Mariner 20 HP User manual

20 25 HP MODELS
n
3

READ THIS MANUAL THOROUGHLY
If you don't understand any portion, contact your dealer for a
demonstration of actual starting and operating procedures.
NOTICE
Throughout this publication, and on your
outboard, DANGER, WARNINGS and
CAUTIONS, accompanied by the inter
-
national HAZARD Symbol A , may be
used to alert the installer/user to special
instructions concerning a particular ser
-
vice or operation that may be hazardousif
performed incorrectly or carelessly.
OB -
SERVE THEM CAREFULLY.
These
" Safety Alerts " alonecannot elim -
inate the hazards that they signal. Strict
compliance to these special instructions
while performing
the service, plus
" common sense " operation, are major
accident prevention measures.
A DANGER
DANGER
- Immediate hazards which
WILL result insevere personal injuryor
death.
WARNING
WARNING
- Hazards or unsafe prac -
tices which COULD result in severe
personal injury or death.
A CAUTION
CAUTION
- Hazardsor unsafepractices
which could result in minor personal
injury or product or property damage.
IMPORTANT
- Indicatesinformationor
instructions that are necessary forpro
-
per operation and/or maintenance.
Theoperator (driver) isresponsiblefor the
correctandsafeoperationof theboat, the
equipment aboard and the safety of all
occupants aboard. We strongly recom
-
mendthattheoperator readthisOperation
and Maintenance Manual and thorough1
understandtheoperationalinstructionsfa
the outboard and all related accessorie
before the boat is used.
The following advantages and disad
vantages of an EMERGENCY STOF
SWITCH (lanyard type) should be con
sideredbefore electing touse, ornot tc
use, such a switch.
ADVANTAGES:Thepurposeof anEMER
GENCY STOP SWITCH is to stop thc
engine when the operator leaves hi:
control station, either accidentally b)
falling into the boat, or by falling 01
being ejected overboard. This is mosl
likely incertain types of boats such as
lowsidedbassboats, highperformance
boatsandlight sensitive handling, fish
-
ing boats operated by hand - tiller. It is
also likelyas a result of poor operating
practices such as sitting ontheback of
theseat at planing speeds. standing at
planingspeeds, operatingathighspeeds
inshallow or obstacle infested waters.
drinking and driving, or daring, high
speed boat maneuvers.
DISADVANTAGES: Inadvertentactiva
-
tion of the switch is also a possibility.
Thiscouldcauseanyorallofthefollow
-
ing potentially hazardous situations:
Lossofbalanceandfallingforwardof
unstable boat passengers
- a particular
concerninbowrider typeboats.
Loss ofpower and directional control
in heavy seas, strong current or high
winds.
* Loss of control whendocking.

As we cannot possibly know of and
advise the boating public of ALL con
-
ceivable boat/motor typesand/or poor
operating practices, the final decision
of whether to use an EMERGENCY
STOPSWITCHrests withyou, theown-
er/driver.
We strongly recommendthat other occu -
pantsbe instructed onproper starting and
operating procedures should they be re
-
quiredto operate theoutboard andboatin
an emergency.
WARNING
A SECURITY LlNE that is long enough
toallowtheoutboardtodisengagefrom
thetransom but too short topermit the
outboardtosubmergeandstoprunningcould
cause theoutboard toreboundintothe
boat and ~njuretheoccupants.
An effective SECURITY LlNEshould
be ofa working strengthapproximately
five
(5) timestheweightoftheoutboard
motor.
* The SECURITY LlNE should be
SHORTenoughandaffixedinamanner
toprevent the outboard from rising up
and disengaging from the transom
-
OR -
@ The SECURITYLINEshouldbeLONG
enough and affixed in a manner to
permittheoutboardtosubmergebehind
the boat and thus stop running.
Itisdifficult tor aperson standing orfloat
-
inginthe water tomove clear if they see a
powerboatheading toward them, even at
slow speed. Shift the unit to neutral and
shut off engine when your boat is near
peoplein the water.
SERIOUS INJURY IS LIKELY IF A PER
-
SON IN THE WATER IS STRUCK BY A
MOVINGBOAT, GEAR HOUSING, PRO
-
PELLER, OR ACCESSORY RIGIDLY
ATTACHED TO YOUR BOAT OR OUT -
BOARD.
WARNING
The use of accessories not manufactured
or sold by Mercury Marine is not recom
-
mendedforusewith youroutboard.Ifyour
outboardor outboard operating system is
equipped withanaccessory not manufac
-
tured by Mercury Marine, be sure to read
theOperationandMaintenanceManualfor
that accessory before operation. If you
haven't beensuppliedwith suchamanual,
contact yourdealer or themanufacturerof
the accessory to secure the applicable
manual.
WARNING
USE CARE when transporting fuel con -
tainer, whetherinaboat orcar.DO NOTfill
fuelcontainertomaximumcapacity.Gaso -
line will expand considerably as it warms
up and can build up pressure in the fuel
container.Thiscancausefuelleakageand
apotential iirehazard.
TABLE OF CONTENTS
Specif~cat~ons .................................................................. s
.............................................................. Motorlnstallat~on 7
................ Propellers 11
............................................. Condit~orisAffect~rigC)pt:rat~ori.. 12
........................................................ Fuel Recomrnendat~uns 1%
Motorcontrols ................................................................ 15
......................................... Operat~on - Models with Tiller tia!~clla.. 17
Shalic~wWater Troll - T~llerHandle Models Only ................................. 19
............................ Qu~cksilverS~deMount Rerriote Control Components
21
........................... Operat~on - Manual Start Models wlth Ren~oteControl
21
...........................
Operat~on - Electric Start Models wlth Remote Control 23
......................................................... Emergency Operation 27
................................................ Cowl Removal and Installation.. 27
LubricationGuide ............................................................. 25
..................................................... Gear Housing Lubr~cation 29
lnspect~onand Maintenance ................................................... 31
Flushing Motor
Cooling System ................................................ 31
lgnltlon Ma~ntenanr.~? ........................................................ 32
.........................................................
Cleaning Fuel Flltrrs.. 33
Fuel Rese~ve (6 6 Gallon Polyetliylenc: Tank CJnIy) .............................. 33
Carburetor Adjirstnionts .................................................... 35
Trailerlng Boat/Motor ......................................................... 30
The descript~onand specifications contained hcre~nwere Ineffect at the t~rnethis gurdc
was approved for prlnting Mercury Mar~ne,whose pol~cy IS one of contlriuousImprove -
ment. reserves the right to dlscont~nuemodels at any tlme, to change spec~f~catlons
designs,methods or procedures w~thoutnotice and w~thoiitIncurring obl~yation
Mercury Mar~ne,Fond duLac, W~sconsin LI S A
Lltho in U 5.A
' 1YYO Brunc,w~i k Lorporat~on
The following are registered tradeniarks ol brunsw~ckCorporat~onAuto -
blend Jet-Prop Marlner Merc MerCathode MerCrufser Mercury Mercury
Marme Qu~cks~lverR~de-Gu~deand Thruster
OUTBOARD SERIAL NUMBER LOCATION
Serial
Number
Plate
q
L Serial Number

