Mercury 250 Jet Installation Manual

250 HP Jet Drive Installation Manual

NOTICE to COMMISSIONING DEALER

Pre-delivery Preparation Instructions Must Be Performed Before Delivering Boat to the Product Owner.

NOTICE to INSTALLER

After Completing Installation, These Instructions Should Be Placed with the Product for the Owner’s Future Use.

NOTICE to INSTALLER

The United States Coast Guard does not have a method to determine the maximum recommended horse­power for Inboard Jet Boats. Therefore, it is the responsibility of the boat manufacturer to install the Mercury
Jet Drive, as well as any other Jet Drive model, in a boat which has been determined to be of suitable size,
weight, construction, and hull configuration for the power chosen. The Mercury
a new level of performance to the jet boat category and is capable of propelling many hulls at speeds exceed­ing 50 miles per hour.

In selecting the proper Jet Drive package for a particular application, please consider the overall performance
capability of the craft. Your boat may react to and handle differently with each Jet Drive model.

PLEASE carefully test and evaluate the overall handling characteristics of the boat package before
distribution for sale.

If you have application or installation questions, please contact your Mercury Marine OEM Sales Coordinator.
The Sales Coordinator will arrange to provide the necessary assistance.

Please assess y o u r boat’s performance completely before making the Jet Drive model selection.

ing is good for everyone.

Jet Drive, in particular, brings

Safe boat-

Table of Contents

General Information 2. . . . . . . . . . . . . . . . . . . . . . . . . .

Notice to Installer 2. . . . . . . . . . . . . . . . . . . . . . . . . .

Torque Specifications 3. . . . . . . . . . . . . . . . . . . . . .

Installation Requirements 3. . . . . . . . . . . . . . . . . . . . .

Battery/Battery Cables 3. . . . . . . . . . . . . . . . . . . . .

Boat Construction 4. . . . . . . . . . . . . . . . . . . . . . . . .

Engine Compartment Ventilation 4. . . . . . . . . . . .

Exhaust System 4. . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel Delivery System 5. . . . . . . . . . . . . . . . . . . . . .

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

Remote Control and Cables 7. . . . . . . . . . . . . . . .

Steering Helm and Cable 8. . . . . . . . . . . . . . . . . . .

Wiring Diagram 9. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Quicksilver Instrumentation,

Typical Analog Installation Shown 9. . . . . . . . . . .

Wiring for SmartCraft Gauges 10. . . . . . . . . . . . . . . . .

Wiring Connections to Paddle Wheel Speed

Sensor, Oil Tank and Fuel Tank 10. . . . . . . . . . . .

Typical System Layouts – Single Engine

Product Configurations 11. . . . . . . . . . . . . . . . . . . .

Wiring Information for CAN Type Gauges 12. . . .

Wiring Accessories for CAN Type Gauges 13. . .
Typical Installation Configurations

for CAN Type Gauges 14. . . . . . . . . . . . . . . . . . . . .

Mercury Jet Drive Hull Dimensions 15. . . . . . . . . . . .

Hull Opening 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installing Jet Pump 16. . . . . . . . . . . . . . . . . . . . . . . . . .

Steering Cable Adjustment 20. . . . . . . . . . . . . . . . . . .

Shift Cable Adjustment 23. . . . . . . . . . . . . . . . . . . . . . .

Installing Powerhead 27. . . . . . . . . . . . . . . . . . . . . . . .

Fuel Line and Fuel Vapor Vent Hose Connections 28.
Battery Cable and Remote Wiring Harness

Connections 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Throttle Cable Installation 30. . . . . . . . . . . . . . . . . . . .

Oil Injection Set-Up 31. . . . . . . . . . . . . . . . . . . . . . . . . .

Bilge Siphon Feature 33. . . . . . . . . . . . . . . . . . . . . . . .

Water By-Pass System 34. . . . . . . . . . . . . . . . . . . . . . .

Installation of Flushing Kit 36. . . . . . . . . . . . . . . . . . . .

