DUROMAX Duro Star DS4400E User manual

DS4400E GENERATOR
This manual provides information regarding the operation
and maintenance of these products. We have made every
effort to ensure the accuracy of the information in this
manual. We reserve the right to change this product at
any time without prior notice.
5800 Ontario Mills Pkwy
Ontario, CA 91764 USA
www.duromaxpower.com
Call our Customer Care Team Toll Free 8-5pm PST Mon-Fri
844-DUROMAX
User Manual
REV: DS4400E-01152018

CONTENTS
1.
Introduction..................................................................................................................... 6
General Safety Procedures............................................................................................ 7
Quick Start Guide.......................................................................................................... 10
Generator Components............................................................................................... 12
Package Contents ......................................................................................................... 14
Introduction
3.
Checking the Oil ............................................................................................................ 22
Check the Gas Level...................................................................................................... 23
Starting the Generator ................................................................................................. 24
Starting the Generator
2.
Shipping Braces............................................................................................................. 16
Wheel Kit Installation.................................................................................................... 17
Adding Oil ...................................................................................................................... 18
Adding Gasoline ............................................................................................................ 19
Grounding the Generator ............................................................................................ 20
High Altitude Operation ............................................................................................... 20
Generator Setup
4.
AC Usage ........................................................................................................................ 28
Connecting a Load to the Generator.......................................................................... 30
Voltage Selector Switch ................................................................................................ 31
DC Usage........................................................................................................................ 32
Using the Generator
3

CONTENTS
5.
6.
7.
Maintenance Schedule................................................................................................. 36
Maintenance Log .......................................................................................................... 37
Checking the Oil ........................................................................................................... 38
Changing the Oil............................................................................................................ 39
Cleaning the Air Cleaner .............................................................................................. 40
Spark Plug Maintenance .............................................................................................. 42
Emptying the Gas Tank ................................................................................................ 44
Cleaning the Fuel Filter Cup......................................................................................... 46
Storage and Transportation ........................................................................................ 47
Specications................................................................................................................. 48
......................................................................................................................... 58
Basic Troubleshooting ................................................................................................. 50
Changing / Inspecting the Carbon Brushes .............................................................. 51
Changing / Inspecting the AVR ................................................................................... 53
Maintenance and Care
Warranty
Troubleshooting
4
8. .................................................................................................. 62
Contact Information

5

INTRODUCTION
Notice Regarding Emissions
DuroMax has cemented its reputation as one of the markets leading power equipment companies
who are headquartered in the US. All of our products are manufactured to the strictest guidelines
and go through countless testing in all phases of production.
Evolving our strong engine line, DuroMax has complemented its oerings to include Pressure
Washers, Water Pumps, Engines and now oering V-Twin engines. Reliability is the highest
standard we hold ourselves to, whether its powering a heater during a winter storm that knocks
out power, dewatering a ooded property, or washing away a deck for the summer season
Engines that are certied to comply with U.S. EPA emission regulations for SORE (Small o Road
Equipment), are certied to operate on regular unleaded gasoline, and may include the following
emission control systems: (EM) Engine Modications and (TWC) Three-Way Catalyst (if so equipped).
6
STOP
Please do not return
to store.
Durostar representatives are ready to help you
with any questions, concerns, or issues about your
new product. We can guide you through assembly,
start up, and how to operate your new generator.
We want you to be able to put your new generator
to use right away!
CALL US BEFORE YOU CONSIDER
RETURNING THE PRODUCT!
1-844-DUROMAX
TOLL FREE

SAFETY ALERT SYMBOL
DANGER: This generator produces poisonous carbon monoxide gas when running. This
gas is both odorless and colorless. Even if you do not see or smell gas, carbon monoxide
may still be present. Breathing this poison can lead to headaches, dizziness, drowsiness,
and eventually death.
●Use outdoors ONLY in non-conned areas.
●Keep several feet of clearance on all sides to allow proper ventilation of the generator.
WARNING: The exhaust from this product contains chemicals known to the State of
California to cause cancer, birth defects, or other reproductive harm.
WARNING: This generator produces heat when running. Temperatures near exhaust can
exceed 150°F (65°C).
●Do not touch hot surfaces. Pay attention to warning labels on the generator denoting
hot parts of the machine.
●Allow generator to cool several minutes after use before touching engine or areas
which heat during use.
The safety alert symbol is used with one of the safety words (DANGER,
CAUTION, or WARNING) to alert you of hazards. Please pay attention to
these hazard notices both in this manual and on the generator.
GENERAL SAFETY PROCEDURES
7
Please familiarize yourself with the following safety symbols and words:
●DANGER: Indicates a hazard that will result in serious injury or death if instructions are not
followed.
●WARNING: Indicates a strong possibility of causing serious injury or death if instructions are not
followed.
●CAUTION: Indicates a possibility of personal injury or equipment damage if instructions are not
followed.

