North Star M157551A User manual

M157551A
Item# 157551
Pressure Washer
Owner’s Manual
Proven Performance
Read and understand this manual before operating
this machine.
Engine is shipped without oil. Use SAE 30 motor
oil.
Pump is shipped with oil. Remove the shipping
plug from the pump and replace it with the vented
dipstick.
00078

2
To the Owner:
Thank you for purchasing a North Star pressure washer. Your machine is
designed for long life, dependability, and the top performance you demand!
Take time now to read through this manual so you better understand the
machine’s operation, maintenance and safety precautions. Everyone who
operates this machine must read and understand this manual. The time
you take now will prolong your machine’s life and prepare you for its safe
operation. Enjoy the exceptional performance of your North Star pressure
washer, the industry leader!
Important
If this machine is used by anyone who is not the
owner or is loaned or rented, make certain the
operator(s) prior tooperating:
- Is instructedin safe andproper
operation of this machine
- Reads and understands the manual(s)
pertaining to this machine
Notice
The manufacturer reserves the right to make
improvements in design and/or changes in
specifications at any time without incurring any
obligation to install them on units previously sold.

3
Table of Contents
Safety Instructions 4-5
Specifications 6
Machine Component Identification 6-8
Assembling the Machine 9
Before Using the Machine the FirstTime 10
Setting up the Machine 11
Start-Up Instructions 12-15
Shut-Down Instructions 16
Operating the Machine 17-19
Routine Maintenance 20-21
Winterizing the Machine 22
Troubleshooting Guide 23
Accessories 24

4
Safety Instructions
Read and understand these instructions
because they deal with safety. Pay particular
attention to this safety symbol throughout this
manual. Failure to comply with these
instructions may result in property damage,
personal injury, or death.
IMPORTANT
United States Government safety standards have been adopted under the Occupational Safety
and Health Act. These standards, particularly the General Standards, Part 1910, and the
Construction Standards, Part 1926, should be consulted wheneverusing airless spray equipment.
NEVER point the spray nozzle at people or
animals. The high pressure the machine
generatesisvery dangerous.
ALWAYS seek emergency medical care if
any fluid penetrates the skin. The cut may
bedeeperand more seriousthan itappears.
NEVER put hands or fingers over the tip of
the spraynozzle.
NEVER use your hands to stop or detect
leaks.
NEVER spray flammable liquids or toxic
chemicalssuch asweed killerorinsecticide.
NEVER allow children to operate or play on
or around the machine.
ALWAYS wear safety glasse s and
appropriate clothing when operating the
machine.
NEVER operate the machine in or around
an explosive environment.
ALWAYS locate the machine so it is
protected from external damage.
NEVER operategasoline powered machines
indoors. Carbon monoxide fumes are
deadly.
ALWAYS place the machine on a level
surface.
NEVER operate the machine with broken or
missingparts.
NEVER alter the machine from the
manufacturer’soriginal design.
ALWAYS keep all safety devices active on
themachine.
ALWAYS follow the chemical
manufacturer’s instructions when using
chemicals.
ALWAYS understand all safety precautions
andfirst aidforany chemicalsbeingused.
NEVER exceed the pressure or temperature
ratingsof the system. Be sure all accessory
equipment used will withstand the system
pressure.
ALWAYS keep the pressure hose
connected to the machine and the spray gun
while the system ispressurized.
NEVER movethe machine by pulling on the
hose.
NEVER secure the spraygun in the “ON” or
“SQUEEZED” position.

5
Safety Instructions
NEVER use the machine when under the
influenceofalcohol or any other drug.
NEVER smoke while operating or fueling
thismachine. Only add fuel to the machine
when thepower isOFF.
NEVER attempt to clean the machine with
its own spray. Cleaning should be done with
a damp sponge withthe power OFF.
NEVER leave an operating machine
unattended. Always shut the engine OFF
and relieve the pressure before leaving the
machine.
NEVER let the pump run without water
flowing throughthemachine.
ALWAYS respect and be alert to the
potential hazardoushigh pressure spray.
ALWAYS keep machine decals clean and
legible, replace any decals that become
damaged or lost.
NEVER route hoses in a manner that will
cause sharp bending, kinking, cutting,
abrasion, or other damage from vehicles or
falling objects.
NEVER use a hose if exterior damage is
evident.
NEVER attempt field repairs through an
unauthorized hydraulic hose repair shop.
Replaceanydamagedhoses.
ALWAYS use water thatisclear and free of
particles.
NEVER run preheated water over 140°F
into the machine.
ALWAYS check and maintain proper oil
levelsin thepumpand engine.
NEVER operate the machine with
insufficient water supply to the pump.
Damage occurs to the pump if run with an
insufficient watersupply.
ALWAYS protect your machine from
freezing during storage as described in this
manual.
ALWAYS follow all other guidelines and
safety instructions as described in this
manual.
Any Questions?
Call 1-800-270-0810
Customer Service

