Our Yamaha EF2000iS review starts with a summary of its most and least attractive features. We also answer a few questions about its operation and compare the Yamaha EF2000iS and the newer Yamaha EF2000iSv2 before ending with a short conclusion.

Yamaha EF2000iS Inverter Generator: Summary

The Yamaha EF2000iS provides 1600 watts running power and up to 2000 watts starting power. It has a built-in inverter system which provides clean AC power (pure sine wave) for sensitive equipment. Its 4-stroke engine runs on unleaded gasoline. It weighs about 45 pounds and can be carried by its single handle. It has a recoil start, Smart Throttle economy switch and a low oil warning system.

The low oil level warning system shuts down the engine if the oil level is too low. The negative thing about the oil warning system is that it might sometimes be too sensitive. You frequently need to check and fill the oil pan to its maximum level to prevent an unexpected shutdown.

You will need a flexible oil funnel to make adding engine oil easier. The oil filler opening is set at an uncomfortable angle. You need to unscrew the back cover to get to the oil filler cap. The least attractive feature of this Yamaha inverter generator is probably the process of checking and adding engine oil.

The Yamaha EF2000iS is one of the quietest 2000-watt generators available. The Honda EU2000i (read its review) is probably the only generator that rivals it when it comes to noise level.

The economy control Smart Throttle system reduces noise as well as fuel consumption when it is turned on. Its noise level is about 52 dBA when operating under a 400 watt power load. Its noise level when operating at 1600 watts is 61 dBA (measured at a distance of 23 feet, or 7 meters).

The Yamaha EF2000iS is definitely one of the best generators for camping or boating. Its portable size, inverter system, DC outlet and relatively quiet operation makes it a welcome camping companion.

Please note that the Yamaha EF2000iS portable inverter generator has been superseded by the EF2200iS (view this 2200W model on Amazon).

Can you use the EF2000iS for power tools?

You might do so if the power tool does not exceed the starting watts, running watts or AC outlet maximum of 13 amps. It would have to be small power tools, not big power tools. Industrial generators are a much better choice for starting and running power tools than inverter generators.

Does it have an electric start button?

This Yamaha generator does not have an electric starter. It does not have its own internal battery. You start the generator with its recoil start. Its auto decompression system helps to decrease engine compression, which makes it easier to pull the recoil starter.

Will it start and run a small air conditioner?

Yes, it can start and run a 5000 to 6000 BTU window air conditioner unit. However, the Yamaha EF2000iS is too small to start and run a 13500 BTU air conditioner.

What type of gasoline should you use?

Its engine has been made to run on regular unleaded gasoline that has an Anti-Knock Index (AKI), or (R+M)/2), number of more than 86. The Research Octane Number (RON) must be 91 or higher.

Is the EF2000iS quieter than similar generators?

It is definitely quieter than other less expensive generators of similar size. Is it quieter than the Honda EU2000i? No, the Yamaha EF2000iS and the Honda EU2000i produces almost the same amount of noise while operating.

How long can it run?

It has a fuel tank capacity of 1.1 US gallons, or 4.2 liters. It will run for at least 4 hours at its rated load of 1600 watts.

Can it run on propane?

This Yamaha inverter generator runs on gasoline. It cannot run on propane, or natural gas, as a fuel source without modification. You will need to buy and install a fuel conversion kit if you want to run the Yamaha generator on three different fuel sources (tri-fuel setup).

Is the EF2000iS generator CARB compliant?

The Yamaha EF2000iS is CARB-compliant and can be used for extended hours in California. The Yamaha generator engine has an air index of 3, which is mostly clean. It meets the exhaust and evaporative emission regulations for small engines in California.

Can you connect two generators in parallel?

Yes, you can. Yamaha calls it Twin Tech, and the parallel running outlets are located on the control panel next to the manual choke lever. You need to buy a Yamaha parallel running kit to make the parallel connection. The kit comes with its own manual which provides instructions and details. The rated output is 3 kVA and the rated current is 25 amps when running two Yamaha EF2000iS generators in parallel with special cables.

Yamaha EF2000iS vs. EF2000iSv2

Yamaha discontinued the EF2000iS model. The EF2000iSv2 replaced the previous version.

What is the biggest difference between the Yamaha EF2000iS and the newer Yamaha EF2000iSv2, except for the addition of the “v2” at the end of the name and the slightly higher price tag?