WARNING: This generator may emit highly ammable and explosive gasoline vapors,
which can cause severe burns or even death. A nearby open ame can lead to an
explosion even if not directly in contact with gas.
●Do not operate near an open ame.
●Do not smoke near generator.
●Always operate on a rm, level surface.
●Always turn generator o before refueling.
●Allow generator to cool for at least 2 minutes before removing fuel cap. Loosen cap
slowly to relieve pressure in tank.
●Do not overll gas tank. Gas may expand during operation. Do not ll to the top of
the tank.
●Always check for spilled gas before operating.
●Empty the gasoline tank before storing or transporting the generator.
●Before transporting, turn fuel valve to the o position and disconnect the spark plug.
WARNING: This generator produces a powerful voltage, which can result in electrocution.
●ALWAYS ground the generator before using it (see the “Grounding the Generator”
portion of the “PREPARlNG THE GENERATOR FOR USE section).
●Generator should only be plugged into electrical devices, either directly or with an
extension cord. NEVER connect to a building electrical system without a qualied
electrician. Such connections must comply with local electrical laws and codes. Failure
to comply can create a backow of power, which may result in serious injury or death
to utility workers.
●Use a ground fault circuit interrupter (GFCI) in highly conductive areas such as metal
decking or steel work. GFCls are available in-line with some extension cords.
●Do not use uncovered in rainy or wet conditions.
●Do not touch bare wires or receptacles (outlets).
●Do not allow children or non-qualied persons to operate.
GENERAL SAFETY PROCEDURES
8

In addition to the above safety notices, please familiarize yourself with the safety and
hazard markings on the generator.
GENERAL SAFETY PROCEDURES
9

QUICK START GUIDE (GASOLINE)
Remove shipping braces
The shipping braces prevent engine movement during
shipment. Flip the generator over and remove the brightly
colored brace between the motor and the frame, and the
wood brace under the generator.
1.
Add gasoline
The fuel cap is located on top of the fuel tank. Fill the tank
with fresh unleaded gasoline 87 octane or higher. The tank
is full when you see fuel in the bottom of the fuel lter cup.
DO NOT overll the tank.
3.
Turn gas valve on
The gas valve is located above the recoil start on the
bottom of the fuel tank. Rotate the valve clockwise to the
vertical position to turn on the gas supply.
5.
Add oil
The oil ll cap is located on the lower engine block to the
right of the recoil start housing. Remove the oil ll cap and
ll with 10w30 oil.
2.
Turn breaker o
The breaker is located on the right side of the front power
panel. Flip the breaker down to prevent accidental load
when starting the generator.
4.
10

Close choke
The choke lever is located above the air lter to the right
of the recoil start. Slide the lever to the left to cut the air
supply and allow more gas into the engine to start.
6.
Open choke
The choke lever is located above the air lter to the right
of the recoil start. Slide the lever to the right to open the
choke and increase air into the carburetor for normal
running.
8.
Connect devices
Connect your devices to the receptacles on the front panel.
Start with the largest loads rst.
10.
Start generator
The key switch is located on the left side of the front power
panel. Insert the key and turn to the start position to start
the generator. Allow the key to return to the run position
once started.
7.
Turn breaker on
The breaker is located on the right side of the front power
panel. Flip the breaker up to allow power to ow to the
receptacles.
9.
11

