NorthStar 15781520 User manual

M15781520C.1
Owner’s Manual
Pressure Washer: Machine that cleans dirty surfaces
with high pressure water.
Instructions for Installation/Set-up, Operation, Maintenance, & Storage
This pressure washer produces cold water high pressure spray. Cleaning chemicals may be incorporated into the
spray if desired. The pressure pump for this equipment is powered by a gasoline internal combustion engine.
WARNING: SPECIAL HAZARDS
CO Poisoning: Exhaust from engine contains carbon monoxide, a poisonous gas that can cause carbon monoxide
poisoning and possible death if inhaled. ONLY run pressure washer OUTDOORS and at least 20 feet from the home, away
from windows, vents and air intakes, to allow proper ventilation. If you start to feel sick, dizzy, or weak while using the
pressure washer, shut off the engine and get to fresh air RIGHT AWAY.
Injection Injury: High-pressure spray can pierce skin and underlying tissues, leading to serious injury and possible
amputation. Such an injection injury can result in blood poisoning and/or severe tissue damage.
Flying Debris: High-pressure spray can cause flying debris and possible surface damage.
Electric shock: Operating equipment in wet conditions or near water can cause electric shock.
Chemical Exposure: Cleaning chemical vapors or contact with skin may be hazardous.
Fire/Explosion: Engine sparking can ignite fuel or other flammable liquids or vapors in the vicinity. Hot exhaust from engine
can ignite combustible materials.
Burns: Pressure Washer pump and engine are hot surfaces that can cause burn injuries.
Detailed safety information about these hazards appears throughout this manual.
Equipment Protection Quick Facts
Inspect Upon Delivery: FIRST! Inspect for missing or damaged components. See “Initial Set-Up”section for where
to report missing or damaged parts.
Add Engine Oil: Engine is shipped without oil. See engine manual for instructions on capacity and viscosity
recommendations.
Replace Temporary Pump Oil Plug: Pump is shipped with oil. Remove shipping tape and black vent plug (if
present) from oil fill cap.
Water Flow Requirements: Make sure your supply water flow rate is 20% higher than the pressure washer's flow
rate (see "Operations", section for detail), and that your water is clean and particle free.
Chemical Spraying: Use only approved pressure washer chemicals designed for high-pressure use.
Storage: Do not allow water to freeze in the pump, hose, or spray gun(s). See “Storage” for more information.
Maintenance Schedule: Engine and pump require periodic inspection and servicing to keep pressure washer
functioning efficiently. See “Maintenance Schedule Summary”for frequency of servicing.
Any Questions, Comments, Problems, or Parts Orders
Call NorthStar Product Support 1-800-270-0810
ITEM NUMBER: 15781520, 15782020
SERIAL NUMBER: _____________

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Table of Contents
Equipment Protection Quick Facts ........................................................................................................................................ 1
TABLE OF CONTENTS................................................................................................................................................2
ABOUT YOUR PRESSURE WASHER.........................................................................................................................4
SPECIFICATIONS ........................................................................................................................................................5
COMPONENT IDENTIFICATION..................................................................................................................................6
SAFETY ........................................................................................................................................................................7
Hazard Signal Word Definitions ............................................................................................................................................ 7
SAFETY LABELING.....................................................................................................................................................8
Safety Decal Locations ......................................................................................................................................................... 8
INITIAL SET-UP..........................................................................................................................................................10
Step 1. Inspect & Unpack...................................................................................................................................................... 10
Step 2. Assembly................................................................................................................................................................... 12
Handle Assembly ................................................................................................................................................................ 12
Spray Gun Assembly .......................................................................................................................................................... 12
Step 3. Select Suitable Location........................................................................................................................................... 12
Moving and Handling .......................................................................................................................................................... 12
Outdoor Use Only ............................................................................................................................................................... 12
Install Spark Arrestor (if Required)...................................................................................................................................... 13
OPERATION ...............................................................................................................................................................14
Follow Safety Rules for Operation ....................................................................................................................................... 14
Preparing for Operation ........................................................................................................................................................ 15
Check/Add Oil to Pump....................................................................................................................................................... 15
Check/Add Engine Oil......................................................................................................................................................... 15
Inspect Fuel System/Check for Leaks................................................................................................................................. 16
Connect Hoses, Water Supply, and Spray Nozzle .............................................................................................................. 17
Prime the Water Supply......................................................................................................................................................... 18
Set Up for Chemical Spray (if desired)................................................................................................................................. 19
Start-Up Procedures.............................................................................................................................................................. 20
Start the Engine to Power the Pump................................................................................................................................... 20
Apply Cleaning Chemical (If Desired) ................................................................................................................................. 20
Begin High Pressure Spray................................................................................................................................................. 20
Shutdown ............................................................................................................................................................................... 21
STORAGE...................................................................................................................................................................22
Between-Use Storage............................................................................................................................................................ 22
Prepare Pressure Washer for Freezing Conditions............................................................................................................ 22
Prepare Engine for Long Term Storage............................................................................................................................... 22
Prepare Pressure Washer for Storage................................................................................................................................. 23
MAINTENANCE & REPAIR........................................................................................................................................24
MAINTENANCE SCHEDULE SUMMARY..................................................................................................................24
DETAILED INSTRUCTIONS –MAINTENANCE & REPAIR ......................................................................................24
Follow Safety Rules ............................................................................................................................................................ 24
Keep Pressure Washer Clean............................................................................................................................................. 24
Inspect Spray System ......................................................................................................................................................... 24
Clean Inlet Filter.................................................................................................................................................................. 25

