Simpson MSH3125-S User manual

Part No. 7104573 Rev. 5 JUN2016
3100 PSI
2.5 GPM
PREMIUM PRESSURE WASHER
INSTRUCTION
MANUAL
MANUAL DE
INSTRUCCIONES
MODEL
MODELO
MSH3125-S
MS31025HT-S
If your pressure washer is not working properly or if there are parts missing or broken,
please DO NOT RETURN IT TO THE PLACE OF PURCHASE. Contact our customer
service department at 1-877-362-4271 or www.simpsoncleaning.com
Si su lavadora a presión no trabaja correctamente ó encuentra partes rotas
ófaltantes, por favor NO LA REGRECE AL LUGAR DONDE LA COMPRO.
Contáctese con nuestro Departamento de Servicio al Cliente llamando al
1-877-362-4271 ou www.simpsoncleaning.com
IMPORTANT: Please make certain that the person who is to use this equipment carefully
reads and understands these instructions before operating.
IMPORTANTE: Aségurese por favor de que la persona que vaya a utilizar este equipo lea
con cuidado y comprenda estas instrucciones antes de operar.
VEA EL ESPAÑOL EN LA CONTRAPORTADA. INSTRUCTIVO DE OPERACIÓN,
CENTROS DE SERVICIO Y PÓLIZA DE GARANTÍA. ADVERTENCIA:
LÉASE ESTE INSTRUCTIVO ANTES DE USAR EL PRODUCTO.
SAVE THIS MANUAL FOR FUTURE REFERENCE
CONSERVE ESTAS INSTRUCCIONES PARA FUTURAS CONSULTAS

2- ENG
SAFETY GUIDELINES - DEFINITIONS
This manual contains information that is important for you to know and understand.
This information relates to protecting YOUR SAFETY and PREVENTING
EQUIPMENT PROBLEMS. To help you recognize this information, we use the
symbols below. Please read the manual and pay attention to these symbols.
DANGER: Indicates an imminently hazardous situation which, if not avoided,
will result in death or serious injury.
WARNING: Indicates a potentially hazardous situation which, if not avoided,
could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation which, if not avoided, may
result in minor or moderate injury.
NOTICE: Indicates a practice not related to personal injury which, if not avoided,
may result in property damage.
IMPORTANT SAFETY INSTRUCTIONS
DANGER: Carbon Monoxide. Using an engine indoors can kill you in
minutes. Engine exhaust contains high levels of carbon monoxide (CO), a
poisonous gas you cannot see or smell. You may be breathing CO even if you
do not smell engine exhaust.
• NEVER use an engine inside homes, garages, crawlspaces or other partly
enclosed areas. Deadly levels of carbon monoxide can build up in these areas.
Using a fan or opening windows and doors does NOT supply enough fresh air.
• ONLY use outdoors and far away from open windows, doors and vents. These
openings can pull in engine exhaust.
• Even when the engine is used correctly, CO may leak into your home. ALWAYS use
a battery-powered or battery backup CO alarm in your house. Read and follow all
directions for CO alarm before using. If you feel sick, dizzy or weak at anytime,
move to fresh air immediately. See a doctor. You could have carbon monoxide
poisoning.
WARNING: Do not operate this unit until you read this instruction manual and
the engine instruction manual for safety, operation and maintenance instructions. If
you have any questions regarding the product, please contact our customer
service department at www.simpsoncleaning.com.
DANGER: Risk of injection or severe injury. Keep clear of nozzle. Do not
direct discharge stream at persons or live animals. This product is to be used
only by trained operators.
WARNING: This product and its exhaust contain chemicals known to the State
of California to cause cancer, birth defects or other reproductive harm. In addi-
tion, some cleaning products and dust contain chemicals known to the State of
California to cause cancer, birth defects or other reproductive harm. Wash hands
after handling.

3- ENG
WARNING: This product may not be equipped with a spark-arresting muffler.
If the product is not equipped and will be used around flammable materials or
on land covered with materials such as agricultural crops, forest, brush, grass or
other similar items, then an approved spark arrester must be installed and is legally
required in the state of California. It is a violation of California statutes section
130050 and/or sections 4442 and 4443 of the California Public Resources Code,
unless the engine is equipped with a spark arrester, as defined in section 4442, and
maintained in effective working order. Spark arresters are also required on some
U.S. Forest Service land and may also be legally required under other statutes and
ordinances.
SAVE THESE INSTRUCTIONS
DANGER: RISK OF EXPLOSION OR FIRE
WHAT CAN HAPPEN HOW TO PREVENT IT
• Spilled gasoline and it’s vapors can
become ignited from cigarette sparks,
electrical arcing, exhaust gases and
hot engine components such as the
muffler.
• Shut off engine and allow it to cool before
adding fuel to the tank.
• Use care in filling tank to avoid spilling fuel.
Move pressure washer away from fueling
area before starting engine.
• Heat will expand fuel in the tank which
could result in spillage and possible
fire explosion.
• Keep maximum fuel level 1/2" (12.7mm)
below bottom of filler neck to allow for
expansion.
• Operating the pressure washer in an
explosive environment could result in
a fire.
• Operate and fuel equipment in well-
ventilated areas free from obstructions.
Equip areas with fire extinguisher suitable
for gasoline fires.
• Materials placed against or near the
pressure washer can interfere with
its proper ventilation features causing
overheating and possible ignition of
the materials.
• Never operate pressure washer in an area
containing dry brush or weeds.
• Muffler exhaust heat can damage
painted surfaces, melt any material
sensitive to heat (such as siding,
plastic, rubber, vinyl or the pressure
hose, itself), and damage live plants.
• Always keep pressure washer a minimum
of 4' (1.2m) away from surfaces (such as
houses, automobiles or live plants) that
could be damaged from muffler exhaust
heat.
• Improperly stored fuel could lead to
accidental ignition. Fuel improperly
secured could get into the hands of
children or other unqualified persons.
• Store fuel in an OSHA approved contain-
er, in a secure location away from work
area.
• Use of acids, toxic or corrosive
chemicals, poisons, insecticides, or
any kind of flammable solvent with
this product could result in serious
injury or death.
• Do not spray flammable liquids.