Electric Start withTiller Handle Shown
1. Top Cowl
2. Cowl Latch
3. " Tell - - Tale " Outlet
4. Bottom Cowl
5. DrweShaft Housing
6. Anti
- Ventilation Plate
7. Trim Tab
8. Propeller
9. ElectrlcStarter Button
10. Tiller Handle
1 1. Primer/Fast IdleKnob
12. Safety Clip
13. Clamp Screw (2)
14. Clarnp Bracket (2)
15. Swivel Bracket
16. Gear Housing Assembly
17. Water Intake (Starboard)
SPECIFICATIONS
-
Stroke 2.36 (60mm) .. -
Recommended Spark Plug
NGK BUHW or AC-V40FFM or
Champion L76V [Use Champ~on
OL78V Where RadioFrequency
Interference (RFI)Suppression
is Reauiredl
. .
mvance
--
25" BTDC @ WOT
~ - --
-,
- -
Automotive Leaded
1 Recommended Gasoline or Unleaded (Lead Free) Gasoline
Quicksilver 2
- Cycle
Outboard Oil
I
Gasoline/Oil Ratio
50:1 (Including Break - In)
j
Fuel Tank Capacity:
- U.S. Gallons
- Imperial Gallons
I Electric Start Models I of 35 Minutes and Cold Crank~ng i
- Liters
Amperage of 180 Amperes
3 Blade Aluminum
i
--
25
I I (10-318''Dia. x 13" P~tch) 1
Gear Ratlo
- . -
Transom He~ght .m5i5" (38cm)
Battery Rating -
I I Long Shaft = 20 " (51cm) 1
MinimumReserve Capacity Rating
'Measured at the propshaft inaccordance with ICOMIA
28.
IMPORTANT: Fasteners (screws and nuts) used in the manufacture of your
outboardmotor are METRIC. (Afewexceptionsare: propeller shaft nutandspark
plugs, whichare 13/16
" , and tilt tubenuts, which are 1 - 1 /4".)
COMBINATIONTOOL alsoincorporates a standard tip
(straight)
screwdriver blade.
A
" Combination Tool " is provided with
the outboard motor (stored inthe "Own- SPARE STARTER ROPE
er's Literature Packet
" ). A spare starter rope also
IS supplied wlth
themotor (storedinthe " Owner's Litera-
This handy tool incorporates a 21 mrn
turePacket " ).The rope may be usedfor a
(13/16 " ) hex socket (fitsspark plugs and replacement in the rewind starter as
-
propeller nut)anda 1 Ommhexsocket(fits sembly or as an emergency starter rope.
10nm fasteners, such as the rewind in event that the rewind starter is In -
starter mounting bolts). The tool handle operable.

MOTOR INSTALLATION
A WARNING
DO NOT OVERPOWER - Most boats
areratedandcertifiedforthemaximum
horsepower capabilities of the boat.
Refer tothe boat
" CertificationPlate "
forthemaximumhorsepower limit.Ifin
doubt, contact your dealer.
LIFTHANDLE
A CAUTION
Afteroutboardremoval,
DO NOTturnout -
boardupsidedownorlayonitsside. Water
could enter powerhead causing
damageto internalengine components.
IMPORTANT:MotorMUSTBEinNEU
-
TRAL (which locks the reverse hooks
over the tilt lock pin) before lifting or
carryingthemotor withthelift handle.
1 Thelift handleislocatedat thefront of
the motor between the clamp brackets.
2 " Finger grip wells " are locatedat the
top rear and along both sides of the
bottom cowl.
TRANSOM HEIGHT
3 Propertransom helght IS Important for
best boatlng performance The gear
houslng antl-ventllatlon plate should be
parallelto theboat bottomandat least
1 "
(25mm)below boat bottom
MOUNTING MOTOR ON TRANSOM
A WARNING
Before operating, motor(s) MUST BE
SECURED to boat transom with two
5/16'' (7.9mm) diameter bolts and
clamp screws tightened securely as
shown.Installationmustbe water tight
and clamp screws and mounting bolts
checked occasionally for tightness
on
the transom. Failure tofasten motor to
transomwithmountingboltsandcidm
screws, may result in damage to boa
and/or lossofmotorandpossibleinjur
tooccupants of boat.
Centerline
4 Center motor onboat transom.
Securing Motor
5 Tighten clamp screws securely
6 Drill through transom and bolt nioto
clamp brackets to transom with bolts
nuts and washers provided.
7 RefertoSecurityLineStatement,Pay(
2.
IMPORTANT: Periodicallycheckclamr
screwsand transom mounting bolts tc
ensurethatmotorissecureontransom
TILTING MOTOR
IMPORTANT: To manually tilt motor
themotor MUST BE shiftedinto FOR
-
WARD gear. DONOT use tiller handle
fortiltingmotor. To
tilt motor, grasptop
rear of cowl and
tilt motorforward.
Tilt Pin (Angle)Adjustment
8 Tilt angle of the lower unit has a
distinct effect on performance and
handling. Adjust by changing location of
tilt oinuntil boat rides level.
IMPORTANT: Propeller shaft tilt will
affect boat performance. Withthe mo
-
tor tilted in, propeller force will make
the boat want to go into a right hand
turn. The situation reverses when the
lowerunitistiltedoutwellpast vertical.
The operator must resist this force to
keep the boat on a straight course.
Refer toTRIMTAB ADJUSTMENT.
IMPORTANT: DONOT operate motor
withtiltpinremoved.