A new controller with advanced programming has been added to the Yamaha EF2000iSv2 inverter generator. The EF2000iSv2 provides improved power output when it runs between its rated power and surge power (between 1600 and 2000 watts) in comparison with the older EF2000iS.

Except for the new controller, the Yamaha EF2000iS and the EF2000iSv2 are basically identical in appearance, parts, operation, performance and maintenance (find sellers on Amazon).

How To Add Gasoline To The Yamaha EF2000iS

You already know that fuel is flammable and poisonous. Treat it with the respect it deserves. Do not overfill the fuel tank. Also, wipe up any fuel that is spilled on the generator because fuel is a solvent, so it can damage paint and plastic. The Yamaha EF2000iS runs on unleaded gasoline. Do not use gasoline that contains lead because it will damage the engine.

You can screw off the fuel tank cap and fill up the tank to the red line. You can also check the fuel gauge to see if it is at the “F” marker. The fuel tank has a capacity of 1.1 US gallons, which translates to 4.2 liters of fuel. Replace the fuel tank cap after filling the tank.

How To Add Oil To The Yamaha EF2000iS

The generator is shipped without oil in the crankcase to prevent leaks and spills. You need to buy and then add engine oil to the crankcase before operating the Yamaha EF2000iS. Unscrew the back cover and then remove the oil filler cap. You should use a flexible oil funnel to add 0.42 US quart of engine oil.

Yamaha recommends using its own YAMALUBE 4 oil, which is a 10W-40 oil. However, you do not have to use Yamaha oil. You may also buy SAE 10W-40, or 10W-30, engine oil according to the environmental temperature in which the generator will usually operate. Be sure to buy an engine oil grade type of API Service SE or better.

What To Check Before Starting The Yamaha EF2000iS

Doing a pre-operation check before you use the generator might seem like an unnecessary and boring chore, but it is quick to do. This way, you might discover a leak or problem before it causes damage or delay. This is the pre-operation inspection:

• Add fuel if the tank is not full.
• Check the fuel line hose for cracks or visible damage.
• Add oil if the oil pan is not full.

How To Start The Yamaha EF2000iS

You can start the generator after checking the fuel and oil levels. This is the starting procedure:

• The economy control switch should be turned OFF.
• The air vent knob on the fuel cap should be turned ON.
• The fuel cock knob should be turned ON.
• The engine switch should be turned ON.
• The choke knob should be pulled OUT (if the engine is cold).
• Use the recoil starter to start the engine.
• Let the engine warm up before pushing the choke knob IN.
• Turn the economy control switch ON if you want to use it.

How To Stop The Yamaha EF2000iS

The correct stopping procedure for this Yamaha inverter generator is almost as long as my weekly shopping list. Here it is:

• Turn OFF all the appliances you powered with the generator.
• Disconnect the electric cables and appliances.
• Turn OFF the economy control switch (if it was turned on).
• Push the engine switch to STOP.
• Turn OFF the fuel cock knob.
• Turn OFF the air vent knob on the fuel cap.

How To Make AC Connections

Calculate the power load of the appliances you want to power with the generator to see if it is within the surge limit of 2000 watts, the rated limit of 1600 watts and the amp limit of the AC receptacles. Turn off all the appliances, and check the power cords for damage, before you connect it to the AC outlet on the generator.

Start the engine by following the starting list we previously discussed. Plug the extension cord into the AC outlet. Check to see if the AC pilot light is ON. You may now turn the economy control switch ON. Turn on the appliances. Do not overload the generator. The overload indicator light will turn on if the generator is being overloaded.

How To Charge Automotive Batteries

The DC outlet of the Yamaha EF2000iS puts out 12 volts (8 amps). Do this to charge a 12-volt battery:

• Start the engine.
• Check to see if the DC protector switch is ON.
• Connect the battery to the generator with a DC charging lead.
• You connect the red lead to the positive battery terminal.
• You connect the black lead to the negative battery terminal.
• Turn OFF the economy control switch.
• Let the battery completely recharge (check the battery’s manual for details).

Conclusion

The Yamaha EF2000iS, and its replacement the EF2000iSv2, is a high quality, expensive, relatively quiet, portable inverter generator. It works well for camping, tailgating, boating and motorcycling events (check price on Amazon).