4- ENG
DANGER: RISK TO BREATHING (ASPHYXIATION)
WHAT CAN HAPPEN HOW TO PREVENT IT
• Breathing exhaust fumes will cause
serious injury or death! Engine
exhaust contains carbon monoxide,
an odorless and deadly gas.
• Operate pressure washer in a well-
ventilated area. Avoid enclosed areas
such as garages, basements, etc.
• Never operate unit in or near a location
occupied by humans or animals.
• Some cleaning fluids contain
substances which could cause injury
to skin, eyes or lungs.
• Use only cleaning fluids specifically rec-
ommended for high pressure washers.
Follow manufacturers recommendations.
Do not use chlorine bleach or any other
corrosive compound.
DANGER: RISK OF FLUID INJECTION AND LACERATION
WHAT CAN HAPPEN HOW TO PREVENT IT
• Your pressure washer operates at fluid
pressures and velocities high enough
to penetrate human and animal flesh
which could result in amputation or
other serious injury. Leaks caused
by loose fittings or worn or damaged
hoses can result in injection injuries.
DO NOT TREAT FLUID INJECTION
AS A SIMPLE CUT! See a physician
immediately!
• Inspect the high pressure hose regularly.
Replace the hose immediately if it is
damaged, worn, has melted from
contacting the engine, or shows any signs
of cracks, bubbles, pinholes, or other
leakage. Never grasp a high pressure
hose that is leaking or damaged.
• Never touch, grasp or attempt to cover a
pinhole or similar water leak on the high
pressure hose. The stream of water IS
under high pressure and WILL penetrate
skin.
• Never place hands in front of nozzle.
• Direct spray away from self and others.
• Make sure hose and fittings are tightened
and in good condition. Never hold onto
the hose or fittings during operation.
• Do not allow hose to contact muffler.
• Never attach or remove wand or hose
fittings while system is pressurized.
• When using replacement lances or guns
with this pressure washer, DO NOT use
a lance and/or lance/gun combination
that is shorter in length than what was
provided with this pressure washer as
measured from the nozzle end of the
lance to the gun trigger.
• Injuries can result if system pressure
is not reduced before attempting
maintenance or disassembly.
• To relieve system pressure, shut off
engine, turn off water supply and pull gun
trigger until water stops flowing.
• Use only accessories rated equal to or
higher than the rating of the pressure
washer.

5- ENG
DANGER: RISK OF INJURY FROM SPRAY
WHAT CAN HAPPEN HOW TO PREVENT IT
• High-velocity fluid spray can cause
objects to break, projecting particles
at high speed.
• Always wear ANSI-approved Z87.1
safety glasses. Wear protective clothing
to protect against accidental spraying.
• Never point wand at or spray people or
animals.
• Light or unsecured objects can
become hazardous projectiles. • Always secure trigger lock when wand is not in service to prevent accidental
operation.
• Never permanently secure trigger in pull-
back (open) position.
DANGER: RISK OF UNSAFE OPERATION
WHAT CAN HAPPEN HOW TO PREVENT IT
• Unsafe operation of your pressure
washer could lead to serious injury or
death to you or others.
• Do not use chlorine bleach or any other
corrosive compound.
• Become familiar with the operation and
controls of the pressure washer.
• Keep operating area clear of all persons,
pets and obstacles.
• Do not operate the product when fatigued
or under the influence of alcohol or drugs.
Stay alert at all times.
• Never compromise the safety features of
this product.
• Do not operate machine with missing,
broken or unauthorized parts.
• Never leave wand unattended while unit is
running.
• If proper starting procedure is not
followed, engine can kickback causing
serious hand and arm injury.
• If engine does not start after two pulls,
squeeze trigger of gun to relieve pump
pressure. Pull starter cord slowly until
resistance is felt. Then pull cord rapidly to
avoid kickback and prevent hand or arm
injury.
• The spray gun/wand is a powerful
cleaning tool that could look like a toy
to a child.
• Keep children away from the pressure
washer at all times.
• Reactive force of spray will cause gun/
wand to kickback, and could cause
the operator to slip or fall or misdirect
the spray. Improper control of gun/
wand can result in injuries to self and
others.
• Do not overreach or stand on an unstable
support.
• Do not use pressure washer while
standing on a ladder.
• Grip gun/wand firmly with both hands.
Expect the gun to kickback when
triggered.