MOTOR INSTALLATION
(Continued)
Tilt Lever
1 Locks motor ina fully tilted position.
CAUTION
Engine must not be run infull
tilt lock
position, as water pickup inlower unit
would be out of the water, and water
pumpand/orengine wouldbedamaged.
DO NOT use
tilt lever when TRAIL-
ERlNGboat/motor(orduringHIGHSPEED
and/or ROUGHWATER operationofa
boat that is powered by a larger, main
power motor) UNLESS lower unit is
supported witha block of wood. Refer
to
TRAlLERlNG BOAT/MOTOR.
To tilt motor up/out:
2 Shift motor into FORWARD geai
3 Grasp motor "finger gripwells"at rear
of top cowl and lift (tilt)motor to full up
position. Tilt lever will automatically en -
gage and lock the motor Iri tilted up/out
position.
To disengage tilt:
T~ltmotor as far as possible, pulltilt lever
toward transom and lower motor to nor
-
mal operating position.
CO
- PILOT ADJUSTMENT
4 Proper co-prlot adjustment w~ll keep
motor ona f~xedcourse (duringNORMAL
operation) while allow~ngeasy manual
steering control
Turn adjusting screw clockwise to In
-
crease friction or counterclockwrse to
decrease friction
IMPORTANT: The trimtabis madeofa
special alloy toprotect motor housings
fromgalvanic corrosion. DONOT paint
or placeprotective coating onthe trim
tab.
TRIMTAB ADJUSTMENT
5 Thetrlmtab willhelp tooffset steel III~
pull caused by propeller torque at high
speedsor extremetilt angles.Ifboat
pulls
to the left, loosen cap screw arid rotate
trailing edge of trim tab to the left (as
viewedfrombehindmotor). If boatpullsto
the riyltt, rotate trimtab toright. Tighten
car, screw.
BATTERY ANDELECTRICAL
ACCESSORIES
Mariual start altenator models are
equipped with a
60 watt alternator
CAUTION
Failure toobservecorrectpolaritywhen
connecting batteryleads tobattery will
resultindamagetothechargingsystem
onelectric starting models.
IMPORTANT: Secure battery in a fav
-
orableposition inthe boat.
Any accessories, such as horns. Iiyrrts,
etc, should be properly fused and in
stalledw~th
connectionsattacheddirectly
to battery ter~n~nals
MOUNTING FUEL TANK AND
CONNECTINGFUEL LINES
Secure fueltank Inaconvenient locatlun
Conriect fuel lmetotank.Insert connector-
and twlst 1/8-turn to lock.
Arrange fuel line so that it does not
become twisted, kinked, pinched or
stretched.

PROPELLER SELECTION
PROPELLERS
The propeller supplied with your motor
provides the best overall performance
under average operating conditions.
Alternative propellers are available for
specific boating requirements. Consult
your Authorized Dealer for recom
-
mendations.
PROPELLER REMOVAL
A WARNING
Before attempting to remove or install
propeller, removesparkplugleadsfrom
sparkplugstopreventenginefromstart
-
ingaccidentally.
1
Remove top cowl (see COWL RE -
MOVAL AND INSTALLATION) and dis -
connect spark plugleads.
2 Place wood block between propeller
bladeandanti
- ventilationplatetoprevent
rotation.
3 Turn propeller shaft nut counter -
clockwise to remove nut (use "Cornb~na-
tion Tool " supplied or 13/16 " wrench).
4 Slidepropeller andsplinedthrust hub
off propeller shaft.
PROPELLER REPAIR
Some darnaged propellers can be re
-
palred Consult your Authorwed Dealer
PROPELLER INSTALLATION
IMPORTANT: Periodically check pro
-
peller nut for tightness during boating
season.
5 Apply a liberal coat of oneof the follow -
ing Quicksilver lubricants tothe propeller
shaft;Special Lubricant
101.2 - 4 - C Marine
Lubricant.
IMPORTANT: The cupped washer at
-
tachedtothe thrust hubpreventsback -
wardinstallationofthehub. Thecupped
washer MUSTREMAIN
IN PLACE.
6 Slidesplinedthrusthubontopropeller
sliaft with thrust hub " shoulder " toward
year housing.
Slrdepropeller onto shaft and ~nstalipro -
peller shaft nut.
Place
a wood block between propelier
blade andanti
- ventilation platetoprevent
rotation.
Turnpropeller shaft nut clockwise.
Using
"Conib~nat~onTool " supplied or 13/16"
wrench, TIGHTEN NUT SECURELY.
Reconnect spark plug leads and install
top cowl.

