plug Type
Spark Plug Gap

Timing @ Idle RPM

Firing Order

Champion RV15YC4 or NGK BR6FS

7.4L Bravo Three

AC-MR43T or

.035 in. (.9mm)

10° BTDC

1

1-8-4-3-6-5-7-2

12-Volt Negative (-) GroundElectrical System

55 AmpsAlternator

Recommended
Battery
Rating

1

A special procedure must be followed to check or adjust Timing. Consult your

Authorized MerCruiser Dealer before attempting this procedure.

Minimum

450 cca, 575

mca or 90Ah

51

CB19

Capacities

MODEL

Crankcase Oil
Capacity
w/New Filter

7.4L Bravo Three

7 U.S. Qts.

(6.6 L)

Drive Unit Oil
Capacity

3 U.S. Qts. (2.9 L)

(w/Reservoir)
Seawater Cooling

System

2

Closed Cooling
System

1

Always use dipstick to determine exact quantity of oil required.

2

Seawater Cooling System capacity information is for winterization use only.

20 U.S. Qts.

(18.9 L)

28 U.S. Qts.

(26.5 L)

52

CA290

Maintenance

!

WARNING

Always disconnect battery cables from battery before working
around electrical system components to prevent injury to your­self or damage to electrical system.

IMPORTANT: Refer to MAINTENANCE CHART for complete
listing of all scheduled maintenance to be performed. Some list­ings can be done by owner/operator, while others should be
performed by an Authorized MerCruiser Dealer. Before attempt­ing maintenance or repair procedures not covered in this manu­al, it is recommended that a MerCruiser Service Manual(s) be
purchased and read thoroughly.

NOTE: Maintenance points are color coded for ease of identifica-

tion. See the decal on engine for identification.

Maintenance Aids

1 Power Steering System - Quicksilver Power Trim and Steering

Fluid or Dexron III automatic transmission fluid (ATF).

2 All Pivot Points - SAE 30W motor oil.
3 Fogging (Winterizing) Engine - Quicksilver Storage Seal or SAE

20W motor oil.

4 Exposed portion of Steering Cable and Propeller Shaft - Quicksil-

ver Special Lubricant 101.

5 Stern Drive Unit - Quicksilver High Performance Gear Lube.
6 Gimbal Bearing - Quicksilver U-Joint and Gimbal Bearing Grease.
7 All Exterior Surfaces - Quicksilver Primer and Spray Paint and

Quicksilver Corrosion Guard.

8 Power Trim System - Quicksilver Power T rim and Steering Fluid,

or SAE 10W-30 motor oil.
(Continued on next page)

53

9 Crankcase Oil - Quicksilver 4-Cycle Marine Engine Oil (Refer to

SPECIFICA TIONS for alternatives and oil recommendations for va­rying ambient temperatures.)

10Closed Cooling System Coolant - 50/50 mixture of ethylene glycol

antifreeze (must meet GM specification 1825 M) and tap water.
Areas where temperatures generally do not go below 32

° F (0° C),

rust inhibitor and tap water is acceptable.

11Gasoline Stabilizer - Quicksilver Gasoline Stabilizer for Marine

Engines.

12 Grease Fittings on Drive Shaft Extension Models - Quicksilver

U-Joint and Gimbal Bearing Grease.

54

CB26

Maintenance Chart

Only perform maintenance which applies to your particular

power package.

SCHEDULED MAINTENANCE TO BE PERFORMED

BY OWNER/OPERA TOR

TASK INTERVAL

Engine Crankcase Oil ­Check level

Closed Cooling Coolant ­Check level

Power Steering Fluid ­Check level

Stern Drive Unit Oil ­Check level

Battery - Check level
and inspect for damage

Fuel Pump Sight Tube ­Check that no fuel
is present

Weekly

Power Trim Pump Oil ­Check level

Anodes - Inspect for
erosion

Gear Housing Water
Pickups - Check for ma­rine growth or debris

55

CB27

Only perform maintenance which applies to your particular

power package.

