Mariner 70, 75, 115, 90, 80 Service Manual

SERVICE

MANUAL

MODELS

70 • 75 • 80 • 90 • 100 • 115

1987–1993 70 • 75 • 75 Marathon •

75XD • 75 Seapro • 80 • 90

with Serial Numbers

UNITED STATES S/N 0A996142 thru 0D283221
BELGIUM S/N 09502135 thru 09793576
CANADA S/N 0A722297 and Above

Printed in U.S.A.

(3 Cylinder)

1995, Brunswick Corporation

1988–1993 100 • 115 (4 Cylinder)

with Serial Numbers

UNITED STATES
BELGIUM

CANADA

S/N 0B209468 thru 0D283221
S/N 09523034 thru 09793576
S/N 0A731673 and Above

90-13645--2 1095

Notice

Notice to Users of This Manual

Throughout this publication, “Dangers”, “Warnings”
and “Cautions” (outlined in a border and accompa­nied by the International HAZARD Symbol ) are
used to alert the mechanic 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.

DANGER

DANGER — Immediate hazards which WILL result
in severe personal injury or death.

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 personal injury or product or
property damage.

This service manual has been written and published
by the service department of Mercury Marine to aid
our dealers’ mechanics and company service person­nel when servicing the products described herein.

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

We could not possibly know of and advise the service
trade of all conceivable procedures by which a ser­vice 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 a service 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 service
procedure selected.

All information, illustrations and specifications con­tained in this manual are based on the latest product
information available at the time of publication. As re­quired, revisions to this manual will be sent to all deal­ers contracted by us to sell and/or service these prod­ucts.

It should be kept in mind, while working on the
product, that the electrical system and ignition system
is capable of violent and damaging short circuits or
severe electrical shocks. When performing any work
where electrical terminals could possibly be
grounded or touched by the mechanic, the battery
cables should be disconnected at the battery .

Any time the intake or exhaust openings are exposed
during service they should be covered to protect
against accidental entrance of foreign material which
could enter the cylinders and cause extensive inter­nal damage when the engine is started.

It is important to note that, during any maintenance
procedure, replacement fasteners must have the
same measurements and strength as those re­moved, whether metric or customary . Numbers on the
heads of the metric bolts and on surfaces of metric
nuts indicate their strength. Customary bolts use ra­dial lines for this purpose, while most customary nuts
do not have strength markings. Mismatched or incor­rect fasteners can result in damage or malfunction, or
possible personal injury. Therefore, fasteners re­moved should be saved for re-use in the same loca­tions whenever possible. Where the fasteners are not
satisfactory for re-use care should be taken to select
a replacement that matches the original.

Cleanliness and Care of

Service Manual Outline

Outboard Motor

A marine power product is a combination of many ma­chined, honed, polished and lapped surfaces with tol­erances that are measured in the ten thousands of an
inch. When any product component is serviced, care
and cleanliness are important. Throughout this
manual, it should be understood that proper cleaning,
and protection of machined surfaces and friction
areas is a part of the repair procedure. This is consid­ered standard shop practice even if not specifically
stated.

Whenever components are removed for service, they
should be retained in order. At the time of installation,
they should be installed in the same locations and
with the same mating surfaces as when removed.

Before raising or removing an outboard engine from a
boat, the following precautions should be adhered to:

1. Check that flywheel is secured to end of
crankshaft with a locknut and lifting eye is
threaded into flywheel a minimum of 5 turns.

2. Connect a hoist of suitable strength to the lifting
eye.

In addition, personnel should not work on or under an
engine which is suspended. Engines should be at­tached to work stands, or lowered to ground as soon
as possible.

We reserve the right to make changes to this manual
without prior notification.

1 - General Information and Specifications
2 - Electrical and Ignition

A - Ignition System
B - Battery, Charging System and

Starting System
C - Timing/Synchronizing and Adjusting
D - Wiring Diagrams

3 A - Fuel System and Carburetion

B - Oil Injection System

4 A - Powerhead (3-Cylinder Engines)

B - Powerhead (4-Cylinder Engines)

5 - Lower Unit

A - Gear Housing
B - Mid Section
C - Shock Absorber

6 - Power Trim

A - Design I (Side Fill Reservoir)
B - Design II (Aft Fill Reservoir)
C - Single Ram

7 - Outboard Motor Installation/Attachments

A - Engine Attachments/Engine Installation
B - Tiller Handle and Co-Pilot

Refer to dealer service bulletins for other pertinent in­formation concerning the products described in this
manual.

GENERAL INFORMATION
AND SPECIFICATIONS

1

Table Of Contents

General Specification 1-1. . . . . . . . . . . . . . . . . . . . . .

Cowl Removal 1-3. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Filling Oil Injection System 1-3. . . . . . . . . . . . . . . . . .

Power Trim General Information 1-4. . . . . . . . . . . . .

Trim “In” Angle Adjustment 1-4. . . . . . . . . . . . . . . . .

Models with Power Trim 1-4. . . . . . . . . . . . . . . .

Checking Trim System Fluid Level 1-5. . . . . . . . . . .

Tilt Angle Adjustment 1-5. . . . . . . . . . . . . . . . . . . . . .

Models without Power Trim 1-5. . . . . . . . . . . . . .

Connecting Engine Wiring Harness and

Routing of Engine Battery Cables 1-6. . . . . . . .

Ride-Guide Steering Cable and

Pivot Points Lubrication 1-7. . . . . . . . . . . . . . . . .

Page Page

Following Complete Submersion 1-8. . . . . . . . . . . .

Salt Water Submersion

(Special Instructions) 1-8. . . . . . . . . . . . . . . .

Submerged While Running

(Special Instructions) 1-8. . . . . . . . . . . . . . . .

Submerged Engine (Fresh Water)

(Plus Special Instructions) 1-8. . . . . . . . . . .

Out-of-Season Outboard Storage 1-9. . . . . . . . . . .

How Weather Affects Engine Performance 1-10. .

Conditions Affecting Operation 1-11. . . . . . . . . . . . .

Detonation: Causes and Prevention 1-12. . . . . . . .

Compression Check 1-12. . . . . . . . . . . . . . . . . . . . . .

90-13645-2 495

General Specification

NOTE:

the respective sections.

Horsepower 70 (52.2 kw) 75 (55.9 kw) 80 (59.6 kw) 90 (67.1 kw)
Idle RPM (in forward gear) 650 - 700
Full Throttle RPM Range 4750 - 5250 5000 - 5500
Piston Replacement 71.12 (1165.7cc)
Cylinder Bore 3.375 (85.7mm)
Stroke 2.65 (67.3mm)
Engine Type 3 Cylinder, 2 Cycle
Ignition Type C.D. Breakerless

Recommended Spark Plug
Cylinder Firing Order 1-3-2
Recommended Power Trim Fluid

Recommended Gasoline
Recommended Oil Quicksilver TC-WII or TC-W3 2-Cycle Outboard Oil

Other specification (torques, etc.) are listed in

Model 70 Model 75 Model 80 Model 90

NGK-BUHW-2 or AC-V40 FFK or

Champion L78V

Quicksilver Power Trim & Steering Fluid or Automotive Transmission

Regular Leaded, Premium, Low-Lead and Lead-Free automotive gaso-

lines with a minimum pump posted octane rating of 86

Inductor Plugs: NGK-BUZHW-2 or

Champion QL78V

Fluid (ATF) Type F, FA or Dexron II

Engine Weight ELO

ELOPT
Fuel Tank Capacity
Gear Housing Lubricant Capacity 22.5 fl. oz. (665.3ml)

Gasoline/Oil Ratio at Idle 80:1
Gasoline/Oil Ratio at W.O.T. 50:1
Gear Ratio 2.3:1
Oil Injection Tank Capacity

Tank Capacity 1 gal. (3.78 liter)
Maximum operation per tank

full of oil at W.O.T.
Oil remaining when warning

buzzer sounds
Operating time remaining at

wide open throttle when warn­ing buzzer sounds

(5 Imp. Gals.; 25 Liters)

260 lbs.
280 lbs.

6.6 U.S. Gallons

6 hours

1 qt. (.95 liter)

1 Hour

1-190-13645--2 1095 GENERAL INFORMATION AND SPECIFICATIONS

General Specification
(continued)

NOTE:

the respective sections.

Horsepower 100 (74.6 kw) 115 (85.8 kw)
Idle RPM (in forward gear) 650 - 700
Full Throttle RPM Range 4750 - 5250
Piston Replacement 105 (1720.9cc)
Cylinder Bore 3.375 (85.7mm)
Stroke 2.930 (74.4mm)
Engine Type 4 Cylinder, 2 Cycle
Ignition Type C.D. Breakerless

Recommended Spark Plug

Cylinder Firing Order 1-3-2-4
Recommended Power Trim Fluid

Recommended Gasoline
Recommended Oil Quicksilver 2-Cycle Outboard Oil

Other specification (torques, etc.) are listed in

Model 100 Model 115

NGK-BPH8H-N-10* Gap - 0.040 in. (1.0mm)

Inductor Plug NGK BPZ 8H-N-10* Gap - 0.040 in. (1.0mm)

NGK-BUHW

Quicksilver Power Trim & Steering Fluid or Automotive Transmission

Fluid (ATF) Type F, FA or Dexron II

Regular Leaded, Premium, Low-Lead and Lead-Free automotive gaso-

lines with a minimum pump posted octane rating of 86

Engine Weight ELO

ELOPT
Fuel Tank Capacity
Gear Housing Lubricant Capacity 22.5 fl. oz. (665.2ml)

Gasoline/Oil Ratio at Idle 80:1
Gasoline/Oil Ratio at W.O.T. 50:1
Gear Ratio 2.07:1
Oil Injection Tank Capacity

Tank Capacity 1.4 gal. (5.3 liters)
Maximum operation per tank

full of oil at W.O.T.
Oil remaining when warning

buzzer sounds
Operating time remaining at

wide open throttle when warn­ing buzzer sounds

*Improves running quality between 1800 – 2000 RPM.

(5 Imp. Gals.; 25 Liters)

340 lbs.
360 lbs.

6.6 U.S. Gallons

5 hours

1 qt. (.95 liter)

50 min. approx.

1-2 90-13645--2 1095GENERAL INFORMATION AND SPECIFICA TIONS

Cowl Removal

Filling Oil Injection System

Pull outward on starboard side of front shield (a).
Remove spring (b) from latch and open cowls.

a

Open starboard cowl (refer to cowl removal on this
page). Some earlier outboards will have a cowl brack­et to hold cowl open as shown.

Fill tank with recommended oil.

a

18291

a - Oil Tank Tube

b

18292

90-13645--2 495 1-3GENERAL INFORMATION AND SPECIFICATIONS

Power Trim System

Trim “In” Angle Adjustment

GENERAL INFORMATION

The power trim system is filled at the manufacturer
and is ready for use.

Trim outboard through entire trailering range several
times to remove any air from the system.

The trim system is pressurized and is not externally
vented. The outboard can be raised or lowered manu­ally by loosening the manual release valve four turns.

The trim “out” angle of this outboard is not adjustable.
The trim system has an internal valve which will
automatically stop the outward trim travel at 20 when
engine RPM is approximately 2000 RPM or higher;
outboard also has to be in water and in gear.

The outboard can be operated beyond the 20 trim
limit for operating outboard in shallow water if engine
RPM is kept below approximately 2000 RPM.

a

MODELS WITH POWER TRIM

WARNING

Operating some boats with outboard trimmed to the
full “in” trim angle [not using trim adjustment bolt
(a)] at planing speed will cause undesirable and/or
unsafe steering conditions. Each boat MUST BE
water tested for handling characteristics after
outboard installation and after any trim adjust­ments.

IMPORTANT: Some boat/motor combinations,
that do not use the trim adjustment bolt (a) and are
trimmed to the full “in” trim angle, will not experi­ence any undesirable and/or unsafe steering
conditions during planing speed. Thus, not using
trim adjustment bolt may be desired. However,
some boats with outboard trimmed to the full “in”
trim angle at planing speeds will cause undesir­able and/or unsafe steering conditions. If these
steering conditions are experienced, under no
circumstances should the outboard be operated
without the trim adjustment bolt and without the
bolt adjusted in the proper holes to prevent un­safe handling characteristics.

b

23321

a - Fill Screw (System is Pressurized, DO NOT Open Unless

Outboard is Tilted to Full Up Position)

b - Manual Release Valve

Water test the boat not using the trim adjustment bolt.
If undesirable and/or unsafe steering conditions are
experienced (boat runs with nose down), install trim
adjustment bolt in proper hole to prevent unsafe han­dling characteristics.

a

1-4 90-13645--2 495GENERAL INFORMATION AND SPECIFICATIONS

22744

Checking Trim System Fluid Level

Tilt Angle Adjustment

IMPORTANT: This trim system is pressurized.
Remove fill screw (b) when outboard is trimmed
to the full “up” position. Retighten fill screw
securely.

1. T rim outboard to full “up” position. Engage tilt lock
lever. T rim system fluid can only be checked when
outboard is in this position.

2. Remove fill screw and check fluid level. Fluid level
should be visible in fill tube.

3. If necessary, add Quicksilver Power Trim and
Steering Fluid; or Automatic Transmission Fluid
(ATF) Type F, FA or Dextron II.

a

MODELS WITHOUT POWER TRIM

WARNING

Operating some boats at minimum trim “In” at
planing speeds will cause undesirable and/or
unsafe steering conditions. Each boat should be
tested for handling characteristics after any
adjustment is made to the tilt angle.

DO NOT OPERATE motor with tilt lock pin removed.
Adjust tilt angle of motor on transom with tilt lock pin

so that anti-ventilation plate is about parallel and even
with bottom of boat. Speed sometimes may be im­proved by tilting motor out one tilt pin hole to raise bow
and reduce wetted surface. If motor is tilted in, boat
will ride bow down, wetting more of the bottom and re­ducing speed, which generally will improve operation
in rough water. Under ideal conditions, efficiency is
best with lower unit operating in level position. Opera­tion with excessive tilt angle will reduce performance
noticeably and may induce ventilation. It is preferable
to level boat by proper loading rather than by extreme
adjustment of tilt angle.

a - Tilt Lock Lever
b - Fill Screw

b

20319

a

22744

a - Tilt Lock Pin

90-13645--2 495 1-5GENERAL INFORMATION AND SPECIFICATIONS

Connecting Engine Wiring
Harness and Routing of
Engine Battery Cables

WARNING

Cables passing through cowl must be protected
from chafing or being cut, by using the neoprene
sheet as described in the following steps. Failure
to protect cables as described could result in
electrical system failure and/or possible injury to
occupants of boat.

c

b

a

1. Plug remote control harness connector into en­gine harness connector, then secure connector in
place with retainer as shown.

2. Wrap neoprene sheet around cable bundle and
secure each end with a sta-strap. Secure to
bracket with retainer.

IMPORTANT: On Models without Power Trim, the
neoprene sheet must be folded once and then
wrapped around cables as shown.

a

c

e

f

Models with Power Trim

b

Models without Power Trim

a - Wiring Harness
b - Neoprene Sheet
c - Sta-Straps

b

a - Engine Connector
b - Retainer
c - Harness Connector

f

20290

d - Harness Retainer
e - Neoprene Sheet
f - Sta-Strap(s)

c

d

Models with Power Trim

a

1-6 90-13645--2 495GENERAL INFORMATION AND SPECIFICATIONS

Lubrication Points

Lubricant Used or

No. Description

1 Ride-Guide

Steering Cable

2 Throttle-Shift

Linkage
3 Upper Shift Shaft
4 Tilt Tube
5 Swivel Pin
6 Tilt Lock Lever

7 Propeller Shaft

8 Gear Housing Quicksilver Gear Lube

Steering Link Rod

9

Pivot Points

Power Trim Pump

10

Oil Level

--- Engine Crankshaft
Splines to Drive
Shaft Splines

Accelerator Pump

11

Stem/Throttle Cam

Maintenance

Quicksilver

2-4-C

w/Teflon

Quicksilver

-2-4-C w/Teflon

Anti-Corrosion Grease

SAE 30W Engine Oil Every 60 Days Every 30 Days

Quicksilver Power Trim

and Steering Fluid

Quicksilver

2-4-C w/Teflon

Quicksilver 2-4-C

w/Teflon

Fresh Water Frequency Salt Water Frequency

Every 60 Days Every 30 Days

Once in Season Every 60 Days

Check and fill after 1st 10 days, then every 30 days

Drain and Refill after 1st 25 hours, then after every

100 hours, or once a year before storing.

Every 100 hours,

or once in season

Once in Season by Dealer

Once in Season Every 60 Days

Same as Fresh Water

Ride-Guide Steering Cable and Pivot
Points Lubrication

WARNING

8

7

27868

5

6

10

20319

Core of steering cable (transom end) must be fully
retracted into cable housing before lubricating
cable. If cable is lubricated while extended,
hydraulic lock of cable could occur.

With core of Ride-Guide Steering cable (transom
end) fully retracted, lubricate transom end of steering
cable thru grease fitting and exposed portion of cable
end with Quicksilver 2-4-C w/Teflon. Lubricate all piv­ot points with SAE 30W engine oil.

1

9

4

50099

1-790-13645--2 495 GENERAL INFORMATION AND SPECIFICA TIONS

NOTE:

4 CYL. MODELS

Following Complete Submersion

Submerged engine treatment is divided into 3 distinct
problem areas. The most critical is submersion in salt
water; the second is submersion while running.

Salt Water Submersion (Special
Instructions)

Due to the corrosive effect of salt water on internal en­gine components, complete disassembly is neces­sary before any attempt is made to start the engine.

11

22509B

1 1 – Lubrication Points for Accelerator Pump Cam on 4 Cylinder

Models Only

Submerged While Running (Special
Instructions)

When an engine is submerged while running, the
possibility of internal engine damage is greatly in­creased. If, after engine is recovered and with spark
plugs removed, engine fails to turn over freely when
turning flywheel, the possibility of internal damage
(bent connecting rod and/or bent crankshaft) exists.
If this is the case, the powerhead must be disas­sembled.

Submerged Engine (Fresh Water)
(Plus Special Instructions)

1. Recover engine as quickly as possible.

2. Remove cowling.

3. Flush outside of engine with fresh water to re­move mud, weeds, etc. DO NOT attempt to start
engine if sand has entered powerhead, as power­head will be severely damaged. Disassemble
powerhead if necessary to clean components.

4. Remove spark plugs and get as much water as
possible out of powerhead. Most water can be
eliminated by placing engine in a horizontal posi­tion (with spark plug holes down) and rotating fly­wheel.

5. Pour alcohol into carburetor throat (alcohol will
absorb water). Again rotate flywheel.

6. T urn engine over and pour alcohol into spark plug
openings and again rotate flywheel.

2

18298

2 – Lubrication Points are indicated with Arrows

1-8 90-13645--2 495GENERAL INFORMATION AND SPECIFICATIONS

7. Turn engine over (place spark plug opening
down) and pour engine oil into throat of carbure­tors while rotating flywheel to distribute oil
throughout crankcase.

8. Again turn engine over and pour approximately
one teaspoon of engine oil into each spark plug
opening. Again rotate flywheel to distribute oil in
cylinders.

9. Remove and clean carburetors and fuel pump
assembly.

10. Reinstall spark plugs, carburetors and fuel pump.
1 1. Attempt to start engine, using a fresh fuel source.

If engine starts, it should be run for at least one
hour to eliminate any water in engine.