ITIONS AFFECTING
OPERATION
WEIGHTDISTRIBUTION
Positioning of we~yht(passengers and
gear) inside the boat has the following
effects:
A SIi~ft~ngwrryht to rear (stern)
@ Generally Incredses speed and englne
RPM
@ At extremes, can cause boat to por -
poise
@ Causesbowtobounce ~nchoppy water
(1 Increases danger of thefollow~ng-wave
splash~ngInto boat when comlng off
plane
B. Shift~ngweight to front (bow)
lmproves ease of planing off
e Improves rough water ride
0 At extremes, can cause boat to veer
back and forth(bowsteer).
BOTTOM OF BOAT
To maintain maxlmumspeed the follow
-
ing cond~tionsof the boat bottom should
beobserved:
A. Clean, free of barnacles and marine
growth.
B. Free of distortion, nearly flat where ft
contacts the water.
C. Straight and smooth, fore andaft.
L RECOMMENDATIONS
Any leaded or unleaded (lead - free) gaso -
line,that willsatisfactorily operateanauto -
mobile engine is suitable for use in these
model outboard motors.
However, gasolines containing alcohol.
e~thermethyl alcohol (methanol)or ethyl
(ethanol)may cause increased:
s Corrosion of metal parts.
c Deteriorat~onof elastomer and plastic
parts.
s Fuel permeation through flexible fuel
lines
Wear and damage of internal engine
parts.
Stiirting and operating diff~cult~es.
Some of these adverse effects are due to
thetendency of gasolinescontaining alco
-
holtoabsorb rnoisturefromthe air, result -
ing in a phase of water and alcohol
separating from the gasoline in the fuel
tank.
The adverse affects of alcohol are more
severe with methyl alcohol (methanol)
and arc worsu w~thIncreasing alcohol
content.
A WARNING
FIREANDEXPLOSIONHAZARD:Fuel
leakagefromanypartofthefuelsystem
canbeafireandexplosionhazardwhich
cancauseseriousbodilyinjuryordeath.
Carefulperiodicinspection oftheentire
fuel system is mandatory, particularly
after storage. All fuel components in
-
cluding fuel tanks, whether plastic,
metal or fiberglass, fuel lines, primer
bulbs, fittings, fuel filters and car
-
buretors should be inspected for leak -
age, softening, hardening, swelling or
corrosion. Any sign of leakage or de
-
teriorationnecessitates replacementbe -
fore further engine operation.
Because ofthe possible adverse effects
ofalcoholingasoline,
it isrecommended
that only alcohol
- free gasoline beused
where possible. If only alcohol-con-
tainingfuelisavailable, orifthepresence
of alcohol is unknown, then increased
inspection frequency for leaks and ab
-
normalities is required.
FUEL RECOMMENDATIONS (Continued)
A wmN1w
USECAREwhentransportingfuelcon -
tainer, whether in a boat or car. DO
NOT fill fuel container to maximum
capacity. Gasoline willexpandconsider
-
ably as it warms up and can build up
pressure inthe fuelcontainer. This can
cause fuel leakage and a potential fire
hazard.
OILRECOMMENDATIONS
A CAUTION
The use of other than recommended
gasoline and Quicksilver 2
- Cycle Out -
boardOiloranacceptableBIATC - Woil
maycausepistonscoring, bearingfailure
or both. DO NOT, under any circum
-
stances. usemulti - gradeorotherhighly
detergent automobileoils or oils which
contain metallic additives.
Mix recommended gasoline w~thQuick
-
silver 2 - CycleOutboardOilinratioshown
inthefollowingchart.Inanemergency, ~f
this is not available, substitute a high
quality 2
- cycle oil that is Intended for
outboarduseandmeetsBIA ratingTC-W,
shownonoilcontainer.Usetheoilmanu -
facturer's recommended gasol~ne-oilmix -
ture as shown on the label (NOT TO
EXCEED 50:
1 RATIO).
MIXINGINSTRUCTIONS
A WARNING
Observe fire prevention rules, particu
-
larly NOSMOKING. Mix fueloutdoors
or inwell ventilated location.
IMPORTANT: Always use fresh
yasc
line. Gasoline whichis keptintank to
longwillformgumand
varnishdeposil
whichmaycausetrouble.
MIX fuel d~rectlyinto remote tank. P OL
small, equal amounts of gasoline ando
into tank. MIX thoroughly, then add re
ma~n~ngoilandgasoline.Mix agai~r.Kee
fuel clean and mlx each batch of fuf
exactly the same way.
IMPORTANT: Use recommende
amount of2
- cycleoil. Toomuchorto
little oil can cause performance prot
lems. aswellasseriousenginedamagf
MOTOR BREAK - IN PROCEDURE
A CAUTION
Follow break
- inprocedurecarefully.
A MIX gasohne and 011at normal 50
ratlo mlxture
B. Operate new motor at varied throttl
sett~ngsfor the fwst hour (one hour).
IMPORTANT: Avoid both wide-ope1
throttle operation andprolonged idlin!
during first hour.
C After f~rsthour(onehour)ofoperatlor
motor IS ready for normal operation an
may he runat any speed
A CAUTION
DONOTEXCEED thefullthrottle RPN
range. See SPECIFICATIONS for RPN
range.
NORMAL
50:l FUELMIXTURE
Type of Oil
/ U.I Measure / lmper~al --- Measur. 1 Metr~cMeasure
-
Quicks~lver 16USozto 15lmpozto 400cc to each
2
- Cycle each 6 gallons each
5 Imp gallons 20 l~tersof
Outboard
011
of gasol~~te of gasol~r~e aasol~ne
-- -
Use at Manufacturer's Recummenddtlons
DO NOT EXCtED 50 1

MOTOR CONTROLS
1 PRlMERlFASTIDLE KNOB
A ROTATE KNOB - Clockwise (to stop)
when starting engine or to increase idle
speed.
B PULL KNOB COMPLETELY OUT -
(Afterrotating fully clockwise) toinject fuel
into rnanifold for fast, easy starting when
engine is cold.
c PUSH KNOB COMPLETELY IN - After
engine starts. As engine warms up, rotate
knobcounterclockwise toreturn tonormal
idle speed.
2 TILLER HANDLE - Provides a means to
steer boat, shift gears, and control engine
speed onmanually operated
- motors.
3 SHIFTINGPOSITIONS
A NEUTRAL - Felt by detent intw~stgrip.
The decal aligns with arrow on handle.
B FORWARD - Rotate twist gripcounter -
clockwise. The decal indicates boat direc -
tion.
c REVERSE - Rotatetwistgripclockwise
The decal indicates boat direction
4 THROTTLEFRICTIONKNOB - Adjusts
twistgripfrictiontoholdthrottleat desired
boatspeed. Turnknobineither direct1011to
increase friction.
STILLER HANDLEMOUNTEDELECTRIC
START BUTTON
- Used to start engine.
6 STOP BUTTON - Used to stop motor
7 EMERGENCY STOPSWITCH - Refer to
page
1 forexplanation. The lanyard, when
used with the emergency stop switch and
connected tothedriver,w~llstop theengine
~fthe driver no longer has access to the
tiller handle.
8 WATER PUMP OPERATION (No
Thermostat)
Normal water pumpoperation isindicated
by a steady,
" Tell - Tale " stream of water
issuing froma small hole
at rear of bottom
cowlwhilethe motor
is runningandremain
steady during the entire operation of the
engine.
Water Pump Operation (Thermostat)
IMPORTANT: On models which are
equipped with a thermostat (OPTIONAL
ACCESSORY)inthecoolingsystem, a"Tell-
Tale " stream may not be visible until the
enginereachesnormal operating tempera
-
ture and the thermostat opens (5 to 45
seconds,dependinguponengineRPMand
water temperature). The
" Tell - Tale " may
become intermittent while running as the
thermostat opens andcloses.
Operation with a defective water pump or
obstruction in the cooling system will
cause overheating and severe damage.
Refer motor to Authorized Service fa
-
cilities.
NOTICE: If your outboard will be operated
primarilyincoldwater areas [normalwater
temperature BELOW5O0F (10' C)]and/or
areaswhereextremeday
- to - dayair temper -
aturevariat~onsof more than 30" F (17 " C)
are common, we recommend
installation
ofathermostat (OPTIONALACCESSORY)
in the engine cooling system.
A thermostat controlledcoolingsystem
maintains a constant, higher engine
operating temperature, thus providing
smootherengineoperation, particularly
at slower operating speeds. See an Au
-
thorized Servicing Dealer for this ac -
cessory.