SCHEDULED MAINTENANCE TO BE PERFORMED

BY OWNER/OPERA TOR

T ASK

Drive Belts (All) ­Inspect condition and
check tension

Propeller Shaft ­Lubricate

Power Package
Exterior Surfaces ­Spray with rust
preventative

Power Package
Exterior Surfaces ­Clean and paint

Cooling System ­Flush seawater
section

INTERVAL

Every 100 Hours of Operation or
120 Days, Whichever Occurs First.

Saltwater use: Every 50 Hours of
Operation or 60 Days, Whichever
Occurs First.
Freshwater use: Every 100 Hours
of Operation or 120 Days, Whichever
Occurs First.

Once a Year

Saltwater use: After Each Use

56

CB258

Only perform maintenance which applies to your particular

power package.

SCHEDULED MAINTENANCE TO BE PERFORMED BY DEALER

TASK INTERVAL

20-Hour Checkup (See

At First 20 Hours of Operation

NOTE 1)
Seawater Pickup Pump

-Disassemble and
Inspect

Crankcase Oil and
Filter - Change

Ignition System - Clean
and inspect condition

Flame Arrestor and
Crankcase Ventilation
Hose - Clean
and inspect

Stern Drive unit Oil ­Change

Gimbal Ring Clamping

Screws - Retorque to

50-55 lb.ft. (67-74 N

⋅m)

Gimbal Bearing ­Lubricate

Closed Cooling System
Pressure Cap - Clean,
Inspect, and Test

Whenever Insufficient Seawater Flow
is Suspected. (If Operating Tempera­ture Exceeds Normal Range)

Every 100 Hours of Operation or
Once Yearly, Whichever Occurs
First.

Rear Engine Mounts ­Check torque to
35-40 lb.ft. (47-54 N

NOTE 1: See “IMPORT ANT INFORMATION” for a list of 20-Hour Checkup maintenance.

⋅m)

57

CB29

Only perform maintenance which applies to your particular

power package.

SCHEDULED MAINTENANCE TO BE PERFORMED BY DEALER

TASK INTERVAL

Engine Alignment ­Check

Engine Coupling,
Universal Joint Shaft

Every 100 Hours of Operation or
Once Yearly, Whichever Occurs
First.

Splines - Lubricate
Universal Joint Cross

Bearings - Inspect

Steering System - Lu­bricate and inspect for
loose, damaged or
missing parts

Electrical System ­Check for loose or
damaged wiring

Cooling System Hoses
and Clamps - Inspect for
damage and deteriora­tion. Check clamps for
tightness

Continuity Circuit ­Check components for
loose connections, bro­ken or frayed wires

Shift and Throttle Cable
and Linkage - Lubricate
and inspect for loose,
damaged or missing
parts

Every 200 Hours of Operation or
Once Yearly, Whichever Occurs
First.

Saltwater use: Every 50 Hours of
Operation or 60 Days, Whichever
Occurs First
Freshwater use: Every 100 Hours
of Operation or 120 Days, Whichev­er Occurs First.

58

CB254

Only perform maintenance which applies to your particular

power package.

SCHEDULED MAINTENANCE TO BE PERFORMED BY DEALER

TASK INTERVAL

Engine Exhaust System­Inspect for external
damage,deterioration
and restrictions. Check
clamps for tightness .

Saltwater use: Every 50 Hours of
Operation or 60 Days, Whichever
Occurs First
Freshwater use: Every 100 Hours
of Operation or 120 Days, Whichev­er Occurs First.