12. If engine fails to start, determine cause (fuel, elec­trical or mechanical). DO NOT allow engine to re­main idle for more than 2 hours, as serious inter­nal damage will occur. If unable to start engine in
this period, disassemble engine and clean all
parts and apply oil as soon as possible.

Out-of-Season Outboard Storage

WARNING

As a safety precaution, when boat is in storage,
remove positive (+) battery cable. This will
eliminate possibility of accidental starting of
engine and resultant overheating and damage to
engine from lack of water.

In preparing an outboard for out-of-season storage,
2 precautions must be considered: 1) The engine
must be protected from physical damage and 2) the
engine must be protected from rust, corrosion and
dirt.

1. Remove cowling from engine.

2. Place outboard in water or install Quicksilver
Flushing Attachment over water intake by follow­ing instructions outlined in “Flushing Cooling Sys­tem” (see “Table of Contents”).

3. Start engine and allow to warm up. Disconnect
fuel line. When engine starts to stall quickly spray
Quicksilver Storage Seal into each carburetor
throat. Continue to spray until engine dies from
lack of fuel.

4. Remove spark plugs and inject a 5 second spray
of Quicksilver Storage Seal around the inside of
each cylinder. Manually turn engine over several
times to distribute Storage Seal throughout cylin­ders. Reinstall spark plugs.

5. If engine fuel filter appears to be contaminated, re­move and replace. Refer to Section 3 “Fuel System
and Carburetion.”

6. Drain and refill lower unit with Quicksilver Gear
Lube, as explained in “Gear Housing Lubrication”
(see “Table of Contents”).

7. Clean outboard thoroughly, including all accessi­ble powerhead parts, and spray with Corrosion
and Rust Preventive.

8. Refer to lubrication chart in this section (see
“Table of Contents”) and lubricate all lubrication
points.

9. Remove propeller. Apply Quicksilver Anti-Corrosion
Grease or 2-4-C w/Teflon to propeller shaft and re­install propeller. Refer to “Propeller Installation” (see
“Table of Contents”).

10. If the water pickup is clogged, the speedometer
will be inoperative. Clean the pickup with a piece
of wire or blow out with compressed air. Before
blowing out with air, disconnect the tubing from
the speedometer.

11. To prevent freeze damage, drain the speedome­ter system of water completely before storage.
Remove tubing from speedometer fitting and
blow thru the tubing to remove water.

12. Store battery as outlined in “Out-of-Season Bat­tery Storage,” following.

13. For out-of-season storage information on
Autoblend units, refer to Section 8 in this service
manual.

IMPORTANT: When storing outboard for the win­ter, be sure that all water drain holes in gear hous­ing are open and free so that all water will drain
out. If a speedometer is installed in the boat, dis­connect the pickup tube and allow it to drain. Re­connect the tube after draining. Trapped water
may freeze and expand, thus cracking gear hous­ing and/or water pump housing. Check and refill
gear housing with Quicksilver Gear Lube before
storage to protect against possible water leakage
into gear housing which is caused by loose lubri­cant vent plug or loose grease fill plug. Inspect
gaskets under lubricant vent and fill plugs, re­placing any damaged gaskets, before reinstalling
plugs.

1-990-13645--2 495 GENERAL INFORMATION AND SPECIFICA TIONS

Out-of-Season Battery Storage

1. Remove battery as soon as possible and remove
all grease, sulfate and dirt from top surface.

2. Cover PLATES with distilled water, but not over
3/16 in. (5mm) above perforated baffles.

3. Cover terminal bolts well with grease.

4. Store battery in a COOL, DRY place in a dry car­ton or box.

5. Remove battery from storage every 60 days.
Check water level and place on charge for 5 to 6
hours at 6 amperes. DO NOT fast charge.

CAUTION

A discharged battery can be damaged by freezing.

How Weather Affects Engine
Performance

Corporations internationally have settled on adoption
of I.S.O. (International Standards Organization)
engine test standards, as set forth in I.S.O. 3046
standardizing the computation of horsepower from
data obtained on the dynamometer, correcting all
values to the power that the engine will produce at
sea level, at 30% relative humidity at 77 F (25 C)
temperature and a barometric pressure of 29.61
inches of mercury.

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-per­hour (3 or 5 Km per-hour) in some cases. (Refer to
previous chart.) 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. The horsepower, that any internal combus­tion engine produces, depends upon the density of
the air that it consumes and, in turn, this density is de­pendent upon the temperature of the air, its baromet­ric pressure and water vapor (or humidity) content.

It is a known fact that weather conditions exert a pro­found effect on power output of internal combustion
engines. Therefore, established horsepower ratings
refer to the power that the engine will produce at its
rated RPM under a specific combination of weather
conditions.

Accompanying this weather-inspired loss of power is
a second but more subtle loss. At rigging time in early
spring, the engine was equipped with a propeller that
allowed the engine to turn within its recommended
RPM range at full throttle. With the coming of the sum­mer weather and the consequent drop in available
horsepower, this propeller will, in effect, become too
large. Consequently , the engine operates at less than
its recommended RPM.

Due to the horsepower/RPM characteristics of an en­gine, this will result in further loss of horsepower at the
propeller with another decrease in boat speed. This
secondary loss, however, can be regained by switch­ing to a smaller pitch propeller that allows the engine
to again run at recommended RPM.

1-10 90-13645--2 495GENERAL INFORMATION AND SPECIFICA TIONS

For boaters to realize optimum engine performance
under changing weather conditions, it is essential that
the engine have the proper propeller 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.

Conditions Affecting Operation

1. Proper positioning of the weight inside the boat
(persons and gear) has a significant effect on the
boat’s performance, for example:

a. Shifting weight to the rear (stern)

(1.) Generally increases top speed.
(2.) If in excess, can cause the boat to por-

poise.

(3.) Can make the bow bounce excessively in

choppy water.

(4.) Will increase the danger of the following -

wave splashing into the boat when coming
off plane.

b. Shifting weight to the front (bow)

(1.) Improves ease of planing off.

(3.) If excessive, can make the boat veer left

and right (bow steer).

2. Boat Bottom: For maximum speed, a boat bot­tom should be nearly a flat plane where it contacts
the water and particularly straight and smooth in
fore-and-aft direction.

a. Hook: Exists when bottom is concave in fore-

and-aft direction when viewed from the side.
When boat is planing, “hook” causes more lift
on bottom near transom and allows bow to
drop, thus greatly increasing wetted surface
and reducing boat speed. “Hook” frequently is
caused by supporting boat too far ahead of
transom while hauling on a trailer or during stor­age.

b. Rocker: The reverse of hook and much less

common. “Rocker” exists if bottom is convex in
fore-and-aft direction when viewed from the
side, and boat has strong tendency to porpoise.

c. Surface Roughness: Moss, barnacles, etc.,

on boat or corrosion of outboard’s gear housing
increase skin friction and cause speed loss.
Clean surfaces when necessary.

3. Gear Housing: If unit is left in the water, marine
vegetation may accumulate over a period of time
in certain types of water. This growth must be re­moved from unit before operation, as it may clog
the water inlet holes in the gear housing and
cause the engine to overheat.

(2.) Generally improves rough water ride.

1-1190-13645--2 495 GENERAL INFORMA TION AND SPECIFICATIONS

Detonation: Causes and Prevention

Compression Check

Detonation in a 2-cycle engine somewhat resembles
the “pinging” heard in an automobile engine. It can be
otherwise described as a tin-like “rattling” or “plinking”
sound.

Detonation generally is thought of as spontaneous ig­nition, but it is best described as a noisy explosion in
an unburned portion of the fuel/air charge after the
spark plug has fired. Detonation creates severe, un­timely, shock waves in the engine, and these shock
waves often find or create a weakness: The dome of
a piston, piston rings or piston ring lands, piston pin
and roller bearings.

While there are many causes for detonation in a
2-cycle engine, emphasis is placed on those causes
which are most common in marine 2-cycle applica­tion. A few, which are not commonly understood, are:

1.Over-advanced ignition timing.

2.Use of low octane gasoline.

3.Propeller pitch too high (engine RPM below rec­ommended maximum range).

4.Lean fuel mixture at or near wide-open-throttle.

5.Spark plugs (heat range too hot – incorrect reach
– cross-firing).

1.Remove spark plugs.

2.Install compression gauge in spark plug hole.

3.Hold throttle plates at W.O.T.

4.Crank engine thru at least 4 compression strokes
to obtain highest possible reading.

5.Check and record compression of each cylinder.
Variation of more than 15 psi (103.5 kPa) between
cylinders indicates that lower compression cylin­der is in some way defective, such as worn or
sticking piston rings and/or scored piston and cyl­inder.

6.Compression check is important because an en­gine with low or uneven compression cannot be
tuned successfully to give peak performance. It is
essential, therefore, that improper compression
be corrected before proceeding with an engine
tune-up.

7.Cylinder scoring: If powerhead shows any indica­tion of overheating, such as discolored or
scorched paint, visually inspect cylinders for scor­ing or other damage as outlined in Section 4
“Powerhead.”

6.Inadequate engine cooling (deteriorated cooling
system).

7.Combustion chamber/piston deposits (result in
higher compression ratio).

Detonation usually can be prevented, provided that

1) the engine is correctly set up and 2) diligent mainte-

nance is applied to combat the detonation causes,
listed, preceding.

51115

Damaged Piston Resulting from Detonation

1-12 90-13645--2495GENERAL INFORMATION AND SPECIFICATIONS

ELECTRICAL AND
IGNITION

2

A

IGNITION SYSTEM

Table Of Contents

Description 2A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Test Procedures 2A-1. . . . . . . . . . . . . . . . . . . . . . . . . .

Direct Voltage Adapter (DVA) Tests 2A-1. . . . . .

Troubleshooting Tips 2A-1. . . . . . . . . . . . . . .

Test Sequence 2A-2. . . . . . . . . . . . . . . . . . . . . . .

Ignition System Test Chart 2A-3. . . . . . . . . . . . . . . . .

Stator Test 2A-3. . . . . . . . . . . . . . . . . . . . . . . .

9/18/24 Ampere Stators 2A-4. . . . . . . . . . . .

Ignition Coil Test 2A-5. . . . . . . . . . . . . . . . . . .

Trigger Test 2A-5. . . . . . . . . . . . . . . . . . . . . . .

Ignition (Key) Switch Test 2A-5. . . . . . . . . . .

Commander 2000 Key Switch 2A-5. . . . . . .

Commander Key Switch 2A-5. . . . . . . . . . . .

Page Page

Ignition Components Removal and

Installation 2A-6. . . . . . . . . . . . . . . . . . . . . . . . . . .

Flywheel 2A-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 2A-6. . . . . . . . . . . . . . . . . . . . . . . . . .

Installation 2A-6. . . . . . . . . . . . . . . . . . . . . . . .

Stator 2A-7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 2A-7. . . . . . . . . . . . . . . . . . . . . . . . . .

Installation 2A-7. . . . . . . . . . . . . . . . . . . . . . . .

Trigger 2A-8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 2A-8. . . . . . . . . . . . . . . . . . . . . . . . . .

Installation 2A-8. . . . . . . . . . . . . . . . . . . . . . . .

Ignition Coils (3 Cylinder Models) 2A-9. . . . . . .

Ignition Coils (4 Cylinder Models) 2A-9. . . . . . .

Switch Box 2A-10. . . . . . . . . . . . . . . . . . . . . . . . . .

90-13645--2 1095

Description

Test Procedures

The outboard ignition system is alternator-driven with
distributor-less capacitor discharge. Major compo­nents of the ignition system are the flywheel, stator,
trigger, switch box, ignition coils and spark plugs.

The stator assembly is mounted stationary below the
flywheel and has 2 capacitor charging coils. The
flywheel is fitted with permanent magnets inside the
outer rim. As the flywheel rotates the permanent
magnets pass the capacitor charging coils. This
causes the capacitor charging coils to produce AC
voltage. The AC voltage then is conducted to the
switch box where it is rectified and stored in a
capacitor.

The trigger assembly (also mounted under the
flywheel) has 3 coils. The flywheel has a second set
of permanent magnets (located around the center
hub). As the flywheel rotates the second set of
magnets pass the trigger coils. This causes the
trigger coils to produce an AC voltage that is
conducted to an electric Silicon Controlled Rectifier
(SCR) in the switch box.

The switch discharges the capacitor voltage into the
ignition coil at the correct time and firing order
sequence.

Capacitor voltage is conducted to the primary side of
the ignition coil. The ignition coil multiplies this voltage
high enough to jump the gap at the spark plug.

The preceding sequence occurs once-per-engine­revolution for each cylinder.

Spark timing is changed (advanced/retarded) by
rotating the trigger assembly which changes each
trigger coil position in relation to the permanent
magnets on the flywheel center hub.

IMPORT ANT: If the engine misfires, runs rough or
does not start, the ignition system should be
checked using a Multi-Meter/DVA Tester
(91-99750), or a voltmeter (capable of measuring
400 volts DC, or higher) and Direct V oltage Adap­tor (91-89045).

Direct Voltage Adapter (DVA) Tests

WARNING

DANGER - HIGH VOLTAGE/SHOCK HAZARD! Do
not touch ignition components and/or metal test
probes while engine is running and/or being
“cranked.” STAY CLEAR OF SPARK PLUG
LEADS. To assure personal safety, each
individual spark plug lead should be grounded to
engine.

CAUTION

To protect against meter and/or component
damage, observe the following precautions:

 400 VDC* test position (or higher) MUST BE

used for all tests.

 INSURE the Positive (+) lead/terminal of DV A is

connected to the Positive (+) receptacle of
meter.

 DO NOT CHANGE meter selector switch

position while engine is running and/or being
“cranked.”

 Switch box MUST BE GROUNDED during tests.

Running or “cranking” engine with switch box
ungrounded may damage switch box.

* If using a meter with a built-in DV A, the DVA/400 VDC test posi-

tion should be used.

NOTE:

test leads supplied with meter.
Test procedures and specifications are provided for

checking primary ignition voltage while the engine
is running and/or being “cranked.”

TROUBLESHOOTING TIPS:

1. Intermittent, weak, or no spark output at two

2. Intermittent, weak, or no spark output at all three

Test leads are not supplied with the DVA. Use

spark plugs usually indicates a bad TRIGGER.

spark plugs usually indicates a bad STATOR or

SWITCH BOX.

90-13645--2 1095 2A-1ELECTRICAL AND IGNITION

3. Intermittent, weak, or no spark at any one spark
plug usually indicates a bad SPARK PLUG,

COIL, or SWITCH BOX.

Test Sequence

k

1-A) Check primary input voltage to coils. (See
Test Chart).

1. If voltage readings to coil(s) are BELOW specifi­cation, proceed with Step 2-A.

2. If voltage readings to coil(s) are WITHIN specifi­cations, proceed with Step 1-B.

1-B) Check coils for spark. [Connect Spark Gap
Tester (91-63998A1) between coil high voltage
tower and spark plug.]

1. No spark or weak spark. COIL is bad.

2. Spark is OK, proceed with Step 1-C.

1-C) If Step 1-A and 1-B check OK, replace spark
plugs.

If problem exists after replacing spark plugs, proceed
with Step 1-D.

1-D) If Steps 1-A, 1-B, and 1-C check OK, check
ignition timing.

1. If ignition timing does not check to specification
(or a sudden or unexplained timing change
occurs) check trigger advance linkage for loose
and/or broken parts and check trigger magnet
ring (on flywheel hub) for looseness and/or a shift
in position.

3. If reading is still BELOW specification, proceed
with Step 3-A.

4. If reading is WITHIN specification, either the

ignition switch, stop switch, or wiring is bad.

3-A) Check stator low speed and high speed input
to switch box. (See Test Chart).

1. If either the low speed or high speed reading to
switch box is BELOW specification, Stator or
Switch Box is bad (test stator as outlined in this
service manual section; if stator checks to specifi­cation replace switch box and repeat check).

2. If both the low speed and high speed reading are
WITHIN specification, replace switch box and re­peat test.

2. If ignition checks to specification and engine does
not run or runs poorly, trouble exists with fuel

system or engine mechanical.

2-A) Check switch box “stop” circuit. (See Test
Chart).

1. If reading is BELOW specifications, proceed with
Step 2-B.

2. If reading is ABOVE specifications, the Trigger or
Switch Box is bad (test trigger as outlined in this ser-

vice manual section; if trigger checks OK, replace
switch box and repeat check).

3. If reading is WITHIN specifications, proceed with

Step 3-A.

2-B) Check ignition switch/wiring, as follows:

CAUTION

To prevent engine from starting, remove spar
plug leads from ALL spark plugs and ground
leads to engine.

1. Disconnect ignition switch and stop switch
leads from switch box and isolate the leads.

2. Repeat check in Step 2-A.

2A-2 90-13645--2 1095ELECTRICAL AND IGNITION

Ignition System Test Chart

g

(1)

g

gg

gg

S

20 VDC

g

(1)

g

gg

gg

S

20 VDC

g

(1)

g

gg

gg

S

20 VDC

IMPORTANT: BEFORE attempting the ignition system checks, following, thoroughly read the preceding
pages of these instructions to become familiar with the proper Automatic Distributorless Ignition (ADI)
test sequence and procedures (particularly any “Safety Warnings” and “Cautions”). ALL tests are per­formed with lead wires connected – terminals exposed. SWITCH BOX MUST BE GROUNDED (CASE TO
ENGINE BLOCK) FOR ALL TESTS – IF NOT, SWITCH BOXES MAY BE DAMAGED.

3 Cylinder Stators – 398-9710A13/14/28 and all 398-8778A– Stators
4 Cylinder Stators – 398-9710A15/31 and all 398-8778A– Stators

ADI Test Selector Sw.

Seq.

1-A Coil Primary 400 VDC* Coil (+) Terminal Coil (–) Terminal 150-250 180-280
2-A
3-A

4-A
3-A

4-A

5-A

(1)Using meter only, REVERSE LEAD POLARITY; connect leads as specified.
* If using a meter with a built-in DVA, place selector switch in the DVA/400 VDC position.

T est

Sw. Box –
Stop Circuit

Stator –
Low Speed

Stator –
High Speed

w. Box –

Bias

Position

400 VDC*

400 VDC*

400 VDC*

or

40 VDC

Black/Yellow (3)

Sw. Box Terminal

Blue Sw.

Box Terminal

Red Sw.

Box Terminal

Ground

DVA Leads

Red Black

Ground 200-360 200-360

Ground 200-300 200-330

Ground 20-90 130-300

[See Note (1)]

White/Black

Sw. Box Terminal

V oltage Readin

@ 300-1000 RPM

2-10 10-30

Voltage Readin

@ 1000-4000 RPM

3 Cylinder Stator – 9 Ampere 398-9873A21 & 15 Ampere 398-9873A24

ADI Test Selector Sw.

Seq.

1-A Coil Primary 400 VDC* Coil (+) Terminal Coil (–) Terminal 145-250 210-240
2-A
3-A

4-A
3-A

4-A

5-A

(1)Using meter only, REVERSE LEAD POLARITY; connect leads as specified.
* If using a meter with a built-in DVA, place selector switch in the DVA/400 VDC position.

T est

Sw. Box –
Stop Circuit

Stator –
Low Speed

Stator –
High Speed

w. Box –

Bias

Position

400 VDC*

400 VDC*

400 VDC*

or

40 VDC

Black/Yellow (3)

Sw. Box Terminal

Blue Sw.

