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What Stands Out About The Yamaha EF2000iS Portable Generator?

23 June 2011 5,591 views One Comment

The Yamaha EF2000iS portable generator is really an amazing piece of machinery. It is a testament to what fine craftsmanship and innovation can produce.

My family and I really like to travel and go camping. We’ve been all over the US, to several National Parks like the Grand Canyon, and even to South America. Last year we visited a beautiful park on the north coast of Colombia called Parque Tayrona. It has some of most gorgeous beaches and tropical rain forest you’ll find in all of South America. We camped right on the beach along with my sister and my brother-in-law. What a fantastic trip. I still remember the sweet taste of the fresh mangos that we ate right off the tree and the delicious fresh caught fried fish that we had for dinner on the beach. No portable generators on that trip, just a couple of backpacks, tents, and a long hike through the stunning rain forest to the beach.


Now I do like to rough it to a certain extent when I camp and my wife generally likes to also. But there are many times, especially for longer trips, where you just want to power up a few things and have some of the comforts of home. I’ve checked out a bunch of portable generators designed for camping, boating, RV’ing, or tailgating and none match the quality and dependability of the Yamaha EF2000iS. And of course you can use the Yamaha in emergency situations too, if there’s a blackout at home.

Here’s why the Yamaha stands out from the crowd.

The Yamaha EF2000iS Generates Clean AC Power

There are two types of alternators that you can find on portable generators, conventional and inverter style. Generators that have conventional alternators are cheaper but the electrical power they produce is not as clean as that produced by portable generators with inverter style alternators. You don’t want to run sensitive electronic equipment without some type of surge protector on a conventional alternator. The power fluctuations can damage the sensitive components found in devices like your computer or microchip controlled electric tools. Conventional alternators are also louder and less fuel efficient than inverter style alternators.

An inverter style alternator can vary its speed based on the electrical demand at the time, making them much more efficient and quieter. They produce very clean AC power. The Yamaha EF2000iS uses an inverter style alternator with Pulse Width Modulation (PWM) control. You can read more about PWM if you’d like but basically it involves smoothing out the electrical sine wave and power fluctuations that a generator creates. The smoother the wave, the more stable and cleaner the power and the safer it is to use with sensitive electronic equipment.

The following video from Yamaha talks about the difference between conventional and inverter style generators.

To further protect your equipment and the generator itself, the Yamaha comes with an electrical overload breaker. This will cut the current in case there is an unplanned overload and prevent any damage from occurring to your devices or to the generator.

So, the bottom line is that the EF2000iS is ideally suited for you to use on delicate electronics, it is quieter than conventional portable generators, and it is more energy efficient.

How Quiet is the EF2000iS?

The Yamaha uses a high tech muffler that makes it one of the quietest portable generators on the market. It also features a glass wool noise absorbing design and rubber feet that help to isolate engine vibrations.

At full rated load it produces about 61 decibels of sound from about 23 feet away. At 25% of rated load, the sound level goes down to 51.5 decibels. Most portable generators on average will produce about 68 decibels at the same distance. 60 decibels is about the level of a conversation whereas 70 decibels is about like average street noise in the city. 50 decibels is about like the background noise you would hear in a quiet office. This is a pretty big difference and you can really tell when you listen.

In many of the owner reviews that I checked out, people talked about how, after a while, that they forgot the Yamaha was even running. Now that’s pretty amazing for a portable generator!

The Yamaha EF2000iS Is One of the Best In Terms of Fuel Efficiency

The Yamaha can run 8 hours at a 50% load on a full tank of gas. It holds about 1 gallon of gas, which means you get 8 hours of run time per gallon. At a 50% load, most other generators will average about 3 hours of run time per gallon of gas. So the EF2000iS is over 2.5 times more fuel efficient than other models. I wish my car engine was like that!

The EF2000iS achieves its energy efficiency in a couple of different ways. First is employs an inverter style alternator as I talked about earlier. Then it uses a smart throttle and a dual core stator which will take the power load into account and vary the engine speed. So if you need more power to start up your portable AC unit, for example, the smart throttle will give it to you and then pull back when the AC unit is at running speed. Most portable generators will just run at the same throttle engine speed regardless of the power needs at the time. This is very inefficient and uses a lot more fuel than is necessary. The Yamaha intelligently uses its engine power.