Ignition System ­Check timing and
adjust if needed

Fuel filters - Replace
Steering Head and

Remote Control ­Inspect and lubricate

Quicksilver
MerCathode System ­Test output

Closed Cooling

Once a Year

Coolant - Test for
alkalinity

Heat Exchanger ­Clean seawater section

Carburetor - Inspect
and adjust

Drive Unit Bellows and
Clamps - Inspect

Closed Cooling Coolant

- Replace

Every Two Years

59

CB33

3

71451

2

1

7054270543

6

71773

70548

60

4

5

70547

4

70546

70545

CA54

Checking Fluid Levels

CHECKING CRANKCASE OIL

Stop engine. Allow approximately five minutes for oil to drain into oil
pan. Boat must be at rest in water.

1 Remove dipstick. Wipe clean and reinstall fully into dipstick tube.
2 Remove dipstick and observe oil level. Oil level must be between

FULL and ADD. If oil level is below ADD:

3 Remove oil filler cap. Add specified oil to bring level up to, but not

over, FULL mark on dipstick.

IMPORTANT: Do not overfill crankcase oil.

CA55

CHECKING POWER STEERING PUMP FLUID

Stop engine and position drive unit Straight back.

4 Remove FILLCAP/DIPSTICK and observe level. Add specified

fluid if required. Reinstall FILLCAP/DIPSTICK.

IMPORT ANT : If fluid is not visible in pump, contact your Autho­rized MerCruiser Dealer.

CA56

CHECKING ENGINE COOLANT - CLOSED COOLED
MODELS ONLY

!

WARNING

Do not remove coolant cap when engine is hot Coolant may dis­charge violently.

5 Check coolant level in coolant recovery bottle. Add specified cool-

ant as required.

6 Periodically remove cap from coolant reservoir to ensure that

coolant recovery system is functioning properly. Coolant level must
be at top of reservoir filler neck. If coolant is low , inspect gasket in cap
for damage and replace if necessary. To have cap tested, contact
your Authorized MerCruiser Dealer. Inspect coolant recovery system
for leaks.

61

CB207

71773

A

1

71987

B

2

62

70979

2

70551

CB40

CHECKING DRIVE UNIT OIL

1 Check gear lube monitor oil level; keep oil level at or near “Fill”

line. Check for water at bottom of monitor and/or if oil appears a milk­tan, contact your Authorized MerCruiser Dealer immediately; both
conditions indicate a water leak somewhere in the drive unit. See
“Filling Reservoir.”

IMPORTANT: If more than 2 fl. oz. (59ml) of Quicksilver High
Performance Gear Lube is required to fill monitor, a seal may be
leaking. Damage to drive unit may occur due to lack of lubrica­tion. Contact your Authorized MerCruiser Dealer for service.

CB41

CHECKING POWER TRIM PUMP FLUID

Place drive unit in full down/in position.

2 Remove fill cap from reservoir and observe oil level. Level must

be up to, but not over bottom of filler neck. Add Quicksilver Power
Trim and Steering Fluid or SAE 10W-30 motor oil, if required, to bring
level to bottom of filler neck. Replace cap.

A Check that “Cap plug” has been removed

filler neck.

B Fill cap is vented; frequently check that vent is open and unre-

stricted.

and discarded from

63

CB43

3

71451

2

70572

1

71773

70571

64

CA63

Changing Fluids

See MAINTENANCE CHART for lubricant change frequency. Lubri­cant should be changed before placing boat in storage.

Power Trim or Power Steering fluids do not require changing.
Coolant in closed cooling system should be changed at specified in-

tervals by your Authorized MerCruiser Dealer.

CHANGING CRANKCASE OIL AND FILTER

IMPORT ANT: Change oil when engine is warm from operation.
Warm oil flows more freely , carrying away more impurities. Use
only recommended motor oil (see SPECIFICATIONS).

1 With engine at normal operating temperature, remove dipstick. In-

stall Quicksilver Crankcase Oil Pump onto dipstick tube.
Insert hose end of crankcase oil pump into an appropriate container

and using pump handle, pump until crankcase is empty. Remove
crankcase oil pump.

2 Turn oil filter counterclockwise (to left); remove and discard old oil

filter and old sealing ring.
Coat sealing ring on new filter with motor oil. Install new sealing ring

and filter by turning clockwise (to right). Tighten filter securely . Do not
overtighten.