Box Terminal

Red Sw.

Box Terminal

Ground

DVA Leads

Red Black

Ground 215-340 280-320

Ground 215-340 280-320

Ground 10-55 45-255

[See Note (1)]

White/Black

Sw. Box Terminal

V oltage Readin

@ 300-1000 RPM

2-30 10-30

Voltage Readin

@ 1000-4000 RPM

4 Cylinder Stator – 16 Ampere 398-9710A33

ADI Test Selector Sw.

Seq.

1-A Coil Primary 400 VDC* Coil (+) Terminal Coil (–) Terminal 110-300 215-265
2-A
3-A

4-A
3-A

4-A

5-A

(1)Using meter only, REVERSE LEAD POLARITY; connect leads as specified.
* If using a meter with a built-in DVA, place selector switch in the DVA/400 VDC position.

T est

Sw. Box –
Stop Circuit

Stator –
Low Speed

Stator –
High Speed

w. Box –

Bias

Position

400 VDC*

400 VDC*

400 VDC*

or

40 VDC

Black/Yellow (3)

Sw. Box Terminal

Blue Sw.

Box Terminal

Red Sw.

Box Terminal

Ground

DVA Leads

Red Black

Ground 160-385 270-330

Ground 160-385 270-330

Ground 8-33 33-205

[See Note (1)]

White/Black

Sw. Box Terminal

V oltage Readin

@ 300-1000 RPM

2-30 10-30

Voltage Readin

@ 1000-4000 RPM

90-13645--2 1095 2A-3ELECTRICAL AND IGNITION

WARNING

When testing or servicing the ignition system,
high voltage is present, be extremely cautious!
DO NOT TOUCH OR DISCONNECT any ignition
parts while engine is running, while key switch is
on, or while battery cables are connected.

CAUTION

Failure to comply with the following items may
result in damage to the ignition system.

1. DO NOT reverse battery cable connections.
The battery negative cable is (-) ground.

2. DO NOT “spark” battery terminals with battery
cable connections to check polarity.

3. DO NOT disconnect battery cables while en­gine is running.

4. DO NOT crank engine when switch box is not
grounded to engine.

A process of elimination must be used when checking
the ignition system without a Multi-Meter/DVA Tester
(91-99750) or a voltmeter (capable of measuring 400
volts DC, or higher) and Direct Voltage Adaptor
(91-89045), as the switch box and ignition coils
cannot be thoroughly checked with conventional test
equipment.

All other components can be tested with an
ohmmeter. Before troubleshooting the ignition
system, check the following:

1. Make sure that electrical harness and ignition
switch are not the source of the problem.

2. Check that plug-in connectors are fully engaged
and terminals are free of corrosion.

STATOR TEST

NOTE:

Stator can be tested without removing from

engine.

1. Disconnect stator leads from switch box.

2. Use an ohmmeter and perform the following tests.

IMPORT ANT : If stator is mounted on engine, black
stator lead must be grounded to powerhead when
testing.

9/18/24 AMPERE STATORS (3 CYLINDER)

T est Leads

Between Blue Stator Lead
and Red Stator Lead (Low
Speed)

Between Red Stator Lead and
Engine Ground* (Hi-Speed)

Resistance

(OHMS)

3600-4200

(90-140)

90-140

Scale Reading

(x__________)

3.6-4.2

(R x 1000)

90-140
(R x 1)

9/18/24 AMPERE STATORS (4 CYLINDER)

T est Leads

Between Blue Stator Lead
and Blue/White Stator Lead
(Low Speed)

Between Red Stator Lead and
Red/White Stator Lead* (Hi­Speed)

* Connect test lead to black stator lead if stator is removed from

engine.

NOTE:

Above readings are for a cold engine (room

Resistance

(OHMS)

6800-7600

(90-140)

90-140

Scale Reading

(x__________)

6.8-7.6

(R x 1000)

90-140
(R x 1)

temperature). Resistance will increase slightly, if en­gine is warm.

3. If meter readings are other than specified, replace
stator assembly.

3. Make sure that wire connections are tight and free
of corrosion.

4. Check all electrical components, that are
grounded directly to engine, and all ground wires
to see that they are grounded to engine.

5. Check for disconnected wires, and short and
open circuits.

2A-4 90-13645--2 1095ELECTRICAL AND IGNITION

IGNITION COIL TEST
IMPORT ANT : Ohmmeter tests can only detect cer-

tain faults in the ignition coil. Replace ignition
coil, if ohmmeter readings (listed in chart, follow­ing) are not as specified. If coil tests OK, and coil
is still suspected of being faulty , use Multi-Meter/
DVA Tester (91-99750) or a voltmeter (capable of
measuring 400 volts DC, or higher) and Direct
Voltage Adaptor (91-89045) to thoroughly check
coil.

1. Disconnect wires from coil terminals.

2. Pull spark plug lead out of coil tower.

3. Use an ohmmeter and perform the following tests.

T est Leads

Between (+) and
(–) Coil Terminals

Between Coil Tower and
(–) Coil Terminal

* The primary DC resistance of these coils generally is less than

one (1) OHM. If a reading resembling a short is obtained, this
would be acceptable.

** Copper wire is an excellent conductor, but it will have a notice-

able difference in resistance from cold to hot temperatures.
Reasonable variations from these readings are acceptable.

Resistance

(OHMS)

.02-.04*

800-1100**

Scale Reading
(x__________)

.02-.04*

(R x 1)

8-11**

(R x 100)

T est Leads

Between Brown Trigger Lead
and Black Trigger Lead

Between White Trigger Lead
and Violet Trigger Lead

NOTE:

Above readings are for a cold engine (room

Resistance

(OHMS)

700-1000

700-1000

Scale Reading
(x__________)

7-10

(R x 100)

7-10

(R x 100)

temperature). Resistance will increase slightly, if en­gine is warm.

3. If meter readings are not as specified, replace
trigger.

IGNITION (KEY) SWITCH TEST

1. Disconnect remote control wiring harness and
instrument panel connector.

NOTE:

Wiring diagram for control boxes is located in

SECTION 2D.

2. Set ohmmeter on R x 1 scale for the following
tests:

COMMANDER 2000 KEY SWITCH

4. If meter readings are not as specified, replace
ignition coil.

TRIGGER TEST (3 CYLINDER)

1. Disconnect all trigger leads from switch box.

2. Use an Ohmmeter and perform the following
tests.

T est Leads

Between Brown Trigger Lead
and White/Black Trigger Lead

Between White Trigger Lead
and White/Black Trigger Lead

Between Violet Trigger Lead
and White/Black Trigger Lead

NOTE:

Above readings are for a cold engine (room

Resistance

(OHMS)

1 100-1400

1 100-1400

1 100-1400

Scale Reading
(x__________)

1 1-14

(R x 100)

1 1-14

(R x 100)

1 1-14

(R x 100)

temperature). Resistance will increase slightly, if en­gine is warm.

3. If meter readings are not as specified, replace
trigger.

TRIGGER TEST (4 CYLINDER)

1. Disconnect all trigger leads from switch box.

2. Use an Ohmmeter and perform the following
tests.

23894

COMMANDER KEY SWITCH

BLKD BLACK
PURD PURPLE
REDD RED
YEL D YELLOW

KEY

POSITION

OFF
RUN

START

CHOKE*

* Key switch must be positioned to “RUN” or “STAR T” and key pushed

in to actuate choke, for this continuity test.

BLK BLK/YEL RED YEL/RED PUR YEL/BLK

(BLK/YEL)

(RED)

CONTINUITY SHOULD BE INDICATED

AT THE FOLLOWING POINTS:

•

•

(PUR)

A

(BLK)

M

M

B

C

(YEL/BLK)

••

•

••

•

•

•

•

(YEL/RED)

S

•

•

• •

•

3. If meter readings are other than specified in the
preceding test, verify that switch and not wiring is
faulty. If wiring checks OK, replace switch.

90-13645--2 1095 2A-5ELECTRICAL AND IGNITION

Ignition Components

INSTALLATION

Removal and Installation

Flywheel

REMOVAL

1. Remove flywheel cover from engine.

WARNING

Engine could possibly start when turning flywheel
during removal and installation; therefore,
disconnect (and isolate) spark plug leads from
spark plugs to prevent engine from starting.

2. Disconnect spark plug leads from spark plugs.

3. While holding flywheel with Flywheel Holder
(91-52344), remove flywheel nut and washer.

WARNING

Engine could possibly start when turning flywheel
during installation; therefore, disconnect (and
isolate) spark plug leads from spark plugs to
prevent engine from starting.

1. Disconnect spark plug leads from spark plugs.

2. Place flywheel key into slot in crankshaft.

a

a

51123

a - Flywheel Holder (91-52344)

4. Install Crankshaft Protector Cap (91-24161) on
the end of crankshaft, then install Flywheel Puller
(91-73687A1) into flywheel.

5. Remove flywheel.

NOTE:

wheel to aid in removal as damage to flywheel or elec­trical components under flywheel may result.

Neither heat or hammer should be used on fly-

a

b

51123

a - Flywheel Key

3. Align slot in flywheel center bore with flywheel key
and install flywheel onto crankshaft.

4. Install washer and locknut.

5. Hold flywheel with Flywheel Holder (91-52344);
torque locknut to 120 lb. ft. (162.7 Nm).

a

51123

a - Flywheel Holder (91-52344)

6. Install flywheel cover.

51124

a - Flywheel Puller
b - Flywheel

2A-6 90-13645--2 1095ELECTRICAL AND IGNITION

Stator

REMOVAL

1. Remove flywheel; refer to “Flywheel Removal.”

2. Remove screws.

a

INSTALLATION

1. Install stator as shown.

a

51123

a - Screws

3. Remove starter motor as outlined in Section 2B.

4. Remove sta-strap.

5. Disconnect stator leads from switch box and re­move stator.

b

a - Screws; apply Loctite Grade “A” on threads (unless Patch

Screw used) and torque to 60 lbs. in. (6.6 Nm)

b - Stator

51124

2. Connect stator leads; refer to wiring diagrams in
Section 2D.

3. Install sta-strap.

4. Install starter motor; refer to Section 2B.

a - Sta-Strap

90-13645--2 1095 2A-7ELECTRICAL AND IGNITION

a

19453

a

19453

a - Sta-Strap

5. Install flywheel; refer to “Flywheel Installation”,
preceding.

Trigger

REMOVAL

1. Remove flywheel and stator; refer to “Flywheel”
and “Stator” removal, preceding.

2. Disconnect link arm and remove trigger.

b

a

19459

a - Link Arm
b - Trigger

3. Remove starter motor; refer to Section 2B.

4. Remove sta-strap.

INSTALLATION

1. Install trigger and connect link arm.

a

b

19459

a - Trigger
b - Link Arm

2. Connect trigger leads to switch box; refer to wiring
diagrams in Section 2D.

3. Install sta-strap.

4. Install starter motor; refer to Section 2B.

5. Disconnect trigger leads from switch box and re­move trigger.

a

19453

a - Sta-strap

a

19453

a - Sta-strap

5. Install stator; refer to “Stator Installation,”
preceding.

6. Install flywheel; refer to “Flywheel Installation,”
preceding.

2A-8 90-13645--2 1095ELECTRICAL AND IGNITION

Ignition Coils (3 Cylinder Models)

Ignition Coils (4 Cylinder Models)

1. Refer to wiring diagrams in Section 2D when con­necting wires.

cd

e

a

b

c

a - Coils
b - Cover
c - Hex Nuts; Torque to 30 lb. in. (3.4 N·m),coat with Quicksilver

Liquid Neoprene
d - Bolts; torque to 20 lb. in. (2.3 Nm)
e - Coil Tower Boots; form a water tight seal between coil tower

and spark plug lead using Quicksilver Insulating Compound

d

19455

1. Refer to wiring diagrams in Section 2D when con­necting wires.

c

e

a

d

b

c

a - Coils
b - Cover
c - Hex Nuts; Torque to 30 lb. in. (3.4 N·m), coat with Quicksilver

Liquid Neoprene
d - Bolts; torque to 20 lb. in. (2.3 Nm)
e - Coil Tower Boots; form a water tight seal between coil tower

and spark plug lead using Quicksilver Insulating Compound

25931

90-13645--2 1095 2A-9ELECTRICAL AND IGNITION

Switch Box

1. Refer to wiring diagrams in Section 2D when con­necting wires.

f

a

e

b
d

b

cd

a - Switch Box
b - Bushings
c - J-Clip
d - Bolt [Torque to 40 lb. in. (4.5 N·m)]
e - Screw (Secure coil ground wires under screw)
f - Coil Ground Wires (BLACK)

19454

2A-10 90-13645--2 1095ELECTRICAL AND IGNITION

ELECTRICAL AND
IGNITION

2

B

11669

BATTERY, CHARGING SYSTEM, AND
STARTING SYSTEM

Table of Contents

Battery 2B-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Precautions 2B-1. . . . . . . . . . . . . . . . . . . . . . . . . .

Recommended Battery 2B-1. . . . . . . . . . . . . . . .

Operating Engine without Battery 2B-1. . . . . . .

Specific Gravity Readings 2B-2. . . . . . . . . . . . . .

Specific Gravity Cell

Comparison Test 2B-2. . . . . . . . . . . . . . .

Electrolyte Level 2B-2. . . . . . . . . . . . . . . . . . . . . .

Charging a Discharged Battery 2B-3. . . . . . . . .

Winter Storage of Batteries 2B-3. . . . . . . . . . . . .

Optional Voltage

Regulator Test 2B-4. . . . . . . . . . . . . . . . . . . . . . . .

Battery Charging System

(9 Ampere Alternator) 2B-4. . . . . . . . . . . . . . . . .

Description 2B-4. . . . . . . . . . . . . . . . . . . . . . . . . . .

Models Equipped with Rectifier 2B-4. . . . . .

Models Equipped with Regulator 2B-4. . . . .

Battery Charging System

Troubleshooting 2B-5. . . . . . . . . . . . . . . . . . .

Stator Ohms Test

(Alternator Coils Only) 2B-5. . . . . . . . . . . . . .

Standard Stator (Alternator Coils)

9 Amperes Output 2B-6. . . . . . . . . . . . . . . . .

16 Amp Alternator System Test 2B-6. . . . . . . . .

(Large Finned Voltage

Regulator/Rectifier) 2B-6. . . . . . . . . . . . .

16 Ampere Alternator System Test 2B-7. . . . . .

(Small Voltage Regulator/Rectifier) 2B-7. . .

Optional 24 Amp Alternator System Test 2B-7.

(Large Finned Voltage

Regulator/Rectifier) 2B-7. . . . . . . . . . . . .

Tachometer Terminal Block (Design 1) 2B-8. . .

Description 2B-8. . . . . . . . . . . . . . . . . . . . . . .

Testing Tachometer Terminal Block

(Design 1) 2B-8. . . . . . . . . . . . . . . . . . . . .

Tachometer Terminal Block (Design 2) 2B-8. . .

Description 2B-8. . . . . . . . . . . . . . . . . . . . . . .

Tachometer Terminal Block

(Design 1 and 2) 2B-8. . . . . . . . . . . . . . . . . . .

Removal 2B-8. . . . . . . . . . . . . . . . . . . . . . . . . .

Installation 2B-8. . . . . . . . . . . . . . . . . . . . . . . .

Page Page

3 Cylinder 16 and 24 Ampere Battery

Charging Wiring Diagram 2B-9. . . . . . . . . . .

3 Cylinder 16 Ampere Battery Charging

Wiring Diagram (with Small Voltage

Regulator/Rectifier) 2B-10. . . . . . . . . . . . . . . .

4 Cylinder 16 and 24 Ampere Battery

Charging Wiring Diagram 2B-11. . . . . . . . . . .

4 Cylinder 16 Ampere Battery Charging

Wiring Diagram (with Small Voltage

Regulator/Rectifier) 2B-12. . . . . . . . . . . . . . . .

3 Cylinder Battery Charging Diagram

with Battery Isolator 2B-13. . . . . . . . . . . . . . . .

3 Cylinder Battery Charging Diagram

with Battery Isolator (Small Voltage

Regulator) 2B-14. . . . . . . . . . . . . . . . . . . . . . . .

4 Cylinder Battery Charging Diagram

with Battery Isolator 2B-15. . . . . . . . . . . . . . . .

4 Cylinder Battery Charging Diagram

with Battery Isolator (Small Voltage

Regulator) 2B-16. . . . . . . . . . . . . . . . . . . . . . . .

Rectifier Test 2B-17. . . . . . . . . . . . . . . . . . . . . . . . .

Starting System 2B-18. . . . . . . . . . . . . . . . . . . . . . . . . .

Starting System Components 2B-18. . . . . . . . . . .

Description 2B-18. . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting the Starting Circuit 2B-18. . . . .

Starting Circuit Troubleshooting

Flow Chart 2B-19. . . . . . . . . . . . . . . . . . . . . . . .

Starter Motor 2B-21. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Removal 2B-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Disassembly 2B-21. . . . . . . . . . . . . . . . . . . . . . . . .

Starter Cleaning, Inspection and Testing 2B-22.

Cleaning and Inspection 2B-22. . . . . . . . . . . .

T esting 2B-22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Armature Test for Shorts 2B-22. . . . . . . . . . . .

Armature Test for Ground 2B-22. . . . . . . . . . .

Checking Positive Brushes and

Terminal 2B-23. . . . . . . . . . . . . . . . . . . . . . .

Testing Negative Brushes for

Ground 2B-23. . . . . . . . . . . . . . . . . . . . . . .

Starter Solenoid Test 2B-23. . . . . . . . . . . . . . .

Brush Replacement 2B-24. . . . . . . . . . . . . . . . . . .

Starter Reassembly 2B-24. . . . . . . . . . . . . . . .

Installation 2B-26. . . . . . . . . . . . . . . . . . . . . . . . . . .

90-13645--2 495

Battery

Recommended Battery

Precautions

When charging batteries, an explosive gas mixture
forms in each cell. A portion of this gas escapes thru
holes in vent plugs and may form an explosive atmo­sphere around battery if ventilation is poor. This ex­plosive gas may remain in or around battery for sever­al hours after it has been charged. Sparks or flames
can ignite this gas and cause an internal explosion
which may shatter the battery.

The following precautions should be observed to pre­vent an explosion.

1. DO NOT smoke near batteries being charged or
which have been charged very recently.

2. DO NOT break live circuits at terminals of batter­ies because a spark usually occurs at the point
where a live circuit is broken. Always be careful
when connecting or disconnecting cable clamps
on chargers. Poor connections are a common
cause of electrical arcs which cause explosions.

3. DO NOT reverse polarity of battery cables on bat­tery terminals.

The 2-cycle Outboard type engine requires a 12 volt
battery with a “Cold Cranking Amperage” rating for
cranking and a “Reserve Capacity” rating. The mini­mum should be a “Cold Cranking Amperage” of 350
amperes and a “Reserve Capacity” of 100 minutes for
engines outlined in this manual.

Operating Engine Without Battery

If desired (or in an emergency), engines equipped
with an alternator can be started and operated with­out a battery (either disconnected or removed) if
“Warning”, below, is followed.