Flushing Instructions 38. . . . . . . . . . . . . . . . . . . . . .

Suggested Flushing Intervals 38. . . . . . . . . . . . . .

Trim Plate Adjustment 39. . . . . . . . . . . . . . . . . . . . . . .

Exhaust System Installation 40. . . . . . . . . . . . . . . . . .

General Exhaust System Notes 40. . . . . . . . . . . .

Exhaust Outlet Measurement Procedure 40. . . .

Top View 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Aft View 42. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Side View 43. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Side View of Expansion Chamber Outlet

Pipe and Exhaust Pipe Connection 44. . . . . . . . .

Pre-delivery Inspection 45. . . . . . . . . . . . . . . . . . . . . . .

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250 HP JET DRIVE INSTALLATION MANUAL

General Information

Notice to Installer

Throughout this publication, Warnings and Cautions (accompanied by the International
Hazard Symbol) are used to alert the installer 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 to these special instructions when performing the service, plus common sense oper­ation, are major accident prevention measures.

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

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
installation and/or operation.

WARNING

CAUTION

This installation manual has been written and published by the service department of
Mercury Marine to aid installers when installing the products described herein.

It is assumed that these personnel are familiar with the installation procedures of these
products, or like or similar products manufactured and marketed by Mercury Marine. Also,
that they have been trained in the recommended installation procedures of these products
which includes the use of mechanics’ common hand tools and the special Mercury Marine
or recommended tools from other suppliers.

We could not possibly know of and advise the marine trade of all conceivable procedures
by which an installation might be performed and of the possible hazards and/or results of
each method. We have not undertaken any such wide evaluation. Therefore, anyone who
uses an installation procedure and/or tool, which is not recommended by the manufacturer,
first must completely satisfy himself that neither his nor the product’s safety will be
endangered by the installation procedure selected.

All information, illustrations, and specifications contained in this manual are based on the
latest product information available at time of publication. As required, revisions to this
manual will be sent to all OEM boat companies.

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90-10240040 DECEMBER 2003

Torque Specifications

NOTE: Tighten all fasteners, not listed, securely.

10 mm Fasteners
(Powerhead to Pump) 47 Nm (35 lb ft)

Reverse Stop Screw 14 Nm (120 lb in.)

Forward Stop Screw 14 Nm (120 lb in.)

Ride Plate-to-Pump Screws 8.5 Nm (75 lb in.)

Pump Cover to
Pump Housing Nuts 47 Nm (35 lb ft)

Installation Requirements

IMPORTANT: The Jet Drive is considered an INBOARD engine. The boat it is installed
in must meet industry standards (ABYC, NMMA, etc.), federal standards and Coast
Guard regulations for INBOARD engine installations.

250 HP JET DRIVE INSTALLATION MANUAL

Battery/Battery Cables

IMPORT ANT: Boating industry standards (ABYC, NMMA, etc.), federal standards and
Coast Guard regulations must be adhered to when installing battery. Be sure battery
cable installation meets the pull test requirements and that positive battery terminal
is properly insulated in accordance with regulations.

IMPORTANT: Engine electrical system is negative (–) ground. It is recommended
(required in some states) that battery be installed in an enclosed case. Refer to
regulations for your area.

1. Select a battery that meets all of the following specifications:
FOR OPTIMAX ENGINES –

a. 12-volt marine type.
b. 1000 Marine Cranking Amps (MCA) or 750 Cold Cranking Amps (CCA) minimum.
c. Reserve capacity rating of at least 105 minutes.

IMPORTANT: Terminals must be soldered to cable ends to ensure good electrical
contact. Use electrical grade (resin flux) solder only. Do not use acid flux solder, as
it may cause corrosion and a subsequent failure.