3 Remove oil filler cap. Add correct type oil (see SPECIFICA TIONS)

to bring level up to, but not over FULL mark on dipstick.

IMPORTANT: Always use dipstick to determine exactly how
much oil is required.

65

CB46

3

71773

71987

2

66

70570

1

72522

CB49

CHANGING DRIVE UNIT OIL

IMPORTANT: Use only Quicksilver High Performance Gear
Lube in drive unit.

1 Place drive unit in full trim limit (out) position, remove OIL FILL/

DRAIN SCREW and sealing washer.

2 Remove OIL VENT screw and sealing washer. Allow oil to drain

completely.

IMPORT ANT : If any water drained from OIL FILL/DRAIN hole, or
if oil appears milky tan, drive unit is leaking and should be
checked immediately by your Authorized MerCruiser Dealer.

Lower drive unit so anti-ventilation plate is level. Fill drive unit,
through OIL FILL/DRAIN hole, with Specified Gear Lube until an air–
free stream of lubricant flows from OIL VENT hole.

Remove tube from OIL FILL/DRAIN hole. Quickly install sealing
washer and OIL FILL/DRAIN screw. Tighten securely.

3 Fill gear lube monitor with Specified Gear Lube. When oil starts

to run out the vent hole (Monitor circuit completely filled), reinstall
vent plug and seal, and tighten securely.

4 Fill monitor to “FILL” mark. Lubricate O-ring on monitor neck with

stern drive oil, to ensure ease of installation and removal of cap; in­stall cap, do not over tighten.

5 Recheck oil level after first use.

IMPORTANT: Oil level in monitor will rise and fall during drive
operation; always check oil level when drive is cool and engine
is shut down.

67

CB79

71773

1

70573

68

71169

2

CB82

Water Separating Fuel Filter

!

WARNING

Be careful when changing water separating fuel filter. Gasoline
is extremely flammable and highly explosive under certain con­ditions. Be sure ignition key is OFF . Do not smoke or allow spark
or open flame in area when changing fuel filter. Wipe up any
spilled fuel immediately.

1 Remove water separating fuel filter (by turning counterclockwise)

and sealing ring(s) (two rings on older style filters - one ring on newer
style filter) from mounting bracket and discard.

Coat sealing rings on new filter with motor oil. Thread filter clockwise
onto bracket and tighten securely by hand. Do not use a filter wrench.

Start and run engine. Check filter connection for gasoline leaks. If
leaks exist, recheck filter installation. lf leaks continue, stop engine
immediately and contact your Authorized MerCruiser Dealer.

!

WARNING

Make sure no leaks exist before closing engine hatch.

CB85

Fuel Pump Sight Tube Inspection

2 The engine fuel pump is equipped with a sight tube which gives

visible evidence of a ruptured fuel pump diaphragm.

If fuel is visible in tube, fuel pump should be replaced by your
Authorized MerCruiser Dealer immediately.

69

CB177

1

71903

3

71904

2

71901

70

4

70556

5

71359

CA286

Lubrication

STEERING SYSTEM

1 If Steering Cable Has Grease Fittings: With cable fully retracted

into cable housing, lubricate fitting with 2-4-C Marine Lubricant with
Teflon.

!

W ARNING

Do not grease steering cable while extended. Hydraulic lock
could occur and cause loss of steering control.

NOTE: If steering cable does not have grease fitting, inner wire of

cable cannot be greased.

2 With steering cable fully extended lubricate exposed part of cable

with Special Lubricant 101.

3 Lubricate steering system pivot points with SAE 30W motor oil.

On dual engine boats, lubricate all pivot points, including tie bar pivot
points, with SAE 30W motor oil.