2B-190-13645--2 495 ELECTRICAL AND IGNITION

Specific Gravity Readings

Use a hydrometer to measure specific gravity of elec­trolyte in each cell.

a

22532

a - Hydrometer

Hydrometer measures percentage of sulphuric acid
in battery electrolyte in terms of specific gravity. As a
battery drops from a charged to a discharged condi­tion, acid leaves the solution and chemically com­bines with the plates, causing a decrease in specific
gravity of electrolyte. An indication of concentration of
electrolyte is obtained with a hydrometer.

When using a hydrometer, observe the following
points:

1. Hydrometer must be clean (inside and out) to in­sure an accurate reading.

2. Never take hydrometer readings immediately af­ter water has been added. Water must be thor­oughly mixed with electrolyte by charging for at
least 15 minutes at a rate high enough to cause
vigorous gassing.

3. If hydrometer has built-in thermometer, draw liq­uid in several times to ensure correct temperature
before taking reading.

5. Avoid dropping electrolyte on boat or clothing, as
it is extremely corrosive. Wash off immediately
with baking soda solution.

Specific gravity of electrolyte varies not only with per­centage of acid in liquid but also with temperature. As
temperature drops, electrolyte contracts, so that spe­cific gravity increases. Unless these variations in spe­cific gravity are taken into account, specific gravity ob­tained by hydrometer may not give a true indication
of concentration of acid in electrolyte.

A fully charged battery will have a specific gravity
reading of approximately 1.270 at an electrolyte
temperature of 80 F (27 C). If electrolyte tempera­ture is above or below 80 F , additions or subtractions
must be made in order to obtain a hydrometer reading
corrected to 80 F standard. For every 10 F (3.3 C)
above 80 F, add 4 specific gravity points (.004) to
hydrometer reading. Example: A hydrometer reading
of 1.260 at 110 F (43 C) would be 1.272 corrected
to 80 F, indicating a fully charged battery.

For every 10 below 80 F, subtract 4 points (.004)
from the reading. Example: A hydrometer reading of

1.272 at 0 F (–18 C) would be 1.240 corrected to

80 F, indicating a partially charged battery.

SPECIFIC GRAVITY CELL COMPARISON TEST

This test may be used when an instrumental tester is
not available. To perform this test, measure specific
gravity of each cell, regardless of state of charge, and
interpret results as follows: If specific gravity readings
show a difference between highest and lowest cell of
.050 (50 points) or more, battery is defective and
should be replaced.

Electrolyte Level

Check electrolyte level in battery regularly. A battery
in use in hot weather should be checked more fre­quently because of more rapid loss of water. If electro­lyte level is found to be low, then distilled water should
be added to each cell until liquid level rises approxi­mately 3/16″ (4.8mm) over plate. DO NOT OVER­FILL, because this will cause loss of electrolyte and
result in poor performance, short life and excessive
corrosion.

4. Hold hydrometer vertically and draw in just
enough liquid from battery cell so that float is free­floating. Hold hydrometer at eye level so that float
is vertical and free of outer tube, then take reading
at surface of liquid. Disregard curvature where liq­uid rises against float stem due to capillary action.

2B-2 90-13645--2 495ELECTRICAL AND IGNITION

Charging a Discharged Battery

The following basic rules apply to any battery charg­ing situation:

1. Any battery may be charged at any rate (in am­peres) as long as spilling of electrolyte (from vio­lent gassing) does not occur and as long as elec­trolyte temperature does not exceed 125 F
(52 C). If spewing of electrolyte occurs, or if elec­trolyte temperature exceeds 125 F , charging rate
(in amperes) must be reduced or temporarily
halted to avoid damage to the battery.

2. Battery is fully charged when, over a 2-hour peri­od at a low charging rate (in amperes), all cells are
gassing freely (not spewing liquid electrolyte),
and no change in specific gravity occurs. Full
charge specific gravity is 1.260-1.275, corrected
for electrolyte temperature with electrolyte level at
3/16″ (4.8mm) over plate. For most satisfactory
charging, lower charging rates in amperes are
recommended.

3. If, after prolonged charging, specific gravity of at
least 1.230 on all cells cannot be reached, battery
is not in optimum condition and will not provide op­timum performance; however, it may continue to
provide additional service, if it has performed sat­isfactorily in the past.

4. To check battery voltage while cranking engine
with electric starter motor, place red (+) lead of
tester on positive (+) battery terminal and black (–)
lead of tester on negative (–) battery terminal. If
the voltage drops below 9-1/2 volts while crank­ing, the battery is weak and should be recharged
or replaced.

1. Remove battery from its installation as soon as
possible and remove all grease, sulfate and dirt
from top surface by running water over top of bat­tery . Be sure, however, that vent caps are tight be­forehand, and blow off all excess water thorough­ly with compressed air. Check water level, making
sure that plates are covered.

2. When adding distilled water to battery, be ex­tremely careful not to fill more than 3/16″ (4.8mm)
over plate inside battery. Battery solution or elec­trolyte expands from heat caused by charging.
Overfilling battery will cause electrolyte to over­flow (if filled beyond 3/16″ over plate).

3. Grease terminal bolts well with Quicksilver 2-4-C
w/teflon, and store battery in COOL-DRY place.
Remove battery from storage every 30-45 days,
check water level (add water if necessary), and
put on charge for 5 or 6 hours at 6 amperes. DO
NOT FAST CHARGE.

4. If specific gravity drops below 1.240, check bat­tery for reason, and then recharge. When gravity
reaches 1.260, discontinue charging. To check
specific gravity, use a hydrometer, which can be
purchased locally.

5. Repeat preceding charging procedure every
30-45 days, as long as battery is in storage. When
ready to place battery back in service, remove ex­cess grease from terminals (a small amount is de­sirable on terminals at all times), recharge again
as necessary and reinstall battery.

Winter Storage of Batteries

Battery companies are not responsible for battery
damage, either in winter storage or in dealer stock, if
the following instructions are not observed:

2B-390-13645--2 495 ELECTRICAL AND IGNITION

Optional Voltage

Battery Charging System

Regulator Test

1. Check battery voltage at
battery with engine running.

2. If battery voltage is above 14.5 volts, replace volt­age regulator. Check condition of battery as over­charging may have damaged battery.

3. If battery voltage is below 14.5 volts, charge bat­tery; refer to “Charging a Discharged Battery”,
preceding. If battery can NOT be satisfactorily
charged, replace battery.

4. If battery accepts a satisfactory charge, check
battery voltage while cranking engine; refer to
“Charging a Discharged Battery”, preceding. If
cranking voltage is not acceptable, replace bat­tery.

5. If cranking voltage is acceptable, disconnect end
of RED wire (located between rectifier (+) terminal
and starter solenoid) from rectifier. Secure RED
wire (from voltage regulator) to rectifier (+) termi­nal with hex nut.

6. Connect RED (+) ammeter lead to (+) terminal of
rectifier and BLACK (–) ammeter lead to RED wire
(disconnected in last step).

IMPORT ANT: For accurate test results the voltage
at battery with engine running, in next step, must
be 13.5 volts or less. It may be necessary to oper­ate electrical accessories to drop voltage to 13.5
volts or less.

(9 Ampere Alternator)

Description

The battery charging system components are the sta­tor, rectifier, and battery. Alternating current (gener­ated in stator alternator coils) flows to the rectifier,
which changes the alternating current to direct cur­rent for charging the battery.

MODELS EQUIPPED WITH RECTIFIER

a

b

c

a - Stator
b - Rectifier
c - Battery

MODELS EQUIPPED WITH REGULATOR

a

7. Run engine at 3000 RPM.

8. Meter should read between 7 - 9 amperes.

9. If meter reads 7 - 9 amperes, this indicates the
charging system is functioning properly and the
battery is being discharged because the amper­age draw on the system is greater than the amper­age output of the system.

NOTE:

the ammeter should indicate the following approxi­mate amperes:

10. If the meter reads less than 7 amperes, test the

2B-4 90-13645--2 495ELECTRICAL AND IGNITION

With engine running at the following RPM’S,

RPM AMPERES

IDLE 1
1000 4
2000 8
3000 9

stator; refer to “Standard Stator (Alternator Coils)
Amperes Output”, following. If stator tests OK, re­place voltage regulator.

a - Stator
b - Regulator
c - Battery

The charging system may be damaged by: 1) re­versed battery cables, 2) running the engine with bat­tery cables disconnected and stator leads connected
to rectifier, and 3) an open circuit, such as a broken
wire or loose connection.

b

c

Battery Charging System
Troubleshooting

A fault in the battery charging system usually will
cause the battery to become undercharged. Check
battery electrolyte level, and charge battery. See
“Electrolyte Level”, and “Charging a Discharged
Battery”.

If battery will NOT accept a satisfactory charge, re­place battery.

If battery accepts a satisfactory charge, determine
the cause of the charging system problem as follows.

1. Check for correct battery polarity [RED cable to
positive (+) battery terminal]. If polarity was incor­rect, check for damaged rectifier. See “Rectifier
Test”, following.

2. Check for loose or corroded battery connections.

3. Visually inspect wiring between stator and battery
for cuts, chafing; and disconnected, loose or cor­roded connection.

4. Excessive electrical load (from too many acces­sories) will cause battery to run down.

If visual inspection determines that battery connec­tions and wiring are OK, perform the following stator
and rectifier tests.

Stator Ohms Test
(Alternator Coils Only)

2. Use an ohmmeter and perform the following test.

IMPORT ANT : If stator is mounted on engine, black
stator lead (if provided) must be grounded to pow­erhead when testing.

3. Replace stator if readings are outside ranges
shown.

Scale

Reading

(x

.6 – 1.1*

(R x 1)

No

Continuity

(R x 1000)

.17 – .19

(R x 1)

No

Continuity

(R x 1000)

.05 – .15

(R x 1)

No

Continuity

(R x 1000)

)

Test Leads

9 AMPERE STATOR

Between YELLOW
stator leads

Between either
YELLOW stator lead
and engine ground**

16 AMPERE STATOR

Between YELLOW
stator leads

Between either
YELLOW stator lead
and engine ground**

24 AMPERE STATOR

Between YELLOW
stator leads

Between either
YELLOW stator lead
and engine ground**

Resistance

(Ohms)

.6 – 1.1*

No

Continuity

.17 – .19

No

Continuity

.05 – .15

No

Continuity

NOTE:

engine.

1. Disconnect both YELLOW (stator leads) from ter-

Stator can be tested without removing from

minals on rectifier (or terminal block).

* DC resistance of these windings generally is less

than 1.5 ohms. If a reading (resembling a short) is
obtained, this would be acceptable.

** If stator is removed from engine, connect test lead

to black stator lead, if provided.

4. If meter readings are other than specified, replace
stator.

2B-590-13645--2 495 ELECTRICAL AND IGNITION

Standard Stator (Alternator Coils)
9 Amperes Output

IMPORTANT: Rectifier must be functioning prop­erly for accurate test results to be obtained.

1. If engine is equipped with a voltage regulator,
disconnect voltage regulator leads at rectifier;
reinstall hex nut on rectifier terminal that has
yellow stator lead.

2. Remove red wire from (+) terminal of rectifier.

3. Connect RED (+) ammeter lead to rectifier (+) termi­nal and BLACK (–) ammeter lead to red rectifier
wire.

4. Run engine at 3000 RPM.

5. Meter should read 7 - 9 amperes; if not, replace
stator.

9. With engine running at the indicated RPM’s, the
ammeter should indicate the following approxi­mate amperes:

RPM

IDLE
1000
2000
3000

AMPERES

2
10
17
18

10. If ammeter indicates approximately 18 amperes
at 3000 RPM, this indicates the charging system
is functioning properly and the battery is being
discharged because the amperage draw on the
system is greater than the amperage output of the
system.

11. If ammeter reads less than 18 amperes, test the
stator; refer to “Stator Ohms Test (Alternator Coils
Only)” [18 Ampere Stator], preceding. If stator
tests OK, replace voltage regulator/rectifier.

16 Amp Alternator System Test

(LARGE FINNED VOLTAGE
REGULATOR/RECTIFIER)

1. Check battery voltage at battery with engine
running.

2. If battery voltage is above 14.5 volts, replace volt­age regulator/rectifier. Check condition of battery
as overcharging may have damaged battery.

3. If battery voltage is below 14.5 volts, charge bat­tery; refer to “Charging a Discharged Battery”,
preceding. If battery can NOT be satisfactorily
charged, replace battery.

4. If battery accepts a satisfactory charge, check
battery voltage while cranking engine; refer to
“Charging a Discharged Battery”, preceding. If
cranking voltage is not acceptable, replace battery.

5. If cranking voltage is acceptable, disconnect RED
harness wire from center terminal.

6. Secure RED wire (d) on terminal (c) using hex nut.

7. Connect RED (+) ammeter lead to terminal (c)
and BLACK (–) ammeter lead to RED harness
wire (b).

c

b

d

a

a - Voltage Regulator/Rectifier
b - RED Harness Wire

NOTE:

If one or more of the 3 terminals on the termi-

c - Center Terminal
d - RED Sense Lead

nal block are shorted to ground, the battery charging
system output will be reduced.

21619

a

8. Secure wires away from flywheel.

IMPORT ANT: For accurate test results the voltage
at battery with engine running, in next step, must
be 13.5 volts or less. It may be necessary to oper­ate electrical accessories to drop voltage to 13.5
volts or less.

a - Terminal Block

2B-6 90-13645--2 495ELECTRICAL AND IGNITION

26001

16 Ampere Alternator System Test

Optional 24 Amp Alternator System Test

(SMALL VOLTAGE REGULATOR/RECTIFIER)

1. Check battery voltage at battery with engine run­ning.

2. If battery voltage is above 14.5 volts, replace volt­age regulator/rectifier. Check condition of battery
as overcharging may damage battery.

3. If battery voltage is below 14.5 volts, charge bat­tery; refer to “Charging a Discharged Battery”,
preceding. If battery can NOT be satisfactorily
charged, replace battery.

4. If battery accepts a satisfactory charge, check
battery voltage while cranking engine; refer to
“Charging a Discharged Battery”, preceding. If
cranking voltage is not acceptable, replace battery.

5. If cranking voltage is acceptable, disconnect larg­er diameter Red wire from ST ARTER SOLENOID
terminal.

6. Remove smaller diameter RED wire (SENSE
LEAD) from STARTER SOLENOID terminal and
connect to the POSITIVE (+) terminal of a 9 VOL T
transistor battery. Ground the NEGATIVE (–) ter­minal of the 9 VOLT battery to the engine.

7. Connect RED (+) ammeter lead to larger diameter
RED wire, and BLACK (–) ammeter lead to POS­ITIVE terminal on STARTER SOLENOID.

8. Secure wires away from flywheel.

9. With engine running at the indicated RPM’s, the
ammeter should indicate the following approxi­mate amperes:

RPM

IDLE
1000
2000
3000

10. A reading of 18 amperes at 3000 RPM indicates
the charging system is functioning properly. The
battery is discharging due to the amperage draw
on the system is greater than the amperage out­put of the engine charging system.

AMPERES

2
10
17
18

(LARGE FINNED VOLTAGE
REGULATOR/RECTIFIER)

1. Check battery voltage at battery with engine
running.

2. If battery voltage is above 14.5 volts, replace volt­age regulator/rectifier (a). Check condition of bat­tery as overcharging may have damaged battery.

3. If battery voltage is below 14.5 volts, charge bat­tery; refer to “Charging a Discharged Battery”,
preceding. If battery can NOT be satisfactorily
charged, replace battery.

4. If battery accepts a satisfactory charge, check
battery voltage while cranking engine; refer to
“Charging a Discharged Battery”, preceding. If
cranking voltage is not acceptable, replace battery.

5. If cranking voltage is acceptable, disconnect RED
harness wire (b) from terminal (c).

6. Secure RED wire (d) on terminal (c) using hex nut.

7. Connect RED (+) ammeter lead to terminal (c)
and BLACK (–) ammeter lead to RED harness
wire (b).

8. Secure wires away from flywheel.

IMPORT ANT: For accurate test results the voltage
at battery with engine running, in next step, must
be 13.5 volts or less. It may be necessary to oper­ate electrical accessories to drop voltage to 13.5
volts or less.

9. Run engine at 3000 RPM.

10. Meter should read 20 or more amperes.

1 1. If meter reads 20 or more amperes, this indicates

the charging system is functioning properly and
the battery is being discharged because the am­perage draw on the system is greater than the am­perage output of the system.

12. If meter reads less than 20 amperes, test the sta­tor; refer to “Optional 24 Amp Stator (Alternator
Coils) Amperes Output”, following. If stator tests
OK, replace voltage regulator rectifier (a).

11. If ammeter reads less than 18 amperes, test the
stator; refer to “Stator Ohms Test (Alternator Coils
Only)”, [18 Ampere Stator], preceding. If stator
tests OK, replace voltage regulator/rectifier.

b

c

d

a

21619

2B-790-13645--2 495 ELECTRICAL AND IGNITION

Tachometer Terminal Block (Design 1)

DESCRIPTION

Contains a diode which blocks high voltage AC
pulses (180 VAC) coming from the stator and allows
low voltage DC pulses (20-30 VDC) to pass through
to be counted by the tachometer. This terminal block
(with diode) is only used with large, finned type regu­lators. This block is BLACK in color.

WARNING

HIGH VOLTAGE is present at the tachometer
block’s stator side terminals, while the outboard
is running. To avoid electrical shock, physical
contact should not be made on these terminals or
ANY IGNITION RELATED COMPONENT WHILE
THE OUTBOARD IS RUNNING.

IMPORT ANT : The following ohm test is used to de­termine the proper functioning of the diode lo­cated in the tachometer block. If the diode is
OPEN (NO CONTINUITY IN EITHER DIRECTION),
the tachometer will be inoperative.

TESTING TACHOMETER TERMINAL BLOCK
(DESIGN 1)

With outboard NOT running, remove all leads from
block. Using an ohmmeter, test block as shown, fol­lowing. Continuity should be observed on the ohm­meter with the needle swinging in only ONE direction.
NO CONTINUITY should be observed when test
leads are reversed. If CONTINUITY is observed in
BOTH directions or NO CONTINUITY is observed in
either direction when leads are reversed, diode is de­fective and MUST BE REPLACED.

NOTE:

eter block. It may be located either between the cen­ter (TACH) terminal and the top (AL T) terminal or be­tween the center (T ACH) terminal and the lower (AL T)
terminal.

There is only one diode located in the tachom-

ALT YEL

GREY

TACH

ALT YEL

50644

Tachometer Terminal Block (Design 2)

DESCRIPTION

This block is a junction point for stator and tachometer
signal wiring. It contains no electrical components.
This block is LIGHT GREY in color and is to be used
ONLY with small, non-finned voltage regulators. No
test is required for this terminal block.

