Brunswick bravo one Manual

OPERATION &
MAINTENANCE MANUAL
1996,BrunswickCorporation 90-806294962 196
5.7L/5.7LX/7.4L
Bravo
One/Two/Three

0
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
whichapplytoyourMerCruiserpowerpackage.WhencontactingyourAuthorized
MerCruiser Dealer about service, always specify model and serial numbers.
The description and specifications contained herein were in effect at the time this
guidewas approved for printing. Mercury Marine, whose policy is oneofcontinuous
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.
1996, Brunswick Corporation
The following are registered trademarks of Brunswick Corporation: Auto-
blend, Jet-Prop, Mariner, Merc, MerCathode, MerCruiser, Mercury, Mercury
Marine, Quicksilver, Ride-Guide, and Thruster.

1
CA310
74677
71352 71350
71360
ABC12345Z123
-19 48-12345
71345
5
6
712
2
3
4
4
1
23
456
7
COLOR CODE
MERCRUISER
Division of Mercury Marine
Stillwater, OK, U.S.A.
SPECIFICATIONS
MODEL MCM 5.7 LITRE LX. . . . . . .
DISPLACEMENT 350 CID. . . . . . . . .
IGNITION TIMING 10 BTDC. . . . . . .
CYL. FIRING ORDER 1-8-4-3-6-5-7-2
SPARK PLUGS AC-MR43T. . . . . . . .
ENGINE ROTATION LH. . . . . . . . . . .
MAX W.O.T. RPM 4400-4800. . . . . .
IDLE RPM IN NEUTRAL 650. . . . . . .
PLUG GAP .035’. . . . . . . . . . . . . . . . .
For Fuel and Oilrequirements refer to
Operations & Maintenance Manual
SERIAL NUMBERS

2
CB538 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. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller Selection 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
How Elevation And Climate Affect Performance 15. . . . . . . . . .
Important Information 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation And Maintenance 16. . . . . . . . . . . . . . . . . . . . . . . . . . .
Freezing Temperature Operation 17. . . . . . . . . . . . . . . . . . . . . . .
Drive Unit Impact Protection 17. . . . . . . . . . . . . . . . . . . . . . . . . . .
Emissions Information 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20-Hour Checkup 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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. . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Recommendations 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Crankcase Oil 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tune-Up 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacities 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3
Page
Maintenance 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Aids 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Chart 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Fluid Levels 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing Fluids 65. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller 73. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flushing Cooling System 79. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seawater Pump Impeller Inspection 79. . . . . . . . . . . . . . . . . . . . .
Cleaning Seawater (Raw Water) Section Of Heat
Exchangers - Closed Cooling Models Only 81. . . . . . . . . . . . . .
Drive Belts 83. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Water Separating Fuel Filter 85. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel Pump Sight Tube Inspection 85. . . . . . . . . . . . . . . . . . . . . . .
Corrosion And Corrosion Protection 87. . . . . . . . . . . . . . . . . . . . .
Emissions 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Changing Positive Crankcase Ventilation (PCV) Valve 93. . .
Emissions Testing 93. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation of Test Probes 95. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Miscellaneous Maintenance 96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cold Weather Or Extended Storage 98. . . . . . . . . . . . . . . . . . . . . . .
Power Package Lay Up 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Draining Instructions 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery Winter Storage 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Package Recommissioning 112. . . . . . . . . . . . . . . . . . . . .
Troubleshooting 113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warranty Information 120. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Owner Warranty Registration 120. . . . . . . . . . . . . . . . . . . . . . . . .
International Owner Registration 121. . . . . . . . . . . . . . . . . . . . . .
Warranty Policies 122. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mercruiser Limited Warranty - Gasoline Engines 122. . . . . . . .
Mercruiser International Warranty - Gasoline Engines 124. . .
3 Year Limited Warranty Against Corrosion Failure 126. . . . . . . . .
Warranty Coverage 128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transferable Warranty 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Q-Guard Product Protection Plan 132. . . . . . . . . . . . . . . . . . . . . . . .
Owner Service Assistance 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Centers 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Customer Service Literature 140. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Maintenance Parts 141. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Literature Order Form 145. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4
CA165 WELCOME!
You 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

5
CA166 Read This Manual Thoroughly
IF YOU DON’T UNDERSTAND 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 !, may be used to alert the installer/user to special
instructions concerning a particular service or operation that may be
hazardous if performed incorrectly or carelessly. Observe them
carefully.
These “Safety Alerts” alone cannot eliminate the hazards that they
signal. Strict compliance with these special instructions while
performing the service, plus ”common sense” operation, are major
accident prevention measures.
!WARNING
WARNING-Hazards or unsafe practices which could result in
severe personal injury or death.
!CAUTION
CAUTION-Hazardsorunsafepracticeswhich couldresultinmi-
nor 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.