OPERATION
MODELS WITH TILLER HANDLE
BEFORESTARTING
A CAUTION
This motor is water cooled. DO NOT
operate motor out
- of - water. Serious
damage to motor could result from
overheating.
DO NOT attempt to shift motor into
REVERSEgearWHENENGINEISNOT
RUNNING. Damagetothe shift mech
-
anism could result.
OPERATOR and PASSENGERS
SHOULDBE SEATEDWHENEVER
AT -
TEMPTING to START the MOTOR.
Before attempting to start motor,
MAKE CERTAIN that motor is shifted
into NEUTRAL and that area around
boat isclear (toget underway).
1 Check fuel tank for suff~c~entfuel dnd
that tank IS secure ~nboat
2 Open alr vent on fuel tank cap
3 Squeeze fuel prlnrer bulb untrl ~t rs
firm
4 Check that emergency stup svv~tc:lr IS
~nRUN posltlon.
STARTING
IMPORTANT: Manual starting motors
are equipped with a rewind starter
"lock-out" mechanism -- motor MUST
BE inNEUTRAL, or twistgripinSLOW
position, inorder tostart motor.
ELECTRICstartingmotorsareequipped
with a starter
" cut - out " switch -- the
control handle twist grip or the remote
control handle MUST
BE inNEUTRAL
position inorder tostart the engine.
5 Twist grip to NEUTRAL (N)positron.
6 Ef engineiscold,rotate PrimerJFast Idle
Knob clockwise (tostop)and pullknobfull
out and push full
in 3 times, leaving knob
completely out. When restarting warm
engine, rotate knob to full clockwise posi -
tion. Do not pull out knob.
7A On ntanual start models, pull Starrcr
Rope Handle slowly until engaged, then
vigorously. Allow rope to rewind slowly.
Repeat until engine starts.
78 On electric start models, press
STARTER BUTTON
- as soon as engine
starts, release button.
A CAUTION
DO
NOToperatestartermotor forlonger
than
30 seconds or starter motor may
be damaged. Allow at least
2 minutes
between starting attempts.
AFTER STARTING
As soonas englnestarts, push PrimerIFast
IdleKnobcompletely in. Asengine warnis-
up, turn knob slowly counterclockwise to
stop (idleposition).
8 WATER PUMP OPERATION (No
Thermostat)
Normal water pumpoperation IS indicated
by a steady,
" Tell - Tale " stream of water
issuirrgfron-I a small holeat rear of bottom
cowl while the engine is running and
remairr steady during the entire operation
of the
engine.
Water Pump Operation (Thermostat)
IMPORTANT: On models which
are
equipped with a thermostat (OPTIONAL
ACCESSORY) in the cooling system,
a
" Tell - Tale " stream may not be visible
untilthe engine reachesnormal operating
temperature and the thermostat opens
(5 to 45 seconds,depending upon engine
RPM and water temperature). The
" Tell -
Tale " may becomeintermittent while run -
ning as the thermostat opensand closes.
Operbtiori w~th a dcfectrve water pump or
obstruct~onin the cool~ngsystem will
cause overheating and severe damage.
Refer motor to Authorized Service facili -
ties.

OPERATION
MODELS WITH TILLER HANDLE
(Continued)
SHIFTING GEARS CAUTION
re when operatlny fn
CAUTION REVERSE GEAR. DO NOT operate motor
PrimerfFast ldle Knob must be rotated at high speeds when inREVERSE.
completely counterclockwise BEFORE
2 HEVERSE GEAR . engaged by
c
l
oc
k -
shifting- Shift gears with a firm, quick
w
i
s e
rotatron of twist grip Continued rotd
motion toavoid " gear chatter " . tton mcreasesspeed
1 FORWARDGEAR - ennacledbv STOPPING
- -
counterclockw~serotation of twlst grip
3 Press Stop Button at end of tw~st yrli~
Continued rotatlonincreases speed and hold until motor stops
During operation, the Prirner/Fast ldle IMPORTANT: Inan emergency the motor
Knob can be adjusted
to set an idle speed can be stopped at any speed, in or out of
for trolling, etc. Turning c1oc;kwise in
-
gear. For normalstopping, idle motor and
creases idle speed. Turningcounterclock
- shift to NEUTRAL before pressing STOP
wise decreases idle speed. BUTTON.
SHALLOW WATER TROLL
TILLER HANDLE MODELS ONLY
Tiller handle models are equlpped w~tha
7A Grasp motor "finger grtp wells" at
shallow water " Troll " feature that canbe rear of top cowl
engaged when operating In shallow
water ~ngagementof thetiollfeature,in
effect, tilts the motor outward an addl-
7B ~~ft (tilt) motor up to enydge stw~~ufl
tional 6 tdt plnholes water
" 1 roll "
IMPORTANT: Reverse lock is disen-
4 Return twist grip to neutral posttion. gaged. DoNotoperatemotorinreverse.
5 Troll lever is located on starboard
(right)sldeof motor behindclampbracket.
DISENGAGING SHALLOW WATER
6 Push troll lever downward to troll
position.
8 Release troll lever by ralslng upward
IMPORTANT: Troll lever disenaaaes
- -
reverse lock so motor can be tilted
9 Tilt motor up/out sl~ghtly,thenlowerit
up/out manually. to normaloperating position.