Tachometer Terminal Block
(Design 1 and 2)

REMOVAL

1. Remove two YELLOW alternator wires from
block.

2. Remove GREY tachometer wire from block.

3. Remove two attaching screws and remove diode
block.

INSTALLATION

1. Secure diode block to powerhead with two
screws. Torque screws to 30 lb. in. (3.4 Nm).

2. Attach two YELLOW wires to “ALT YEL”
terminals.

3. Attach GREY wire to “GREY TACH” terminal.

ALT YEL

GREY

TACH

ALT YEL

50644

2B-8 90-13645--2 495ELECTRICAL AND IGNITION

3 Cylinder 16 and 24 Ampere Battery
Charging Wiring Diagram

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK
BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

h

a

g

f

a - Stator
b - Terminal Block
c - ToTachometer
d - Voltage Regulator/Rectifier

b

c

d

e

50405
e - To Remote Control Harness
f - 20 Ampere Fuse
g - To Battery
h - Starter Solenoid

2B-990-13645--2 495 ELECTRICAL AND IGNITION

3 Cylinder 16 Ampere Battery
Charging Wiring Diagram (with Small
Voltage Regulator/Rectifier)

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

h

BLK

YEL

a

YEL

g

a - Stator
b - Terminal Block
c - ToTachometer
d - Votage Regulator/Rectifier

YEL

GRY

YEL

b

c

GRY

BLK

RED

RED

RED

RED

BLK

f

d

e

GRY

YEL

YEL

RED

RED

51000
e - To Remote Control Harness
f - 20 Ampere Fuse
g - Battery (+) Positive Terminal
h - Starter Solenoid

90-13645--2 4952B-10 ELECTRICAL AND IGNITION

4 Cylinder 16 and 24 Ampere Battery
Charging Wiring Diagram

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

h

a

g

f

a - Stator
b - Terminal Block
c - ToTachometer
d - Voltage Regulator/Rectifier

b

c

d

e

50406
e - To Remote Control Harness
f - 20 Ampere Fuse
g - Battery (+) Positive Terminal
h - Starter Solenoid

2B-1190-13645--2 495 ELECTRICAL AND IGNITION

4 Cylinder 16 Ampere Battery
Charging Wiring Diagram (with Small
Voltage Regulator/Rectifier)

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

h

a

YEL

YEL

g

f

a - Stator
b - Terminal Block
c - ToTachometer
d - Voltage Regulator/Rectifier

RED

e

RED

RED

b

GRYRED

c

GRY

YEL

YEL

YEL

YEL

RED

RED

e - To Remote Control Harness
f - 20 Ampere Fuse
g - Battery (+) Positive Terminal
h - Starter Solenoid

d

GRY

51001

90-13645--2 4952B-12 ELECTRICAL AND IGNITION

3 Cylinder Battery Charging Diagram
with Battery Isolator

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

j

a

b

c

i

h

Move Red Lead From
Start Solenoid to
Position Shown

d

g

Start

Battery

e

User Supplied Red Lead
(10 Gauge Minimum Diameter
with Protective Abrasive Sleeve
Installed)

f

Move Lead From Red
Stud to Position Shown

Screw Size
#10-16x3/8”
P/N 10-62568

a - Stator
b - Terminal Block
c - To Tachometer
d - Voltage Regulator/Rectifier
e - Battery Isolator

50403
f - Auxiliary Battery
g - Start Battery
h - To Remote Control Harness
i - 20 Ampere Fuse
j - Starter Solenoid

2B-1390-13645--2 495 ELECTRICAL AND IGNITION

3 Cylinder Battery Charging Diagram
with Battery Isolator (Small Voltage
Regulator)

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

j

a

YEL

YEL

BLK

g

a - Stator
b - Terminal Block
c - To Tachometer
d - Voltage Regulator/Rectifier
e - Battery Isolator

RED

RED

RED

h

RED

i

B1

B2

YEL

b

GRY

YEL

GRY

c

BLK

BLK

Small

Red

(Sense)Lead

d

RED

A

GRY

YEL

YEL

e

Large Red

(Output) Lead

RED

RED

f

51051
f - Auxiliary Battery
g - Start Battery
h - To Remote Control Harness
i - 20 Ampere Fuse
j - Starter Solenoid

90-13645--2 4952B-14 ELECTRICAL AND IGNITION

4 Cylinder Battery Charging Diagram
with Battery Isolator

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

j

a

b

c

i

h

Move Red Lead From
Start Solenoid to
Position Shown

d

g

e

User Supplied Red Lead
(10 Gauge Minimum Diameter
with Protective Abrasive Sleeve
Installed)

f

Screw Size
#10-16x3/8”
P/N 10-62568

Move Lead From Red
Stud to Position Shown

a - Stator
b - Terminal Block
c - To Tachometer
d - Voltage Regulator/Rectifier
e - Battery Isolator

50404
f - Auxiliary Battery
g - Start Battery
h - To Remote Control Harness
i - 20 Ampere Fuse
j - Starter Solenoid

2B-1590-13645--2 495 ELECTRICAL AND IGNITION

4 Cylinder Battery Charging Diagram
with Battery Isolator (Small Voltage
Regulator)

IMPORTANT: After electrical connections are
made, coat all terminal connections using Quick­silver Liquid Neoprene (92-25711), to avoid corro­sion.

BLK BLACK

BLU BLUE
GRY  GRAY
RED RED

YEL YELLOW

j

a

YEL

YEL

g

a - Stator
b - Terminal Block
c - To Tachometer
d - Voltage Regulator/Rectifier
e - Battery Isolator

RED

RED

RED

h

RED

i

B1

B2

b

GRY

c

YEL

YEL

GRY

d

GRY

YEL

YEL

RED

RED

Small

Red (Sense)

Lead

RED

A

e

Large Red

(Output) Lead

f

51050
f - Auxiliary Battery
g - Start Battery
h - To Remote Control Harness
i - 20 Ampere Fuse
j - Starter Solenoid

90-13645--2 4952B-16 ELECTRICAL AND IGNITION

Rectifier Test

WARNING

Disconnect battery leads from battery before
testing rectifier.

d

a

c

b

f

NOTE:

Rectifier can be tested without removing from

engine.

1. Disconnect all wires from terminals on rectifier.

2. Use an ohmmeter (R x 1000 scale) and perform
the following test. Refer to illustration for rectifier
terminal identification.

Rectifier Test

Connect RED meter lead to ground,
BLACK lead alternately to terminals “a”
and “c”.

Continuity Indicated.
Connect BLACK meter lead to ground,
RED lead alternately to terminals “a”
and “c”.

a - Terminal
b - Terminal
c - Terminal

e

07300

d - Stator Terminals
e - Positive Terminal
f - Ground

No Continuity Indicated.
Connect BLACK meter lead to ground,
RED lead alternately to terminals “a”
and “c”.

No Continuity Indicated.
Connect BLACK meter lead to terminal “b”,
RED lead alternately to terminals “a” and
“c”.

No Continuity Indicated.

Replace Rectifier.

Continuity Indicated.
Connect RED meter lead to terminal “b”,
BLACK lead alternately to terminals “a” and
“c”.

Continuity Indicated.

Replace Rectifier.

No Continuity Indicated.

Rectifier tests OK.

Continuity Indicated.

Replace Rectifier.

Continuity Indicated.

Replace Rectifier.

Connect BLACK meter lead to terminal “b”,
RED lead alternately to terminals “a” and
“c”.

No Continuity Indicated.

Replace Rectifier.

Connect RED meter lead to terminal “b”,
BLACK lead alternately to terminals “a” and
“c”.

No Continuity Indicated.

Replace Rectifier.

Continuity Indicated.

No Continuity Indicated.

Continuity Indicated.

Rectifier tests OK.

2B-1790-13645--2 495 ELECTRICAL AND IGNITION

Starting System

Starting System Components

The starting system consists of the following compo­nents:

1. Battery

2. Starter Solenoid

3. Neutral Start Switch

4. Starter Motor

CAUTION

The starter motor may be damaged if operated
continuously. DO NOT operate continuously for
more than 30 seconds. Allow a 2 minute cooling
period between starting attempts.

Troubleshooting the Starting Circuit

Before beginning the starting circuit troubleshooting
flow chart, following, check first for the following
conditions:

5. Ignition Switch

Description

The function of the starting system is to crank the en­gine. The battery supplies electrical energy to crank
the starter motor. When the ignition switch is turned
to “Start” position, the starter solenoid is activated
and completes the starting circuit between the battery
and starter.

The neutral start switch opens the start circuit when
the shift control lever is not in neutral. This prevents
accidental starting when engine is in gear.

1. Make sure that battery is fully charged.

2. Check that control lever is in “neutral” position.

3. Check terminals for corrosion and loose connec­tions.

4. Check cables and wiring for frayed and worn in­sulation.

5. Check in-line fuse in red wire; see diagram.

2B-18 90-13645--2 495ELECTRICAL AND IGNITION

Battery

Fuse Holder

(If Equipped)

(20 Amp Fuse)

Starter Solenoid

Ignition Switch

Starter Solenoid

Starter

Neutral Start Switch

(Located in Control Housing)

Starter Circuit

Starting Circuit Troubleshooting Flow Chart

Starter Motor Does Not Turn

SAFETY WARNING: Disconnect BLACK (starter motor)
cable from starter solenoid test point 1 BEFORE making
tests 1-thru-7 to prevent unexpected engine cranking.

TEST 1

Use an ohmmeter (R x 1 scale) and connect meter leads between
NEGATIVE (–) battery post and common powerhead ground.

No continuity indicated; there is an open circuit in the
BLACK negative (–) battery cable between the nega­tive (–) battery post and the powerhead.

 Check cable for loose or corroded connections.
 Check cable for open.

Continuity Indicated

Proceed to TEST 2, on next page

2B-1990-13645--2 495 ELECTRICAL AND IGNITION

No voltage reading;
proceed to TEST 3.

TEST 2

a- Disconnect BLACK ground wire(s) from Test Point 2.
b- Connect voltmeter between common engine ground and Test Point 2.
c- Turn ignition key to “Start” position.

TEST 3

a- Reconnect BLACK ground wire(s).
b- Connect voltmeter between common engine ground and Test Point 3.
c- Turn ignition key to “Start” position.

No voltage reading;
proceed to TEST 4.

12 Volt Reading

Defective starter solenoid.

TEST 4

a- Connect voltmeter between common

No voltage reading;
proceed to TEST 5.

engine ground and Test Point 4.

b- Turn ignition key to “Start” position.

TEST 5

No voltage reading;
proceed to TEST 6.

Connect voltmeter between common
engine ground and Test Point 5.

TEST 6

Connect voltmeter between common engine ground and Test Point 6.

12 Volt Reading*

Check BLACK ground wire for
poor connection or open circuit.
Reconnect ground wire to start­er solenoid; proceed to TEST 7.

12 Volt Reading*

Neutral start switch is open,
or YELLOW/RED wire is
open between Test Points 4
and 3.

12 Volt Reading*
Defective ignition switch.

No voltage reading; check RED wire be­tween battery (+) positive terminal and Test
Point 6.

12 Volt Reading*

Check fuse in RED wire between test points 5 and 6.
Check for open RED wire between test points 5 and

6.

TEST 7

a- Connect voltmeter between common engine ground and Test Point 1.
b- Turn ignition key to “Start” position.

No voltage reading;
Defective starter solenoid.

12 Volt Reading*
Should hear solenoid click; proceed to Test 8.

TEST 8

a- Reconnect BLACK (starter motor) cable to starter solenoid Test Point 1.
b- Connect voltmeter between common engine ground and Test Point 7.
c- Turn ignition key to “Start” position.

No voltage reading; check BLACK cable for
poor connection or open circuit.

12 Volt Reading*

Check BLACK ground cable at starter for loose or cor­roded connection, or open circuit. If cable is OK, check

*

Battery Voltage

2B-20 90-13645--2 495ELECTRICAL AND IGNITION

starter motor.

Starter Motor

Disassembly

Removal

CAUTION

Disconnect battery leads from battery before
removing starter.

1. Disconnect battery leads from battery.

2. Disconnect YELLOW cable.

3. Remove 4 bolts and remove starter clamps.

4. Remove starter.

5. Remove BLACK cable.

c

b

1. Remove 2 thru bolts and commutator end cap,
taking care not to lose brush springs.

a

a

a - Thru Bolts
b - Commutator End Cap

2. Pull armature from starter frame.

3. Remove locknut.

b

11646

a

b

d

c

20412

a - YELLOW Cable
b - Bolts (4)

c - Starter Clamps
d - BLACK Cable

6. Remove 2 rubber collars and 2 rubber bumpers.

a

a

a

11659

a - Hold Armature Shaft With Wrench on Hex Portion of Drive

Assembly

4. Remove components from armature.

efg

b

a - Rubber Collar b - Spacer (If Equipped)

11645

a - Locknut
b - Spacer
c - Spring
d - Drive Assembly

cd

ba

e - Drive End Cap
f - Armature Shaft
g - Washer

11658

2B-2190-13645--2 495 ELECTRICAL AND IGNITION

Starter Cleaning, Inspection and
Testing

CLEANING AND INSPECTION

1. Clean all starter motor parts.

2. Check pinion teeth for chips, cracks or excessive
wear.

3. Replace the drive clutch spring and/or collar if ten­sion is not adequate or if wear is excessive.

4. Inspect brush holder for damage or for failure to
hold brushes against commutator.

5. Replace brushes that are pitted or worn to less
than 1/4″ (6.4mm) in length.

6. Inspect the armature conductor (commutator bar
junction) for a tight connection. A loose connec­tion (excessive heat from prolonged cranking
melts solder joints) results in a burned commuta­tor bar.

7. Resurface and undercut a rough commutator as
follows:

1 1. Check the armature for ground. See the following

procedure (“Testing”).

Testing

ARMATURE TEST FOR SHORTS

Check armature for short circuits by placing on
growler and holding hack saw blade over armature
core while armature is rotated. If saw blade vibrates,
armature is shorted. Recheck after cleaning between
commutator bars. If saw blade still vibrates, replace
armature.

CAUTION

Do not turn down the commutator excessively.

a. Resurface the commutator and undercut the in-

sulation between the commutator bars 1/32″
(0.8mm) to the full width of the insulation and so

that the undercut is flat.
b. Clean the commutator slots after undercutting.
c. Sand the commutator lightly with No. 00 sand-

paper to remove burrs, then clean the commu-

tator.
d. Recheck the armature on a growler for shorts

as specified in the following procedure (“Test-

ing”).

8. Open-circuited armatures often can be repaired.
The most likely place for an open circuit is at the
commutator bars, as a result of long cranking peri­ods. Long cranking periods overheat the starter
motor so that solder in the connections melts and
is thrown out. The resulting poor connections then
cause arcing and burning of the commutator bars.

11669

ARMATURE TEST FOR GROUND

1. Set ohmmeter to (R x 1 scale). Place one lead of
ohmmeter on armature core or shaft and other
lead on commutator.

2. If meter indicates continuity, armature is
grounded and must be replaced.

9. Repair bars, that are not excessively burned, by
resoldering the leads in bars (using rosin flux sol­der) and turning down the commutator in a lathe
to remove burned material, then undercut the
mica.

10. Clean out the copper or brush dust from slots be­tween the commutator bars.

2B-22 90-13645--2 495ELECTRICAL AND IGNITION

11675

CHECKING POSITIVE BRUSHES AND
TERMINAL

Set ohmmeter to (R x 1 scale). Connect meter leads
between POSITIVE brushes. Meter must indicate full
continuity or zero resistance. If resistance is indi­cated, inspect lead to brush and lead to POSITIVE
terminal solder connection. If connection cannot be
repaired, brushes must be replaced.

a

STARTER SOLENOID TEST

1. Disconnect all wires from solenoid.

2. Use an ohmmeter (R x 1 scale) and connect meter
leads between solenoid terminals 1 and 2.

3. Connect a 12-volt power supply between sole­noid terminals 3 and 4. Solenoid should click and
meter should read 0 ohms (full continuity).

4. If meter does not read 0 ohms (full continuity), re­place solenoid.

a

11673

a - POSITIVE (+) Brushes

TESTING NEGATIVE BRUSHES FOR GROUND

Set ohmmeter to (R x 1 scale). Place one lead of the
ohmmeter on the NEGATIVE brush and the other
lead on the end cap (bare metal). If the meter indi­cates NO continuity, replace the NEGATIVE brush.
Repeat this procedure on the other NEGATIVE
brush.

b

a

b

a

a - 12-Volt Supply
b - VOA Leads

4.

2.

1.

b

a

3.

51809

a - NEGATIVE (–) Brushes
b - End Cap

11674

2B-2390-13645--2 495 ELECTRICAL AND IGNITION

Brush Replacement

STARTER REASSEMBLY

1. If brushes were removed, replace as follows:
a. Install POSITIVE brushes (along with POS-

ITIVE terminal) into commutator end cap.

a

b

i

2. If removed, reinstall parts on armature shaft. Use
a new locknut and tighten securely on end of
shaft.

e

f

g

h

d

d
e

f
g

a - End Cap
b - POSITIVE Brushes
c - POSITIVE Terminal
d - Insulating Bushing
e - Washer

b. Install NEGATIVE brushes (along with brush

holder).

a

c

f - Split Washer
g - Hex Nut
h - Long Brush Lead
i - Push Lead into Slot

c

b

11660

ab d

a - Locknut
b - Spacer
c - Spring
d - Drive Assembly
e - Drive End Cap
f - Armature Shaft
g - Washer

c

11658

3. Lubricate helix threads on armature shaft with a
drop of SAE 10W oil.

4. Lubricate bushing in drive end plate with a drop of
SAE 10W oil.

d

d

a

b

11656

a - POSITIVE (+) Brushes
b - NEGATIVE (–) Brushes
c - Brush Holder
d - Bolts (Fasten NEGATIVE Brushes and Holder)

2B-24 90-13645--2 495ELECTRICAL AND IGNITION

5. Position armature into starter frame.

6. To prevent damage to brushes and springs when
installing commutator end cap, it is recommended
that a brush retaining tool be made as shown:

2”

2″

7. Lubricate bushing (located in commutator end
cap) with one drop of SAE 10W oil. DO NOT over
lubricate.

8. Place springs and brushes into brush holder and
hold in place with brush retainer tool.

a

b

11661

1-11/16″

3″

3/4″

1/2″

90

Bend

1-3/4″

a - Brush Retainer Tool
b - Bushing (DO NOT Over Lubricate)

9. Install armature into starter frame and align match
marks (a). Install commutator end cap onto starter
frame and align match marks (b). Remove brush
retainer tool. Install through bolts (c) and torque to
70 lb. in. (7.9 N·m).

c

c

a

Brush Retainer Tool Layout (Full Size)

18-Gauge Sheet Metal

Metric Scale

3″ = 76.2mm
2″ = 50.8mm
1-3/4″ = 44.5mm
1-11/16 ″ = 42.9mm
3/4″ = 19.1mm

1/2″ = 12.7mm

b

11648

a - Alignment Marks
b - Alignment Marks
c - Bolts [Torque to 70 lb. in. (7.9 N·m)]

2B-2590-13645--2 495 ELECTRICAL AND IGNITION

Installation

1. Install 2 rubber collars and 2 rubber bumpers.

a

2. Install components as shown.

3. Connect battery leads to battery.

a

l

c

b

i

e

a - Rubber Collars
b - Rubber Bumpers

b

11645

k

j

d

a
f

i

h

g

19452

a - Starter
b - Rubber Mount, oil tank
c - Clamp, upper
d - BLACK Cable
e - Bolt and Lockwasher
f - Clamp, lower
g - J-Clip (If Equipped)
h - BLACK Negative (-) Battery Cable
i - Bolts [Torque to 14.5 lb. ft. (19.7 N·m)]
j - Fuse Holder (If Equipped)
k - YELLOW Cable [Torque to nut to 60 lb. in. (6.7 N·m)]
l - Fuse Holder (If Equipped)

2B-26 90-13645--2 495ELECTRICAL AND IGNITION

ELECTRICAL AND
IGNITION

2

22480

TIMING/SYNCHRONIZING/ADJUSTING

C

Table Of Contents

Timing/Synchronizing/

Adjusting (3 Cylinder Models) 2C-1. . . . . . . . . . .