6
Specifications
Item Number #157551
Pressure Rating (psi) 2500
Flow Output (gpm) 3
Pump Type Triplex Ceramic Plunger
Water Supply Standard tapwater @ 20-100psi
Engine Horsepower 5
Fuel Capacity (quarts) 3
Discharge Hose 3/8” x 30’
Dimensions
Length 28”
Width 19.5”
Height 24”
Approximate Weight 88 lbs.
Machine Component Identification
1. Engine
2. Pump
3. Cart
1
2
30007
8

7
Machine Component Identification
1. Engine ON-Off Switch
2. Choke
3. Fuel Shut-OFF
4. Throttle
5. Fuel Tank Fill
6. Recoil
7. Oil Fill
8. Oil Drain
9. Air Filter
10. Muffler (Caution Hot!)
8
7
7
1
4
3
5
2
8
7
9
1
0
60007
9
0008
0
Engine Features Benefits
•Overhead Valves
(OHV) •More fuel efficient
•More powerful
•CastIron Cylinder
Sleeve
•Less wear,longer life
•Low Oil Shutdown •Won’trun withoutoil

8
Machine Component Identification
4
5
1
32
6
Pump Features Benefits
•Triplexceramic plungers •Long life,no corrosion
•Triplexdesign •Less vibration
•Industrial crankshaft •Dependable,proven design
•Thermal protector •Protects pump from hotwater
•Safety reliefvalve •Prevents pump from
overpressurizing
00089
1. Unloader Valve
2. Thermal Protector
3. Safety Relief Valve
4. Inlet
5. Outlet
6. Dipstick

9
Assembling the Machine
Step 1
Your pressure washer is shipped in two boxes. Separate and identify the components
found in both boxes. Use the assembly instructions found in the cart box to assemble the
cart. The components shown below will be in the same box as the engine/pump.
Step 2
You w ill need the following tools to fasten the pump/engine to the cart.
1. 1/2” socketwith ratchet
2. 1/2” open end wrench
The cart comes w ith (4) 5/16” x 1 1 /2” bolts, (4) 5/16” nuts,(8) 5/16” flatwashers, and
(4) 5/16” lockwashers to be used to fasten the cart to the engine. Use the slotted holes
in the base to mount the engine.
00073
Garden Hose Quick
Couple Socket
Qty-1
Gun & Grip
Qty-1 Lance Extension with Idrojet
Qty-1
Hose, Quick Couple
Qty-1
Bolt
En
g
ine Base
Flat Washe
r
Cart Base
Flat Washer
Lock Washe
r
Nut
Fastener Detail

10
Before Using the Machine the First Time
Fill engine with oil.
1.The engine is shipped withoutoil.
2.Use SAE 30 motoroil.
3.Fill oil to top offill neck.
Remove pump shipping plugs.
1.Remove the red plugs from the
water inletand the oil venthole
and discard them.
2.Checkoil level in the pump. Make
sure itis halfwayup the sight
glass.
3.Insertthe vented dipstickinto the
oil fill hole.
Follow these instructions before you use the
pressurewasher the first time.
Oil Fill
Remove
Sightglas
s
Remov
e

11
Setting-Up the Machine
Pre-Operation Checklist
;1.) Position the machine for easy access to all controls, power, and water
supply.
;2.) Position themachine outdoors on asolid levelsurface.
;3.) Fill gas tank with gasoline.
;4.) Check engine oil. Use SAE 30 motor oil.
;5.) Check the pump oil. Make sure itis to the fullmark on the dipstick. Use a
NON-DETERGENTSAE 30Woil (Item# 4043).
;6.) Check for worn or damaged equipment. Replace ifnecessary.
;7.) Check and clean the nozzle orifice.
;8.) Check and clean the water inlet screen and filter.
Water Supply Checklist
;1.) Make sure the water supply is clean. Debris can cause excess pump
wear and reduce performance.
;2.) An insufficient water supplywill damage your pump. Make sure the water
supplyis steadyand is more than 3 gpm. If you can fill a 1 gallon bucket
in less than 20 seconds,you have a sufficientwatersupply.
;3.) The water supply garden hose must have an inside diameter of at least
5/8”. If the hose is more than 100 ft. long, the diameter must be at least
3/4”.
;4.) Never use a reservoir tank as a water source. This pressure washer is
designed for a pressurized water source such as a city water faucet.
Sucking water out of a tank may cause pump cavitation and damage to
your pump.
;5.) Always use a flexible rubber hose for your water supply. Do not use rigid
piping.
Read and understand the entire manual
before operating the pressure washer.
Follow the checklists below every time
you use the pressure washer.