QUICKSILVER SIDE MOUNT
REMOTE CONTROL COMPONENTS
1 Neutral Lock Bar - prevents accidental stop switch SHOULD NOT BE USED as
shiftandthrottleengagement. Bar rnustbe normal engine shut
- off.
squeezed before control handle can be
moved, fromNEUTRAL.
IMPORTANT:TheEmergencyStopSwitch
canberepositioned toRUNwithorwithout
- controls forward, lanyard cordlclip so that engine can be
reverse motion and enginespeed.
restarted.
3A Ignition/ChokeSwitch (Electric Start 5 Engine can be restarted with or without
Models) -turns engineOFF and ON, ach- lanyard cord/clip installedbysimply push -
ates electric starter motor, actuates car - ing switch up to run position. Ifnecessary
buretor choke. pushswitch downwithkeytoreinstall clip.
3B RUN-OFF Toggle Switch (Manual 6 F A S T I D L E L E V E R - AIIOWS engine
Start Models) - turns engine ON and OFF. throttle advancement, without shifting
Used to stop engine under normal condi- gears, to assist engine starting.
tions (non
- emergency situations).
7 THROTTLE FRICTION Adjustment
4 EmergencyStopSwitch - RefertoPage Knob - Adjusts control handle friction so
1 for explanation. The lanyard cord/cli~, thatboat speed canbeset and driver does
when usedwiththeemergency stopswitch not have to hold handle. Turn knob clock -
MUSTBEconnectedtoboat driver. Should wise to increase friction, DO NOT thread
driver beunabletoreach steering wheel or knob all the way
remote control, the lanyard cord/clip will
bepulled fromemergency stop switch and
8 Tachometer Receptacle - Wiring har -
the engine will shut OFF. This emergency ness connector for tachometer.
OPERATION - MANUAL START
MODELS WITH REMOTE CONTROL
CAUTION
OPERATORandPASSENGERSSHOULD DO NOT attempt to shift motor into
BE SEATED WHENEVER ATTEMPTING REVERSE gear WHEN ENGINE IS NOT
toSTART the MOTOR. RUNNING. Damage to the shift mecha-
nism couldresult.
A CAUTION CAUTION
Thismotor is water cooled. DO NOT oper
- Before attempting to start motor, MAKE
atemotor out
- of - water.Seriousdamageto CERTAIN that motor is shifted into NEU-
motor could result from overheating. TRALandthatareaaroundboatisclear(to
get underway).

RUN
RUN
8 7
OPERATION - MANUAL START
MODELS WlTHREMOTE CONTROL
(Continued)
BEFORE STARTING
1 Check fuel tank for sufficient fuel and
that tank
is secure inboat.
2 Open air vent on fuel tank cap.
3 Squeeze fuel primer bulb until it is firm.
4 Place control handle in NEUTRAL.
Check that emergency stop switch is in
RUN position.
STARTING
5 Check to be sure RUN - OFF Toggle
Sw~tchis inRUN Position.
6 If engtne iscold, rotate Primer/Fast ldle
Knobclockwise (tostop)andpullknobfull
out and push full In
3 times, leavmg knob
completely out. When restarting warm
engine, rotate knob tofull clockwise posi
-
tion. Do not pull out knob.
Pull starter handle slowly until engaged,
then vigorously. Allow rope to rewind
slowly. Repeat until motor starts.
AFTER STARTING
Assoon asengine starts,push Pr~mer/Fast
ldleKnob completely in.As engine warms-
up, turn knob slowly counterclockwise to
stop (idleposition).
Check waterpumpoperation as outlinedin
MOTOR CONTROLS onpage
15.
THROTTLE/SHIFTINGGEARS
7 Squeezing Neutral Lock Bar and push -
ing control handle forward engages the
FORWARD GEAR. Pushing handle further
forward increases motor speed.
A CAUTION
Exercise extreme care when operating in
REVERSE GEAR. DO NOT operate motor
at high speeds
in REVERSE.
Squeezing Neutral Lock Bar and pull~ny
backoncontrolhandleengages REVERSE
GEAR.
STOPPING
8 Shift to NEUTRAL and push RUN - OFF
ToggleSwitch down to the
OFF posit~on.
IMPORTANT: Inan emergency the motor
can be stopped at any speed, in or out of
gear.For normaloperation, idlemotor and
shift toNEUTRALbefore turning key OFF.
OPEWATION-ELECTRICSTART
MODELS WlTHREMOTE CONTROL
into NEUTRAL and that area around
A CAUTION boat isclear (toget underway).
OPERATOR and PASSENGERS
SHOULD BE SEATED WHENEVER
IMPORTANT: Remote control must be
ATTEMPTING toSTART the MOTOR. equipped with a starter
" cut - out " switch - -
remote control handle MUST BE in NEU-
Before attempting to start motor. TRAL position in order to operate the
MAKE CERTAIN that motor is shifted starter.