6- ENG
DANGER: RISK OF INJURY OR PROPERTY DAMAGE WHEN
TRANSPORTING OR STORING
WHAT CAN HAPPEN HOW TO PREVENT IT
• Fuel or oil can leak or spill and could
result in fire or breathing hazard.
Serious injury or death can result.
Fuel or oil leaks will damage carpet,
paint or other surfaces in vehicles or
trailers.
• Oil could fill the cylinder and damage
the engine if the unit is not stored or
transported in an upright position.
• If pressure washer is equipped with a fuel
shut-off valve, turn the valve to the OFF
position before transporting to avoid fuel
leaks. If pressure washer is not equipped
with a fuel shut-off valve, drain the fuel
from tank before transporting. Only trans-
port fuel in an OSHA-approved container.
• Always place pressure washer on a
protective mat when transporting to
protect against damage to vehicle from
leaks.
• Always transport and store unit in an
upright position. Remove pressure
washer from vehicle immediately upon
arrival at your destination.
DANGER: RISK OF ELECTRICAL SHOCK
WHAT CAN HAPPEN HOW TO PREVENT IT
• Spray directed at electrical outlets or
switches, or objects connected to an
electrical circuit, could result in a fatal
electrical shock.
• Unplug any electrically operated product
before attempting to clean it. Direct spray
away from electric outlets and switches.
DANGER: RISK OF CHEMICAL BURN
WHAT CAN HAPPEN HOW TO PREVENT IT
• Use of acids, toxic or corrosive
chemicals, poisons, insecticides, or
any kind of flammable solvent with this
product could result in serious injury or
death.
• Do not spray acids, gasoline, kerosene,
or any other flammable materials with this
product. Use only household detergents,
cleaners and degreasers recommended
for use with pressure washers.
• Wear protective clothing to protect
eyes and skin from contact with sprayed
materials.

7- ENG
WARNING: RISK OF BURSTING
WHAT CAN HAPPEN HOW TO PREVENT IT
• Over inflation of tires could result in
serious injury and property damage.
• Use a tire pressure gauge to check the
tires pressure before each use and while
inflating tires; see the tire sidewall for the
correct tire pressure.
NOTE: Air tanks, compressors and similar
equipment used to inflate tires can fill small
tires similar to these very rapidly. Adjust
pressure regulator on air supply to no more
than the rating of the tire pressure. Add air
in small increments and frequently use the
tire gauge to prevent over inflation.
• High-velocity fluid spray directed at
pneumatic tire sidewalls (such as
found on automobiles, trailers and
the like) could damage the sidewall
resulting in serious injury.
• On pressure washers rated above
1600 PSI (11032 kPa) use the widest
fan spray (40º nozzle) and keep the
spray a minimum of 8" (20 cm) from the
pneumatic tire sidewall. Do not aim spray
directly at the joint between the tire and
rim.
WARNING: RISK OF HOT SURFACES
WHAT CAN HAPPEN HOW TO PREVENT IT
• Contact with hot surfaces, such as
engine exhaust components, could
result in serious burn.
• During operation, touch only the control
surfaces of the pressure washer. Keep
children away from the pressure washer
at all times. They may not be able to
recognize the hazards of this product.
WARNING: RISK OF INJURY FROM LIFTING
WHAT CAN HAPPEN HOW TO PREVENT IT
• Serious injury can result from
attempting to lift too heavy an object. • The pressure washer is too heavy to be lifted by one person. Obtain assistance
from others before lifting.
SAVE THESE INSTRUCTIONS
FOR FUTURE USE

8- ENG
QUICK SETUP GUIDE
WARNING: To reduce the risk of injury, read the pressure washer instruction
manual and the engine instruction manual before operating pressure washer.
IMPORTANT: Ethanol ShieldTM (sold separately) is a fuel stabilizer that helps
eliminate and prevent ethanol related problems in power equipment. Follow the
instructions on the container and add to the gasoline.
A
Install the
Handle
Place handle
onto frame, depress the
snap buttons, and slide
the handle assembly
onto the frame until snap
buttons snap into place.
B
Add/Check Oil
The engine
is shipped
without oil. Before
starting engine, add
the oil provided. Check
oil level prior to each
use. Refer to Engine
Owner’s Manual for
complete procedure.
C
Add Gasoline
In a well
ventilated
outdoor area add fresh,
high quality, unleaded
gasoline with a pump
octane rating of 86 or
higher. Do not overfill.
Wipe up spilled fuel
before starting the
engine. Refer to Engine
Owners Manual for
complete procedure.
QUICK START GUIDE
DANGER:
• Never run engine indoors or in enclosed, poorly ventilated areas. Engine
exhaust contains carbon monoxide, an odorless and deadly gas.
• Risk of fluid injection and laceration. When using the high-pressure setting,
DO NOT allow the high-pressure spray to come in contact with unprotected
skin, eyes or with any pets or animals. Serious injury will occur.
WARNING: Do not allow the unit to run for more than two minutes without
the gun trigger being pulled. This could cause overheating and damage to
the pump. When the temperature inside the pump rises too high, the thermal
relief valve will open and release a spray of water from the pump to lower the
internal temperature. The valve will then close.