CA72

Shift Cable

4 Lubricate pivot points with SAE 30W motor oil.

CA73

Throttle Cable

5 Lubricate pivot points with SAE 30W motor oil.

71

CB389

8

6

70558

70559

72

CB372

DRIVE UNIT AND TRANSOM ASSEMBLY

6 Lubricate gimbal bearing with Quicksilver U-joint and Gimbal

Bearing Grease.

7 For propeller shaft lubrication, see PROPELLER.

NOTE: Engine coupling and shaft splines are greased with Quicksil-

ver Engine Coupler Spline Grease, P/N 92-816391A4; universal
joints are greased with Quicksilver U-joint and Gimbal Bearing
Grease. Contact your Authorized MerCruiser Dealer for this service.

IMPORTANT: Stern drive must be removed to lubricate U­joints. Contact your authorized MerCruiser dealer for this ser­vice.

!

CAUTION

Speedometer water hose must be disconnected from drive unit
BEFORE removing drive unit. Failure to do this will result in a
broken fitting if drive unit is removed.

CB56

ENGINE COUPLER

8 Lubricate engine coupler splines with Quicksilver Engine Coupler

Spline Grease P/N 92-816391A4.

73

CB373

74

4

2

72239

CA77

Propeller

!

WARNING

Remote Control must be in NEUTRAL and ignition key removed
from switch before removing and/or installing propeller.

!

WARNING

Place a block of wood between anti-ventilation plate and propel­ler to protect hands from propeller blades and to prevent pro­peller from rotating when removing propeller nut.

!

CAUTION

Periodically check propeller nut for tightness during boating
season. A minimum of 55 lbs. ft. (75 N⋅m) torque is required.

CB157

REMOVAL (BRAVO THREE)

1 Place wood block between propeller blades and anti-ventilation

plate to prevent rotation.

2 Turn aft propeller shaft nut counterclockwise to remove nut.
3 Slide propeller and thrust hub off propeller shaft.
4 Turn front propeller shaft nut counterclockwise to remove nut.
5 Slide propeller and thrust hub off propeller shaft.

CA79

REPAIR

Some damaged propellers can be repaired. See your dealer.

75

CB150

6

76

7

8

9

10

11

12

72239

CB345

INSTALLATION (BRAVO THREE)

6 Apply a liberal coat of one of the following Quicksilver lubricants

to both propeller shafts: Special Lubricant 101, 2-4-C Marine Lubri­cant with Teflon, or Anti-Corrosion Grease.

7 Slide forward thrust hub onto propeller shaft, with tappered side

toward propeller hub (Toward end of shaft).

8 Align splines and place propeller on propeller shaft.
9 Install propeller nut. Tighten nut securely. A minimum of 100 lbs.

ft. (136 N·m) torque is required. Check propeller at least after 20
hours of operation. Do not operate with loose propeller.

10Slide aft thrust hub onto propeller shaft, with tappered side toward

propeller hub (Toward end of shaft).

11Align splines and place propeller on propeller shaft.
12Install propeller nut. Tighten nut securely . A minimum of 60 lbs. ft.

(81 N·m) torque is required. Check propeller at least after 20 hours
of operation. Do not operate with loose propeller.

77

CB64

2

3

70565

71353

4

71170

1

70564

78

CB65

Flushing Cooling System

!

WARNING

When flushing, be certain the area around propeller is clear, and
no one is standing nearby . To avoid possible injury , remove pro­peller.

!

CAUTION

Do not run engine above 1500 RPM when flushing. Suction
created by seawater pickup pump may collapse flushing hose,
causing engine and/or drive unit to overheat.

!

CAUTION

Watch temperature gauge on dash to ensure that engine does
not overheat.

T o prevent silt and/or salt buildup in cooling system, flush with fresh­water at specified intervals.

If flushing cooling system with boat in water, raise drive unit to TRAIL­ER position, install flushing attachment and lower drive unit to full
down/in position.

1 Install Quicksilver flushing attachment (or equivalent) over water

intake openings in gear housing.