OPERATION (Continued)
ELECTRIC START MODELS
WITH REMOTE CONTROL
BEFORE STARTING
Check fuel tank for sufficient fuel and thal
tank is secure in boat.
1 Open air vent on fuel tank cap.
2 Squeeze fuel primerbulb until it 1s firni.
3 Place control handle in NEUTRAL
Check that emergency stop switch is in
RUN position.
A CAUTION
DO NOT operate starter motor for longer
than
30 seconds or starter motor may be
damaged. Allowatleast2minutesbetween
starting attempts.
IMPORTANT: Starter circuit is protected
by SFE
20 AMPfuseaportsideof engine. If
starter fails to operate, check for blown
fuse. BEFORE replacing fuse locate and
correct cause fo overload.
STARTINGCOLD MOTOR
4 Lift up on Fast ldle Lever
IMPORTANT: With Fast ldle Lever in up
position, control handle CANNOT be
moved into FORWARD or REVERSE
GEAR.
5 Turnkey clockwisepast RUNposition to
START and actuate choke by presslng in
on key.
Assoonas motor starts,allow key toreturn
to RUN position and release choke. If
motor falters, push in on key to actuate
choke again.
6 After warm - up, returnFast Idle Lever to
full down oosition.
STARTING WARM MOTOR
Turn key clockwise past RUN position to
START
As soonas motor starts allow key tortturn
toRUN positton If motor falters pushInor)
key to act~latechoke
NOTE If motor falls tostart,follow STAHT-
ING COLD MOTOR Procedure
20/25
Water Pump Operation (No Thermostat)
Normal water pumpoperationis rndicatt ;i
by a steady, " Tell - Tale " stream of water
~ssurngfrom a smallhole at rear of bottom
cowlwhtlethe motor
15 runnlngand renmn
steady during the entlre operatlon of the
engine
Water Pump Operation (Thermostat)
IMPORTANT: On models which are
equipped with a thermostat (OPTIONAL
ACCESSORY) in the cooling system,
a
" Tell - Tale " stream may not be visible until
the engine reaches normal operating
temperature and the thermostat opens
(5
to 45 seconds, depending upon engine
RPM and water temperature). The "Tell-
Tale " may becomeintermittent while run -
ning as the thermostat opens andcloses.
Operation wlth a defrctiv'e water pumpor
obstruction in the cooling system will
cause overheating and severe damage
Refer motor to Authorized Service facilr-
ties
THROTTLE/SHIFTING GEARS
7 Squeezing Neutral Lock Bar and pus/-i-
Ing control handle forward engages the
FORWARD GEAR.Pushing handle further
forward increases motor speed
CAUTION
Exercise extreme care when operating in
REVERSE GEAR. DONOT operate motor
at highspeeds inREVERSE.
Squeezing Neutral Lock Bar and pulri~ig
back oncontrolhandleengagtsREVERSE
GEAR
STOPPING
8 Shift toNEUTRAL aria turnkey c,iiunter-
clockwise to OFF pos~tion
IMPORTANT: Inan emergency the motor
can be stopped at any speed, in or out of
gear. Fornormaloperation, idlemotor and
shift toNEUTRALbeforeturningkey OFF.
25

EMERGENCY OPERATION
If rewind starter becon-ies inoperative, the
niotor can be cranked (util~zlngspare
starter rope supplied) in the following
manner.
1 Remove top cowl (refer to COWL HE-
MOVAL AND INSTALLATION).
2 Remove 3 bolts which secure rewind
starter assembly to engine. Lift rewind
starter fromengine.
3 Sh~ftoutboard or remote control into
neutral.
AWARNING
Whenusingemergency starter ropetostart
outboard, the start
- in - gear protection pro -
vided by the rewind starter or remotecon -
trol is inoperative. Make sure to shift out -
board or position remote control handle
into neutral before starting outboard to
prevent outboard from starting in
gear.
Suddenunexpectedacceleration cancause
serious injury or death.
4 Tie kr~utInend of spare rope Hook rap:
knot In flywheel notch and wind rope
CLOCKWISE around flywheel at least
2
turns
Observe prclrrn~narymotor starting steps
as outlrned InOPERATION irrocedurasand
pull rope to start motor Repeat, ~fmotor
has not started
AWARNING
Caremustbetaken whenusingemergency
starting procedure. DO NOT attempt to
replace rewind starter or cowling after
engine has started. Stay clear of flywheel.
DONOTWEAR loose clothing whenoper
-
ating under these conditions.
COWL REMOVAL and INSTALLATION
DO NOT ATTEMPT TO REMOVE OR 7 Lift cowl off.
INSTALL COWL WHILE MOTOR IS RUN -
NING. INSTALLATION
REMOVAL
Pos~t~oticowl over motor.
STOP MOTOR Llft up on rear of cowl and
tilt ~tforward
shghtly to engage front hook
5 Pushdowntod~sengagecowllatchat rear
of motor Lower cowl ~ntoposltlon and engage rear
latch
6 Lrft up on rear of cowl and t~ltforward to
d~sengagecowl hook at front of motor Push latch upto secure cowl

Throttle/Shift
(AllPivot Points) Every 60 days Every
30 days
I I
1 I I I
2
Tilt Tube/Control
A Every 60 days Every 30 days
Handle Pivot
1 3 1 clamp screws I A
I Every 60days I Every 30 days I
I A I Every 60 days Every 30 days
I I
I I I I
Type of Lubricants
A = Quicksilver 2 - 4 - C Marine Lubricant B
- Quicksilver Gear Lube
4
6
7
GEAR HOUSING LUBRICATI
A
SwivelBracket/
SwivelPin
A CAUTION IMPORTANT: DO NOT use automotive
lubricant in gear housing. Use only Quick
-
Have gear housing checked by your silver Gear Lube.
local service dealer if any of the fol-
lowing are found:
8 Remove fill plug and washer.
Gear Housing
Propeller Shaft
Water drains froin filler hole.
9 Insert lubricant tube into filler hole
Every 60 days
Metal particles are present on magnetic
IMPORTANT: NEVER add lubricant to
fillplug.
gear housing without first removing
vent screw.
NOTE: Presenceof asmallamountof fine
metalparticles(resemblingpowder) indi-
10 Retmove vent screw and washer.
cates normal wear. Addlubricant togearhousinguntilexcess
Lubricant appears milky brown. flows from vent hole.
Every 30 days
B
A
Largeamountsof lubr~cantmustbeadded Replace vent screw and washer
to fill gear housing Hernovc: lubricant tubeandinstallfillplug
Lubricate gear housingas follows: and washer.
After 1st10
days, then
every 30 days
Once aseason
After 1st10
days, then
every 30 days
Every 60 days

