DuroStar DS4000S Review

The DuroStar DS4000S is a great choice for those wanting a mid-range generator with respect to both power and price. It is average-powered with its maximum 4000 watt output and mid to low priced for what it can do.

This is a consumer favorite and delivers what you might expect for the features and price.  Year in and year out, it remains one of the best selling portable generators on the market.

In fact, it is one of the best price to power ratios in this category.  It would be a wise choice as a first generator, or as a workhorse due to its dependability.

There is enough power to run your important household devices in an emergency but you might not find enough power if your intention is to hook into your home’s electrical panel. If you plan to run sensitive electrical equipment, you want to consider an inverter type generator which will deliver a cleaner, more consistent electrical supply.

Table of Contents
(click a title to jump ahead!)
1. Power Considerations – Wattage
2. Engine Type and Fuel Considerations
3. Starting Mechanism
4. Oil Usage Considerations
5. Outlets and Meters
6. Noise Level – Portability
7. Warranty
8. What’s in the Box
9. Dimensions/ Weight
10. Pros and Cons
11. Consumer Reviews
12. Price
13. Summary

If you choose to buy this Durostar model, or with any model you decide on, proper care and maintenance and observing all safety and use recommendations will insure that your unit will be ready when you need it.

If you are considering this unit for use in California, read no further. This unit is NOT California Air Resources Board (CARB) compliant as it does not meet the strict guidelines set forth by California.

As an alternative for those in California, the DuroMax XP4400-CA model is made by the same company (Duro Power) as this reviewed model. It can be purchased and sold in California since it IS CARB compliant.  The DuroMax model includes wheels for easy transport, has 400 more surge watts, and 200 more running watts.  And yes, it does cost a bit more.  The features and specifications for the DuroMax are essentially the same as you will read below except for the customer reviews which were based on those who purchased the DuroStar model. The operating manual is virtually identical.

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Power Considerations – Wattage

The maximum output, or surge watts for this reviewed model is 4000 Watts. Starting up your appliances can take up to two or three times as much wattage as the appliance’s normal running wattage.  You’ll appreciate the surge wattage especially if you’re running and starting numerous appliances or tools along with your continuously running appliances.

Review the estimated wattage table on this site to check your power requirements for this generator.  Estimate if this unit has sufficient wattage (3600 watts) for your needs. Keep in mind that the max 4000 watt output is meant to cover the increased needs of starting your appliances and tools.

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Engine Type and Fuel Considerations

The unit is a gas powered generator and will run on the regular 87 octane available at your local station.  The engine is a powerful 7HP overhead valve (OHV), air cooled, 4-cycle engine.  The overhead valve (OHV) makes the unit efficient with more torque while running cooler.  The 4-cycle vs. two stroke has the obvious benefits of lower fuel consumption, cleaner fuel burn, and no need for the expensive two stroke oil.

The steel gas tank holds 4 gallons (15L) of regular unleaded fuel. If you plan to use it for an extended period, fill it to capacity and it should run about 8 hours at ½ load, or approximately 1600 watts of draw.  This may be a conservative estimate as many reviewers reported up to 10 – 12 hours at 1/2 load.  Of course, approaching the maximum of 3,300 watts will cut the run time accordingly.

Keep in mind that if you plan to use your DuroStar sporadically or infrequently, that you should either add a fuel stabilizer, or keep the tank less than full, where you can run the fuel out if you don’t plan to drain it for longer periods of storage.

Being able to easily drain the tank is a nice feature as many portable generators do not have this ability without siphoning or running until empty, or worse yet, tipping it on its side.  Replacing the sediment bowl on the fuel line and its O-ring can be challenging if not done carefully.