The Yamaha is Ideal for Outdoor Use

Check out the video below to see how small and portable the EF2000iS is and how easy it is to use outside. It’s perfect for camping, boating, and RV use. It weighs only 44 pounds so just about anyone can easily pick it up and carry it around. (I know when I pack up the family cooler for a road trip; that durned thing weighs way more than 44 pounds. But I carry it anyway – sometimes with help though. :))

The EF2000iS also has a USFS (United States Forest Service) approved spark arrestor. A spark arrestor is a mechanical device that helps to prevent forest fires by destroying or trapping hot particles that shoot out of an engine’s exhaust pipe. If your portable generator does not have one, you can’t use it on public land, including National Parks and some state parks, or risk getting fined. With the Yamaha you are good to go.

The Yamaha Has Several Different Outlets for You to Use


There are two 120 volt 16.7 amp AC outlets to choose from on the EF2000iS. You can plug in your appliances here or use multiple extensions cords. You can also use the 8 amp 12V DC outlet to recharge 12 volt batteries which is perfect if you have a boat or RV. You can even use it on your car battery and the cables are included.

The Yamaha Engine Is Built To Last

The EPA (Environmental Protection Agency) has given the EF2000iS its longest engine emission life rating called an “Extended Life Rating.” This means that the Yamaha engine has a 500 hour life. Most other inverter generators only have a 250 or 125 hour rating, so the Yamaha has more than twice the engine life. A 500 hour life rating doesn’t mean the generator will stop working at hour 501, it just means that the engine parts and seals will start to show the effects of wear and tear around that time. You can rest assured that the Yamaha engine is one of the highest quality portable generator engines on the market.

When reading through some more owner reviews on the EF2000iS, I found one owner that talked about using the unit out camping. He wrote that he had logged 832 hours on it without any problems! He had an hour meter added so that he could keep track of maintenance. And the only maintenance he’d had to do was clean the sparkplug at 500 hours.

Knowing Your Energy Requirements

The Yamaha EF2000iS is able to generate 2,000 watts of power at maximum output and 1,600 watts at rated output. What this means is that when you’re using it to power your appliances and equipment you need to make sure that the total running wattage of everything does not exceed 1,600 watts. The maximum wattage figure is there to account for the starting power surge that many appliances need to start the motor. For example, your fridge may only need 600 watts to run, but to start and to have enough power when the condenser and cooling fan kick in, it could need up to 1,800 watts. You can find the starting or surge wattage and the running wattage for various appliances in the Owner’s Manuals or on the actual devices themselves.

So, when you’re running your portable generator you always need to keep in mind how much wattage your devices are using. You need to add up the running wattage of all of the devices and the surge wattage of the most energy hungry device. Ideally you should plan this before buying a generator so that you know what wattage capacity you need. Keep in mind too, you won’t be running all of your appliances at once. You can always unplug some things to get the portable AC unit up and running for a while, for example.


One really cool thing about the Yamaha EF2000iS is that you can combine two units to nearly double your power if you feel like 2,000 watts is not going to be enough. Yamaha calls this “TwinTech Capability” and you’ll be able to generate 3,600 watts of maximum output. This is easily done using the parallel function setup shown in the picture. You just need to buy the cable which is not included.

If you happen to hook up too many devices to the EF2000iS then the overload indicator light comes on and the AC protector will trip which stops the generator. This helps to protect both the generator and any devices you have hooked up to it.

Starting Made Easy

We all want an easy starting generator and the Yamaha delivers. It has an auto-warm up feature that can power high demand appliances immediately by increasing engine speed when you first start it. The EF2000iS also has an auto-decompression system that makes pull starting it even easier.

Ready For Storage

When you’re done with the Yamaha for the season and want to store it, there is a gasoline petcock that lets you turn off the gas so that you can run the fuel system dry. This lets you store it away with no gas left in the tank to go bad over time.


