Yamaha EF1000iS – Portable Inverter Generator Review

Analysis:

I camp a lot so I decided to purchase a small gas-powered generator to use at our campsite. It would also be used for charging my RC batteries (drone and cars) and for when I took my ATV out to Pismo beach. I only needed a small generator for powering small lights, charging phones/tablets, charging small RC lipo batteries and running my laptop, and maybe powering our refrigerator in an emergency.

I tallied up the watts and decided a 1000 watt generator was what I needed. The Yamaha EF1000iS is usually the smallest, lightest, most economical, and quiet generator. I did a lot of research and I narrowed my choices down to the Honda, Yamaha, and Buffalo (Sportsman) generators.

I wanted a 4 stroke model which is usually quieter, gets better gas mileage and doesn’t need to have oil mixed in with the gas. I have been riding/maintaining motorcycles/ATVs for over 40 years so I know a little bit about 4 stroke engines and what I wanted was a generator that had a separate fuel cut-off and/or floats bowl drain. What I mean is I wanted to be able to turn off the fuel supply without turning off the generator, this would allow me to run the carb dry.

You want to do this for long-term storage because gas sitting in the carb can gum up over time and clog the carb causing issues with starting. The Honda and Buffalo models had a fuel shut-off that also stopped the engines so I could not run the carbs dry on these models.

The Yamaha EF1000iS had a separate fuel shut-off and a manual carb (float bowl) drain. The Honda model is very popular (rightfully so) because of its reputation for quality and reliability. The Buffalo is not as well known but is American-made and very inexpensive. But Yamaha has been building motorcycles and outboard engines (and great musical instruments) for years.

I owned several Yamaha motorcycles and was always impressed with their quality and innovation. So I purchased the Yamaha generator based on my previous experience with Yamaha products and the separate fuel cutoff feature. I received the generator and it came well packaged and was in good condition.

After doing a quick check (for damage, items that may have come loose, etc) and reading the manual I filled up the tank with gas and tried to start it. I switched on the gas, pulled out the choke knob, set the eco switch to off, and start the switch on I gave it a few pulls on the starter cord. After 4 pulls it started up and I ran it for a minute or so and then turned the choke off.

I let it warm up then set the eco switch to "ON" what this does is lets the generator throttle down and the engine's rpm is based on electrical draw/load. It runs a lot quieter in this mode, and I registered about 60 decibels at 15 feet (iPhone app so not the most accurate measurement).

At 50 feet it was barely above the ambient noise level and was very quiet. I noticed there was a lot of exhaust smell (not smoke but a strong exhaust smell) which I attributed to the engine being new and the piston rings not being 100% seated. After running the generator for 2 hours the smell has almost gone away.

Yamaha EF1000iS Generator starts right up on one pull when warm and 2 or 3 pulls when cold. Later I checked the air filter and found it was oiled but during transit the oil and drain to the bottom half of the filter element, I re-oiled the filter and this is something any buyer should do right away. I ran a few items off the generator (7 watts led light, 400-watt hairdryer, 75 watt TV) and it handled them with no issues. Overall I am very pleased with my purchase and can't wait to go camping this summer.

Characteristics

• 1000 Watts Maximum AC Power / 900 Watts Rated AC Power

• Sound Block Acoustic Design Noise Reduction System

• Long run time - runs for up to 12 hours without refueling

• Smart Throttle Load Sensing Throttle Control

• CARB Compatible

About Yamaha EF1000iS:

• 1000 Watts Maximum AC Power / 900 Watts Rated AC Power

• Sound Block Acoustic Design Noise Reduction System

• Long run time - runs for up to 12 hours without refueling

• Smart Throttle Load Sensing Throttle Control

• CARB Compatible

• This item cannot be returned

Technical details:

• Manufacturer: Yamaha

• Brand: YAMAHA

• Model: EF1000ISC

• Item Weight: 27.9 lbs

• Product dimensions: 44 x 24 x 35 cm

• Item Model Number: EF1000iSC

• Is it discontinued by the manufacturer: No

• Manufacturer Part Number: EF1000IS

• Cover included: 1000 watt generator 50 states legal

• Voltage: 12 volts

• Power: 900 watts

PROS:

• Easy to carry, lightweight structure

• Load sensing speed control, smart throttle

CONS:

• Susceptible to cosmetic damage

• Easy Oil Spill

Conclusion:

Yamaha EF1000iS Generater is really quiet when you have to use the full 1000 watts. It is a bit noisy when you have to run almost at full load. I'd recommend 2K or higher if you're using more watts and if you value silence.

Click here for details about this Yamaha EF1000iS Generater