Specifications 2C-1. . . . . . . . . . . . . . . . . . . . . . . .

Special Tools 2C-1. . . . . . . . . . . . . . . . . . . . . . . . .

Timing Pointer Adjustment 2C-1. . . . . . . . . . . . .

Carburetor Synchronization 2C-2. . . . . . . . .

Carburetor/Oil Pump

Synchronization 2C-3. . . . . . . . . . . . . . . .

Timing Adjustments 2C-3. . . . . . . . . . . . . . . .

Idle Timing Adjustment 2C-3. . . . . . . . . . . . .

Maximum Timing 2C-4. . . . . . . . . . . . . . . . . .

Maximum Throttle 2C-4. . . . . . . . . . . . . . . . .

Idle Adjustment 2C-4. . . . . . . . . . . . . . . . . . . .

Throttle Cable Installation 2C-5. . . . . . . . . . . . . .

Page Page

Timing/Synchronizing/

Adjusting (4 Cylinder Models) 2C-6. . . . . . . . . . .

Specifications 2C-6. . . . . . . . . . . . . . . . . . . . . . . .

Special Tools 2C-6. . . . . . . . . . . . . . . . . . . . . . . . .

Timing Pointer Alignment 2C-6. . . . . . . . . . . . . .

Carburetor Synchronization 2C-7. . . . . . . . .

Carburetor/Oil Pump

Synchronization 2C-8. . . . . . . . . . . . . . . .

Timing Adjustments 2C-8. . . . . . . . . . . . . . . .

Idle Timing Adjustment 2C-8. . . . . . . . . . . . .

Maximum Timing 2C-9. . . . . . . . . . . . . . . . . .

Carburetor Specifications 2C-10. . . . . . . . . . . . . .

Initial Starting Adjustments 2C-10. . . . . . . . . .

Low Speed Mixture Adjustments 2C-10. . . . .

Idle Adjustment 2C-11. . . . . . . . . . . . . . . . . . . . . . .

Throttle Cable Installation 2C-11. . . . . . . . . . . . . .

90-13645--2 495

Timing/Synchronizing/

k

Adjusting (3 Cylinder Models)

Specifications

70, 75 and 80 Models

Serial Number and Above

U.S.
Belgium 9502135
Canada A730007

B239242

Mariner 75 Marathon/Merc 75XD

Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM

(@ Cranking Speed)

Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2

16 B.T.D.C.

(18 B.T.D.C.)

Special Tools

Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM

(@ Cranking Speed)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2

70, 75 and 80 Models

Serial Number and Below

U.S.
Belgium 9502134
Canada A730006

Full Throttle RPM Range 4750 - 5250
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM

(@ Cranking Speed)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2

B239241

26 B.T.D.C.

(28 B.T.D.C.)

22 B.T.D.C.

(24 B.T.D.C.)

Part No. Description

*91-58222A1 Dial Indicator Gauge Kit
*91-59339 Service Tachometer
*91-99379 Timing Light
91-63998A1 Spark Gap Tool

* May be obtained locally.

Timing Pointer Adjustment

WARNING

Engine could start when turning flywheel to chec
timing pointer alignment. Remove spark plugs
from engine to prevent engine from starting.

1. Install Dial Indicator P/N 91-58222A1 into no. 1
(top) cylinder.

2. Turn flywheel clockwise until no. 1 (top) piston is
at top dead center (TDC). Set Dial Indicator to “0”
(zero).

90 Models

Full Throttle RPM Range
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 5000 RPM

(@ Cranking Speed)
Idle Timing 0 - 4 B.T.D.C.
Spark Plug NGK BUHW-2
Firing Order 1-3-2

5000 - 5500

26 B.T.D.C.

(28 B.T.D.C.)

91-58222A1

19062

3. Turn flywheel counterclockwise until Dial Indica­tor needle reads approximately 0.550 (13.97mm)
BTDC, then turn flywheel clockwise so that
needle reads 0.491 in. (12.47 mm) BTDC exactly .

2C-1ELECTRICAL AND IGNITION90-13645--2 1095

4. Reposition timing pointer if necessary, so that tim­ing pointer is aligned with 0.491 in. (12.47 mm)
timing mark on flywheel. Retighten attaching
screws.

b

c

c

b

a

a

22480

a - Timing Pointer
b - Timing Mark
c - Attaching Screws

5. Remove Dial Indicator, and reinstall spark plug
and high tension spark plug lead of no. 1 (top)
cylinder only.

CARBURETOR SYNCHRONIZATION

1. Disconnect remote fuel line from engine.

2. Connect remote control electrical harness to
engine wiring harness.

3. Remove throttle cable barrel from barrel retainer.

4. Remove sound air box cover.

5. Loosen screw from throttle cam follower.

6. Loosen 4 synchronizing screws.

7. Look into throats of carburetors and make sure all
throttle shutters are completely closed. Tighten
synchronizing screws.

8. Recheck throttle shutters and make any
necessary adjustments.

b

20440

a - Set Screw
b - Synchronizing Screws

9. Hold throttle arm so that throttle stop screw is
against stop.

10. Place roller of cam follower against throttle cam
and adjust throttle stop screw to align raised mark
of throttle cam with center of cam follower roller.
Tighten locknut.

e

d

c

a

f

b

20428

a - Throttle Arm
b - Throttle Stop Screw
c - Roller

d - Throttle Cam
e - Raised Mark
f - Lock Nut

2C-2 ELECTRICAL AND IGNITION 90-13645--2 1095

11. Holding throttle arm against throttle stop screw,
adjust cam follower, so that a clearance of 0.005
in. - 0.020 in. (0.127 - 0.508 mm) exists between
roller of cam follower and throttle cam. Tighten set
screw securing cam follower.

0.005″ – 0.020″

b

TIMING ADJUSTMENTS

CAUTION

Engine is timed while cranking engine with starter
motor. To prevent engine from starting when
being cranked, all spark plugs must be removed,
except no. 1 (top) cylinder plug.

a

c

52472

a - Roller
b - Throttle Cam
c - Set Screw

CARBURETOR/OIL PUMP SYNCHRONIZATION
IMPORTANT: Some engines may have an addi-

tional stamped mark (d) which SHOULD NOT be
used.

1. While holding throttle arm at idle position, adjust
length of link rod so that stamped mark of oil pump
body aligns with stamped mark of oil pump lever.

a

NOTE: If initial timing adjustments are made without
engine running, then final timing checks should be
made with engine running due to timing advance
characteristics of ignition system. Minimum engine
RPM required to check maximum timing advance is
3000 RPM.

IDLE TIMING ADJUSTMENT

1. Connect timing light to no. 1 (top) spark plug.

WARNING

Before cranking engine, keep clear of propeller as
it may rotate.

2. Shift engine to “Neutral”.

IMPORTANT: To accurately time engine at cranking
speed, a fully charged battery must be used.

3. Holding throttle arm at idle position, crank engine
with starter motor and adjust idle timing screw to
align 2° BTDC timing mark of flywheel with timing
pointer. Tighten locknut.

2° BTDC

404

a - Link Rod
b - Mark of Oil Pump Body

c - Mark of Oil Pump Lever
d - Mark NOT Used

b

a

b

c
d

22977

a - Idle Timing Screw
b - Locknut

20442

2C-3ELECTRICAL AND IGNITION90-13645--2 1095

MAXIMUM TIMING

1. Hold control arm so that maximum spark advance
screw is against stop.

2. Crank engine with starter motor and adjust maxi­mum spark advance screw to align the specified
BTDC timing mark on flywheel with timing pointer
(due to the advance characteristic of this ignition
system, this cranking speed adjustment will auto­matically be reduced by 2° at an engine speed of
5000 RPM). Tighten locknut.

2. Install remaining spark plugs and high tension
spark plug leads.

b

c

a

20441

a - Control Arm
b - Maximum Spark Advance Screw
c - Locknut

NOTE: If initial timing adjustments are made without
engine running, then final timing checks should be
made with engine running due timing advance char­acteristics of ignition system. Minimum engine RPM
required to check maximum timing advance is 3000
RPM.

MAXIMUM THROTTLE

a

bc

a - Throttle Arm
b - Full Throttle Stop Screw
c - Locknut

IDLE ADJUSTMENT

1. With engine in water, connect electrical harness
and fuel line to engine. Start engine and allow to
warm up.

20443

1. Hold throttle arm against full throttle stop screw.
Adjust full throttle stop screw to allow throttle shut­ters to open fully, then turn stop screw in (clock­wise) an additional 1/2 turn, to prevent throttle le­ver of center carburetor from acting as a stop.
Tighten locknut.

2C-4 ELECTRICAL AND IGNITION 90-13645--2 1095

2. Shift into “Forward” gear and adjust carburetor
low speed mixture screws properly (refer to “Car­buretor” section).

Lightly seated

1-1/2 turns out

3. Holding throttle arm (NO T AG) at idle position, ad­just idle timing screw (NO TAG) to attain an en­gine idle RPM of 650-700 RPM in “Forward” gear.
Tighten locknut (NO TAG) and turn off engine.

Throttle Cable Installation

1. With end of throttle cable connected to throttle le­ver, hold throttle lever against idle stop. Adjust
throttle cable barrel to slip into barrel retainer on
cable anchor bracket with a very light preload of
throttle lever against idle stop. Lock barrel in
place.

IMPORTANT: Excessive preload on throttle cable
will cause difficulty when shifting from forward to
neutral. (Readjust throttle cable barrel, if neces­sary.)

2. Check preload on throttle cable by placing a thin
piece of paper between idle stop screw and idle
stop. Preload is correct when paper can be re­moved without tearing but has some drag on it.
(Readjust throttle cable barrel, if necessary.)

2° BTDC

404

b
c

a

20442

a - Throttle Arm
b - Idle Timing Screw
c - Locknut

NOTE: On this type of engine, idle RPM is adjusted
exclusively with ignition timing.

2C-5ELECTRICAL AND IGNITION90-13645--2 1095

Timing/Synchronizing/

k

Timing Pointer Alignment

Adjusting (4 Cylinder Models)

Specifications

Models 100/115

Full Throttle RPM Range
Idle RPM (in “FORWARD” Gear) 650 - 700
Maximum Timing @ 3000 RPM

(@ Cranking Speed)
Idle Timing 2 - 4 B.T.D.C.
Spark Plug NGK

Firing Order 1-3-2-4

4750 - 5250

23 B.T.D.C.

(25 B.T.D.C.)

BP8H-N-10*

[0.040 in.

(1.0mm) gap]

NGK

BPZ8H-N-10*

[0.040 in.

(1.0mm) gap]

NGK BUHW

WARNING

Engine could start when turning flywheel to chec
timing pointer alignment. Remove all spark plugs
from engine to prevent engine from starting.

1. Remove aft cowl support bracket.

2. Install Dial Indicator 91-58222A1 into no. 1 (top)
cylinder.

3. Turn flywheel in a clockwise direction until no. 1
piston is a TDC, then set Dial Indicator at “0” (zero).

*Improves running quality between 1800 – 2000 RPM

Special Tools

Part No. Description

*91-58222A1 Dial Indicator Gauge Kit
*91-59339 Service Tachometer
*91-99379 Timing Light

* May be obtained locally.

91-58222A1

4. Turn flywheel counterclockwise until Dial Indica­tor needle reads approximately 0.600 in. BTDC,
then turn flywheel clockwise, so that needle reads

0.554 in. BTDC exactly.

5. Reposition timing pointer, if necessary, so that

0.554 in. mark is aligned with groove in timing
pointer.

6. Remove Dial Indicator and reinstall spark plug
and spark plug lead on no. 1 cylinder.

19062

a

a - Timing Pointer

2C-6 ELECTRICAL AND IGNITION 90-13645--2 1095

22480

CARBURETOR SYNCHRONIZATION

1. Remove sound box cover.

2. Loosen cam follower adjustment screw.

3. Loosen 6 synchronizing screws.

4. Look into throats of carburetors and make sure all
throttle shutters are completely closed.

5. Apply light down pressure on carburetor synchro­nizing shaft and tighten 6 synchronizing screws
from top to bottom.

6. Recheck throttle shutters and make any neces­sary adjustment.

7. Hold throttle arm so that the throttle stop screw is
against stop.

8. Place roller of cam follower against throttle cam
and adjust throttle stop screw to align raised mark
of throttle cam with center of cam follower roller.
Tighten locknut.

b

b

a
c

52483

a - Roller
b - Throttle Cam
c - Screw

10. Hold throttle arm against full throttle stop. Adjust
full throttle stop screw to allow throttle shutters to
open fully. To prevent throttle shutters to act as a
stop, screw in stop screw clockwise 1/2 turn and
tighten locknut.

e

f

a
b

g

d

b

c

25498

a - Cam Follower Adjustment
Screw

b - Synchronizing Screws
c - Throttle Arm

9. Holding throttle arm at idle position, adjust cam
follower so that a clearance of 0.005 in. - 0.020 in.
(0.127mm - 0.508mm) exists between roller and
throttle cam. Tighten screw securing cam follow­er.

d - Idle Stop Screw
e - Roller
f - Throttle Cam
g - Locknut

b

a

23004

a - Throttle Arm
b - Full Throttle Stop Screw

2C-7ELECTRICAL AND IGNITION90-13645--2 1095

11. Hold throttle cam in full throttle position. If neces­sary adjust acceleration pump adjusting bolts po­sition so that a gap of 0.030 in. (0.762mm) exists
between throttle cam and top of acceleration
pump aluminum housing.

CARBURETOR/OIL PUMP SYNCHRONIZATION
IMPORTANT: Some engines may have an addi-

tional stamped mark (d) which SHOULD NOT be
used.

1. While holding throttle arm at idle position, adjust
length of link rod so that stamped mark of oil pump
body aligns with stamped mark of oil pump lever.

2. Move throttle arm from idle to wide open throttle
while checking link rod for any interference with
hoses, cable ties, etc.

a

c

d

a - Throttle Cam
b - Bolts
c - 0.030 in. (0.762mm) Gap
d - Accelerator Pump

b

22509

a

b

c
d

22977

a - Link Rod
b - Mark of Oil Pump Body

c - Mark of Oil Pump Lever
d - Mark NOT Used

TIMING ADJUSTMENTS

CAUTION

Engine can be timed while cranking engine with
starter motor. To prevent engine from starting
when being cranked, all spark plugs should be
removed.

NOTE: If initial timing adjustments are made without
engine running, then final timing checks should be
made with engine running due timing advance char­acteristics of ignition system. Minimum engine RPM
required to check maximum timing advance is 3000
RPM.

1. Insert Spark Gap T ool (91-63998A1) in no. 1 (top)
cylinder spark plug boot and attach alligator clip
to good ground.

2. Remove throttle cable barrel from barrel retainer.

IDLE TIMING ADJUSTMENT

WARNING

Before cranking engine, keep clear of propeller,
as it may rotate.

IMPORTANT: To accurately time engine at crank­ing speed, a fully charged battery must be used.

2C-8 ELECTRICAL AND IGNITION 90-13645--2 1095

1. Connect timing light to no. 1 (top) spark plug lead.

MAXIMUM TIMING

2. Shift engine into neutral.

3. Holding throttle arm at idle position, crank engine
with starter motor and adjust idle timing screw to
align 2 degrees BTDC timing mark of flywheel with
timing pointer. Tighten locknut.

a

b

1. Hold control arm against maximum advance stop.
Crank engine with starter motor and adjust maxi­mum advance screw to align 25° BTDC mark on
flywheel with timing pointer (due to the advance
characteristics of ignition system, this cranking
speed adjustment will automatically be reduced
to 23° BTDC at engine speed of 5000 RPM).
Tighten locknut.

NOTE: If initial timing adjustments are made without
engine running, then final timing checks should be
made with engine running due timing advance char­acteristics of ignition system. Minimum engine RPM
required to check maximum timing advance is 3000
RPM.

c

b

a - Idle Timing Screw
b - Locknut

a

23005

23005

a - Control Arm
b - Maximum Advance Screw
c - Locknut

2C-9ELECTRICAL AND IGNITION90-13645--2 1095

Carburetor Specifications

Carburetor number stamped at TOP of carburetor mounting flange

NOTE: Early model engines may have identification stamped on face of air box mounting flange.

Carb Number Location Model HP Main Jet* Bowl* Vent Jet

WME-11, 20- 1

2
3

Top Carburetor
Top Center Carburetor
Bottom Center Carburetor

100 .054 None

Bottom Carburetor

WME-14, 21- 1

2
3

Top Carburetor
Top Center Carburetor
Bottom Center Carburetor

115 .076 None

Bottom Carburetor

* Standard jets listed are for operation of engine from 0-762 m (0-2500 ft.) of elevation (see jet size chart).

INITIAL STARTING ADJUSTMENTS

NOTE: For adjusting carburetor throttle linkage and
synchronizing carburetors, see section “Timing/
Synchronizing/Adjusting” of this manual.

4. DO NOT adjust leaner than necessary to attain
reasonable smooth idling. When in doubt, stay on
the slightly rich side of the adjustment.

a

After service or replacement of carburetor, turn low
speed mixture screw adjustment in (clockwise) until it
seats lightly , then back of f (each carburetor) to speci­fications (100-1-3/4 turns or 115-1-1/2 turns). This will
permit engine start-up.

LOW SPEED MIXTURE ADJUSTMENTS

NOTE: Only the top two carburetors on four cylinder
models have an adjustable low speed mixture screw.

1. Start engine and allow to warm up (run for several
minutes). Throttle back to idle for about one min­ute to allow RPM to stabilize.

2. With engine running at idle speed (in water) in
“Forward” gear (prop on), turn low speed mixture
screw, IN (clockwise) until engine starts to “bog”
down and misfire. Back out 1/4 turn or more.

3. Check for too lean mixture on acceleration.

22990

a - Low Speed Mixture Screw

2C-10 ELECTRICAL AND IGNITION 90-13645--2 1095

Idle Adjustment

Throttle Cable Installation

1. With engine in water, connect electrical harness
and fuel line to engine. Start engine and allow to
warm up.

2. Properly adjust carburetor low speed mixture
screws. Refer to “Carburetor Adjustments” sec­tion 3A.

3. Holding throttle arm at idle position (throttle cable
barrel removed from barrel retainer), adjust idle
timing screw to attain an engine idle RPM of
650-700 RPM in “Forward” gear. Tighten locknut
and turn off engine.

1. With end of throttle cable connected to throttle le­ver, hold throttle lever against throttle stop. Adjust
throttle cable barrel to slip into barrel retainer on
cable anchor bracket with a very light preload of
throttle lever against throttle stop. Lock barrel in
place.

IMPORTANT: Excessive preload on throttle cable
will cause difficulty when shifting from forward to
neutral. (Readjust throttle cable barrel, if neces­sary.)

2. Check preload on throttle cable by placing a thin
piece of paper between throttle stop screw and
stop. Preload is correct when paper can be re­moved without tearing, but has some drag on it.
Readjust throttle cable barrel, if necessary.)