The gas tank is supposed to have a fuel gauge, but recent comments claimed that there was not one on a recent purchase.  Keep in mind, it is not a gauge like in a car, it is a simple fuel level indicator gauge.  Use your common sense in determining how much fuel remains in the tank.  Of course with this or any other gas fueled generator, the gas level should not be manually checked, or gas filled while the unit is running.  See the general safety precautions page on this website to assure a long and safe relationship with your portable generator.  The included owner’s manual is specific and generous with their safety and maintenance information.
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Starting Mechanism

They call it EZ-Pull on the DuroStar line, and in this case the starting mechanism lives up to its name.  When following the start directions of: 1. ON fuel valve, 2. CLOSE choke, 3. ON start switch, 4. PULL cord, starting is a breeze.  (After it starts, after 30 seconds open the choke half-way, then all the way open after a minute).  Even right out the box, few had any difficulty in starting the unit on the first or second pull when following these directions.  This is nice since not all users have Herculean strength.

Over a prolonged period of use as in a power outage, remember you’ll be starting the unit at least a couple of times per day, each time you refill the gas tank.  

Remember as a general rule, when starting any generator, do not have your electrical cords attached.  It may make the unit more difficult to start.  Start with the circuit breaker in the OFF position.  Once the engine starts, then attach cords.  If the cord is attached to an electrical device, that device should be turned OFF when attaching the cords to the unit.  Then turn the circuit breaker to the ON position, then the electrical device should be turned on. You don’t have to memorize it here.  The instruction manual covers this quite nicely.
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Oil Usage Considerations

As with all gas generators, you’ll need to fill the oil reservoir.  You’ll fill it with 20 ounces (0.6L) of 10W-30 (not included) for most environmental temperatures(although some swear by synthetic oil for longer duration between refilling).  DuroStar recommends changing the oil after twenty hours of run time.  If indeed synthetic oil can be changed less frequently, the estimated hours can be a guess.  Although one customer review said that he changed his synthetic oil after 32 hours without issue.  Others state 100 hours as long as you keep it filled.  Vary from the manufacturer’s recommendation with caution.

Please keep in mind that synthetic oil attracts moisture and due to it’s makeup can leak through non-automotive quality gaskets and seals easier, which is why DuroStar does not mention it as an option.  If you do, you should probably drain it when done and don’t store it for any length of time with the oil in it.  You might consider whether or not this would void the manufacturer’s warranty.

Another reviewer recommends with his brand new DuroStar DS4000S, changing the oil for the first time after 4 hours.  He found the oil black with machine shavings present.  Another 12 hours, another change.  Then following the recommended 20 hours oil change.  It’s interesting to note that another similar model made by parent company Duro Power, recommends the early oil change in a new unit after only 5 hours.

Since there is no hour meter, run time becomes a “best guess” scenario.  Depending on how you use this generator, all day on a work site or while out camping, or overnight on a home power outage, estimating the run time is not too difficult.

The low oil warning light is a great feature.  Should you miss this warning, this unit has the automatic shut off feature.  This is important to prevent seizing if you should overlook your oil level.  This should not happen if you maintain the unit and change oil as recommended, but it is nice to know that your investment is protected against this oversight.

One of the most common complaints is the changing of the oil.  The drain plug (10mm hex) is difficult to access, and the straight gravity drip will have oil dripping on the frame, causing you to have to clean the frame after changing oil.  You’ll be able to see where this will happen, so a little ingenuity by slightly propping up one end will cause the oil drip to miss the frame and land in your collection bowl (kitty litter works well for less mess).

The oil change challenge doesn’t end here.  The fill hole is located on the side of the unit under the panel, and somewhat difficult to fill.  You’ll need some sort of funnel.  Sometimes a small funnel is packed but is not listed on the packing list.  When it is supplied, it is wedged in the unit and can melt if not removed.

So you might be wise to be armed with a long or crane neck funnel to fill the oil without spilling.  If you turn the unit sideways, you run the risk of oil spilling out of the fill hole once you lay it flat again.  If you replace the oil cover to eliminate this happening, you run the risk of overfilling with oil.  Spend a few bucks on a good long neck funnel and fill it upright with the recommended amount of oil to avoid the mess.