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250 HP JET DRIVE INSTALLATION MANUAL

Cable Length Cable Gauge

Up to 1.1 m (3-1/2 ft) 4 (25mm2)

1.1-1.8 m (3-1/2 - 6 ft) 2 (35mm2)

1.8-2.3 m (6 - 7-1/2 ft) 1 (50mm2)

2.3-2.9 m (7-1/2 - 9-1/2 ft) 0 (50mm2)

2.9-3.7 m (9-1/2 - 12 ft) 00 (70mm2)

3.7- 4.6 m (12 - 15 ft) 000 (95mm2)

4.6 - 5.8 m (15 - 19 ft)

Boat Construction

IMPORTANT: All applicable U.S. Coast Guard regulations for INBOARD engines must
be complied with, when constructing engine compartment.

Care must be exercised in the design and construction of the engine compartment. Seams
must be located so that any rain water or splash, which may leak through the seams, is
directed away from the engine and its air intake. Also, the passenger compartment drainage
system should not be routed directly to the engine compartment. Water that runs on or is

splashed in the air intake may enter the engine and cause serious damage to internal
engine parts.

0000 (120mm2)

IMPORTANT: Mercury Marine will not honor any warranty claim for engine damage
as a result of water entry.

Engine Compartment Ventilation

Engine compartment must be designed to provide a sufficient volume of air for engine
breathing and also must vent off any fumes in engine compartment in accordance with
industry standards (ABYC, NMMA, etc.), federal standards and U.S. Coast Guard
regulations for inboard engines. Pressure differential (outside engine compartment versus
inside engine compartment) should not exceed 51 mm (2 in.) of water (measured with a
manometer) at maximum air flow rate.

For serviceability , it is recommended that an additional 152 mm (6 in.) minimum (per side)
of clearance be allowed between powerhead and engine compartment walls.

Exhaust System

IMPORTANT: It is the responsibility of the boat manufacturer, or installing dealer, to
properly locate the engine. Improper installation may allow water to enter the
expansion chamber and combustion chambers and severely damage the engine.
Damage caused by water in the engine will not be covered by Mercury Marine Limited
Warranty, unless this damage is the result of defective parts.

The engine must be properly located to ensure that water will not enter the engine through
the exhaust system. Determine the correct engine height by taking measurements (a) and
(b), with boat at rest in the water and maximum load aboard. Subtract (b) from (a) to find
(c). If (c) is less than specified in chart, boat construction must be altered to properly lower
waterline relative to exhaust chamber.

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250 HP JET DRIVE INSTALLATION MANUAL

b

a

c

d

a-From Waterline to Top of Transom
b-From Highest Point on Expansion Chamber to Top of Transom
c-(a) minus (b) = (c)
d-Waterline at Rest (at Maximum Load)

59216

Model

Jet Drive (c) must be 203 mm (8 in.) or more.

Fuel Delivery System

Boating standards (NMMA, ABYC, etc.), federal standards and U. S. Coast Guard
regulations for INBOARD engines must be adhered to when installing fuel delivery
system. Failure to comply could result in severe personal injury or death.

Remove plastic plug from fuel inlet fitting. Attach fuel line to fuel fitting with U.S.
Coast Guard approved hose clamp. Inspect for fuel leaks.

1. Fuel pickup should be at least 25 mm (1 in.) from the bottom of the fuel tank to prevent
picking up impurities.

2. Fuel lines used must be U.S. Coast Guard approved (USCG type A1), fittings and lines
must not be smaller than 8mm (5/16 in.) I.D.

3. On installations requiring long lines or numerous fittings, larger size lines should be
used.

c = (a) minus (b)

WARNING

CAUTION

4. Fuel line should be installed free of stress and firmly secured to prevent vibration and/or
chafing.

5. Sharp bends in fuel line should be avoided.

6. A flexible fuel line must be used to connect fuel line to engine fuel pump to absorb deflec­tion when engine is running.

7. A primer bulb is not necessary with this application. If a primer bulb is used, it must be
U.S. Coast Guard approved for inboard engine installations.

