Mercury SST120 User manual

EPA Emissions Regulations
Outboards manufactured by Mercury Marine in the United
States are certified to the United States Environmental Protec-
tion Agency as conforming to the requirements of the regula-
tions for the control of air pollution from new outboard motors.
This certification is contingent on certain adjustments being
set to factory standards. For this reason, the factory procedure
for servicing the product must be strictly followed and, wherev-
er practicable, returned to the original intent of the design.
Maintenance, replacement, or repair of the emission con-
trol devices and systems may be performed by any marine
engine repair establishment or individual.
Engines are labeled with an Emission Control Information de-
cal as permanent evidence of EPA certification.
WARNING
The engine exhaust from this product contains chemi-
cals known to the state of California to cause cancer,
birth defects or other reproductive harm.
The description and specifications contained herein were in ef-
fect at the time this manual was approved for printing. Mercury
Racing, whose policy is one of continued improvement, re-
serves the right to discontinue models at any time, to change
specifications, designs, methods, or procedures without notice
and without incurring obligation.
Mercury Marine, Fond du Lac, Wisconsin U.S.A. Litho in
U.S.A.
2000, Mercury Marine
The following are registered trademarks of Brunswick
Corporation: AutoBlend, Force, Jet-Prop, Mariner, Merc,
MerCathode, MerCruiser, Mercury, Mercury Marine, Mercury
Racing, Quicksilver, Mercury Precision Parts, RideGuide and
Thruster
90-848719000 100
SST 120 S2000
2000 Mercury Marine

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for your purchase of one of the finest outboards available. You have
made a sound investment in boating pleasure. Your outboard has
been manufactured by Mercury Racing, a unit of Mercury Marine, the
world leader in marine technology and outboard manufacturing since
1939. These years of experience have been committed to the goal
of producing the finest quality products. This has led to Mercury Rac-
ing’s reputation for strict quality control, excellence, durability, lasting
performance and being the best at providing after-the-sale support.
Please read this manual carefully before operating your outboard.
This manual has been prepared to assist you in the operation, safe
use and care of your outboard.
All of us at Mercury Racing took pride in building your outboard and
wish you many years of happy and safe boating.
Again, thank you for your confidence in Mercury Marine.
Mercury Racing
N7480 County Road “UU”
Fond du Lac, WI 54935-9585

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SST120

1
oa TABLE OF CONTENTS
General Information
Boater’s Responsibilities 4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Before Operating Your Outboard 4. . . . . . . . . . . . . . . . . . . . . . . .
Boat Horsepower Capacity 5. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
High-Speed and High-Performance Boat Operation 5. . . . . . . .
Lanyard Stop Switch 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protecting People In The Water 8. . . . . . . . . . . . . . . . . . . . . . . . .
Carbon Monoxide Risk 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wave And Wake Jumping 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Impact With Underwater Hazards 12. . . . . . . . . . . . . . . . . . . . . . . .
Selecting Accessories For Your Outboard 14. . . . . . . . . . . . . . . .
Safe Boating Suggestions 14. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Recording Serial Number 16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications (General) 17. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications (Torques) 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component Identification 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller Selection 20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel & Oil
Gasoline Recommendations 21. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil Recommendation 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
New Engine Gasoline/Oil Break-In Mixture 22. . . . . . . . . . . . . . . .
Filling Gasoline Tank 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Features & Controls
Power Trim 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic Up/Down Adjustment 26. . . . . . . . . . . . . . . . . . . . . . . . .
Trim Pump Thermal Switch Operation 26. . . . . . . . . . . . . . . . . . . .

