Yamaha EF2000iS Portable Inverter Generator

The Yamaha EF2000iS is one of the best portable generatorsThe Yamaha EF2000iS Inverter Generator is constantly ranked among the best portable generators on the market in many categories, like best camping generator and top generator for the money.

The reason why it gets these accolades is because it is very quiet, very fuel efficient, very portable and most importantly very reliable.

These are the main differences between the EF2000iS and the rest of the crop:

  • Quietest. You won’t even know when this puppy is on. This Yamaha is an inverter generator. It uses an integrated computer to coordinate its engine speed to the actual load. This means that if you only have a light plugged in to your generator it will sense what power is required and lower its engine speed to decrease noise, increase fuel efficiency and prolong engine lifespan.
  • The most fuel efficient portable generator

    The most fuel efficient portable generator

    Fuel Efficient. You will continuously wonder why you never have to refill the fuel tank. Because this generator uses inverter technology with a different than conventional alternator it can have a smaller engine size per power requirement and it can adjust its engine speed via its smart throttle. The combination of a smaller engine, and, that smaller engine running at a lower speed equals a highly fuel efficient generator. In fact, this generator when running at half load will only drink through a can of soda worth of fuel per hour.

  • Very Portable. You will find yourself wanting to take your new generator to work with you, to the gym, to the job site – everywhere you go. When you have a generator that is light, compact, reliable, fuel efficient, enviro friendly and powerful enough for your needs you will feel the urge to take it with you everywhere (just in case). Being only the size of a packed briefcase you will definitely be impressed with the places this generator can fit during transport.
  • Very Reliable. The fact that this generator is an inverter generator automatically adds to its reliability. An inverter generator is computer controlled and can adjust its engine speed to match required load. This increases lifespan because the less revolutions the better. Yamaha has also ensured this technological marvel can provide you utility supply quality electricity so you can rest easy powering your sensitive electronics.

So as you can see this generator has some serious benefits. It is the quietest, most fuel efficient, most portable and extremely reliable with at least double the engine lifespan of other conventional generators.

Yamaha EF2000iS Best Features

The generator's control panel is simple and efficient

The generator’s control panel is simple and efficient

Smart Throttle – Used to decrease the engine speed when you do not require full power. This allows for the generator to dramatically save fuel and increase engine lifespan. You will barely ever have to refill the fuel tank (1.1 gallons every 11 hours at 1/2 load). And, you will get to enjoy this generator for years to come by doing the simple maintenance as mentioned in the user manual.

Super-Quiet Muffler – Yamaha has installed a superior sound reducing and emission controlling muffler to their inverter generator. Part of the reason this device is approved for use in all US states is because of this USFS (United States Forestry Service) spark arrestor approved muffler. You will be able to take this generator with you camping, turn it on next to you, and forget it is even on while providing you the electricity you need.

Advanced Inverter System – An inverter generator uses a rectifying bridge diode and computer controlled inverter to turn its 3 phase AC into DC and clean, pure 60 hertz AC. You can rest easy knowing that this electricity is utility supply quality. Good enough to plug your sensitive electronics with microprocessors straight in, like computers, iPods ans smartphones.

TwinTech Parallel Function – You can hook up 2 Yamaha EF2000iS generators to provide you double the electricity. All you need is some inexpensive extra cables and it’s a matter of plug them in an go. A great option for those that require a little extra juice in times of need.

OHV Engine – Yamaha has installed an extremely advanced gasoline powered overhead valve engine to provide the mechanical energy required to produce the electricity you need. The OHV engine is smarter, smaller and can run at lower speeds than conventional generator engines. It has a “smart throttle” which essentially just means it has a computer controlling its speed to maximize fuel economy and engine life.

Oil Watch Warning – Being so quiet and with such a long run-time this generator has the ability to fall into the background with you forgetting it is even on. For this reason, it needs some protection from human error. One of the systems this generator uses is an oil watch warning system. When it senses poor engine lubrication it will shut the engine down preventing engine damage. This is ideal because you can concentrate on more important things like roasting marshmallows, having a chat or drinking beer.

Electrical Overload Breaker – In case you try to hook up more electrical appliances than this generator can power, the generator will not shut on or, it will shut off if it was already running. This is all a good thing and works because of the electrical overload breaker.

Easy Access Side Panels – To keep the warranty valid you will need to follow the generator user manual. In it, you are told to do regular service. For example, you need to check the spark plugs and replace when necessary. To easily perform your required maintenance Yamaha has designed this genset with detachable side panels. When you need to do maintenance all you need to do is detach the panels and take a look. No wasting time unscrewing things…


  1. It’s Light-Weight: With a weight of 44 pounds it is very much a portable generator – about the same weight as a cooler of 15 or so bottles of beer with ice. You can take it with you camping, on your boat, to your friends barbecue and anywhere else that you want your new toy to come with you.
  2. It’s Compact and Very Portable: With a volume of 2.2 cubic feet it is roughly the same size as a briefcase. You will have no trouble squeezing it between the seats on your boat or into the back seat of your car when you head off with the wife and kids for a picnic.
  3. It’s Quiet: With a running sound level of 51 dBA at 1/4 load and 61 dBA at full load it will not interfere with your conversations. And, in fact, it is only about as loud as your refrigerator. Quiet enough?
  4. It’s Environmentally Friendly: With a brushless inverter alternator this Yamaha generator is top of the class when it comes to fuel efficiency and environmentally friendly power generation. It can run for more than 10 hours off 1 gallon of gasoline and it is CARB (California Air Resources Board) compliant. So, if you live in California this generator is good to go.
  5. It Has a 3-Year Warranty: In order to keep your generator warranty valid all you have to do is follow the maintenance tasks outlined in the user manual. This includes simple things like checking for leaks before use, checking and cleaning the air filter, checking the spark plug and other similar small tasks. If you do these in alignment with the Yamaha user manual you will have full protection from defects in material and workmanship for 3 years. You want that right?


It’s Expensive Compared to Similar Generators: This generator hovers around $950 and can provide 1,600 running Watts. Other generators, like the Champion 73536i inverter generator, cost almost half that and provide the same or more power.


Despite the questionable cost/performance ratio, the Yamaha EF2000iS Inverter Generator remains the most popular inverter generator on the market. It even beats the excellent Honda EU2000i, which is our favorite generator for 2016.

Full Specs

Model Details

Brand: Yamaha

Brand Website: www.yamaha-motor.com (click on Outdoors for generators)

Model: EF2000iS (2,000 Surge Watts and 1,600 Running Watts)

Model Webpage: Yamaha EF2000iS Portable Inverter Generator


Fuel Type: Gasoline

Run-Time: 8 – 9 hours at half load

Fuel Tank Size: 1.1 Gallons

Fuel Gauge: Yes

Watts: 2,000 surge Watts, 1,600 running Watts

Alternator: Inverter

Frequency: 60 hertz

Sound Level: 51.5 dbA at 1/2 load (Easily have conversation next to it)

Outlets: (1) 12V DC, (2) 120V AC – up to 16.7 Amps


Brand: Yamaha

Starter: Recoil

Size: 79 cc

Oil Level Alarm: Yes


Dimensions: 19.3″ Length x 11″ Width x 17.9″ Height

Weight: 44 Pounds

Warranty: 3 Years

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