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250 HP JET DRIVE INSTALLATION MANUAL

8. Vapor separator must be vented to fuel tank. Vent hose must comply with U.S. Coast
Guard/ABYC regulations.

Instrumentation

If a fused accessory panel is to be used, it is recommended that a separate circuit
(properly fused) be used from the battery to the fuse panel with sufficient wire size
to handle the intended current load.

NOTE: Check the charging capability of the engine. The electrical load of the boat should

not exceed this capacity.

We recommend the use of Mercury Precision or Quicksilver Instrumentation and Wiring
Harnesses. Refer to Mercury Precision Parts Accessories Guide for selection.

If other than Mercury Precision or Quicksilver electrical accessories are to be used, it is good
practice to use waterproof ignition components (ignition switch, lanyard stop switch, etc.).
A typical jet boat of this nature will see water splashed on these components. Therefore,
precautions must be taken to avoid ignition failure due to shorting out of ignition
components.

CAUTION

WARNING

Sudden stopping of engine (shorting ignition components) while boat is underway
will cause loss of steering control due to loss of thrust. This loss of steering control
may cause property damage, personal injury or death.

A warning horn must be incorporated in the wiring harness (see wiring diagram) to alert the
user of an overheat, low oil condition or oil pump failure.

IMPORTANT: If a warning horn system is not installed by the boat manufacturer,
Mercury Marine will not honor any warranty claims for engine damage as a result of
overheating or lack of engine oil.

Route instrumentation wiring harness back to engine, making sure that harness does not
rub or get pinched. If an extension harness is required, be sure to secure connection
properly. Fasten harnesses to boat at least every 460 mm (18 in.), using appropriate
fasteners.

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90-10240040 DECEMBER 2003

Remote Control and Cables

The remote control must provide the following required features:

• Start in gear protection

• Neutral RPM limit at 2,000 RPM

Note: This applies to dual lever remote controls as well as single lever remote controls.

• High strength mechanism to accommodate loads transmitted to the remote control

• Shift cable travel of 76 mm 3 mm) (3 in. 1/8 in.)

• Ability to use 40 series shift cable

The remote control must meet the above criteria as well as the design criteria outlined in
the ABYC manual pertaining to Mini-Jet Boats (Standard P-23).

SHIFT CABLE

The shift cable to be used MUST MEET the following criteria:

• 40-Series Cable

• 40 Series bulkhead fitting at output end

• Allow for a minimum of 76 mm (3 iin.) of travel.

• A means of attaching and locking the cable to the shift cable bracket (provided).

250 HP JET DRIVE INSTALLATION MANUAL

• Cable end at pump must allow for a 1/4 inch clevis pin and cotter pin (all provided) to

connect cable to the reverse gate.

• Protected against water intrusion and/or corrosion as the cable end (at the pump) is sub-

mersed in water with the boat at rest.

The shift cable end (at the pump) is submersed in water. It should be sealed against water
intrusion, protected against corrosion and be able to withstand the shift loads imparted on
it by the reverse gate.

Follow shift cable adjustment procedure for proper adjustment.

THROTTLE CABLE

The throttle cable must have one end compatible with the control box. The other end must
have Mercury style connectors.

Follow throttle cable adjustment procedures for proper adjustment.

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250 HP JET DRIVE INSTALLATION MANUAL

Steering Helm and Cable

STEERING HELM

The steering helm must limit steering cable travel to 88.9 mm ± 2.5 mm (3-1/2 in. ± 1/8 in.).

Failure to limit steering cable travel at the helm could pre-load the cable resulting
in premature failure of a steering component causing loss of steering. This loss of
steering could cause property damage, personal injury or death.

STEERING CABLE

The steering cable to be used MUST MEET the following criteria:

• 60 Series Steering Cable

• 60 Series bulkhead fitting at output end

• Allow for a minimum of 95.3 mm (3.75 in.) of travel.

• Cable end at pump must allow for a 5/16 in. threaded adaptor shouldered thru-bolt and

locknut to connect the cable to the steering arm.

• A means of attaching and locking the cable to the steering cable bracket (provided).