As with all portable generators, and especially this one, make sure that when operating the unit, that it is on a level surface.  When operated on an incline, oil has been shown to spit out of the air filter.  This does not happen when operating on a flat surface.

One note of concern, some report receiving the unit with oil leakage, possibly having oil in the unit upon receipt.  It is not legal to ship the unit unless dry!  If there is oil, it could be refurbished or used and reason to complain.
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Outlets and Meters

The main power panel can be seen below, and features the main controls, including start switch, volt meter, and circuit breaker.

It offers two 120-volt, 20-amp, 3-prong outlets (NEMA 5-20R) to supply power to all of your home appliances, plus one 120-volt, 30-amp outlet (NEMA L5-30) when you require power from a 30 amp generator cord.

If planning to attached this to your home’s power, be aware that it has a L5-30 (three prong twist-lock) outlet not a L14-30 (4 prong w/ 2 hot leads). According to one reviewer, “most transfer switches (required for connection to your home) will require the 4 prong for more than 4 circuits. You can buy an adapter for $50, but that will leave you with 1/2 of the transfer switch working so you must then bridge the 2 hot leads at the outlet box. While that should work fine, it’s means the single hot is carrying 2x the load which is not ideal.”

The next higher model DuroStar DS4400 takes care of this with the right plug configuration, and should be considered for less than $100 more if you are considering hooking this into your home’s power.

Like most low and mid-range portable generators, this does not have a wattage indicator to let you know when you’re close to using its full capacity.  You’ll have to know how much load you’re putting on the unit, or run the risk of it shutting off if you surpass the maximum wattage, especially when one of your plug-ins powers on with its necessary surge.  You can keep an eye on the volt-meter to see that its staying consistently close to 120volts.

Check out the handy table on the article “What Size Portable Generator Do I Need”, for common appliance draw, for a list of common wattage requirements.

As you can see, you’ll be able to run the many important appliances such as your refrigerator/freezer along with interspersed necessities such as your microwave, light bulbs and your TV during a power outage  (OK so maybe your TV is not a necessity).  Most camping necessities should be no problem with the exception of high draw appliances such as your RV air conditioner.
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Noise Level – Portability

Once started, you’ll be surprised that you’re not going to need your earplugs, or annoy your neighbors or fellow campers with a freight train imitator.  The “Quiet Muffler” reduces the noise level of the generator to a respectable 69 dB (average for a gas generator of this size).  This could be approximated to about the sound level of a vacuum cleaner, meaning you won’t have to shout to be heard over the noise. Decibel readings are taken at 7 meters.

Understand that the engine noise goes up slightly with increasing load.

Keep in mind, when comparing noise levels based on the decibel meter, 10 points more is twice as loud, and 10 points less is half as loud.  So a generator with a 79 dB rating will be twice as loud!  And over a prolonged period, older ear-splitting generators are what gave portable generators their bad reputation as neighbor haters.

For an explanation of quiet generators and decibels you can read the article on this site on how to understand noise levels.

The heavy duty open steel frame has four-point fully isolated motor mounts for smooth and quiet operation.  Some generators shake more than  you’d like, in some cases loosening fasteners over time.  The motor mounts keep the vibration to a minimum.  The open frame of this and most portable generators in this category don’t help the noise level as a higher end, inverter type might, with their enclosed casing.

Let’s face it, generators are heavy (approximately 90 pounds for this one).  Although the frame at least gives you something for one or two people to grab onto for transport, the available wheel kit assembly is the way to go, although not included in the purchase price.  It is available for approximately $30.  The no-flat semi-solid wheels are durable and will last the life of the generator.

You should consider purchasing the wheel kit when you get this or another generator without wheels.  It is much easier to attach the wheel assembly by turning the unit upside down.  Obviously when the unit is new without gas and oil, you won’t have to drain everything if you use it first.  It is easy enough to install and those who purchased it almost universally recommend using your common sense to assemble it to your unit rather than rely on the somewhat humorous instructions that come with it.  We’ve all seen instructions written in English where English was not the writer’s first language!  Or read it for a good laugh.