9- ENG
1
Connect Garden
Hose to Pump
Thread the
garden hose to
the pump inlet.
2
Connect High
Pressure Hose
to Pump
Thread the high pressure
hose to the pump outlet.
3
Connect High
Pressure Hose
to Spray Gun
Connect the other end
of the high pressure
hose to the spray gun.
4
Connect Spray
Wand to Spray
Gun
Thread the spray
wand into the end
of the spray gun.
5
Connect QC
Nozzles to Spray
Wand
Pull quick connect
coupler back and insert
nozzle. Release quick
connect coupler and
twist nozzle to make sure
it is secure in coupler.
6
Turn Water
Faucet
Completely On
Do not run the unit
without water supply
connected and turned on.
Use Cold Water Only.
7
Release Air from
System
Release all
air from pump and
high pressure hose by
depressing trigger until a
steady stream of water is
present. Approximately
30 seconds.
30 S
8
Verify the Engine
Switch is turned
to the ON
Position
OFF
ON
9
Verify the Choke
Pin is Pulled Out
to the CLOSED
Position
The Choke Pin has
been preset by the
factory to be in the
CLOSED Position.

10- ENG
GET TO KNOW THE PRESSURE WASHER
NOTE: Photographs and line drawings used in this manual are for reference
only and do not represent a specific model.
Compare the illustrations with your unit to familiarize yourself with the location of
various controls and adjustments. Save this manual for future reference.
G
C
B
1
D
KL
E
H
I
J
A
10
Pull the Recoil
Starter Grip
Pull the
recoil starter grip to
start the engine.
WARNING: This Guide is not a substitute for reading the operator's manual.
User must read and understand operator's manual before using this product.
11
Push the Choke
Pin to the OPEN
Position
Gradually move the
Choke Pin to the
OPEN Position after
engine starts.

11- ENG
BASIC ELEMENTS OF A PRESSURE WASHER (FIG. 1)
A. High Pressure Pump: Increases the pressure of the water supply.
B. Engine: Drives the high pressure pump. Refer to the Engine Owner's Manual
for location and operation of engine controls.
C. High Pressure Hose: Carries the pressurized water from the pump to the gun
and spray wand.
D. Spray Gun: Connects with spray wand to control water flow rate, direction and
pressure.
E. Quick-Connect Spray Wand: Allows the user to quickly change out high
pressure nozzles. See How To Use Spray Wand instructions in Operation
section.
F. Detergent Siphon Hose not shown): Feeds cleaning agents into the pump to mix
with the water. See
How To Apply Chemicals/Cleaning Solvents instructions
in
Operation section.
G. Handle
H. Frame
I. Pump Outlet
J. Pump Inlet
K. Quick Connect Nozzles
L. Nozzle Holder
BASIC ELEMENTS OF AN ENGINE
Refer to the Engine Owner's Manual for location and operation of engine controls.
Choke Control: Opens and closes carburetor choke valve.
Starter Grip: Pulling starter grip operates recoil starter to crank engine.
Engine Switch: Enables and disables ignition system.
ASSEMBLY INSTRUCTIONS (FIG. 2–4)
1. Locate and remove all loose parts from the carton.
2. Cut four corners of the carton from top to bottom and lay the panels flat.
3.
Place handle (G) onto frame (H), depress the snap buttons, and slide the
handle assembly onto the frame until snap buttons snap into place.
NOTICE: Risk of personal injury. Avoid placing hands between handle and frame
when assembling to prevent pinching.
4. Place the nozzle holder (L) onto the panel (located on the handle assembly)
and push each nozzle holder into place.
5 Remove colored quick connect nozzles (K) from plastic bag and insert them
into correct grommet on the nozzle holder (L). NOTE: Nozzles are color coded
to match colored nozzles on panel.
L
K
L
G
H
22A