• Protected against water intrusion and/or corrosion as the cable end (at the pump) is sub-

mersed in water with the boat at rest.

WARNING

• The steering cable should be able to withstand the steering loads imparted on it by the
rudder.

A locking tab is provided by Mercury to be used with the steering cable having threads and
locknuts located 287 mm (11.31 in.) from cable end at pump with cable at center of travel.

Follow steering cable adjustment procedure for proper adjustment.

METHOD FOR CONTROLLING LOCATION AND SIZE

Mercury Marine recommends that the tunnel opening be done as a part of the manufacture
of the tunnel. This will ensure consistency of location as well as size.

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90-10240040 DECEMBER 2003

Wiring Diagram

Instrumentation, Typical Analog Installation Shown

NOTE: Refer to gauge manufacturer’s instructions for specific connections.

a

250 HP JET DRIVE INSTALLATION MANUAL

b

h

d

c

e

i

f

g

a - Temperature Gauge
b - Key Switch
c - Tachometer Gauge
d - Emergency Stop Switch
e - Tachometer Harness (P/N 84-86396A8) (Not Included
With Key/Choke Harness Kit)
f - Connect Wires Together With Screw and Hex Nut (2
Places) Apply Quicksilver Liquid Neoprene to Connections
and Slide Rubber Sleeve Over Each Connection.
g - To Neutral Start Safety Switch In Remote Control Box
h - Speedometer Gauge

i - Overheat/low oil horn

90-10240040 DECEMBER 2003

P

T

Liquid Neoprene

Dielectric Grease

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250 HP JET DRIVE INSTALLATION MANUAL

Wiring for SmartCraft Gauges

WIRING CONNECTIONS TO PADDLE WHEEL SPEED SENSOR, OIL TANK AND FUEL TANK

a

IMPORTANT: DO NOT connect the Black/Orange wire to
the fuel tank sensor when there is a engine battery ground
strap connected to the fuel tank or sender assembly. If not
used, plug the unused open bullet connector with rubber
plug P/N 13541.

84-859244A1

84-859743T2

Not Used

859223

b

Oil Tank
Sender
816190A1

c

d

a-Engine Plug
b-Paddle Wheel Speed/Outside Water Temp Sensor (If Equipped)
c-Oil Tank
d-Fuel Tank

57738

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90-10240040 DECEMBER 2003

250 HP JET DRIVE INSTALLATION MANUAL

Typical System Layouts – Single Engine Product Configurations

Speedometer and Tachometer (CAN)

NOTE: CAN Type Gauges Can only be used on 2002 Model

Year and newer V-6 models that are equipped for SmartCraft

Tachometer

System Link Gauges

GPS Connection

SC Data Cable

Speedometer

+

–

Terminator

Junction Box

System Monitor (CAN)

NOTE: System Monitor can be used on 2001 model year and

newer jet drives that are equipped for SmartCraft

SC1000-2RSL System Monitor
Harness

System Link Connector

System Monitor

System Link Gauges

System Link Connector

Tachometer Only (CAN)

NOTE: CAN Type Gauges Can only be used on 2002 Model

Year and newer jet drives that are equipped for SmartCraft

SC1000-2RSL System Monitor
Harness

90-10240040 DECEMBER 2003

System Tachometer

System Link Gauges

System Link Connector

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250 HP JET DRIVE INSTALLATION MANUAL

Wiring Information for CAN Type Gauges

REQUIREMENTS

SmartCraft communications are via the Controller Area Network (CAN), electrically imple­mented on a t wisted pair of wires. Note: SmartCraft harnesses include other signals besides
CAN.

The maximum distance between any two modules on the SmartCraft bus is 40 meters (130
feet). This distance is calculated as the total harness length between the modules (trunk
length plus drop lengths).

There must be exactly two termination resistors on the CAN bus.
No more than 20 modules may be connected to the bus. This is the maximum number of

connections supported by the engine control module software.

