Honda EM4000SX (Discontinued)
The Honda EM4000SX is a portable open frame generator with a rated wattage of 3,500 W and a starting wattage of 4,000 W. (Read full specs)
This product has been discontinued. We've kept this page live for reference.
If you were hoping to purchase it, you might want to take a look at the Honda EG4000CL, which offers similar specs.
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Description
Zoom on the Honda EM4000SX
In a few words, the Honda EM4000SX is a portable generator perfectly suited for:
- RV travellers wishing to enhance their freedom and nomad lifestyle
- People occasionally participating in outdoor fairs, festivals or events
- DIYers who wish to improve their efficiency with tools
- Homeowners who want to be able to use the most necessary devices in their household, even during a blackout
- Professionals who want to ensure that a power failure will not prevent them from working
Over the following sections, you'll uncover its power characteristics, the selection of outlets it offers, its overall portability, and the supplementary features it includes.
Power & Run Time
The Honda EM4000SX's core is the 270 cc Honda iGX270 OHV 4-stroke engine with cast iron sleeve, which runs on gasoline. With an output of 120/240V, it provides a running wattage of 3,500W and a peak wattage of 4,000W (and even up to 5,000 W thanks to the iAVR technology).
The generator, rated for a noise of 61 dBA (just slightly more noisy than a normal conversation), provides flexibility in starting, offering both a simple traditional pull-start mechanism and a simple and elegant electric starter (battery included). To increase convenience, the EM4000SX offers remote starting functionality, allowing for easy operation from a distance (separate purchase).
Equipped with a 6.2 gallons fuel tank, the EM4000SX ensures continuous operation for around 16 hours at 50% load with a full tank (fuel usage approximately 0.39 gallons per hour).
Outlets
The control panel features 6 AC outlets as follows:
Moreover, it comes equipped with 1 DC outlet: there's a 12V 8A output providing easy battery charging capabilities.
Despite not meeting the 'RV Ready' criteria, this Honda generator grants the advantage of simple RV compatibility via its L5-30R receptacle, enabling you to conveniently power your RV by using an L5-30P to TT-30R adaptor.
Portability
Measuring L41.1 x W27.8 x H28.3 in, the Honda EM4000SX showcases a classic open frame layout, offering stability and simple maintenance access to components, while facilitating air circulation. The design is ideal for rough environments and demanding outdoor use.
With a weight of 204 lbs, the generator is still labeled as 'portable,' denoting its ability to be moved, although its heaviness might restrict easy portability. However, the limited maneuverability is remedied with its wheel kit and its folding handle, facilitating convenient shifting once the generator is positioned on the ground.
Features
Equipped with a built-in fuel gauge, the generator facilitates swift gas level checks.
Regarding security, the generator comes with an automatic low oil shut-off (Oil Alert®) and an overload protection (circuit breaker), providing peace of mind during operation.
Besides the features previously mentioned, accessory-wise, the Honda EM4000SX comes with the usual documentation and owner's manual (opens in a new tab) needed to get you promptly started. An official storage cover is available, as a separate purchase.
iAVR Technology
Honda’s iAVR (opens in a new tab) (Intelligent Automatic Voltage Regulation) reduces voltage fluctuation by up to 50% over current AVR systems.
In conventional generators, when a load is applied, the engine’s rpm drops, which causes the voltage and frequency to drop as well, until the rpm recovers.
iAVR is a combination of the DAVR (opens in a new tab) technology and the iGX (opens in a new tab) engine technology, which serves to provide advanced and instantaneous engine rpm control when a load is applied.
As a result, voltage and frequency are precisely regulated and the EM4000SX is able to produce a starting wattage above the maximum rating, for up to 10 seconds. Therefore, thanks to iAVR, the EM4000SX is able to “overclock” itself above its 4000 starting watts and provide up to 5000 W.
Product Videos
The Honda EM4000SX versus other generators
The following charts are provided to give you an idea of how some of the key specs of the Honda EM4000SX compare to generators of similar power (between 3000 and 4000 W).
- With a weight of 204 lbs, the Honda EM4000SX is notably on the heavier side among generators in the 3000-4000 rated wattage range. If weight is a key factor for your needs, the Pulsar PGD40iSCO is noteworthy for being one of the top contenders in this power range, with a dry weight of 46 pounds.
- At a lowest noise rating of 61 dBA, this generator is one of the quieter devices of similar power. If you'd like a less noisy alternative, the Westinghouse iGen5000DF is a strong contender. It boasts a noise rating of 52 dBA, placing it among the quietest generators in its power category.