12- ENG
6. Connect wand (E) to gun (D). Tighten securely.
7. Attach high pressure hose (C) to gun (D). Tighten securely.
E
4
D
C
3
D
NOTICE: The engine is shipped without oil. Before starting engine, add the oil
provided. Damage to the engine will occur if the engine is run without oil, this
damage will not be covered under warranty.
NOTE: The pump on this unit is maintenance free and requires no oil. If
there is a problem with the pump, contact our Customer Service Group on
www.simpsoncleaning.com as soon as possible.
OPERATION
PRESSURE WASHER TERMINOLOGY
PSI: Pounds per Square Inch. The unit of measure for water pressure. Also used
for air pressure, hydraulic pressure, etc.
GPM: Gallons per Minute. The unit of measure for the flow rate of water.
CU: Cleaning Units. GPM multiplied by PSI equals CU.
Bypass Mode: Allows water to re-circulate within the pump when the gun trigger is
not pulled. This feature allows the operator to release the trigger gun and reposition
themselves without having to turn the engine off in between cleaning actions.
WARNING: Do not allow the unit to run for more than two minutes without
the gun trigger being pulled. This could cause overheating and damage to
the pump. When the temperature inside the pump rises too high, the thermal
relief valve will open and release a spray of water from the pump to lower the
internal temperature. The valve will then close.
Thermal Relief Valve (P, Fig. 5): When the temperature inside the 5
P
pump rises too high, this valve will open and release a gush of water
in an effort to lower the temperature inside the pump. The valve will
then close.
Detergent Injection System: Mixes cleaners or cleaning solvents with the water
to improve cleaning effectiveness.
Water Supply: All pressure washers must have a source of water. The minimum
requirements for a water supply are 20 PSI and 5 Gallons Per Minute. If your water
source is a well, the garden hose length can only be 30ft. (9m) max.
WARNING: To reduce the possibility of contamination always protect
against backflow when connected to a potable water system.
PRESSURE WASHER OPERATING FEATURES
PRESSURE ADJUSTMENTS
The pressure setting is preset at the factory to achieve optimum pressure and
cleaning. If you need to lower the pressure, it can be accomplished by these meth-
ods.

13- ENG
1. Back away from the surface to be cleaned. The further away you are, the
less the pressure will be on the surface to be cleaned.
2. Change to the 40˚ nozzle (white). This nozzle delivers a less powerful stream
of water and a wider spray pattern. Refer to How To Use Spray Wand.
NOTICE: DO NOT attempt to increase pump pressure. A higher pressure setting
than the factory set pressure may damage pump.
HOW TO USE SPRAY WAND
The nozzles for the spray wand are stored in the nozzle holder on the panel assembly.
Colors on the panel identify nozzle location and spray pattern. Refer to the following
chart to choose the correct nozzle for the job to be performed.
CHANGING NOZZLES ON SPRAY WAND (FIG. 6)
DANGER: Risk of fluid injection. Do not direct discharge stream toward
persons, unprotected skin, eyes or any pets or animals. Serious injury will
occur.
WARNING: Flying objects could cause risk of serious injury. Do not
attempt to change nozzles while pressure washer is running. Turn engine off
before changing nozzles.
1. Pull quick-connect coupler (E) back and insert nozzle (K). 6
KE
2. Release quick-connect coupler and twist nozzle to
make sure it is secure in coupler.
WARNING: Flying object could cause risk of serious
injury. Ensure nozzle is completely inserted in quick-
connect socket and quick-connect collar is fully engaged
(forward) before squeezing gun trigger.
NOZZLE COLOR SPRAY PATTERN USES SURFACES*
Red
0˚ powerful pinpoint
for spot cleaning
of hard, unpainted
surfaces or for
high reach areas
unpainted metal
or concrete;
DO NOT use on wood
Yellow
15˚ intense cleaning
of unpainted
hard surfaces
grills, driveways, concrete
or brick walkways,
unpainted brick or stucco
Green
25˚ standard cleaning
nozzle for most
applications
yard tools, sidewalks,
lawn furniture, unpainted
siding, stucco, gutters
and eaves, concrete,
brick surfaces
White
40˚ cleaning of
painted or delicate
surfaces
auto/RV, marine, wood,
painted brick and stucco,
vinyl, painted siding
Black
low pressure applies cleaning
solutions Low pressure spray is safe on all
surfaces. Always verify
compatibility of cleaning
solution prior to use.