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Inspect Fuel System............................................................................................................................................................ 25
Check Tire Pressure ........................................................................................................................................................... 25
Perform Engine Maintenance.............................................................................................................................................. 26
Change Pump Oil................................................................................................................................................................ 26
TROUBLESHOOTING................................................................................................................................................27
PARTS EXPLOSION- MODEL # 15781520, 15782020- REV C.1..............................................................................28
PARTS LIST- MODEL #15781520 & 15782020- REV C.1 .........................................................................................29
PUMP ASSEMBLIES..................................................................................................................................................30
PUMP ASSEMBLIES PARTS LIST............................................................................................................................31
PUMP EXPLODED VIEW- COMET AWD (MODEL 15781520)..................................................................................32
PUMP EXPLODED VIEW- CAT 66DX (MODEL 15782020).......................................................................................34
LIMITED WARRANTY ................................................................................................................................................35

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About Your Pressure Washer
Thank you for purchasing a NorthStar Pressure Washer!
It is designed for long life, dependability, and top
performance.
Intended Use. Produce a high-pressure water spray.
Incorporate cleaning chemicals into a low-pressure
water spray.
Note: Do not use for other purposes, as unforeseen
hazards or equipment damage may result.
Power Source. The pressure washer is powered by a
gasoline engine.
Supplies Required. Normal operation will require you
to supply:
Pressure Washer pump oil
Gasoline
Engine oil
Personal Protection Equipment
See “Specifications”section of this manual for more
detail.
Site Location. Intended for outdoor use only.
Personal Protection. Wear safety apparel during
operation, including safety glasses with side and top
protection. Ear protection is also recommended if
working near any operating engine. Other safety apparel
includes waterproof insulated gloves, and non-slip
protective footwear. Cleaning chemicals may require the
use of respiration mask; refer to chemical label for
further instruction.
Adult control only. Only trained adults should set up
and operate the pressure washer. Do not let children
operate.
Under The Influence. Never operate, or let anyone else
operate, the pressure washer while fatigued or under
the influence of alcohol, drugs, or medication.
Keep this manual for reference and review.
ATTENTION: Rental Companies and Private
Owners who loan this equipment to others!
All persons to whom you rent/loan this pressure washer
to must have access to and read this manual. Keep this
owner’s manual with the pressure washer at all times
and advise all persons who will operate the machine to
read it. You must also provide personal instruction on
how to safely set-up and operate the pressure washer
and remain available to answer any questions a
renter/borrower might have. Owner’s Manuals are
available from NorthStar at 1-800-270-0810.

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Specifications
15781520
15782020
FLOW OUTPUT
FLOW OUTPUT
PSI (bar)
4000 (275)
PSI (bar)
4000 (275)
GPM (I/min)
3.5 (13.2)
GPM (I/min)
3.5 (13.2)
Max Water Temp
140° F (60°C)
Max Water Temp
140° F (60°C)
ENGINE
ENGINE
Engine
Honda GX 390
Engine
Honda GX 390
Horsepower
390cc
Horsepower
390cc
DIMENSIONS/COMPONENTS
DIMENSIONS/COMPONENTS
Length
34″
Length
34″
Width
21″
Width
21″
Height
38″
Height
38″
Pump Model
Comet AWD
Pump Model
CAT 66DX
Pump Oil Capacity
10 oz. (.29L)
Pump Oil Capacity
18 oz. (.53L)
SUPPLIES REQUIRED (not included)
SUPPLIES REQUIRED (not included)
Engine Oil
Refer to Engine Owner’s Manual
Engine Oil
Refer to Engine Owner’s Manual
Pump Oil (Shipped
with Oil, but refills
required
Universal Tractor Transmission
Oil (part # COCP2101) or
Mobil 1 Synthetic Oil 15W50
Pump Oil (Shipped
with Oil, but refills
required
SAE 30 Non-Detergent Oil or
Cat Pump Oil (part # 22158)