2 Connect hose between flushing attachment and water tap.
3 With drive unit in normal operating position, partially open water

tap (about 1/2 maximum). Place remote control in NEUTRAL, idle
speed position and start engine. Operate engine at idle speed, in
NEUTRAL, for about 10 minutes, or until discharge water is clear.
Stop engine, shut off water and remove flushing attachment.

CB66

Seawater Pump Impeller Inspection

This maintenance should be performed by an Authorized MerCruiser
Dealer.

4 Seawater pump impeller should be inspected whenever insuffi-

cient seawater flow is suspected (if operating temperature exceeds
normal range).

79

CB68

5

70566

6

70567

80

CB71

Cleaning Seawater (Raw Water) Section Of Heat
Exchanger And Oil/Power Steering Cooler ­Closed Cooling Models Only

Seawater sections of heat exchanger and oil/power steering cooler
should be cleaned at least once a year or whenever decreased cool­ing efficiency is noticed.

HEAT EXCHANGER

5 Remove end plate(s), O-rings and gaskets. Inspect O-rings and

gaskets for deterioration and replace if necessary . Install gaskets, O­rings and end plates. Tighten screws securely.

OIL COOLER/POWER STEERING COOLER

6 Remove end plates and gaskets. Inspect gaskets for deterioration

and replace if necessary. Install gaskets and end plates. Tighten
screws securely.

Start engine and inspect cooling system for leaks.

81

CB75

2

70562

6

3

1

70353

5

82

70351

70351

4

70563

CB77

Drive Belts

!

WARNING

Make sure engine is shut off and ignition key is removed before
inspecting belts.

All drive belts must be periodically inspected for condition and ten­sion.

Perform the following inspections of alternator drive belt, power
steering pump drive belt (if so equipped) and seawater pickup pump
drive belt.

If any drive belts need replacement or tension needs adjustment, see
your Authorized MerCruiser Dealer.

1 Alternator Drive Belt - Inspect drive belt for excessive wear or

damage.

2 Check belt tension by depressing upper strand of belt at point

shown. Belt should depress 1/2 in. (13mm).

3 Power Steering Pump Drive Belt - Inspect drive belt for excessive

wear or damage.

4 Check belt tension by depressing upper strand of belt at point

shown. Belt should depress 1/4 in. (6mm).

5 Seawater/Fuel Pump (Combination) - Inspect drive belt for exces-

sive wear or damage.

6 Check belt tension by depressing upper strand of belt at point

shown. Belt should depress 1/4 in. (6mm).

83

CB88

1

70575

3

70577

2

84

70578

CB383

Corrosion And Corrosion Protection

Whenever two or more dissimilar metals (like those found on the
stern drive) 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 is known as galvanic corrosion
and, if not controlled, it will in time cause the need for replacement
of power package components exposed to water.

IMPORT ANT : Replace sacrificial anodes if eroded 50% or more.

1 Anodic Plate - serves as a sacrificial anode. Unscrew both at-

taching screws and remove. Install a new anodic plate and tighten
securely.

2 MerCathode System - System should be tested to ensure ade-

quate output.
T est should be made where boat is moored, using Quicksilver Refer-

ence Electrode and T est Meter . Contact your Authorized MerCruiser
Dealer to arrange for this test.

3 Anode Kit (if so equipped) - Mounted to boat transom. Acts as

a sacrificial anode. Replace as required.

85

CB384

1

71966

2A

2B

86

2B

71804

72029

CA163

1 Trim Cylinder Anodes - are mounted on each trim cylinder. To

replace the trim cylinder anodes:

A Remove two screws from each anode.
B Install new anodes and tighten securely.

CB329

NOTE: Bravo Three Models may be equipped with one or two pro­peller anodes.

2 Propeller Anodes (Bravo Three Model) - are located in the

splash plate, just above the propellers. To replace the propeller
anodes:

A Remove the bolts that secure the anodes to the splash plate.
B Install new anodes and tighten securely.