14- ENG
*NOTICE: The high pressure spray from your pressure washer is capable of
causing damage to surfaces such as wood, glass, automobile paint, auto striping
and trim, and delicate objects such as flowers and shrubs. Before spraying, check
the item to be cleaned to assure yourself that it is strong enough to resist damage
from the force of the spray.
HOW TO APPLY CHEMICALS/CLEANING SOLVENTS (FIG. 7)
Applying chemicals or cleaning solvents is a low pressure operation. NOTE: Use
only soaps and chemicals designed for pressure washer use. Do not use bleach.
To Apply Chemicals:
1. Ensure detergent siphon hose (F, Figure 7) is attached F
7
tobarbed fitting location near high pressure hose
connection of pump as shown.
2. Place other end of detergent siphon hose with filter on
it into container holding chemical/cleaning solution.
NOTE: For every 7 gallons of water pumped 1 gallon
of chemical/cleaning solution will be used.
3. Install low pressure (black) nozzle into quick connect
fitting of spray wand, see How To Use Spray Wand paragraph in this section.
4. After use of chemicals, place detergent siphon hose into container of clean
water and draw clean water through chemical injection system to rinse system
thoroughly. If chemicals remain in the pump, it could be damaged. Pumps
damaged due to chemical residue will not be covered under warranty.
NOTE: Chemicals and soaps will not siphon if the black soap nozzle is not installed
on the spray wand.
STARTING (FIG. 8–10)
WARNING: To reduce the risk of injury, read the pressure washer instruction
manual and the engine instruction manual before starting pressure washer.
DANGER: Risk of fluid injection and laceration. When using the high
pressure setting, DO NOT allow the high pressure spray to come in contact
with unprotected skin, eyes, or with any pets or animals. Serious injury will
occur.
• Your washer operates at fluid pressures and velocities high enough to penetrate
human and animal flesh, which could result in amputation or other serious injury.
Leaks caused by loose fittings or worn or damaged hoses can result in injection
injuries. DO NOT TREAT FLUID INJECTION AS A SIMPLE CUT! See a physician
immediately!
DANGER: Carbon Monoxide. Using an engine indoors can kill you in
minutes. Engine exhaust contains high levels of carbon monoxide (CO), a
poisonous gas you cannot see or smell. You may be breathing CO even if you
do not smell engine exhaust.
• Breathing exhaust fumes will cause serious injury or death! Engine exhaust
contains carbon monoxide, an odorless and deadly gas.
• Operate pressure washer in a well-ventilated area. Avoid enclosed areas
such as garages, basements, etc.
• Never operate unit in or near a location occupied by humans or animals.

15- ENG
WARNING: Risk of Fire, Asphyxiation and Burn. Never fill fuel tank when
engine is running or hot. Do not smoke when filling fuel tank.
• Never fill fuel tank completely. Fill tank to 1/2" (12.7 mm) below bottom of filler
neck to provide space for fuel expansion. Wipe any fuel spillage from engine and
equipment before starting engine.
• DO NOT let hoses come in contact with very hot engine muffler during or
immediately after use of your pressure washer. Damage to hoses from contact with
hot engine surfaces will NOT be covered by warranty.
NOTICE: Risk of property damage. Never pull water supply hose to move pressure
washer. This could damage hose and/or pump inlet.
• DO NOT use hot water, use cold water only.
• Never turn water supply off while pressure washer engine is running or damage to
pump will result.
• DO NOT stop spraying water for more than two minutes at a time. Pump operates
in bypass mode when spray gun trigger is not pressed. If pump is left in bypass
mode for more than two minutes internal components of the pump can be
damaged.
If you do not understand these precautions, please contact our customer service
department at www.simpsoncleaning.com
Prior to starting, refer to your engine manual for proper starting procedure.
1. In a well ventilated outdoor area add fresh, high quality, unleaded gasoline
with a pump octane rating of 86 or higher. Do not overfill. Wipe up spilled
fuel before starting the engine. Refer to Engine Owner's Manual for correct
procedure.
IMPORTANT: Ethanol ShieldTM (sold separately) is a fuel stabilizer that helps
eliminate and prevent ethanol related problems in power equipment. Follow the
instructions on the container and add to the gasoline.
NOTICE: Use of fuels with greater than 10% ethanol are
not approved for use in this product per EPA regulations
and will damage the unit and void the warranty.
2. Check engine oil level. Refer to Engine Owner's Manual for correct procedure.
3. Connect the water hose to the water source. Turn the water source on to
remove all air from the hose. When a steady stream of water is present, turn
the water source off.
4. Verify the filter screen (M) is in
M
89
J
C
N
I
water inlet of pump. NOTE:
Convex side faces out.
5. Connect water source (N) to
pump inlet (J). NOTE: Water
source must provide a minimum
of 5 gallons per minute at 20
PSI.
6. Connect
high pressure hose (C)
to pump outlet (I).
WARNING: To reduce the
possibility of contamination always protect against backflow when connected
to a potable water system.

16- ENG
7. Choose the correct nozzle for the job to be performed. See How To Use spray
Wand instructions in this section. NOTE: If applying a chemical or cleaning
solution, see How To Apply Chemicals/Cleaning Solvents instructions in this
section.
8. Turn water source on.
NOTICE: Risk of property damage. Failure to do so could cause damage to the
pump.
9. Remove all air from the pump and high pressure hose by depressing trigger
until a steady stream of water is present.
10. Start engine. See Engine Owner's Manual for correct procedure.
WARNING: Risk of unsafe operation. If engine does not start after two
pulls, squeeze trigger of gun to relieve pump pressure. Pull starter cord slowly
until resistance is felt. Then pull cord rapidly to avoid kickback and prevent
hand or arm injury.
NOTE: If the oil level in the engine is low, the engine will not start. If the engine does
not start, check the oil level and add oil as needed.
11. Depress trigger on gun to start water flow.
WARNING: Risk of unsafe operation. Stand on a stable surface and
grip gun/spray wand firmly with both hands. Expect the gun to kick when
triggered.
12. Release trigger to stop water flow.
WARNING: Do not allow the unit to run for more than two minutes without
the gun trigger being pulled. This could cause overheating and damage to
the pump. When the temperature inside the pump rises too high, the thermal
relief valve will open and release a spray of water from the pump to lower the
internal temperature. The valve will then close.
WARNING: Risk of injury from spray. Always engage 10
O
the trigger lock (O) when gun is not in use. Failure to do
so could cause accidental spraying.
SHUTTING DOWN
1. After each use, if you have applied chemicals, place
detergent siphon hose into container of clean water and
draw clean water through chemical injection system to
rinse system thoroughly.
NOTICE: Risk of property damage. Failure to do so could cause damage to the
pump.
2. Turn engine off. See Engine Owner's Manual.
NOTICE: Risk of property damage. NEVER turn the water off with the engine
running.
3. Turn water source off.
4. Pull trigger on spray gun to relieve any water pressure in hose or spray gun.
NOTE: Failure to release system pressure will prevent removal of high pressure
hose from spray gun or pump connection.
5. See Storage section in this manual for proper storage procedures.