18. Muer
GENERATOR COMPONENTS
12
2. Choke Lever
1. Air Filter
10. Volt Meter 8. 120v 3-Prong
Receptacle
6. 120/240v 4-Prong
Receptacle
19. Power Boost
5. Circuit Breaker
7. Ground Terminal
9. Battery
12. Oil Fill and Dipstick
13. Engine Switch
14. Recoil Start
11. 12v DC Charging Posts
1. Air Cleaner - a removable, cleanable, oiled, sponge-like element that cleans the air going into
the engine.
2. Choke Lever - Allows the airow into the carburetor to be restricted to assist in starting the
engine.
3. Fuel Gauge - Indicates the amount of fuel in the gasoline tank.
4. Fuel Cap - Allows access to ll the gasoline tank.
5. Circuit Breaker - Resettable switch that protects the generator from electrical overload.
6. 120/240v 4-Prong Receptacle - Use to connect electrical devices that run 120 or 240 Volt,
60Hz, single phase, AC current (NEMA L14-30).
7. Ground Terminal - Connect a ground wire here to properly ground the generator.
8. 120v 3-Prong Receptacle - Use to connect electrical devices that run 120 Volt, 60 Hz, single
phase, AC current (NEMA 5-20).
9. Battery - 12V DC 7ah Battery that powers the Electric Start System.
10. Volt Meter - Provides reading of voltage output.
16. Fuel Valve

4. Fuel Cap
15. Fuel Filter Cup
18. Muer
17. Spark Plug
3. Fuel Gauge
11. 12v DC Charging Posts – DC Output for charging batteries or running small DC powered items.
12. Oil Fill and Dipstick - Use to add or check the oil.
13. Engine Switch – 3 Position Switch to “Start”, “Run”, or turn “O” the generator.
14. Recoil Start – Easy Pull Recoil Start to start the engine without the electric start.
15. Fuel Filter Cup - Traps dirt and debris in gasoline before it enters the engine.
16. Fuel Valve - On/O Valve that allows fuel into the engine.
17. Spark plug – Provides ignition to the engine.
18. Muer – Reduces engine emissions and reduces noise.
19. Power Boost – DuroMax exclusive Power Boost doubles the amperage available in “120v Only”
for heavy loads like RV air conditioners.
13

PACKAGE CONTENTS
Your generator comes with the items listed below. Please check to see that all of the following
items are included with your generator.
●Note: Actual tools may dier in appearance or design from image shown.
Double Sided
Screw Driver
Oil Funnel w/ hose
Spanner
DC Charge Cables
Spark Plug Wrench
Plug Ends
Phillips and slot blade
screwdriver used for generator
maintenance.
Used to add oil to the
generator without messy spills.
Assorted wrenches used in
generator maintenance and
assembly. Commonly 8mm,
10mm, 13mm, and 15mm.
Used in conjunction with the
charging posts to charge 12v
automotive style batteries or
small DC appliances.
Used in spark plug
maintenance, inspection, and
installation.
Plug heads for the receptacles
found on the generator are
included to make or rewire
your own cords.
14

GENERATOR SETUP
Proper setup of your generator will get you going as soon as possible while making sure you and
your equipment are safe and cared for.

GENERATOR SETUP
Unpack
a. Remove the generator from the box.
b. Place the largest piece of packing foam on a at surface.
c. Flip the generator upside down on the pad.
CAUTION: NEVER Attempt this if you have put fuel or oil
in the generator.
1.
Step 1 - Remove Shipping Braces
Remove braces
a. Completely remove each of the 4 bolts holding the
orange metal brace in place.
b. Remove the brace.
c. Cut the nylon tie strap holding the wood brace in
place.
d. Grab the end of the second brace and pull it out.
e. This piece is no longer needed and can be discarded.
2.
16
Note: Shipping braces can be thrown away.
They will not be needed again.

17
Install support legs
Secure the support legs to the frame with provided bolts and
lock nuts.
1.
Step 2 - Wheel Kit Installation (Optional)
Install wheels
Install Handles
a. Securetheaxlebracketweldedtoaxletotheframewith
the provided bolts and lock nuts.
b. Secure the loose axle bracket to the frame with the
provided bolts and lock nuts.
c. Slide one wheel over each axle end and secure with
the provided retaining pins.
Attach the handles to the brackets on the frame using the
provided bolts and nuts.
Do not over tighten the handles, it will prevent
free movement.
2.
3.

