Model EF5500DEThe Yamaha EF5500DE is a versatile dual 120/240 volt generator, ideal for emergency backup power for home, cottage, or business, as well as primary power on job sites. It features a 358cc OHV engine, electric start, and offers 5500 watts maximum AC output with outstanding fuel efficiency.
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Here's the quick tradeoff view — what this model does well, and where it may not fit.
The Yamaha EF5500DE is a gasoline-powered generator built around 4500 running watts with 5500 starting watts. That combination targets steady output for ongoing loads while also giving extra headroom for the brief surge that happens when certain equipment first kicks on.
Because it runs on gasoline, the EF5500DE pairs its wattage with a familiar fuel choice for many shoppers who want a conventional portable generator setup.
With 4500 running watts and 5500 starting watts, the EF5500DE is set up to handle continuous demand while also accommodating higher start-up draw when needed. In practical use, that starting-watt buffer helps when powering devices that momentarily require more power at startup than they do once running.
Noise is rated at 74.1 dBA, giving you a concrete reference point for how present the generator will sound while operating. For runtime, Yamaha lists 13.5 hours at 50 percent load, which supports extended operation without constant refueling. A 6.9-gallon fuel tank complements that mid-load runtime figure, and the generator also lists a runtime value of 0 hours at 25 percent load.
The EF5500DE weighs 238.1 lbs, so moving it is a more deliberate task than with lighter units. Its dimensions are 29.1 x 29 x 31.5 in, which helps set expectations for the floor space it occupies during use and the room it will take up when stored.
Starting is covered two ways, with both recoil and electric starting systems, letting you choose between manual pull-starting and electric start depending on preference and situation. A built-in fuel gauge supports quick checks on fuel status, and the presence of indicators adds at-a-glance feedback while the generator is running.
On the safety and standards side, the EF5500DE lists CARB and EPA compliance and includes a spark arrestor. It also includes GFCI outlets, adding an extra layer of protection on connected circuits, and AVR automatic voltage regulation to help keep output steadier for powered equipment. Yamaha backs the generator with a 3-year warranty.
May struggle with startup surge
May struggle with startup surge
Exceeds capacity
Exceeds capacity
Est. running: 1,800W
Peak surge (single motor): 2,000W
Avoid starting multiple motor loads at the same time.
Est. running: 3,500W
Peak surge (single motor): 2,000W
Avoid starting multiple motor loads at the same time.
Est. running: 1,600W
Peak surge (single motor): 2,800W
Avoid starting multiple motor loads at the same time.
These are estimates using typical wattage assumptions. Real appliances vary. Startup surges can be 2–6× the running wattage for motor-driven loads. 240V loads require a 120/240V generator and proper connection. Use a transfer switch or interlock kit; never backfeed a panel.
Yamaha is a respected leader in the generator industry, recognized for their innovation, quality, and reliability in portable and backup power solutions.
| Fuel | Running | Starting | Runtime @50% | Runtime @25% |
|---|---|---|---|---|
| Gasoline | 4500W | 5500W | 13.5h | Not available |
| Running Watts | 4,500 watts |
|---|---|
| Starting Watts | 5,500 watts |
| Starting Watts (Gasoline) | 5,500 W |
| Running Watts (Gasoline) | 4,500 W |
| Engine | Yamaha MZ360 OHV 4-stroke |
|---|---|
| Engine Type | OHV 4-stroke |
| Engine Displacement | 358 cc |
| Engine Oil Capacity | 1.1 Qt |
| Spark Arrestor | Yes |
| Emissions Compliance | CARB, EPA |
| Voltage (AC) | 120/240V 60 Hz |
|---|---|
| Phase | Single |
| AC Frequency | 60 hz |
| Current | 36.0 / 44.0 amps @ 120V - 18.75 / 22.9 amps @ 240V amps |
| GFCI Outlets | Yes |
| Neutral | Yes |
| AC Outlets | 2x Duplex 120V 20A (5-20R) 1x 120V 30A (L5-30R)1x 120/240V 30A (L14-30R) |
| Dimensions | 29.1 x 29 x 31.5 in inches |
|---|---|
| Weight | 238.1 lbs |
| Automatic Low Oil Shutdown | Yes |
|---|---|
| Emissions Compliance | CARB, EPA |
| Automatic Voltage Regulation | Yes |
| Automatic Voltage Regulator | Yes |
| Carbon Monoxide Sensor | Yes |
| Covered Outlets | No |
| Display Type | Data center |
| Documentation | Data center |
| Electric Start | Yes |
| Fuel Gauge | Yes |
| Fuel Tank Capacity | 6.9 gallons |
| Included Accessories | Tool kit, battery, and wheel kit |
| Indicators | Yes |
| Inverter | No |
| Noise Level | 74.1 dBA |
| Overload Protection | Low oil and overload protection |
| Parallel Capable | No |
| Part Number | EF55DEX |
| Recoil Start | Yes |
| Remote Start | No |
| RV Ready | No |
| Starter Type | Recoil, Electric |
| Starting System | Recoil, Electric |
| UPC | 765,053,823,098 |
| Warranty | 3 years |
| Wheels | Yes |
| Fuel Type | Gasoline |
|---|
| Runtime @ 50% | 13.5 hours |
|---|---|
| Runtime @ 50% Load (Gasoline) | 13.5 hours |
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