17- ENG
MAINTENANCE
WARNING: Risk of burn hazard. When performing maintenance, you may
be exposed to hot surfaces, water pressure or moving parts that can cause
serious injury or death.
WARNING: Risk of fire hazard. Always disconnect, spark plug wire,
let the engine cool and release all water pressure before performing any
maintenance or repair. The engine contains flammable fuel. Do not smoke or
work near open flames while performing maintenance.
To ensure efficient operation and longer life of your pressure washer, a routine
maintenance schedule should be prepared and followed. If the pressure washer is
used in unusual conditions, such as high-temperatures or dusty conditions, more
frequent maintenance checks will be required.
ENGINE
Consult the Engine Owner's Manual for the manufacturer's recommendations
for any and all maintenance. NOTE: The engine drain plug is located at the rear of
the unit.
PUMP
The pump was filled with oil at the factory. The pump on this unit is maintenance
free and requires no oil. If there is a problem with the pump contact us at
www.simpsoncleaning.com
CONNECTIONS
Connections on pressure washer hoses, gun and spray wand should be cleaned
regularly and lubricated with light oil or lithium grease to prevent leakage and
damage to the o-rings.
NOZZLE CLEANING (FIG. 11)
If the nozzle becomes clogged with foreign materials, such as dirt, excessive
pressure may develop. If the nozzle becomes partially clogged or restricted, the
pump pressure will pulsate. Clean the nozzle immediately using the nozzle kit
supplied and the following instructions:
1. Shut off the pressure washer and turn off the water supply.
2. Pull trigger on gun handle to relieve any water pressure.
3. Disconnect the spray wand from the gun.
4. Remove the high pressure nozzle (K) from the spray wand. 11 K
K
N
Remove any obstructions with the nozzle cleaning tool
provided and backflush with clean water.
5. Direct water supply (N) into nozzle to backflush loosened
particles for 30 seconds.
6. Reassemble the nozzle to the wand.
7. Reconnect spray wand to gun and turn on water supply.
8. Start pressure washer and place spray wand into high
pressure setting to test.

18- ENG
CLEAN THE WATER INLET FILTER (FIG. 8)
This screen filter should be checked periodically and cleaned if necessary.
1. Remove filter by grasping end and removing it from water inlet of pump.
2. Clean filter by flushing it with water on both sides.
3. Re-insert filter into water inlet of pump. NOTE: Convex side faces out.
NOTE: Do not operate the pressure washer without filter properly installed.
STORAGE
ENGINE
Consult the Engine Owner's Manual for manufacturer’s recommendations for
storage.
TO PREVENT FUEL-RELATED PROBLEMS
1. Add Ethanol ShieldTM fuel stabilizer following the manufacturer’s instructions.
When adding a gasoline stabilizer, fill the fuel tank with fresh gasoline. If only
partially filled, air in the tank will promote fuel deterioration during storage.
If you keep a container of gasoline for refueling, be sure that it contains only
fresh gasoline.
2. After adding a gasoline stabilizer, run the engine outdoors for 10 minutes
to be sure that treated gasoline has replaced the untreated gasoline in the
carburetor.
3. Turn the fuel valve to the OFF position.
4. Continue to run the engine until it stops from the lack of fuel in the carburetor
fuel bowl. Running time should be less than 3 minutes.
PUMP
The manufacturer recommends using SIMPSON®/ POWERWASHER®Pump
Guard or equivalent when storing the unit for more than 30 days and/or when
freezing temperatures are expected. SIMPSON®/ POWERWASHER® Pump Guard
is environmentally friendly.
NOTE: Using pump guard helps provide proper lubrication to the internal seals of
the pump regardless of temperature or environment.
NOTICE: Risk of property damage. Use only SIMPSON®/ POWERWASHER®
Pump Guard or equivalent. Other products could be corrosive and/or contain alco-
hol which may cause pump damage.
1. Turn off pressure washer and disconnect hoses from pump.
2. Unscrew bottle valve from Pump Guard bottle and remove seal.
3. Screw bottle valve back onto bottle.
4. Attach bottle to water inlet of pump.
5. Squeeze bottle to inject contents into pump.
6. With ignition switch off, simultaneously pull starter rope and squeeze bottle.
Repeat until protector fluid exits pump outlet. NOTE: This step may require
two people.