3. Reinstall sound box cover.

a - Idle Timing Screw
b - Locknut

a

b

23005

2C-11ELECTRICAL AND IGNITION90-13645--2 1095

ELECTRICAL AND
IGNITION

WIRING DIAGRAMS

2

D

Table Of Contents

Page Page

Engine Wiring Diagram (3 Cylinder

Models with Low Oil Warning Module) 2D-1. . . .

Engine Wiring Diagram (3 Cylinder

Models without Low Oil Warning Module) 2D-2.

Engine Wiring Diagram (3 Cylinder Models

with Small Voltage Regulator/Rectifier) 2D-3. . . .

Engine Wiring Diagram

(4 Cylinder Models) 2D-4. . . . . . . . . . . . . . . . . . . .

Engine Wiring Diagram (4 Cylinder Models

with Small Voltage Regulator/Rectifier) 2D-5. . . .

Power Trim System Wiring Diagram . . . . . . . . . . . . . .

(3 Cylinder Models using COMMANDER

2000 Side Mount Remote Control) 2D-6. . . . . . .

Power Trim System Wiring Diagram

(3 Cylinder Models using COMMANDER

Side Mount Remote Control) 2D-7. . . . . . . . . . . .

Power Trim System Wiring Diagram

(4 Cylinder Models using COMMANDER

2000 Side Mount Remote Control) 2D-8. . . . . . .

Tachometer (with Adjustable Dial) and

Trim Indicator Gauge Wiring Diagram 2D-9. . . . .

Key/Choke Switch Continuity Test

(COMMANDER 2000 Side Mount

Remote Control) 2D-10. . . . . . . . . . . . . . . . . . . . . .

COMMANDER 2000 Side Mount Remote Control

(Power Trim/Tilt Electric Start with

Warning Horn) Wiring Diagram 2D-11. . . . . . . . .

COMMANDER 2000 Side Mount Remote Control

(Electric Start With Warning Horn)

Wiring Diagram 2D-12. . . . . . . . . . . . . . . . . . . . . . .

COMMANDER Side Mount Remote Control

(Power Trim/Tilt Electric Start with Warning

Horn) Wiring Diagram 2D-13. . . . . . . . . . . . . . . . .

90-13645--2 495

Engine Wiring Diagram (3 Cylinder
Models With Low Oil Warning Module)

a

c

j

BLK  BLACK
BLU  BLUE

h

BRN  BROWN
GRY  GRAY
GRN  GREEN
PUR  PURPLE
RED  RED

b

i

o

TAN  TAN

VIO  VIOLET

WHT  WHITE

YEL  YELLOW

k

d

e

f

a - Stator
b - Trigger
c - Switch Box
d - Ignition Coil Cylinder No. 1
e - Ignition Coil Cylinder No. 2
f - Ignition Coil Cylinder No. 3
g - Mercury (Tilt) Stop Switch
h - Starter Motor
i - Starter Solenoid

g

n

o

o

m

l

p

q

r

50388

j - Voltage Regulator/Rectifier
k - Fuse Holder (20 Amp Fuse)
l - Battery
m- Wiring Harness Connector
n - Enrichment Valve
o - Terminal Block
p - Temperature Switch – Opens [170F

Closes [190F
q - Low Oil Warning Module
r - Low Oil Sensor

 8 (77C  8)]

 8 (88C  8)]

2D-190-13645--2 495 ELECTRICAL AND IGNITION

Engine Wiring Diagram (3 Cylinder
Models Without Low Oil Warning Module)

a

c

BLK  BLACK

h

BLU  BLUE

BRN  BROWN

GRY  GRAY

GRN  GREEN

b

i

j

PUR  PURPLE
RED  RED

TAN  TAN

VIO  VIOLET

WHT  WHITE

YEL  YELLOW

k

d

e

f

a - Stator
b - Trigger
c - Switch Box
d - Ignition Coil Cylinder No. 1
e - Ignition Coil Cylinder No. 2
f - Ignition Coil Cylinder No. 3
g - Mercury (Tilt) Stop Switch
h - Starter Motor
i - Starter Solenoid

g

n

l

m

o

p

q

r

23888

j - Rectifier
k - Fuse Holder (20 Amp Fuse)
l - Battery
m- Wiring Harness Connector
n - Enrichment Valve
o - Terminal Block
p - Temperature Switch – Opens [170F

Closes [190F
q - Test Button
r - Low Oil Sensor

 8 (77C  8)]

 8 (88C  8)]

2D-2 90-13645--2 495ELECTRICAL AND IGNITION

Engine Wiring Diagram (3 Cylinder Models
With Small Voltage Regulator/Rectifier)

a

h

b

c

i

BLK  BLACK

BLU  BLUE
BRN  BROWN
GRY  GRAY
GRN  GREEN
PUR  PURPLE
RED  RED

TAN  TAN

VIO  VIOLET

WHT  WHITE

YEL  YELLOW

j

k

d

g

m

e

f

q

a - Stator
b - Trigger
c - Switch Box
d - Ignition Coil Cylinder No. 1
e - Ignition Coil Cylinder No. 2
f - Ignition Coil Cylinder No. 3
g - Mercury Switch
h - Starter Motor
i - Starter Solenoid

l

n

n

o

p

51003

j - Voltage Regulator/Rectifier
k - 20 Amp Fuse
l - Battery
m- Fuel Enrichment Valve
n - Terminal Block
o - Overheat Temperature Sensor
p - Warning Module
q - Low Oil Sensor (Float)

2D-390-13645--2 495 ELECTRICAL AND IGNITION

Engine Wiring Diagram
(4 Cylinder Models)

a

b

i

c

j

o

l

h

d

k

m

e

p

o

f

q

n

BLK  BLACK
BLU  BLUE

BRN  BROWN

GRY  GRAY

GRN  GREEN

PUR  PURPLE
RED  RED

TAN  TAN

VIO  VIOLET

WHT  WHITE

YEL  YELLOW

p

g

r

s

a - Stator
b - Trigger
c - Switch Box
d - Ignition Coil Cylinder No. 1
e - Ignition Coil Cylinder No. 2
f - Ignition Coil Cylinder No. 3
g - Ignition Coil Cylinder No. 4
h - Mercury (Tilt) Stop Switch
i - Starter Motor
j - Starter Solenoid

2D-4 90-13645--2 495ELECTRICAL AND IGNITION

k - Voltage Regulator/Rectifier
l - Fuse Holder (20 Amp Fuse)
m- Battery
n - Wiring Harness Connector
o - Enrichment Valve
p - Terminal Block
q - Temperature Switch – Opens [170F

r - Low Oil Warning Module
s - Low Oil Sensor

Closes [190F

50389

 8 (77C  8)]
 8 (88C  8)]

Engine Wiring Diagram (4 Cylinder Models
With Small Voltage Regulator/Rectifier)

BLK  BLACK

BLU  BLUE
BRN  BROWN
GRY  GRAY

GRN  GREEN

PUR  PURPLE

RED  RED

TAN  TAN

VIO  VIOLET

WHT  WHITE

YEL  YELLOW

a

j

i

b

c

j

o

l

h

d

e

f

g

a - Stator
b - Trigger
c - Switch Box
d - Ignition Coil Cylinder No. 1
e - Ignition Coil Cylinder No. 2
f - Ignition Coil Cylinder No. 3
g - Ignition Coil Cylinder No. 4
h - Mercury Switch
i - Starter Motor

k

m

o

n

p

o

q

r

51002

j - Starter Solenoid
k - Voltage Regulator/Rectifier
l - 20 Amp Fuse
m- Battery
n - Fuel Enrichment Valve
o - Terminal Block
p - Overheat Sensor
q - Warning Module
r - Low Oil Sensor (Float)

2D-590-13645--2 495 ELECTRICAL AND IGNITION

Power Trim System Wiring Diagram (3 Cylinder Models
Using COMMANDER 2000 Side Mount Remote Control)

b

c

BLK  BLACK
BLU  BLUE

GRN  GREEN

RED  RED

WHT  WHITE

a

d

e

f

g

h

23886

a - Power Trim Pump Motor
b - Trim Solenoid “UP”
c - Trim Solenoid “DOWN”
d - Engine Starter Motor Solenoid

2D-6 90-13645--2 495ELECTRICAL AND IGNITION

e - Red (+) Battery Cable
f - Fuse Holder (20 Amp Fuse)
g - Engine Wiring Harness Connector
h - Remote Control Wiring Harness Connector

Power Trim System Wiring Diagram (3 Cylinder Models
Using COMMANDER Side Mount Remote Control)

b

c

BLK  BLACK

BLU  BLUE
GRN  GREEN
PUR  PURPLE
RED  RED

WHT  WHITE

a

e

f

d

3

1

2

g

g

23884

a - Power Trim Pump Motor
b - Trim Solenoid “UP”
c - Trim Solenoid “DOWN”
d - Engine Starter Motor Solenoid

e - Fuse Holder (20 Amp Fuse)
f - Red (+) Battery Cable
g - Wires from Remote Control

2D-790-13645--2 495 ELECTRICAL AND IGNITION

Power Trim System Wiring Diagram (4 Cylinder Models
Using COMMANDER 2000 Side Mount Remote Control)

b

c

BLK  BLACK
BLU  BLUE

GRN  GREEN

RED  RED

WHT  WHITE

d

a

f

e

g

h

23885

a - Power Trim Pump Motor
b - Trim Solenoid “UP”
c - Trim Solenoid “DOWN”
d - Engine Starter Motor Solenoid

2D-8 90-13645--2 495ELECTRICAL AND IGNITION

e - Red (+) Battery Cable
f - Fuse Holder (20 Amp Fuse)
g - Engine Wiring Harness Connector
h - Remote Control Wiring Harness Connector

Tachometer (With Adjustable Dial) and
Trim Indicator Gauge Wiring Diagram

BATT GND

SENDER

BLK  BLACK
BRN  BROWN
GRY  GRAY
PUR  PURPLE

TAN  TAN

WHT  WHITE

b

c

a

d

e

a - Tachometer
b - Position Dial to Point Toward “4”
c - Trim Indicator Gauge (Optional)

d - Tachometer/Accessories Harness Plug from Remote Control
e - Tachometer/Accessories Harness

2D-990-13645--2 495 ELECTRICAL AND IGNITION

Key/Choke Switch Continuity Test
(COMMANDER 2000 Side Mount Remote Control)

BLK  BLACK
PUR  PURPLE
RED  RED

YEL  YELLOW

“OFF” BLK/YEL – BLK
“RUN” RED – PUR
“START” RED – PUR – YEL/RED
PUSH (CHOKE)* RED – YEL/BLK

*Key switch must be positioned to “RUN”
or “START” and key pushed in to actuate
choke, for this continuity test.

23894

2D-10 90-13645--2 495ELECTRICAL AND IGNITION

COMMANDER 2000 Side Mount Remote Control
(Power Trim/Tilt Electric Start With Warning Horn)
Wiring Diagram

g

BLK  BLACK

BLU  BLUE
BRN  BROWN
GRY  GRAY

GRN  GREEN

PUR  PURPLE
RED  RED

TAN  TAN

WHT  WHITE

YEL  YELLOW

d

f

e

a

b

c

a - Ignition/Choke Switch
b - Emergency Stop Switch
c - Neutral Start Switch
d - Tachometer/Accessories Harness Connector

23891

e - Wiring Harness Connector
f - Warning Horn
g - Trim/Tilt Switch

2D-1190-13645--2 495 ELECTRICAL AND IGNITION

COMMANDER 2000 Side Mount Remote Control
(Electric Start With Warning Horn) Wiring Diagram

BLK  BLACK

BLU  BLUE
BRN  BROWN
GRY  GRAY

GRN  GREEN

PUR  PURPLE
RED  RED

TAN  TAN

WHT  WHITE

YEL  YELLOW

d

e

a

b

f

a - Ignition/Choke Switch
b - Emergency Stop Switch
c - Neutral Start Switch

c

23892

d - Tachometer/Accessories Harness Connector
e - Wiring Harness Connector
f - Warning Horn

2D-12 90-13645--2 495ELECTRICAL AND IGNITION

COMMANDER Side Mount Remote Control
(Power Trim/Tilt Electric Start With Warning
Horn) Wiring Diagram

e

k

WHT  WHITE

BLK  BLACK

BLU  BLUE
BRN  BROWN
GRN  GREEN
GRY  GRAY

PUR  PURPLE

RED  RED

TAN  TAN
YEL  YELLOW

LIT  LIGHT

g

h

a

l

d

b

c

a - Ignition/Choke Switch
b - Emergency Stop Switch
c - Neutral Start Switch
d - Tachometer/Accessories Harness Connector
e - Wiring Harness Connector
f - Warning Horn

i

f

j

g - Trim/Tilt Switch
h - Wire Retainer
i - Control Handle
j - Trim Harness Bushing
k - Trim Harness Connector
l - Lead to Trim Indicator Gauge

24072

2D-1390-13645--2 495 ELECTRICAL AND IGNITION

FUEL SYSTEM AND
CARBURETION

3

A

Table Of Contents

Fuel Pumps 3A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

General Information 3A-1. . . . . . . . . . . . . . . . . . .

Fuel Pump Description/Operation 3A-1. . . .

Checking For Restricted Fuel Flow

Caused By Anti-siphon Valves 3A-1. . .

T esting 3A-1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Troubleshooting Fuel Pump 3A-1. . . . . . . . . . . .

Fuel Pump Components (Design 1) 3A-2. . . . .

Fuel Pump Removal/Installation

(Design 1) 3A-3. . . . . . . . . . . . . . . . . . . . . . . .

Fuel Pump Cleaning, Inspection,

Disassembly and Reassembly

(Design 1 and 2) 3A-3. . . . . . . . . . . . . . . . . . . . . .

Fuel Pump – Cleaning/Inspection 3A-3. . . . . . .

Check Valve Reassembly 3A-4. . . . . . . . . . . . . .

Carburetion 3A-12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel System Troubleshooting 3A-12. . . . . . . . . . .

Checking for Restricted Fuel Flow

Caused by Anti-Siphon Valves 3A-13. . . . . . .

Fuel System (Carburetor) 3A-14. . . . . . . . . . . . . . . . .

Fuel System (Linkage) 3A-16. . . . . . . . . . . . . . . . .

Carburetor Adjustments 3A-17. . . . . . . . . . . . . . . .

Initial Starting Adjustment 3A-17. . . . . . . . . . .

Low Speed Mixture Adjustment 3A-17. . . . . .

Carburetor Float Adjustment 3A-17. . . . . . . .

Specification Sheet - WME Carburetors 3A-18. . . . .

Carburetor Fastener Torques: 3A-18. . . . . . .

Settings 3A-18. . . . . . . . . . . . . . . . . . . . . . . . . .

Fuel Pump Specifications 3A-18. . . . . . . . . . .

Fuel Pump Pressure 3A-18. . . . . . . . . . . . . . .

Sealants 3A-18. . . . . . . . . . . . . . . . . . . . . . . . . .

Page Page

Idle Speed Adjustment 3A-19. . . . . . . . . . . . .

Main (High Speed) Jet Adjustment 3A-19. . .
Rejetting Carburetors For High

Altitude Operation 3A-19. . . . . . . . . . . . . .

Jet Orifice Size/Part Number Chart 3A-20. . .
Carburetor Removal and

Disassembly 3A-20. . . . . . . . . . . . . . . . . . .

Carburetor Disassembly 3A-21. . . . . . . . . . . . . . .

Cleaning and Inspection 3A-22. . . . . . . . . . . .

Carburetor Reassembly 3A-22. . . . . . . . . . . . . . . .

Idle Air Screw 3A-23. . . . . . . . . . . . . . . . . . . . .

Enrichener System 3A-24. . . . . . . . . . . . . . . . . . . . . . .

Description for Three Cylinder Engines 3A-24. .
Enrichener Valve Hose Installation - Three

Cylinder Engines 3A-24. . . . . . . . . . . . . . . . . .

Description for Four Cylinder Engines 3A-24. . .
Enrichener Valve Hose Installation - Four

Cylinder Engines 3A-24. . . . . . . . . . . . . . . . . .

Enrichener Valve Test 3A-25. . . . . . . . . . . . . .

Acceleration Pump Circuit Operation -

Four Cylinder Engines 3A-26. . . . . . . . . . . . . .

Accelerator Pump Fuel Flow Circuit 3A-26. .

Acceleration Pump Fuel Flow Circuit for

Four Cylinder Engines 3A-27. . . . . . . . . . . . . .

Fuel Tank 3A-28. . . . . . . . . . . . . . . . . . . . . . . . . . . .

Maintenance 3A-28. . . . . . . . . . . . . . . . . . . . . .

Fuel Tank Components 3A-28. . . . . . . . . . . . . . . .

Fuel Line and Primer Bulb Assembly 3A-29. . . .

Maintenance 3A-30. . . . . . . . . . . . . . . . . . . . . . . . .

Fuel Line Clamp Removal and

Installation 3A-30. . . . . . . . . . . . . . . . . . . . .

90-13645--2 495

Fuel Pumps

General Information

FUEL PUMP DESCRIPTION/OPERA TION

The fuel pump is a crankcase-pressure-operated, di­aphragm-type pump. Crankcase pulsating pressure
(created by the up-and-down movement of piston) is
transferred to fuel pump by way of a passage (hole)
between crankcase and fuel pump.

When piston is in an upward motion, a vacuum is
created in the crankcase, thus pulling in a fuel/air mix­ture (from carburetor) into crankcase. This vacuum
also pulls in on the fuel pump diaphragm, thus the in­let check valve (in fuel pump) is opened and fuel (from
fuel tank) is drawn into fuel pump.

Downward motion of the piston forces the fuel/air mix­ture out of the crankcase into the cylinder. This motion
also forces out on the fuel pump diaphragm, which, in
turn, closes the inlet check valve (to keep fuel from re­turning to fuel tank) and opens the outlet check valve,
thus forcing fuel to the carburetors.

CHECKING FOR RESTRICTED FUEL FLOW CAUSED
BY ANTI-SIPHON V ALVES

While anti-siphon valves may be helpful from a safety
stand-point, they clog with debris, they may be too
small, or they may have too heavy a spring. Summa­rizing, the pressure drop across these valves can,
and often does, create operational problems and/or
powerhead damage by restricting fuel to the fuel
pump and carburetor(s). Some symptoms of re­stricted (lean) fuel flow, which could be caused by use
of an anti-siphon valve, are:

 Loss of fuel pump pressure
 Loss of power
 High speed surging
 Preignition/detonation (piston dome erosion)
 Outboard cuts out or hesitates upon acceleration
 Outboard runs rough
 Outboard quits and cannot be restarted
 Outboard will not start
 Vapor lock

Since any type of anti-siphon device must be located
between the outboard fuel inlet and fuel tank outlet,
a simple method of checking [if such a device (or bad
fuel) is a problem source] is to operate the outboard
with a separate fuel supply which is known to be
good, such as a remote fuel tank.

If, after using a separate fuel supply, it is found that
the anti-siphon valve is the cause of the problem,
there are 2 solutions to the problem; either (1) remove
the anti-siphon valve or (2) replace it with a solenoid­operated fuel shutoff valve.

Testing

Install clear fuel hose(s) between fuel pump and car­buretor(s). Run engine, and inspect fuel passing thru
hose(s) for air bubbles. If air bubbles are found, see
“Air Bubbles in Fuel Line,” below. If air bubbles are
NOT found, see “Lack of Fuel Pump Pressure,” con­tinued on next page.