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oa TABLE OF CONTENTS
Operation
Engine Break-In 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pre-Starting Check List 28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating in Freezing Temperatures 28. . . . . . . . . . . . . . . . . . . . .
Operating In Salt Water or Polluted Water 28. . . . . . . . . . . . . . . .
Operating at High Elevations 29. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starting the Engine 30. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stopping the Engine 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine Overheating 32. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance
Outboard Care 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Submerged Outboard 33. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selecting Replacement Parts For Your Outboard 33. . . . . . . . . .
Inspection and Maintenance Schedule 34. . . . . . . . . . . . . . . . . . .
Fuel System 35. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steering and Throttle Systems 37. . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller Repair 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller Replacement 38. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spark Plug Inspection 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery Inspection 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication Points 40. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Power Trim or Hydraulic Up/Down Fluid 41. . . . . . . . .
Maintenance Log
Maintenance Log 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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TABLE OF CONTENTS
Storage
Storage Preparation 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Protecting Internal Engine Components 45. . . . . . . . . . . . . . . . . .
Protecting External Outboard Components 46. . . . . . . . . . . . . . .
Gear Case 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting
Troubleshooting 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Diagrams
Engine Wiring Diagram
All 12v Run-24v Start 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boat Wiring Diagram
All 12v Run-24v Start 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Owner Service Assistance
Local Repair Service 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service Away From Home 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts And Accessories Inquiries 52. . . . . . . . . . . . . . . . . . . . . . . . .
Service Assistance 53. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mercury Marine Service Offices 54. . . . . . . . . . . . . . . . . . . . . . . . .
Ordering Literature
Ordering Literature 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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GENERAL INFORMATION
oba1
Boater’s Responsibilities
The boat (driver) is responsible for correct and safe operation of the
boat and safety of its occupants and general public. It is strongly rec-
ommended that each operator (driver) read and understand this en-
tire manual before operating the outboard.
Be sure at least one additional person on board is instructed in the
basics of starting and operating the outboard and boat handling in
case the driver is unable to operate the boat.
obb1
Before Operating Your Outboard
Read this manual carefully. Safety and operating information that is
practiced along with using good common sense can help prevent
personal injury and product damage. If you have any questions, con-
tact your dealer.
This manual as well as safety labels posted on the outboard use
safety alerts to draw your attention to special safety instructions that
must be followed.
WARNING
WARNING – Hazards or unsafe practices which COULD result
in severe personal injury or death.
CAUTION
CAUTION – Hazards or unsafe practices which could result in
minor injury or product or property damage.

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GENERAL INFORMATION
12
U.S. COAST GUARD CAPACITY
MAXIMUM HORSEPOWER XXX
MAXIMUM PERSON
CAPACITY (POUNDS) XXX
MAXIMUM WEIGHT
CAPACITY XXX
Boat Horsepower Capacity
1Do not overpower or overload your boat. Most boats will carry a
required capacity plate indicating the maximum acceptable pow-
er and load as determined by the manufacturer following certain
federal guidelines. If in doubt, contact your dealer or the boat
manufacturer.
WARNING
Overpowering a Boat Can Cause:
•Serious injury, death, or boat damage.
•Loss of Boat Control.
•Flotation Characteristics of Boat to be Altered from Placing
Too Much Weight on Transom.
•Boat to Break Apart, Particularly Around the Transom Area.
High-Speed and High-Performance Boat
Operation
2If you are not familiar with high-performance boat operation we
recommend that you first request an orientation/demonstration
ride with your dealer or an operator experienced with your boat/
outboard combination. Refer to the “Guide to Hi-Performance
Boat Operation” booklet included in your literature packet.

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GENERAL INFORMATION
Lanyard Stop Switch
WARNING
Should the operator fall out of the boat, the possibility of seri-
ous injury or death from being run over by the boat can be
greatly reduced by stopping the engine immediately. Always
properly connect both ends of the stop switch lanyard – to the
stop switch and the operator.
1The purpose of a lanyard stop switch is to turn off the engine
when the operator moves far enough away from the operator’s
position (as in accidental ejection from the operator’s position) to
activate the switch. A lanyard stop switch can be installed as an
accessory – generally on the dashboard or side adjacent to the
operator’s position.
2While activation of the lanyard stop switch will stop the engine im-
mediately, a boat will continue to coast for some distance de-
pending 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 se-
riously as the boat would when under power.
(continued on next page)