4000 watt 120/240V generator

  • Provides 5,000 watts for 10 sec. to start larger equipment
  • Powers fridge, furnace, lights, TV, and much more
  • Long run time - up to 16 hrs
  • Electric start (battery included) with recoil back-up




Powers your fridge, furnace, lights, TV, and much more.
Powers your fridge, furnace, lights, TV, and much more.

The EM4000S can power a wide variety of appliances in your home. Check the applications tab for more examples.

Consistent power with iAVR (Intelligent Automatic Voltage Regulation) technology
Consistent power with iAVR (Intelligent Automatic Voltage Regulation) technology

Honda's exclusive iAVR technology ensures a consistent flow of power regardless of the load. This translates into stable power for sensitive equipment and a more reliable power source for you.

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Provides 5,000 watts for 10 sec to start larger equipment
Provides 5,000 watts for 10 sec to start larger equipment

Honda exclusive iAVR technology lets the generator operate well above its maximum rating for up to 10 seconds to start high initial amp draw equipment.

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Powerful Honda iGX commercial engine
Powerful Honda iGX commercial engine

Honda’s innovative iGX series engines deliver exactly what you’ve always wanted: reliable, optimal performance. These intelligent computer-controlled engines operate automatically with much better, simpler, and faster controls.

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120/240V Selector switch - More usable power, more flexibility
120/240V Selector switch - More usable power, more flexibility

Choose between using both 120 and 240 Volts, or 120 Volts only. This allows for the total generator output to be available through any of the 120 volt outlets, limited only by the capacity of the individual outlet. This enables you to power units with larger wattage requirements.

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3 year residential and commercial warranty
3 year residential and commercial warranty

You can rest easy, knowing your generator is covered from top to bottom for 3 full years.

Easy folding handles
Easy folding handles

Wide, positive lock folding handles offer convenient transport and storage and a more compact unit.

Runs up to 16 hours on 6.2 gallon tank
Runs up to 16 hours on 6.2 gallon tank

Runs approximately 16 hours at half load and 10.1 hours at full load. This makes the EM4000S great for overnight power.

Electric start

Recoil back-up is also included.

Wheel kit standard

The EM4000S is easy to maneuver and transport.

12V DC Auto Charging

Use when charging 12-volt automotive type batteries. (Requires an optional charging cord.)

Multiple front panel outlets for easy power connections

Low 61-63 dB(A) sound level

Full Frame Protection

Protected by Honda Oil Alert®

Protects the generator by shutting the engine off when low oil is detected.

Reinforced standing legs

Electronic ignition

GFCI protection

The EM4000 offers 2 duplex outlets with GFCI protection.

USDA-qualified spark arrestor/muffler

Optional remote start available

Allows for convenient starting of your generator from a remote location.

Electronic circuit breakers

Protects the generator from being overloaded.

Fuel gauge standard


Engine Honda iGX270
Displacement 270 cc
AC Output 120/240V 4000W max. (33.3/16.7A) / 3500W rated (29.2/14.6A))
iAVR Output 5000W (41.7/20.8A) for 10 sec.
Receptacles 20A 125V GFCI Duplex (2), 30A 125V Locking Plug, 20A 125/250V Locking Plug
DC Output 12V, 100W (8.3A)
Starting System Electric & Recoil
Fuel Tank Capacity 6.2 Gallons
Run Time per Tankful 10.1 hrs.@ rated load, 16.0 hrs. @ 1/2 load
Dimensions (L x W x H) 41.1" x 27.8" x 28.3"
Noise Level 63 dB(A) @ rated load; 61 db(A) @ 50% load
Dry Weight 204 lb.
Residential Warranty 3 Years
Commercial Warranty 3 Years


Remote Control Kit
DC Charging Cord
Transfer Switch
Hanger Kit
Storage Cover


This generator can power the following common applications. Please note: not all applications can be powered simultaneously. For more help, see our power needs page.

  • Refrigerator or Freezer (Energy Star)
  • Microwave Oven
  • Furnace Fan, gas or fuel oil
  • Sump Pump
  • TV / DVD
  • Hair Dryer
  • Coffee Maker
  • Computer
  • Garage Door Opener
  • Incandescent Lights


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Overall Rating   
(3 Customer Reviews)
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A thing of beauty

Model Reviewed: EM4000 Sunday, September 1, 2019
Type of use:  Home Back Up
I only wish it came with an hour meter, hence only 4 stars on features. All else is perfect.

After 4 years and even in zero degrees, it's a trooper!

Model Reviewed: EM4000 Wednesday, January 17, 2018
Ridge Dweller
Washburn, TN
Type of use:  Home Back Up
I live off the grid in East Tennessee, and rely on my Honda 4000SX generator to power my home when we have extended partly or no sunny days.  We are a Honda family, with a Honda trained son, and are true to the brand, whether in vehicles or other products, because Honda/Acura's dedication to quality, fit, and finish is consistently reliable.  This morning was no exception.  At 3am, with temps at 2 degrees F., I walked out to the porch and turned the key.  My back-up didn't fail me...maybe a little hiccup, but what wouldn't be daunted by this weather?  Now, with the sun up and shining brightly, and my battery state of charge approaching 100%, I am so thankful that I didn't listen to folks who suggested I opt for a less expensive model!  Kudos to Honda and Acura for your consistent dedication to high quality and high performance products.  As an Acura owner for 20+ years, I know where to put my trust.  Thank you!

Excellent Generator

Model Reviewed: EM4000 Wednesday, June 11, 2014
Leesburg, VA
Type of use:  Home Back Up
I've owned this generator for about 3 years now.  I bought it after a "Derecho" event hit our area and we were without power for a week.  I ran it for 4 days straight during some of the hottest weather primarily to keep 2 refrigerators, and a 7 cubic foot chest freezer running.  I added a 10,000 BTU window A/C unit to the mix after calculating the load of all my devices and was able to keep the temperature in the house tolerable.  I dragged it out again about 6 months later when a hurricane knocked out power for about 24 hours.  I fire it up for 15 minutes every month or two and follow the maintenance plan in the manual.  No issues so far.  My two biggest issues: 1. I wish it were a bit quieter .  At load it is about as loud as a push lawn mower, when the load drops low enough it idles back and is about 1/2 as loud when you have the feature enabled. 2. I wish it were propane.  My vehicle is diesel, my lawn equipment is all rechargeable battery-driven so this generator is the only reason I have to keep gasoline around.  Propane is much more stable and doesn't have issues of "going bad".
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