6
CA280 Lanyard Stop Switch
74608
21
1Someboatscome equipped with alanyardstop switch. A lanyard
stopswitchcanalsobeinstalledasanaccessory.Thepurposeofthis
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.
2Thelanyardisacordusuallybetween4and5feet(1220and1524
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
stretchedconditiontominimizethelikelihoodofaccidentalactivation
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.

7
ADVANTAGES: The purpose of a lanyard stop switch is to stop
theengineignitionwhenevertheoperator(whenattachedtothe
lanyard)movesfarenoughawayfrom theoperator’spositionto
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
passengers - 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.

8
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.
Boatoperatorsshouldcompleteaboatingsafetycourse.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.
YoushouldalsoreviewtheNMMA SourcesofWaterwayInformation
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. Herearesuggestionsofthe
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

9
•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.
•Passengerboarding.Stoptheenginewheneverpassengersare
boarding, unloading or are near the back (stern) of the boat. Just
shifting the drive unit into neutral is not sufficient.
•Usepersonal flotationdevices.FederalLawrequiresthatthere
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.Knowyourboat’soperatingandloadinglimitations.
•Makesureeveryoneintheboatisproperlyseated.Don’tallow
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
“maintain a proper lookout by sight (and hearing).” The operator
must have an unobstructed view particularly to the front. No
passengers,load,orfishingseatsshouldblocktheoperatorsview
when operating the boat above idle or planing transition speed.
Watch “the other guy,” the water and your wake.

10
•Never drive your boat directly behind a water skier in case
theskierfalls. Asanexample,yourboat travelingat25milesper
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.

11
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
Shiftthedriveunitintoneutralandshutofftheenginebeforeallowing
people to swim or be in the water near your boat.
!WARNING
Stop your engine immediately whenever anyone in the water is
nearyour boat. Seriousinjuryto the personinthe water islikely
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
withwhichyouareunfamiliar,werecommendthatyouneveroperate
it at its high speed capability without first requesting an initial
orientation and familiarization demonstrationride with your dealeror
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.

12
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
To 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.

13
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.

14
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”.
IMPORTANT: Theengines coveredinthismanualare 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.
Selectapropellerthatwillallowtheenginepowerpackagetooperate
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
thannormalwearand/ordamage.Generally,thereisa200-300RPM
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.

15
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 temperaturedo 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
perhourinsomecases.Nothingwillregainthisspeed 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
ofasmuchas14%ofthehorsepoweritwouldproduceonadry,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
weatherconditions,itisessentialthattheenginebeproppedtoallow
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.

16
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
responsibilityof theowner/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.
•Priortodelivery,makecertainthattheMerCruiserpowerpackage
and other equipment are in proper operating condition.
•Make all necessary adjustments for maximum efficiency.
•Familiarize the customer with the on-board equipment.
•Explainanddemonstratetheoperationofthepowerpackageand
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.

17
CA318
Freezing Temperature Operation
IMPORTANT: 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. Damage
caused by freezing IS NOT covered by the MerCruiser Limited
Warranty.
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
movingforward,thehydraulicsystemwill 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.
IMPORTANT: Impact protection system cannot be designed to
ensuretotalprotectionfromimpactdamageunderallconditions.

18
CA331
Emissions Information
Your engine may be equipped with special design features and
specialtuningtominimizetheemissionoutputfromtheengine.Ifso,
it is very important that you strictly adhere to the following:
•Recommended maintenance schedules particularly the ignition
system.
•Properenginetuningprocedurestoensurethesefeaturesremain
in good operating order.
•Proper steps to maintain the engine within specifications.
Use only MerCruiser replacement parts to ensure compliance with
emission regulations.
IMPORTANT: The testing dealer or agency will be equipped
with the appropriate test equipment and adapters for this
engine. The only item that must be supplied by the boat
owner/operator is the exhaust elbow test probes. These test
probes should have been provided with your power package.
They should be carried aboard your boat at all times. Refer to
“Emissions Testing” procedure found later in this manual.
CA18
Attention Required After Submersion
•Before recovery, contact an 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.
Adequateroadclearanceisrequiredbetweenroadandgearhousing
skeg when trailering with drive unit in “down” position.
Ifadequate roadclearance is a problem, placedrive unit in full trailer
positionandsupportwithanoptionaltrailerkitwhichisavailablefrom
your Authorized MerCruiser Dealer.