The Yamaha EF2000iS Gets 5.0 out of 5.0 Stars

Check for the Best Prices for the Yamaha EF2000iS Portable Generator

The Good

  • Very quiet – You may even forget it’s there. Just don’t go off without it!
  • CARB Compliant – The California Air Resources Board has very strict guidelines for engine emissions in the state. If a product does not meet this requirement then it cannot be sold or used in California. The EF2000iS meets the criteria which makes it a low emission device and better for the environment.
  • A 3 year warranty – Most portable generators will only offer a one or two year warranty, so a three year warranty is a real testament to the quality of Yamaha built products.
  • Nice control panel – All of the functions are centralized, easy to access and use, including a fuel gauge.
  • Easy start up – The Yamaha uses an auto-decompression system which makes starting the engine a snap.
  • Low oil warning light – When the oil level gets too low the light comes on and the generator will shut off. This is a great safety feature and it lets you know when to add or change the oil.
  • Easy to move around – The unit only weighs 44 pounds and it has nice comfortable grip handles.

The Bad

  • A Bit Expensive – Conventional alternator generators (non-inverter style) will generally run you under $500 for 2,000 watts of capacity. But I have to say that you get what you pay for here, which is the best. Yamaha clearly produces a high quality product with a durable, long-lasting, quiet engine. So for an inverter style CARB compliant 2,000 watt portable generator the Yamaha EF2000iS is really a good buy.

What’s Included

  1. Yamaha portable generator
  2. Battery charging cables
  3. Owner’s manual


You can read the Yamaha EF2000iS Owner’s Manual if you’d like to learn even more. You can download it right from my site.

PortableGeneratorAdvisor.com Consumer Reviews Summary

Summary of the most helpful positive reviews:

Many owners like the sleek stylish design of the Yamaha and how the control panel is very easy to read. They also talk about how quiet it is and were really surprised that they could carry on a conversation easily only about 6 feet away from the unit. Many people said after a time they even forgot that the generator was even there. Campers and boaters seem to really love the Yamaha because it’s so versatile and can charge marine batteries. Owners also say the EF2000iS easily handles many of their power tools. Many reviewers also like that the Yamaha is an inverter style generator which means they can use it with their TV, DVD player, or computer. There were also a lot of comments about the unit being easy to start up; with it starting almost all the time on the first pull. Many, many people said that despite the higher price, the Yamaha EF2000iS was well worth it and they felt that it was money well spent to get a high quality, dependable portable generator.

Summary of the most helpful negative reviews:

There were not many negative comments about the Yamaha at all. A couple of owners felt that they should have included oil and an oil funnel for pouring it, with the unit at shipping.

Where Can I Buy the Yamaha EF2000iS Portable Generator?

I checked a couple Big Box stores and a few online retailers and found the best deal on Amazon.com. Amazon sells just about everything these days and they have great prices on portable generators. You can even grab all the accessories you need like surge protectors, and extension cords in one shopping trip. Amazon will ship everything for free as well! Search for the Best Deals for the Yamaha EF2000iS Portable Generator.

Where Can I Read More Reviews About the Yamaha EF2000iS?


There are a bunch of owner reviews out there on the Yamaha with over 30 reviews on Amazon.com alone. Amazingly the EF2000iS gets 4.9 out of 5.0 stars on Amazon, with over 90% of the people rating it 5 stars. I’ve never seen a portable generator get such high ratings. That’s a real testament to Yamaha’s quality. Read More Reviews About the Yamaha EF2000iS.

More About Yamaha Motors

Yamaha Motor Corporation makes a full line of really fun, high performing, and high quality recreational and outdoor products. You can find Yamaha outboard motors, motorcycles, ATVs, snowmobiles, personal watercraft, power equipment, race cart engines, apparel, and accessories.

Yamaha Motor Company was founded in Japan in 1955.

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One Comment »

  • cody said:

    I really like the 3 year warranty, as I’ve heard that with other brands, sometimes the generators breakdown right out of the box or after a month. Also i really like the gas gauge and the Low oil warning light included with the ef 2000. Awesome review and really appealing video thanks. :)