Troubleshooting Fuel Pump

PROBLEM: AIR BUBBLES IN FUEL LINE

Possible Cause Corrective Action

Low fuel in fuel tank. Fill tank with fuel.
Loose fuel line

connection.
Fuel pump fitting loose. Tighten fitting.
A hole or cut in fuel line. Check condition of all

Fuel pump anchor
screw(s) loose.

Fuel pump gasket(s)
worn out.

PROBLEM: LACK OF FUEL PUMP PRESSURE

Possible Cause Corrective Action

An anti-siphon valve. Read “Checking for

Air in fuel line. “Air Bubbles in Fuel

A dirty or clogged fuel
filter.

The fuel pickup in fuel
tank clogged or dirty.

Worn out fuel pump
diaphragm.

Defective (hole or crack)
check valve(s) in fuel
pump (unlikely).

Broken check valve
retainer.

Pulse hole plugged. Remove fuel pump and

Check and tighten all
connections.

fuel lines and replace
any found to be bad.

Tighten all screws
evenly and securely.

Rebuild fuel pump.

Restricted Fuel Flow,
Caused by Anti-Siphon
Valves” preceding.

Line”, preceding.
Clean or replace fuel

filter.
Clean or replace pickup.

Rebuild fuel pump.

Rebuild fuel pump.

Rebuild fuel pump.

clean out hole.

3A-190-13645--2 495 FUEL SYSTEM AND CARBURETION

Troubleshooting Fuel Pump
(continued)

PROBLEM: LACK OF FUEL PUMP PRESSURE

Possible Cause Corrective Action

Hole in pulse hose
(1 pulse hose).

Loose pulse hose. Tighten connection.

Replace pulse hose.

Fuel Pump Components (Design 1)

NOTE:

spective diaphragms go against the mating surfaces
of the fuel pump body , and respective gaskets are be­tween the diaphragms and end caps. Gaskets should
always be replaced on fuel pump assembly.

In fuel pump reassembly, remember that re-

d

Boost diaphragm gasket
distorted or out of place.

Check seal between
mating surfaces where
“rib” divides pulse
chamber – gasket must
align with rib; check for
distorted gasket. Align
or replace gasket if
necessary.

e

a
f

g

h

i

k
l

j

b

s

q

r

m

n
o

p
c

t

a - Fuel Pump Base
b - Fuel Pump Body
c - Chamber Plate
d - Gasket, Base
e - Fuel Filter – Inline
f - Gasket, Pulse Chamber
g - Diaphragm, Fuel Pump
h - Retainer, Check Valve
i - Check Valve
j - Check Valve Rubber Disc
k - Main Compression Spring End Cap
l - Main Compression Spring
m- Boost Diaphragm
n - Boost Chamber Gasket
o - Boost Compression Spring End Cap
p - Boost Compression Spring
q - Retainer, Check Valve
r - Check Valve
s - Check Valve Rubber Disc
t - Check Valve Assembly

3A-2 90-13645--2 495FUEL SYSTEM AND CARBURETION

Fuel Pump Removal/Installation
(Design 1)

 Attach fuel lines (inlet and outlet).

 Attach oil injection hose.
 Remove 4 hoses from fuel pump.
 Remove 2 phillips-head screws -- lift off fuel pump.
 Remove 2 hex-head bolts to disassemble fuel

pump.

c

b

a

a

20427

a - Fuel Pump
b - Screws (2 Each)
c - Bolts (2 Each)

 Remove gasket from backside (fuel pump base) --

replace gasket as necessary -- check gasket in
port area carefully.

 Attach pulse hose.

 Secure each hose connection with a sta-strap.

d

b

a

c

a - Inlet Fuel Hose

b - Outlet Fuel Hose

c - Oil Injection Hose

d - Pulse Hose

a

b

20417

a - Gasket
b - Port Area

Reinstall Fuel Pump (Design 1)

CAUTION

After reinstalling fuel pump, ALWAYS check all
fuel line connections for leaks, with engine
running.

 Reinstall fuel pump to powerhead, as shown, with

2 phillips-head screws.

Fuel Pump Cleaning,

Inspection, Disassembly and

Reassembly (Design 1 and 2)

 Disassemble by removing 2 hex-head bolts;

remove/disassemble fuel pump parts.

Fuel Pump – Cleaning/Inspection

Clean fuel pump housing, check valves, pulse cham-

ber, and pump base in solvent, and dry all but check

valves with compressed air.

Inspect each check valve (2 ea.), for cracks and/or

holes. Check each black rubber disc (2 ea.) to see

that the black coating is not coming off. Unless dam-

aged while disassembled, replacement is seldom

necessary. Inspect the Check Valve Assembly on

Chamber Plate (check by both pressure and suction

to hose barb), to see that check ball is moving and

functioning (1-3 psi required).

Inspect fittings on fuel pump housing for looseness or

any signs of fuel or air leaks. Replace or tighten fitting

if leak is found, or replace chamber Plate Assembly.

3A-390-13645--2 495 FUEL SYSTEM AND CARBURETION

Check Valve Reassembly

ASSEMBLY (DESIGN I)

1. Insert retainer thru plastic disc and rubber check
valve.

b

c

4. Reinstall rod into retainer cap and, use a small
hammer or hammer and punch to tap rod down
into retainer until flush with top of retainer.

a

b

a

23601

a - Retainer
b - Plastic Disc
c - Check Valve

2. Install check valves and retainers into fuel pump
body.

23601

a - Rod
b - Retainer Cap

Check Valve Reassembly

ASSEMBLY (DESIGN II)

1. Insert retainer thru plastic disc and rubber check
valve.

a

c

b

a - Retainer
b - Plastic Disc
c - Check Valve

51530

24514

3. With retainer installed in pump body, break retain­er rod from retainer by bending sideways.

a
b

23601

a - Retainer Rod
b - Retainer

3A-4 90-13645--2 495FUEL SYSTEM AND CARBURETION

2. Install check valves and retainers into fuel pump
body.

51530

3. Reinstall rod into retainer cap and, use a small
hammer or hammer and punch to tap rod down
into retainer until flush with top of retainer.

Step-by-Step Reassembly

IMPORTANT: ALWAYS REPLACE GASKETS.

STEP-BY -STEP FUEL PUMP REASSEMBLY

After reassembling check valve in fuel pump body,
using the following procedure will help insure proper
reassembly:

1. Insert two 3 in. minimum length 1/4″ bolts (not the
fuel pump bolts) OR 1/4″ dowels, through the
opposite large holes (6mm bolt holes) in the
chamber plate, as locating dowels, and turn plate
upside down so that the inner side is facing up.

2. Insert coil spring and cap in place.

3. Place Boost Chamber GASKET over dowels
(bolts) and lower onto Chamber Plate -- BE SURE
that gasket directional alignment is correct and
that “V-tabs” are aligned.

4. Place Boost DIAPHRAGM over dowels, and
lower to assembly.

5. Place Fuel Pump Body over dowels, and lower to
assembly .

6. Insert Coil Spring and Cap in pump body.

7. Place Fuel Pump DIAPHRAGM over dowels, and
lower to assembly.

a - Rod
b - Retainer Cap

8. Place Pulse Chamber GASKET over dowels, and
lower to assembly.

9. Place Fuel Pump Base over dowels, and lower to

a

b

assembly .

10. Grasp assembly firmly and clamp together with
hands--turn over, and insert the 5mm Fuel Pump
BOLTS (hex-head); After tightening, remove
dowels (1/4″ bolts) used for locators.

1 1. Check that the directional alignment of all parts is

correct and that the “V-Tabs” are aligned.

3A-590-13645--2 495 FUEL SYSTEM AND CARBURETION

70-75-80-90 (3 cyl.)
(Design 1)

Previous body with rubber check
valve retainers was colored black.

a

b

c

e

f

d

i

g

h

a - Body (Opposite Side View)
b - Natural Body (Off White)
c - Rubber Valve
d - Cover (Opposite Side View)
e - Plastic Disc
f - Plastic Check Valve Retainer
g - Two Oil Passage Holes
h - Cast Aluminum Cover
i - One Tab
j - Two Tabs

3A-6 90-13645--2 495FUEL SYSTEM AND CARBURETION

j

50289

100-115 (4 cyl.)
(Design 1)

Previous body with rubber check
valve retainers was colored black.

a

b

c

e

f

d

i

g

h

a - Body (Opposite Side View)
b - Natural Body (Off White)
c - Rubber Valve
d - Cover (Opposite Side View)
e - Plastic Disc
f - Plastic Check Valve Retainer
g - Two Oil Passage Holes
h - Cast Aluminum Cover
i - One Tab
j - Two Tabs

j

50291

3A-790-13645--2 495 FUEL SYSTEM AND CARBURETION

REASSEMBLY SEQUENCE (DESIGN 1)

j

CAUTION

Observe position of both Pulse Chamber
DIAPHRAGM and GASKET. The two larger holes
allow oil injection output to enter the gas flow.
Failure to reinstall as shown WILL result in
extensive damage to engine.

i

h

g
f

e

d

c

b
a

a - Chamber Plate (Step 1)
b - Boost Compression Spring & Cap (Step 2)
c - Boost Chamber Gasket (Step 3)
d - Boost Diaphragm (Step 4)
e - Fuel Pump Body (Step 5)
f - Main Compression Spring & Cap (Step 6)
g - Fuel Pump Diaphragm (Step 7)
h - Pulse Chamber Gasket (Step 8)
i - Fuel Pump Base (Step 9)
j - Fuel Pump to Powerhead Gasket - Shown for

Identification Purposes Only

Reinstalling Fuel Pump to Powerhead ­see preceding page

51119

3A-8 90-13645--2 495FUEL SYSTEM AND CARBURETION

70-75-80-90 (3 cyl.)
(Design 2)

a

b

c

e

d

a - Body (Opposite Side View)
b - Rubber Valve
c - Plastic Disc
d - Cover (Opposite Side View)
e - Plastic Check Valve Retainer
f - Cast Aluminum Cover
g - Three Tabs
h - Three Tabs

g

f

h

51549

3A-990-13645--2 495 FUEL SYSTEM AND CARBURETION

100-115 (4 cyl.)
(Design 2)

a

g

b

c

d

e

h

f

i

a - Body (Opposite Side View)
b - Rubber Valve
c - Plastic Disc
d - Cover (Opposite Side View)
e - Plastic Check Valve Retainer
f - Cast Aluminum Cover
g - Body
h - Three Tabs
i - Three Tabs

3A-10 90-13645--2 495FUEL SYSTEM AND CARBURETION

51548

Installation of Design 2 Fuel Pump

MODEL 100, 115

MODEL 70, 75, 80, 90

a

c

f

a - Clear Tube [5.5 in. (139.7mm)]
b - To Oil Pump Outlet
c - Check Valve
d - Hose [1.5 in. (38.1mm)]
e - Hose [2.5 in. (63.5mm)]
f - Fuel Line Connector
g - Y-Fitting
h - Hose [3 in. (76.2mm)]
i - Fuel Pump
j - 90 Degree Elbow
k - Fuel Outlet to Filter
l - Hose [2.5 in. (63.5mm)]
m- To Pulse Fitting on Powerhead

MODEL 70, 75, 80, 90

d

e

g

h

a

c

m

n

b

l

k

51519

b

j

l

m

efg hi j

k

i

51519

a - Clear Tube [8 in. (203.2mm)]
b - To Oil Pump Outlet
c - Check Valve
d - Hose [1.5 in. (38.1mm)]
e - Fuel Connector
f - Hose [1.5 in. (38.1mm)]
g - T-Fitting (EXISTING)
h - Y-Fitting
i - Hose [1.75 in. (44.5mm)]
j - Fuel Pump
k - Fuel Outlet to Filter
l - 90 Degree Elbow
m- Hose [4 in. (101.6mm)]
n - To Pulse Fitting on Powerhead

MODEL 100, 115

d

f

d

b

h

e

i

c

f

a

h
j

g

a - Fuel Pump
b - Pulse Hose
c - Inlet Hose
d - Outlet Hose (Replace with Molded Hose)
e - Elbow [Apply PERFECT SEAL (92-34227--1) to threads]
f - Check Valve
g - Y-Connector
h - Screws [Torque to 55 lb. in. (6.2 Nm)]
i - Clear Tubing [5.5 in. (139.7mm)]
j - Gasket (Cylinder Block to Fuel Pump) (HIDDEN)

51516

b

i

h

e

d

c

f

a

j

h

g

a - Fuel Pump
b - Pulse Hose
c - Inlet Hose
d - Outlet Hose
e - Elbow [Apply PERFECT SEAL (92-34227--1) to threads]
f - Check Valve
g - Y-Connector
h - Screws [Torque to 55 lb. in. (6.2 Nm)]
i - Clear Tubing [8 in. (203.2mm)]
j - Gasket (Cylinder Block to Fuel Pump) (HIDDEN)

51516

3A-1190-13645--2 495 FUEL SYSTEM AND CARBURETION

Carburetion

Fuel System Troubleshooting

Troubles, that are caused by items 1-thru-5, listed be­low, may give the impression that a problem exists in
the fuel system:

1. Spark plugs

2. Ignition spark voltage

3. Cylinder compression

4. Reed valves

5. Ignition timing

Troubleshooting Charts

PROBLEM 1: ENGINE TURNS OVER BUT WILL NOT

START OR STARTS HARD WHEN
COLD

Possible Cause Corrective Action

Improper starting
procedure.

Fuel tank empty;
improperly mixed fuel;
contaminants (water,
dirt, etc.) in fuel.

Fuel tank air vent closed
or restricted.

A pinched or restricted
fuel line.

Dirty or restricted fuel
filter.

Enrichener valve not
operating.

An inlet needle (in
carburetor) that is stuck
open or closed. (A
needle stuck open, will
cause a flooding
condition. A needle stuck
closed, will prevent fuel
from entering carburetor.)

Anti-Siphon valve
restricting fuel flow.

See “Checking for Restricted Fuel Flow caused
by Anti-Siphon Valves”, page 3A-1.

Check procedure, as
outlined in “Operation
and Maintenance
Manual.”

Check fuel in fuel tank
and replace or add.

Air vent must be open
and free from
contaminants.

Check, and replace as
needed.

Check, replace or clean.

Check enrichener
system. (Refer to
“Enrichener System”
following.)

Remove, clean, or
replace.

Refer to “Checking for
Restricted Fuel Flow
caused by Anti-Siphon
Valves”, following.

PROBLEM: ENGINE FLOODS

Possible Cause Corrective Action

Dirt or foreign particles
are preventing inlet
needle from seating.

Worn inlet needle. Replace.
Punctured float. Replace.
Incorrect float setting. Reset float.

PROBLEM: ENGINE RUNS TOO LEAN

Possible Cause Corrective Action

Carburetor is loose. Air
leaks past mixing
chamber cover.

Fuel level too low. Reset float level.
Clogged high speed jet. Check and clean.
Restricted fuel flow to

carburetor.

Incorrect high speed jet. Refer to main jet chart

Idle mixture set too
lean.

Air leakage into fuel
system.

Anti-Siphon valve
restricting fuel flow.

PROBLEM: ENGINE RUNS TOO RICH

Possible Cause Corrective Action

Fuel level too high. Reset float to correct

Carburetor floods. See preceding “Engine

Idle nozzle air holes
plugged.

Restricted air flow. Check cowl air inlet and

Main Fuel Jet loose. Retighten Jet.

Flush out inlet seat and
clean inlet needle.

Tighten bolts securely.
Tighten cover or replace
gasket.

Check fuel lines and
filter(s) for restricted
flow.

and replace with proper
jet.

Adjust to run richener.

Check fuel line
connections, hose
clamps, fuel pump, and
fuel outlet tube (located
in fuel tank) for loose
fittings.

Refer to “Checking for
restricted fuel flow
caused by Anti-Siphon
valves.”

level.

Floods”
Blow out with

compressed air.

carburetor for
obstructions.

3A-12 90-13645--2 495FUEL SYSTEM AND CARBURETION

PROBLEM 1: ENGINE IDLES ROUGH AND

STALLS

PROBLEM 2: ENGINE RUNS UNEVEN OR

SURGES

PROBLEM 3: ENGINE WILL NOT ACCELERATE

Possible Cause Corrective Action

Fuel tank air vent closed
or restricted.

A pinched, cut or
restricted fuel line; also
loose fuel line
connection.

A dirty or restricted fuel
filter.

Restricted filter in fuel
tank.

Improperly mixed fuel;
contaminants (water,
dirt, etc.) in fuel.

An inlet needle (in
carburetor) that is either
stuck open or closed. (A
needle, that is stuck
open, will cause a
flooding condition. A
needle, that is stuck
closed, will prevent fuel
from entering
carburetor.)

Incorrect idle mixture
adjustment.

Damaged fuel pump
diaphragm.

Carburetor is loose. Tighten bolts securely.
Chamber cover leaking

air.
Off idle holes plugged. Blow out with

Main nozzle or idle
nozzle air bleed holes
plugged.

Improper main jet or
restricted jet.

Damaged reed(s). Inspect reeds as

A crack in the fuel
pick-up outlet tube
(located in fuel tank).

Check - Air vent must
be open all-the-way and
free from restrictions.

Check all fuel lines and
replace as needed.
Check and tighten all
fuel line connections.

Check, replace, or clean
all fuel filters.

Clean by rinsing in
clean lead-free gasoline
or kerosene.

Check fuel and replace,

if necessary.

Remove and replace
with new inlet needle.

Re-adjust.

Replace.

Tighten or replace
gasket.

compressed air.
Blow out with

compressed air.

Clean or replace with
proper jet (refer to “Main
Jet Chart”).

outlined in Section 4A.
Replace.

A crack in the fuel outlet
tube (located in fuel
tank.)

Anti-Siphon valve
restricting fuel flow.

PROBLEM: FUEL BLOW-BACK OUT OF

CARBURETOR

Possible Cause Corrective Action

Chipped/Broken
(reed-block) Reeds

PROBLEM: ROUGH IDLE

If related to reed-block,
indicates excessive
preload in reeds.

PROBLEM: CAN’T REDUCE ENGINE RPM TO

SLOW IDLE

Multiple Chipped Reeds. Replace Reeds.

Replace.

Refer to “Checking for
Restricted Fuel Flow
Caused by Anti-Siphon
Valves,” following.

Replace Reeds.

Replace Reeds.

Checking for Restricted Fuel Flow
Caused by Anti-Siphon Valves

While anti-siphon valves are helpful from a safety
standpoint, they clog, they may be too small, or they
may have too heavy a spring. The pressure drop
across these valves can, create operational problems
and/or powerhead damage by restricting fuel. Some
symptoms of restricted (lean) fuel flow, are:

1. Loss of fuel pump pressure

2. Loss of power

3. High speed surging

4. Preignition/detonation (piston dome erosion)

5. Outboard cuts out or hesitates upon acceleration

6. Outboard runs rough

7. Outboard quits and cannot be restarted

8. Outboard will not start

9. Vapor lock

Any type of anti-siphon device must be located be­tween the outboard fuel inlet and fuel tank outlet. A
method of checking [if such a device (or bad fuel) is
a problem source] is to operate the outboard with a
separate fuel supply which is known to be good.

If, it is found that the anti-siphon valve is the cause of
the problem, either 1) replace the anti-siphon valve or

2) replace it with a solenoid-operated fuel shutoff

valve.

3A-1390-13645--2 495 FUEL SYSTEM AND CARBURETION