12
Start-Up Instructions
I.) Attach a Garden Hose
Your pressure washer is equipped with a garden hose quick couplers. Follow
these steps to use the quick couplers.
A.) Spin the socket onto
your garden hose.
B.) Spin the nipple into the
machine’s water inlet (the nipple
may already be spun into your
water inlet).
C.) Pull back the sleeve on the
socket.
D.) Snap thesocketonto the nipple.
Make sure to follow the pre-operation checklist and
water supply checklist on the previous page before
proceeding.
Socket
(Item# 30624) Spin onto Garden
Hose HandTight
Nipple
(Item# 30623)
Spin into Water
Inlet Hand Tight
Pull Back the
Sleeve
Snap the Socket onto
Nipple

13
Start-Up Instructions
II. Attach the Pressure Hose
Specifications:
Your pressure hose is equipped with 22MM thread-on quick couplers on both
ends. One end threads onto the water outlet on the unloader and the other
threads onto the gun inlet. The o-ring seals the connection so you only have to
tighten the quickcoupler hand tight.
We use 22MM thread-on quick couplers for a number of reasons:
1.) Itis an industrystandardso theywill workwithmanyothermachines.
2.) Theyhandleside torque betterresulting in fewer leaks.
3.) The o-rings lastlonger so theyrequire lessmaintenance.
4.) Theyare safer because theyprovide a more definite connection.
Length 30 feet
Inside Diameter 3/8 inch
Maximum Pressure 3000 psi
Reinforcement 1wire
Bend Radius 6 inches
Mater ial Neoprene
Spray Gun
22MM Female Thread 22MM Male Thread
22MM Female Threa
d
Unloader 22 MM Male Thread

14
Start-Up Instructions
III.) Connect the Lance
Your spraylance has the following features and benefits:
Connect the lance together using the 22MM thread-on quick coupler.
The o-rings seal the connection so you only have to tighten the quick
coupler hand tight.
Features Benefits
•4 footlength •Longer reach
•Meets UL safety standard
•Splits in the middle •Quick accessory changes
•Ships in smallerbox
•Less shipping damage
•Vented grip •More Comfortable
tri
gg
er safet
y
latch
NEVER point the nozzle or lance at people or
animals. The high pressure the machine creates is
verydangerous.
ALWAYS keep the high pressure hose connected to
the machine and thespraygun while spraying water.
Your spray gun is equipped with a built-in trigger
safety latch to guard against accidental trigger
release and potentially dangerous high pressure
spray. Fold the latch in the full down position when
not spraying.

15
Start-Up Instructions
IV.) Turn the Water Supply ON
Make sure the hose is not“kinked”.Akinked hose will provide insufficient water
supplyto the pump and will reduce its life.Make sure the hose remains unkinked
after moving the pressure washer.
V.) Squeeze the Trigger
Squeeze the triggeruntil asteadyflow of water sprays outthe nozzle. Make
sure all the air is outofthe hoses before running the pressure washer. This step
is veryimportant,itwill prolong the pump’s life. NEVER run the pump dry.
You can change between high and low pressure by pushing or pulling the
adjustable nozzle. Pull the nozzle back for high pressure. Push the nozzle
forward for low pressure. Low pressure is used for spraying chemicals.
VI.) Start the Engine
Refer to the enginemanual tostartyour engine.Once the engine is started,
begin cleaning.
Ifthe engine doesn’tstarton the firstpull,pressure maybuild up in the pump.
Relieve the pump pressure bysqueezing the spraygun trigger. This willmake
starting easier.
high pressure lowpressure

16
Shut-Down Instructions
I.) Turn the engine OFF.
II.) Turn the water supply OFF.
III.) Squeeze the spray gun trigger to relieve the system
pressure.
IV.) Remove the water supply garden hose from the pump inlet.
V.) Remove the high pressure hose from the pump outlet.
NEVER disconnect the high pressure hose from the
pump or spray gun while the system is pressurized.
Depressurize the system by squeezing the spray gun
triggerafter the engine is turned OFF.