INSTALLATION GUIDELINES

SmartCraft installations should use Mercury Marine harnesses and junction boxes. This as­sures a robust mechanical implementation as well as proper connection of all signals.

The ideal installation uses a single trunk line with short drops to individual modules. Two
termination resistors, one at each end of the trunk line, minimize signal reflections. Signal
reflections can increase radio frequency interference and the potential for bit errors on the
bus.

The trunk line is not defined by junction boxes. The trunk should be considered to be the
distance between the termination resistors. Drops may be at the ends of the trunk line or
anywhere else that is convenient for the installation. Note that the trunk line can “loop-back”
in some installations.

• The single engine System Monitor example on page 14 illustrates a trunk line with two
drops of essentially zero length, one at the engine and the other at the gauge.

• The single engine System Tach and Speedo example on page 14 illustrates a trunk line
with one zero length drop at the engine and two three foot drops at the gauges.

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Wiring Accessories for CAN Type Gauges

250 HP JET DRIVE INSTALLATION MANUAL

Junction Boxes

6 Way

4 Way

878492A4

* For correct placement on these terminator/resistors, refer to Wiring Installation
Guidelines preceding and Typical Installation configurations following.

* * All unused junction box ports must be covered using these weather caps.

878492A6

8 Way

878492A8

Junction Box

*

Terminator/Resistor

859318T-1

SC1000 Series (Blue Cable)

84-879968T_ Harness without Terminator/Resistor

6 Ft
10 Ft
15 Ft

20 Ft
30 Ft

84-879978T-1 System Speed Harness

3 Ft

Junction Box

**

Weather Cap

859318T-2

84-879981T_ Harness with Terminator/
Resistor on One End

10 Ft

15 Ft
20 Ft
30 Ft

84-879982T_ Harness with Terminator/
Resistor on Both Ends

20 Ft
30 Ft

SC100 Series

84-880756b_ System Link Extension
Harness

3 Ft
10 Ft
30 Ft

84-879979T-1 System Monitor and
Tachometer Harness

3 Ft

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250 HP JET DRIVE INSTALLATION MANUAL

Typical Installation Configurations CAN Type Gauges

NOTE: The typical installation configurations shown on this page and the next few pages

are the lowest cost solutions. Other solutions are also possible. See Page 15 for general
guidelines.

SINGLE ENGINE APPLICATIONS

System Monitor– 2001 Model Year and Newer

Accessory Horn (816492A9) Connection
for Water Depth Warning

a

Engine

c

Ref. Part Number Description Qty.

a 879982T_ Wiring Harness SC1000-2RSL (20,30 ft) 1
b 879896K2 System Monitor – Front Mount (Outboard Only) 1
b 879896K1 System Monitor – Rear Mount (Outboard Only) 1
b 879896K4 System Monitor 2 – Front Mount (All Models) 1
b 879896K3 System Monitor 2 – Rear Mount (All Models) 1

c 881931A1 Depth Transducer – Transom Mount 1
c 881932A1 Depth Transducer – In Hull 1
c 881933A1 Depth Transducer – Through Hull 1

Optional Depth
Transducer

b

System Link
Connection

Monitor

System Tach and Speedo – 2002 Model Year and Newer

Accessory Horn (816492A9) Connection
for Water Depth Warning

b

Engine

a

c

Termination

Optional Depth Transducer is
Available

Ref. Part Number Description Qty.

a 879981T_ Wiring Harness SC1000R (10,15,20,30ft) 1
b 859318T1 Terminator/Resistor 1
c 878492T_ Junction Box (4,6,8) 1
d 879899K1 System Speedo and Tach – Single Application Kit – Gray Color 1
d 879899K11 System Speedo and Tach – Single Application Kit – White Color 1
e 879978T1 Wiring Harness SC1000-(3ft) Speed Harness 1

f 879979T1 Wiring Harness SC1000-SL-(3ft) Tach Harness 1

Resistor
On This End

Air Temp
Sensor

d

e

f

BLUE

WHITE

–+

NMEA GPS
Connection

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