• 2,000 Watt Maximum AC Output/1,600 Watt Rated AC Output
• Super-quiet muffler with USFS-approved Spark Arrestor
• Smart Throttle varies engine speed based on load
• Inverter system with Pulse Width Modulation (PWM) control
• CARB Compliant

I have had this for about a month. This is a very high quality unit, nicely designed. I chose it over the Honda Eu2000i because it has a fuel gage and is a hair lighter (2 pounds), and liked the styling better. Specs are so close it’s a tie… the Yamaha unit specs a bit quieter in “eco” throttle but the Honda specs a bit quieter at full power. Prior to this purchase I had bought a Honeywell inverter generator (a much less expensive Chinese-made knock-off) from Costco which I returned, because I was unimpressed with the Honeywell unit’s quality and noise level. While the price difference is major, you get what you pay for in this case. Anyone looking at the cheaper knock-offs should really consider that a 5db increase in noise level is about twice as loud, the way humans perceive it.

The most impressive thing about this unit is how quiet it is. Even at full engine speed you can stand about 6 feet away and have a normal conversation without raising your voice, or talk on a cell phone without undue distraction. It features an “eco” setting which tapers down the engine throttle and noise when full load isn’t required. At half-throttle or less, from about 6 feet away it is about half as loud and amazingly quiet. I used it to run a 50-amp 12v battery charger and at full charge level the charger only required the generator to operate at about half-speed, and when the charger tapered down the charge level to under 30-amps the generator became so quiet I literally forgot about it. It is MUCH quieter than my boat’s inboard diesel engine, and more efficient than running the main engine just to top off the batteries. I also used it to power a heavy duty 120v grinder and it had no problems supplying the needed power, even on electric motor start-up.

I got this mainly for charging our boat’s batteries at anchor but I also wanted the ability to run power tools. The lighter 1000-watt inverter generators could easily handle the charging application but not the more power-hungry tools. Having the extra power also means the eco-throttle will likely kick in earlier and the unit will operate quieter. The number-1 purchase criteria was “quiet” because I don’t want to be distracted by incessant noise or be a bad neighbor in anchorages. The Honeywell was not quiet enough in my opinion.

An appeal to other boaters and to campers: Please don’t settle for “cheap”. Get a better quality inverter-generator unit that’s quieter so you minimize noise pollution in get-away places. (Leave your “contractors generator” at home!!!) Also, please be considerate of neighbors and limit running it to times/places you aren’t as likely to disturb others… and don’t leave your boat or campsite while it runs and runs. We all like our electric conveniences, but if you really need 120v power more or less constantly; you should stay home or get a dock/parking space where you can plug into “the grid”. It’s rude to disturb others who are trying to get away to find some peace and quiet. If generators are abused it will lead to regulations banning them.

Negative: The unit ships without engine oil, so you need to buy a quart of standard 4-stroke engine oil and fill it. You will also need a funnel, and a pan to catch excess oil. There is no dipstick; you need to fill to the level of the bottom of the filler hole until any more runs out. It uses less than 3/4 quart. I think they should have included the required amount of oil, and a plastic filler container with a spout, marked to show the proper amount of oil to use.

The Yamaha EF2000 is portable generator is super quiet and the engine runs really smoothly. It instantly changes it’s operating speed just as fast as I can move the speed switch on a 1850 watt hair dryer I used to test it. It doesn’t include oil and the angle of the oil fill hole is nearly horizontal, making it a little difficult to fill even with a funnel, but they did put a nice little drip tray right below the opening so it doesn’t go everywhere. The gas gauge is really nice. Made in Japan. Their competitor (Honda) has some nice videos on their website demonstrating the sound level of actual generators running and the equivalent size Honda generator is very close in noise level to this one. Yamaha should do the same but until then, check out the Honda website.

Yamaha says this is CARB compliant. The label on the generator says it is a 3 on the 10 point California emission scale. Yamaha simply isn’t making a big deal of it like some others do I suppose. This is a new model as of summer 2009. The starter cord is really easy to pull – unlike any other engine I’ve ever started by hand.