17
Operation Instructions
I.) Spray Angle
Your pressure washer is equipped with a 0 to 80° adjustable nozzle designed to
tackle a varietyof cleaning jobs. Generally,narrow sprayangles have greater
cleaning impact,wider angles cover large areas in less time. Usesmall angles
for the toughestcleaning jobs. Use wide angles for rinsing largesurfaces and
water sweeping.
Change thesprayangle byturning the adjustable nozzle counter-clockwise for
narrow angles and clockwise for wide angles.
II.) General Cleaning
a.) Adjust the nozzle’s sprayangle for your application
b.) Hold the nozzle 6” to 12” from the cleaning surface.
c.) Use long,slow,deliberatestrokes from side toside similar to using a paint
sprayer. This technique will provide the most effective cleaning impact
andminimize streaks andskips in the cleaning surface.
narrowangles wide angles
trigger safety latch
NEVER point the nozzle or lance at people or
animals. The high pressure the machine creates is
verydangerous.
ALWAYS keep the high pressure hose connected to
the machine and thespraygun while spraying water.
Your spray gun is equipped with a built-in trigger
safety latch to guard against accidental trigge
r
release and potentially dangerous high pressure
spray. Fold the latch in the full down position when
not spraying.

18
Operation Instructions
III.) Applying Chemicals
a.) Spin the quick couple chemical
injector onto the pump outlethand
tight.
b.) Submerge the suction strainer in a
chemical solution.
c.) Adjust the nozzle holder to low
pressure bypushing the adjustable nozzle out. You need to change to
low pressure ifyou wantto spraychemicals onto the cleaning surface.
d.) Squeeze the spraygun trigger. The chemical injector will draw the
chemical into the waterstream.
e.) Turn the chemical adjustmentknob
to increase or decrease the
chemical concentration.
f.) Applychemicals evenlyto the
cleaningsurface. Allow the
chemicals to reactwith the dirt,
then rinse athigh pressure.
g.) Never usemore chemical than is
necessaryto clean thesurface.
highpressure lowpressure
Chemical Adjustment Knob
ALWAYS follow the chemical manufacturer’s
recommendations when using chemicals in the chemical
injector.
ALWAYS understand all safetyprecautions and first aid
for the chemicals being used.

19
Operation Instructions
IV.) Adjusting the Unloader Valve
The unloader valve determines the operating pressure of the pump. You can
adjustthe pressure byturning the black knob. However, the unloader is factory
pre-setto the maximum system pressure.
V.) Safety Relief Backup
The safety relief or “pop-off” valve is a backup safety feature located at the
bottom ofthe unloader valve. In the unlikelyeventthe unloadermalfunctions,the
safetyrelief valve is designed to be the weak link in the system and will open
before the pressure reaches a dangerous level.
VI.) Thermal Protector
The thermal protector or “pumpsaver” valve protects your pump from overheated
water. When the spraygun triggeris released,the pump DOES NOT stop
pumping. Water is recirculated through the unloader valve and by-pass hose.
The recirculating waterheats up quickly. The thermal protector senses the
temperature ofthe water and discharges itat140°Fpreventing pump damage.
NEVER alter the unloader valve from the
manufacturer’s design. Excess pressures could cause
serious injury and/or pump damage. Any alteration
other than turning the black knob will void your
warranty.
If the safety relief valve ever discharges water, turn
the engine off and do not use the machine. See a
dealer or call Customer Service at1-800-270-0810.

20
Routine Maintenance
I.) Changing the Engine Oil
Refer to the engine manual for complete
maintenance schedule and engine component
identification.
1.) Place an oil pan or container beneath the
pressure washer cart.
2.) Drain the old oil by removing the oil plug
found near the base ofthe engine. There is a
hole in the cart to allow the oil to drain
through.
3.) Replace the oil plug.
4.) Remove the oil fill cap and fill with oil.
5.) Use SAE 30 high detergent motor oil for
general all-temperature use. For extremely
hotclimates, refer to the enginemanual.
6.) Replace the oil fill cap.
II.) Pump Maintenance
Refer to the pump manual for complete maintenance schedule and pump
component identification.
SERVICEPERIOD
ITEM EACH USE FIRST 40 HRS
EVERY3
MO. OR 500
HRS
PUMP OIL-CHECK LEVEL X
PUMP OIL-CHANGE XX
INLET SCREENS-CHECK & CLEAN X
FITTINGS-CHECK FOR LEAKS X
NOZZLE-CHECK & CLEAN* X
*Use a pin to dislodge anydebris in the nozzle orifice.
Oil Drain
Oil Fill
Oil Fill