- At 50% load, the EM4000SX boasts a higher run time than most similarly powerful products, reaching around 16 hours. If concerned with autonomy, one of the products of a comparable power output, which offers the highest run time, is the Firman W03663OF, boasting with around 18 hours.
- The run time is important, but also hugely depends on the capacity of the fuel tank and doesn't mean much if we don't talk about fuel consumption as well. In terms of fuel efficiency within its wattage range, this generator falls short: it consumes approximately 0.39 GPH at a 50% load. If gasoline efficiency is at the top of your list, you may want to have a look at the Pulsar PGD40iSCO, which has great fuel efficiency, with a gas consumption of only 0.22 gallons per hour.
The bottom line
- GFCI Outlets
- Remote start capable
- iAVR technology pushes starting watts up to 5,000
- Quiet for its power (61 dBA)
- High run time
- No data center
- On the heavy side (204 lbs)
- Low fuel efficiency
Features and Specifications
| Inverter | No |
|---|---|
| Parallel capable | No |
| RV ready | No |
| Fuel | Gasoline |
| Engine | 270 cc Honda iGX270 OHV 4-stroke, cast iron sleeve |
| Starting system | Recoil, Electric, Remote |
| Warranty | 3 years |
| Voltage | AC: 120/240V 60 Hz, DC: 12V |
|---|---|
| Running watts | 3,500 W |
| Starting watts | 4,000 W |
| Running amps (@120/240V) | 29.2/14.6 amps |
| Peak amps (@120/240V) | 33.3/16.7 amps |
| Run time @50% load | 16 h |
| Run time @25% load | Unknown |
| GFCI outlets | Yes |
|---|---|
| Covered outlets | No |
| Automatic Voltage Regulation | iAVR |
| AC outlets |
|
| DC outlets | 1x 12V 8A output |
| Data center | No |
| Indicators | No |
| Fuel tank | 6.2 gal |
| Fuel gauge | Yes |
| Weight | 204 lbs |
|---|---|
| Approx. dimensions (L x W x H) | 41.1 x 27.8 x 28.3 in |
| Noise (lower limit) | 61 dBA |
| THD | Unknown |
| Compliance | CARB, EPA |
| Security | Low oil and overload protection |
| Spark arrestor | Yes |
| Neutral | Floating |
| Accessories included | Battery and wheel kit |
| Series | Deluxe |
| Other model numbers | EM4000SXAT1 |
| UPC | 786102005265 |
We've taken extra care to research and verify each of the specifications above. That said, occasional mistakes or omissions are still possible. If you spot any missing or inaccurate information, feel free to suggest a correction so we can address it.
About Honda
Founded in 1948, the Japanese Honda Motor Company has gained notoriety for consistently producing top quality engines, motor-powered vehicles and devices. Over the years, the company has gained a strong reputation in the motorcycle, automobile, but also power tool industry. Honda’s power tool division has been producing power tools since 1953, including tillers, mowers, blowers, sprayers and of course, power generators. While the company has expanded globally and moved a majority of its production out of Japan into other Asian countries, Honda is to this day known as a legend among the generator manufacturers.
Warranty Information
The Honda EM4000SX is covered under a warranty for up to 3 years. This warranty may be limited and may not cover all parts of the generator.
For more information about the warranty of Honda generators, please consult Honda's warranty policies (opens in a new tab). Alternatively, you can also contact their Customer Support: 1-770-497-6400.
Questions & Answers
What can it power?
| Item | Running Watts | Starting Watts | |
|---|---|---|---|
| At home | AC (10,000 BTU) | 1500 | 2200 |
| Sump pump (1/2 hp) | 1050 | 2150 | |
| Refrigerator (energy star) | 192 | 1192 | |
| Set of 5 LED light bulbs | 55 | 55 | |
| Total | 2797 W | 3897 W | |
| For camping | RV AC (11,000 BTU) | 1010 | 1600 |
| RV refrigerator | 180 | 600 | |
| Microwave (1000 watts) | 1500 | 1500 | |
| Radio | 100 | 100 | |
| Total | 2790 W | 3380 W | |
| For work | Grinder | 1400 | 2500 |
| Demolition hammer | 1260 | 1260 | |
| Bug zapper | 80 | 80 | |
| Total | 2740 W | 3840 W |
What is the difference between the EM4000S, the EM4000SX and the EM4000SXAT1?
These model numbers refer to the same unit, but simply include more or less information regarding its specs, production batch, etc. Read how Honda name their generators.