INSPECTION AND MAINTENANC
lnspect motor often, and at regular in -
tervals, tohelp maintain its topoperating
performance, andcorrect potential prob
-
lemsbefore they occur. Theentiremotor
shouldbe checked carefully, including all
accessibleengine parts.
Check for loose, damaged or missing
parts. Tighten or replace as required.
Lubricate andcheck gear housmgoillevel
per LUBRICATION GUIDE.
Servicespark plugs.Check plug leadsand
electrical leads for damage.
lnspectfuellinesfor damage.Servicefuel
filters.
FLUSHING MOTOR
A CAUTION
When flushing, be certain the area
aroundpropeller isclear, andnooneis
standing nearby. To avoid possible in
-
jury, removethe propeller.
To prevent silt and/or salt bu~ldupin
cooling system, flush with fresh water
periodically.
1 Install Quicksilver Flushing Attach -
ment (or equivalent) over water intake
openings.
2 Connect hose between flushtng at -
tachment and water tap.
3 With ntotor In normal operatildg po-
sitlon, open water tap and adjust flow so
that some water leaks from aroundcups
4 Shift motor to NELJTRAL and start.
Check that water
IS running fron-I " Tell -
Tale " .
Remove and inspect propeller. If badly
nicked, bent or cracked, refer toAuthor
-
ized Service Facilities. (Refer to PRO -
PELLER - INSTALLATION.)
Repair nicks and corrosion damage on
finish.Use Quicksilver spraypaints
- see
your Dealer.
Inspecttrimtab.Replace if
50% oftabhas
been eroded away.
IMPORTANT: DO NOT apply paint
or
protective coatings totrimtab.
Check that remote control harness is
connected and control is correctly
adjusted.
COOLINGSYSTEM
A CAUTION
DO
NOToverrev. RUNatslowerspeeds
only.
With motor running at Idle speed, con
-
tinue flushing until water becomes clear
(3 to 5 minutes for salt water units).
5 Stop motor,turn - off water andranlove
flushing attachment
IMPORTANT: Keep motor in upright
positionuntilall waterhas drained out.
Waterlefttrappedinmotorcouldcause
engine damage.
6 Clean n~otorsurfaces and wtbe witi-I
Qu~cks~lverCorrosion and Rust Praven-
tive Type IIto protect f~nish

ION MAINTENANCE
CAUTION
DO NOT touch or disconnect any igni -
tion system parts while engine is run -
ning, as high voltage is present.
If electrical/~gnitionsystem is not oper
-
ating, DO NOTattempttorepair, butrefer
lo your authorized service fac~lity.
SPARK PLUGS
Periodic irlspection, cleaning and/or re
-
placement of spark plugs will enhance
rnotorperformance. Alwaysreplacespark
plugs with type specified in SPEC -
IFICATIONS.
Hoplsce spark plugs as follows:
Remove cowl.(RefertoCOWLREMOVAL
AND INSTALLATION.)
1 Disconnect spark plug leads and use
" Combination Tool " supplied, or 13/16 "
wrench, to remove spark plugs.
2 Check that gaskets are in place and
install newplugs.
Thread spark plugs in by hand until fin
-
ger-t~ght.Use "Too1"or wrenchtotighten
an additional
1 /4 turn. DO NOT OVER--
TIGHTEN.
3 Reconnect spark plug leads to correct
plugs.
Inspect spark plug leads for damage
-
replace as necessary.
CLEANING FUEL FILTERS
A WARNING Loosen screws and remove fuel pickup
Be careful when cleaning fuel filter ele- tube with gauge and float.
ments; gasoline is extremely flammable
and highly explosive under certain con~i- Clean filter by rinsing inclean gasoline.
tions. Alwaysstoptheengineand
DO NOT
smoke or allow open flames in the area Reinstall on fuel tank.
while cleaning fueifilter elements.
1 If engine fuelfilterappears tobecontam-
inated, remove and replace.
FUELTANK
PICKUP FILTER Prime fuel system and check for fuel leaks
Disconnect fuel line from tank. after replacing f~lter.
FUEL RESERVE
(6.6 GallonPolyethyleneTank Only)
The 6.6 gallon polyethylene tank incorpo- 2 To utilize fuel reserve, tip tank toward
rates a fuel reserve of approximately
1 fuel plckupand allow reserve fuel to flow
gallon. into fuel pickup chamber.

CARBURETOR ADJUSTMENTS
The carburetor has been calibrated and B Back - out screw 2 turns countet-
re-set at factory to provide best per - clockwise.
formanceunder normalconditions. How
-
ever, extremechangesinweatherand/or Start engine
- AllowtorunatIDLEfor sev-
elevation mav necessitate further car- era1minutes.
buretor adjusiments.
2 With engineatIDLE, shift toFORWARD
IMPORTANT: To maintain peak engine GEAR.
pertormance when operating at HIGHER 3 Turn screw counterclockwise until
ELEVATIONS,itwill benecessarytoinstall starts to or fire unevenly
aLEANER fixedhighspeed jet. (See your (TOO RICH).
authorized sewicefacility).
4 Slowly turn screw clockwise until
engine fires evenly and RPM increases.
LOW
SPEED MIXTURE Continue turning clockwise until RPM de
-
creases and engine misfires (TOOLEAN).
1 Pre - set low speed mixture screw as set
low speedmixture screw atpoint mid-
follows: way betweenTOO RICH and TOO LEAN.
When in doubt, set slightly RlCH rather
A Lightlytightenscrew -. turnclockwise. than
TOO LEAN.
Whentraileringor transporting theboat/ -
motor, it is recommended that motor
remaininnormaloperating position, with
steeringfrictionco
- pilottightenedenough
to hold forward direction.
CAUTION
Tiltlockmechanism isNOTintendedto
support motor during trailering. Dam
-
age to boat or motor could occur if
additional support isnotused.
5 If adequate road clearance presents a
problem, either remove the motor froin
the transom and store securely, or place
motor infulltilt
- uppositwn(see MOTOR
INSTALLATION -TILTLEVER)andplace
a
suitable block of wood between swivel
bracket and clamp brackets to support
motor. MAKECERTAIN that block is posi
-
tioned toprovide adequate clearance for
the reverse lock hooks and/or
" troll "
bracket, then, d~sengagetilt lever and
lower motor torest onblock.
Merc 20/25 35