19- ENG
PRESSURE WASHER
1. Drain all water from high pressure hose and wrap it onto hose wrap.
2. Drain all water from the spray gun and wand by holding spray gun in a vertical
position with nozzle end pointing down and squeezing trigger. Store in gun
holder.
3. Wrap up and secure detergent siphon hose so it is protected from damage.
ACCESSORIES
DANGER: Risk of fluid injection. When using replacement spray wands or
guns with this pressure washer, DO NOT use a spray wand and/or spray gun/
wand combination that is shorter in length than what was provided with this
pressure washer as measured from the nozzle end of the wand to the gun
trigger.
NOTICE: The use of any other accessory not recommended for use with this tool
could be hazardous. Use only accessories rated equal to or greater than the rating
of the pressure washer.
SPECIFICATIONS
MODEL MSH3125-S / MS31025HT-S
PSI Max* 3100 PSI
GPM Max* 2.5 gpm
High Pressure Hose 25 ft. (7.6 m)
Presure of Inlet Water 20–100 PSI
Inlet Water cold tap (100 °F max)
Soap Consumption Rate 10% max
* Rated Pressure and Rated Water Flow is within manufacturing tolerance of
(+/- 10%).
In a continued commitment to improve quality, the manufacturer reserves the right
to make component changes, design changes, or specification changes when
necessary and without notice.
SERVICE INFORMATION
Do not return this product to your retailer. Please contact our customer service
department at www.simpsoncleaning.com
LIMITED WARRANTY
90 DAY LIMITED WARRANTY ON PRODUCT COMPONENTS EXCLUDING PUMP
SIMPSON®warrants to the original purchaser that the wheels, gun, hose, wand, spray
nozzle(s) and other components of the SIMPSON®pressure washer covered under this
warranty are free from defects in material and workmanship for 90 days from the date
of purchase.
ONE YEAR LIMITED WARRANTY ON PUMP AND FRAME
SIMPSON® warrants to the original purchaser that the pump of the SIMPSON®
pressure washer covered under this warranty is free from manufacturer’s defects in
material and workmanship for one year from the date of purchase. The one year limited
warranty applies to the pump only.

20- ENG
SIMPSON® will repair or replace, at SIMPSON®'s option, products or components
which have failed within the above warranty periods. Service will be scheduled
according to the normal work flow and business hours at the service center location,
and the availability of replacement parts. All decisions of SIMPSON®with regard to this
limited warranty shall be final.
This warranty gives you specific legal rights, and you may also have other rights which
vary from state to state.
ENGINE WARRANTY
The engine warranty is covered under the terms and conditions as outlined by the
engine manufacture’s warranty contained herein and is sole responsibility of the engine
manufacturer.
RESPONSIBILITY OF ORIGINAL PURCHASER (INITIAL USER):
• To process a warranty claim on your SIMPSON®pressure washer, report the
concern to www.simpsoncleaning.com for authorization and direction to the
nearest authorized service centre in your area.
• Retain original cash register sales receipt as proof of purchase for warranty work.
• Use reasonable care in the operation and maintenance of the product as described
in the Owners Manual(s).
THIS WARRANTY DOES NOT COVER:
• Merchandise sold as reconditioned, used as rental equipment, or floor or display
models.
• Merchandise that has become damaged or inoperative because of ordinary wear,
misuse, cold, heat, rain, excessive humidity, water quality, freeze damage, use
of improper chemicals, negligence, accident, failure to operate the product in
accordance with the instructions provided in the Owners Manual(s) supplied with
the product, improper maintenance, the use of accessories or attachments not
recommended by SIMPSON®, or unauthorized repair or alterations.
• Repair and transportation costs of merchandise determined not to be defective.
• Damage due to chemical deterioration, scale build up, rust, corrosion or
thermal expansion
• Costs associated with assembly, required oil, adjustments or other installation and
start-up costs.
• Expendable parts or accessories supplied with the product which are expected to
become inoperative or unusable after a reasonable period of use, including but not
limited to springs, nozzles, o-rings, washers, and similar accessories.
• Merchandise sold by SIMPSON®which has been manufactured by and identified
as the product of another company, such as gasoline engines. The product
manufacturer’s warranty, if any, will apply.
•ANY INCIDENTAL, INDIRECT OR CONSEQUENTIAL LOSS, DAMAGE,
OR EXPENSE THAT MAY RESULT FROM ANY DEFECT, FAILURE OR
MALFUNCTION OF THE PRODUCT IS NOT COVERED BY THIS WARRANTY.
Some states do not allow the exclusion or limitation of incidental or consequential
damages, so the above limitation or exclusion may not apply to you.
• IMPLIED WARRANTIES, INCLUDING THOSE OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE, ARE LIMITED TO ONE YEAR FROM
THE DATE OF ORIGINAL PURCHASE. Some states do not allow limitations on
how long an implied warranty lasts, so the above limitations may not apply to you.