-20 20 40 60 800 100 F
-30-40 -10 0 10 20 30 -20 40 C
30
10W-30
ENVIRONMENTAL TEMPERATURE
5W-30
SAE
GENERATOR SETUP (CONTINUED)
Add oil
The generator requires engine oil to operate properly. The generator, when new from the package
contains no oil in the crankcase*. You must add the proper amount of oil before operating the
generator for the rst time. This amount is equal to the oil capacity of the engine crankcase:
WARNING: Do not apply engine oils with additives or 2-stroke gasoline engine oils. They don’t
have enough lubrication, and may shorten the engine’s service life.
a. Make sure the generator is on a level surface.
b. Unscrew the oil ller/dipstick cap from the engine .
c. Using a funnel, add the appropriate amount of oil
into the crankcase. You will know the crankcase is
full when the oil level has reached the lower lip of
the opening you have just poured the oil into.
d. Replace oil ller cap.
1.
Step 3 - Adding Oil
Engine oil recommended: SAE 10W-30. Viscosity varies with
regions and temperatures. Choose your oil viscosity using the
chart to the left.
* A small amount of oil from factory testing may be present on
arrival.
Model Number DS4400E
Engine Oil Capacity 20 . oz (0.6L)
18
WARNING: DO NOT overll the crankcase. This
may damage the motor and shorting overall life
of your generator.

WARNING: Gasoline and gas fumes are highly ammable.
●Do not ll tank near an open ame.
●Do not overll. Always check for fuel spills.
19
Step 4 - Adding Gasoline
Add Gasoline
a. Make sure the generator is on a level surface.
b. Unscrew gas cap and set aside (NOTE: the gas cap
may be tight and hard to unscrew).
c. Slowly add unleaded gasoline to the fuel tank. Be
careful not to overll. Please refer to the chart below
to nd the gas capacity of your generator model. The
fuel gauge on the top of the gas tank indicates how
much gasoline is in the generator gas tank.
d. Replace fuel cap and wipe up any spilled gasoline
with a dry cloth.
NOTE: Gas can expand. Do not ll the gas tank
to the very top. Leave a minimum of 1.5 in of open
space.
IMPORTANT:
●Never use an oil/gasoline mixture. Never use old gas.
●Avoid getting dirt or water in the fuel tank.
●Gas can age in the tank and make it hard to start up
the generator in the future.
●Never store generator for extended periods of time
with fuel in the tank.
2.
To ensure that the generator runs smoothly use only FRESH, UNLEADED GAS WITH AN OCTANE
RATING OF 87 OR HIGHER.
Model Number DS4400E
Gas Tank Capacity 3.96 US Gallons (15L)
WARNING: DO NOT overll the crankcase. This
may damage the motor and shorting overall life
of your generator.

GENERATOR SETUP (CONTINUED)
Attach grounding wire
a. Ground the generator by tightening the grounding
nut against a grounding wire.
b. Connect the other end to a copper or brass
grounding rod that’s driven into the earth.
A generally acceptable grounding wire is a No. 12 AWG
(American Wire Gauge) stranded copper wire.
Grounding codes can vary by location. Please contact a local
electrician to check the grounding regulations for your area.
1.
Step 5 - Grounding the Generator
WARNING: Failure to properly ground the generator can result in electrocution.
20
High Altitude Operation
At high altitude, the standard carburetor air/fuel mixture will be too rich. Performance will decrease, and
fuel consumption will increase. A very rich mixture will also foul the spark plug and cause hard starting.
Operation at an altitude that diers from that at which this engine was certied, for extended periods of
time, may increase emissions. High altitude performance can be improved by specic modications to the
carburetor. If you always operate your generator at altitudes above 5,000 feet (1,500 meters), have a dealer
perform this carburetor modication. This engine, when operated at high altitude with the carburetor
modications for high altitude use, will meet each emission standard throughout its useful life. Even with
carburetor modication, engine horsepower will decrease about 3.5% for each 1,000-foot (300-meter)
increase in altitude. The eect of altitude on horsepower will be greater than this if no carburetor
modication is made.
When the carburetor has been modied for high altitude operation, the air/fuel mixture will be too lean
for low altitude use. Operation at altitudes below 5,000 feet (1,500 meters) with a modied carburetor may
cause the engine to overheat and result in serious engine damage.