87

CB392

1

88

2

74631

3

CA168

In addition to the corrosion protection devices, the following steps
should be taken to inhibit corrosion:

IMPORT ANT : Corrosion damage that results from the improper
application of anti-fouling paint will not be covered by the lim­ited warranty.

1 Painting Boat Hull or Boat Transom: Antifouling paint may be

applied to boat hull and boat transom
lowing precautions:

IMPORT ANT : DO NOT paint anodes or MerCathode System ref­erence electrode and anode, as this will render them ineffective
as galvanic corrosion inhibitors.

IMPORT ANT: If anti-fouling protection is required for boat hull
or boat transom, copper or tin base paints, if not prohibited by
law, can be used. If using copper or tin based anti-fouling
paints, observe the following:

but you must observe the fol-

2 Avoid any electrical interconnection between the MerCruiser

Product, Anodic Blocks, or MerCathode System and the paint
by allowing a minimum of 1-1/2 in. (40mm) UNP AINTED area on
transom of the boat around these items.

3 Painting Drive Unit or Transom Assembly: Drive unit and tran-

som 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, and items specified by boat
manufacturer.

4 Spray power package components on inside of boat every 2-3

weeks with Quicksilver Corrosion Guard to protect finish from dulling
and corrosion. External power package components may also be
sprayed.

5 All lubrication points, especially steering system, shift and throttle

linkages, should be kept well lubricated.

6 Flush cooling system periodically, preferably after each use.

89

CA103

Miscellaneous Maintenance

Battery

All lead acid batteries discharge when not in use. Recharge every 30
to 45 days, or when specific gravity drops below battery manufactur­er’s specifications.

Refer to specific instructions and warnings accompanying your bat­tery . If this information is not available, observe the following precau­tions when handling a battery.

!

WARNING

Do not use jumper cables and a booster battery to start engine.
Do not recharge a weak battery in the boat. Remove battery and
recharge in a ventilated area away from fuel vapors, sparks or
flames.

!

WARNING

Batteries contain acid which can cause severe burns-Avoid
contact with skin, eyes and clothing. Batteries also produce hy­drogen and oxygen gases when being charged. This explosive
gas escapes fill/vent cell caps and may form an explosive atmo­sphere around the battery for several hours after it has been
charged. Sparks or flames can ignite the gas and cause an ex­plosion which may shatter the battery and could cause blind­ness or other serious injury.

Safety glasses and rubber gloves are recommended when han­dling batteries or filling with electrolyte. Hydrogen gases that
escape from the battery during charging are explosive. When
charging batteries, be sure battery compartment or area where
batteries are located, is well-vented. Battery electrolyte is a cor­rosive acid and should be handled with care. If electrolyte is
spilled or splashed on any part of the body, immediately flush
the exposed area with liberal amounts of water and obtain medi­cal aid as soon as possible.

90

CA104

Bottom Of Boat

T o maintain maximum speed, the following conditions of the boat bot­tom should be observed:

• Clean, free of barnacles and marine growth.

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

• Straight and smooth, fore and aft.

ANTIFOULING PAINTS

See Antifouling Paint recommendations and related information on
previous pages.

IMPORTANT: Refer to CORROSION AND CORROSION PRO­TECTION for additional information.

CA105

Inspection And Maintenance

Inspect 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.

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

Check plug leads and electrical leads for damage.
Remove and inspect propeller. If badly nicked, bent or cracked, see

your dealer.
Repair nicks and corrosion damage on power package exterior fin-

ish. Use Quicksilver spray paints - see your Authorized MerCruiser
Dealer.

91

CA278

Cold Weather Or Extended

Storage

Power Package Lay Up

IMPORTANT: This service should be performed by an Autho­rized MerCruiser Dealer.

!

CAUTION

DO NOT operate engine without water flowing thru seawater
pickup pump, as pump impeller may be damaged and subse­quent overheating damage to engine or stern drive unit may re­sult.