The tools for assembly are minimal screwdriver, spanner (fixed gap wrench), spark plug wrench.  You probably have these tools as you should not rely on the tools that come with the unit.

Unpacking the DuroStar from its packing materials is also better done with your own tools than with the supplied ones.  You’ll need 10mm for the bolts and 12mm for the nuts, and an extender will make it much easier.
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Warranty

The unit is backed by a 1-year limited warranty.  It should last much longer than that, barring something wrong with the unit which could happen from time to time (as with anything with moving parts).

The recommended maintenance is minimal as like you’ve heard before, “you take care of it and it will take care of you.”  Aside from changing the oil every 20 hours of run time, it is recommended “to check the oil level at every use, along with the air cleaner.  The gas tank should be cleaned every year or 300 hours to eliminate sludge, and clean the air cleaner every 3 months or 50 hours.  You should check or clean the spark plug every 6 months or 100 hours.”  This is more maintenance that admittedly most of us will do, but not too much to ask to protect your investment.
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What’s in the Box

What’s in the box is the DuroStar DS4000S Portable Generator, a tool kit (screwdriver, spanner, plug wrench), and operation manual.  Just as important to know is what’s not in the box.  Of course you’d expect that the oil and gas are on you.  It’s important to know that once oil or gas is put in the unit it CANNOT be shipped back. If there is an issue, it becomes an issue between customer service and you.

A simple socket and wrench set with 10mm and 12mm fittings and extensions is about all you’ll need for unpacking from shipping and assembling the optional wheel kit.

The one thing you’ll be happy to have is a long neck funnel, or an angled neck funnel for the inconvenient oil opening.  You MAY get one in your box, tucked away in the unit.  Look for it, because if it remains lodged, it will melt.  It is not listed in the packing list.

Of course, you’ll need other things, some of which you’ll already have, some of which you’ll wish you did and will soon need to get.  Most important is good quality extension cords that you can read about on this site.
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Dimensions/Weight of the DuroStar DS4000S

Dimensions:

• 27 inches wide
• 20 inches deep
• 22 inches height

Weight:

• 92 pounds shipping weight (42Kg)

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Pros and Cons

PROS:

• good price to power ratio – a lot of power for the money
• easy to start with one or two easy pulls
• low oil shutoff and warning light
• reliable and durable – last long past the 1 year warranty
• relatively quiet operation
• efficient  7 HP 4-cycle engine
• generous run time at ½ load
• gas drain capability

CONS

• inconvenient oil fill and change
• poor packing
• insufficient tools supplied
• not CARB compliant
• wheel kit not standard

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Consumer Reviews

With the popularity of the DuroStar DS4000S, you can rest assured that is because it is initially loved for the features and price.  The fact that it remains a bestseller over the years shows that consumers are happy with this generator and are not afraid to tell others.  Not only does it sell well to new users, but repurchases tells the true story.

Users love the dependability and ease of use.  Many reviews praised the generator as exceeding their expectations.

Read more here directly from Amazon:  DuroStar DS4000S Portable Generator

Average Rating 4.4 Stars

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Price

The price of this portable generator varies depending on where you buy it but Amazon tends to have the lowest price.

Check current pricing discounts at:

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Summary

After reviewing the DuroStar DS4000S, I confirm that it’s a great choice for someone looking for a dependable portable generator with mid-level needs.  Many have owned theirs for years, with it performing nicely when they needed it most; during the many days of power outages during recent hurricanes.

It’s a great choice for the outdoorsman, RV’r, handyman, or professional, and especially for the person who wants peace of mind in case of emergency.  You want it to be ready when you need it.

You will not be disappointed with this portable generator.  Over 340 people have reviewed this unit on Amazon with over 290 of those being 4-5 stars. That’s a lot of satisfied customers!
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Filed under: $250 - $499 • DuroStar • Reviews