Product Code: EF6300iSDE

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Yamaha EF6300iSDE 6300 Watt Generator with CO Sensor
The Yamaha EF6300iSDE weighs 200 pounds, starts with ease with its electric starter, and is capable of running an RV air conditioner, microwave oven and more all at the same time. Designed to be acoustically sound, this extremely quiet generator (58-64 dBA) features Smart Throttle which allows greater fuel efficiency and noise reduction. It will run up to 19 hours at ¼ rated load on a tank of gas. With features such as Built-In Wheels, Electric Start, Power Meter and an Oil Watch Warning System, the EF6300iSDE is one of the most powerful well equipped portable inverters in its class!

Top Features

CO Sensor for Safety
Shuts off at high level CO detection
Oil Watch Warning System
Prevents engine damage from low oil
Dual 120/240V Power
Run almost any type of equipment
Smart Throttle
Greater fuel efficiency, noise reduction

Additional features

  • Noise Block ‐ Quiet, pleasant to use.
  • Pure Sine Wave (Pulse Width Modulation) Inverter System ‐ Run electronic equipment, appliances, variable-speed power tools and computers.
  • Smart Throttle ‐ Automatically adjusts engine speed to match power demand, reduces noise, fuel consumption and engine wear.
  • Wireless Remote (Optional) ‐ Start & Stop the generator from up to 66 feet away.
  • Electric start ‐ Effortless starting (battery included).
  • Automatic choke ‐ Effortless starting.
  • Low oil shutoff ‐ Protects engine from low oil damage.
  • Fuel level gauge ‐ See fuel level at a glance.
  • Dual voltage 120/240 volt ‐ Versatile, operate variety of 120V and 240V tools and appliances.
  • Power meter ‐ See how much power is being used and how much power is available.
  • Hour meter ‐ Shows accumulated running time for refueling and service scheduling.
  • Lightweight ‐ Easy transport.
  • Twin bar ‐ Aid lift, transport and provide security point.
  • Stylish design ‐ Nice appearance and Modern design.
  • 50 state legal ‐ Meets CARB emission regulations and given highest EPA rating.


  • Model / Model Code: EF6300iSDE
  • Warranty Type: 3 Year Limited Warranty
  • Dimensions (length/width/height): 30.7" x 24.3" x 27.2"
  • Dry Weight: 200 lbs
  • Engine Type: OHV, Air-Cooled, Four-Stroke, Single Cylinder
  • Displacement: 357cc
  • Capacity: 4.5 Gallons
  • Fuel Type: Unleaded Regular
  • Cooling Type: Air Cooled
  • Generator Type: Brushless, Inverter
  • Maximum AC Output: 6300 Watts
  • Rated AC Output: 5500 Watts
  • Rated AC Current / Max AC Current: 45.8 amps /52.5 amps @120V | 22.9 amps/26.3 amps @ 240V
  • Noise Level 1/4 Load/ Full Load: 58 dBA / 64 dBA
  • Continuous Operation at 1/4 Rated Load: 13.3 hours

Customer Reviews

Based on 71 reviews
Karla B.
Still waiting

We are still awaiting our generator unfortunately. Shipping issues. We are holding out hope!

Rufino S.
Great Dealer / Excellent Generator

Bought a cabin in the Sierra last year and after numerous outages, one over 24 hours long, I decided to get a generator. Question was whether I buy a stand by whole house generator or a portable generator. My neighbors convinced me that a portable generator would be the better option. After some research and recommendations I decided the Yamaha isde6300 from National Supply was the way to go.
Their website indicated that if the delivery address was not the same as the billing address I should expect a confirmation phone call which I got soon after I completed the order. The customer rep was professional, friendly, and apologetic about having to make the call explaining that this was to try to avoid fraudulent purchases. No problem there but a problem arose with the delivery cost. Long story short is that National Supply made it work for everyone. The delivery company Nation Supply works with was very efficient with accommodating my schedule and the delivery guy dropped off generator where I asked him to.
The isde 6300 is more than I expected. I was hoping the generator would power up the essentials (fridge, central heating, electric water heater, a few lights and plugs). When I used it the first time, I was able to run the house normally with the power load meter at 2 of 10. I did not run my electric dryer but I think the generator could have handled that too. It’s also very quiet. My wife has very acute hearing and she could barely hear the generator inside the house.
A few things to keep in mind: 1) it’s on the heavy side so maneuvering it is not easy, 2) you will need a flexible funnel to fill the generator with oil, and 3) you need a charger to top off the battery.
My only critique would be that I wished National Supply also sold generator cables for attaching the generator to the power inlet box. Having to buy it from another source is not onerous but the convenience of one stop shopping would be nice.

Great Dealer, OK Generator

Fast delivery and great price from National Supply. This is our 4th Yamaha .Not because they're good but because generator box was built for this unit so we have to keep using them or have a new box built ($2200).

Wylie D.

We love this generator. Also have a 3000 watt Yamaha we have had for 6 years that runs perfectly. Never have had an issue. Decided to purchase a larger Yamaha for back up at the cabin. Followed the directions and one push of the button started right up. Yamaha may be a little more expensive when compared to other generators. They are worth every penny!!


Excellent customer service. The rep even called back the next day to be sure I was getting the right size for my property and needs. I'm so grateful to the company. THANK YOU for an excellent support system and great service.


Perfect size to run the whole house and my water pump. Living in the country the power goes out alot. This generator provides power to the water supply for my large animals and heat in the house. WHEW! It's a blessing. Thank you

Yamaha EF6300 Generator

Impressed, struggled with battery, but once installed started with no problem, very satisifed!

G t.
Co2 sensor is awful

Love the generator when it’s working properly and running ., but the co2 sensor keeps shutting it off if the wind is blowing the exhaust right back at it and you know how wind can be. As long as you have the wind blowing it away works just fine

Bright E.R.
Exactly What We Were Looking For!

Great product and great customer service! We look forward to working with our rep again.

Victoria Z.
Great Customer Service

Thanks to Larry for working with me the order and delivery process. Very glad to finally have my generator - delayed due to global supply chain issues for several months. However as soon as the items came in my experience was fast and easy through to delivery.

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