IMPORTANT: Before starting engine, a water source must be
attached to the seawater intake openings in gear housing. Fol­low all warnings, and flushing attachments procedures stated,
in “FLUSHING COOLING SYSTEM.”

1 Run engine sufficiently to bring it up to normal operating tempera-

ture. Shut off engine and change oil and oil filter.

2 Flush cooling system.

!

WARNING

Be sure engine compartment is well ventilated and no gasoline
vapors are present during the following operation - to prevent
a potential fire hazard.

92

3 Remove flame arrestor and restart engine. While operating en-

gine at fast idle (1000-1500 RPM), fog internal surfaces of engine by
squirting approximately 8 ounces (227 g) of Quicksilver Storage Seal
(or if not available, SAE 20W motor oil) into carburetor bores. Stall
engine by squirting last 2 ounces (57 g) of Storage Seal (or oil) rapidly
into carburetor. Turn ignition key to OFF position.

4 Fill fuel tank(s) with fresh gasoline (that does not contain alcohol)

and a sufficient amount of Quicksilver Gasoline Stabilizer for Marine
Engines to treat gasoline. Follow instructions on container.

5 If boat is to be placed in storage (with fuel containing alcohol in fuel

tanks), carburetors must be run dry at idle RPM. Fuel tanks should
be drained completely and Quicksilver Gasoline Stabilizer for Marine
Engines added to any fuel remaining in the tank. Also, refer to FUEL
REQUIREMENTS.

6 Close fuel shutoff valve, if so equipped.

!

CAUTION

Stern drive unit should be stored in full “down” position. Uni­versal Joint bellows may develop a “set” if unit is stored in
raised position and may fail when unit is returned to service.

93

CB241

94

3

2

74073

CB242

Draining Instructions

DRAINING SEAWATER (RAW-WATER) COOLED MODELS

!

CAUTION

If boat is to remain in water after draining, seawater inlet hose
must be removed and plugged to prevent a siphoning action
that may occur, allowing seawater to flow from the drain holes
or removed hoses.

IMPORT ANT : Boat must be as level as possible to ensure com­plete draining of cooling system.

!

CAUTION

Seawater section of cooling system MUST BE COMPLETELY
drained for winter storage, or immediately after cold weather
use, if the possibility of freezing temperatures exist. Failure to
comply may result in trapped water causing freeze and/or corro­sion damage to engine.

1 Ensure engine is as level as possible to ensure complete draining

of cooling system.

2 Remove drain plugs (port and stbd) from cylinder block.
3 Remove drain plugs (port and stbd) from bottom of exhaust man-

ifolds.

4 Repeatedly clean out drain holes using a stiff piece of wire. Do

this until entire system is drained.

95

CB105

5

71448

7

71217

6

71334

96

8

71758

CB108

Loosen hose clamps and remove the following hoses:

5 From engine circulating pump.
6 From oil/power steering fluid cooler.
7 Make sure that speedometer pitot tube, trim tab cavity vent hole,

and trim tab cavity drain passage are unobstructed.
After cooling system has been drained completely, install drain

plugs, reconnect hoses and tighten all hose clamps securely.

IMPORT ANT : MerCruiser recommends that propylene glycol (a
nontoxic and environmentally safe) antifreeze be used in the
seawater section of the cooling system for cold weather or ex­tended storage. Make sure that the propylene glycol antifreeze
contains a rust inhibitor and is recommended for use in marine
engines. Be certain to follow the propylene glycol manufactur­er’s recommendations.

8 For additional assurance against freezing and rust, remove the

thermostat cover and thermostat. Fill the engine seawater cooling
system with a mixture of antifreeze and tap water mixed to manufac­turer’s recommendation to protect engine to the lowest temperature
to which it will be exposed during cold weather or extended storage.
Using a new gasket, reinstall thermostat and cover. Tighten cover
bolts securely.

Perform all checks, inspections, lubrication, and fluid changes out­lined in MAINTENANCE CHART under AT LEAST ONCE A YEAR.

97

CB111

98

2

70583