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Generac

Generac 7128 GP3500iO 3,500-Watt Gas Powered Open Frame Portable Inverter Generator - Quieter & Lighter Design with Increased Starting Capacity - Produces Clean, Stable Power - CARB Compliant

    • Based on 359 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Brinstar E-commerce
Arrives May 11 – May 12
Order within 23 hours and 37 minutes
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Style: 3500-Watt + Open Frame


Pattern Name: Generator


Features

  • Portable Power Solution: Weighing 25% less than comparable models, the lightweight GP3500iO is designed to reduce fatigue and enhance portability, making it an excellent choice for camping, RV essentials, or powering tools on the go
  • High Quality and Consistent Power: With TruePower Technology, this generator delivers clean power that's safe for sensitive electronics, tools, and appliances, so you can stay connected even in the great outdoors
  • PowerRush Advance Technology: This portable open frame inverter generator offers over 50 percent more starting capacity, making it perfect for powering tools and motor-driven equipment, allowing you to accomplish more with ease
  • Quieter Operation: This Generac generator operates at 50% less noise, making it ideal for noise-sensitive environments while providing the power you need without causing disruptions
  • Smart and Reliable: Benefit from USB outlets for convenient charging of electronic devices. Featuring a single, user-friendly dial that seamlessly integrates start, run, and stop functions, simplifying operation and making it easy for anyone to use

Description

Generac's GP3500iO Open Frame Inverter Generator is the ideal for camping, RV and powering your jobsite. Featuring Generac's POWERRUSH patented technology that delivers over 50% more starting capacity allowing you to do more with less. The PowerDial integrates START/RUN/STOP functions into one simple-to-use dial while the (2) USB outlets allows you to charge smart phones, tablets and other electronics. Connect two inverters together for twice the power (parallel kit sold separately).

Brand: Generac


Wattage: 3500 watts


Fuel Type: Gasoline


Power Source: Gas Powered


Recommended Uses For Product: Residential, Camping


Item Weight: 74.3 Pounds


Voltage: 120 Volts


Output Wattage: 3500


Special Feature: Portable, Super Quiet, Low Oil Shutdown, Hour Meter


Included Components: Generac 7128 GP3500iO Portable Open frame Inverter Generator, Engine Oil, Oil Funnel, Tool Kit, Owner's Manual See more


Brand: Generac


Wattage: 3500 watts


Fuel Type: Gasoline


Power Source: Gas Powered


Recommended Uses For Product: Residential, Camping


Item Weight: 74.3 Pounds


Voltage: 120 Volts


Output Wattage: 3500


Special Feature: Portable, Super Quiet, Low Oil Shutdown, Hour Meter


Included Components: Generac 7128 GP3500iO Portable Open frame Inverter Generator, Engine Oil, Oil Funnel, Tool Kit, Owner's Manual


Color: Orange


Product Dimensions: 19.7"L x 16.5"W x 16.4"H


Material: Steel and Plastic


Model Name: GP3500iO


Engine Type: 4 Stroke


Ignition System Type: Recoil Pull Start


Tank Volume: 2.37 Gallons


Engine Displacement: 212 Cubic Centimeters


Runtime: 11 hours


Total Power Outlets: 4


Frequency: 60 Hz


Starting Wattage: 3500 Watts


Running Wattage: 3000 Watts


UPC: 696471072020


Manufacturer: Generac


Item Weight: 74.3 pounds


Item model number: 7128


Is Discontinued By Manufacturer: No


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: May 11 – May 12

This item is non-returnable:

Non-returnable. Transportation of this item is subject to hazardous materials regulation

View our full returns policy here.

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  • Affirm Financing
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  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

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Top Amazon Reviews

    • Excellent Generator
I own a Honda EU2000 which cost $1200 and love it but I wanted a 3500 and didnt want to spend $2000+. So I bought a Generac 3500iO last year, used it on my farm that does not have electric and it worked great. Strong generator. I put it in storage for a year in 2021, then came back to my farm in 2022. Filled it with fuel, and it started easily on the 2nd pull. I put about 10 hours on it this year and still works perfect and starts very easy. Love it just as much as my Honda so far. And its very quiet, super pleased with this product. Its easy to carry with the medal frame. Love it. I like the open frame so that the engine gets plenty of air and runs cool. Perfect balance and design and function. So I just ordered a 2nd so I can run parallel for more power when needed. Highly Recommended. 2 generators for twice the power and half the price. This is the only brand I could take a chance on other then Honda. Generac did a great job with this model. ... show more
Reviewed in the United States on December 27, 2022 by J M
    • excellent lighter weight generator
It is small enough to fit in my truck bed with the tonneau cover on and light weight enough (74 lbs) to manage. It provides as many watts (3,500) as much heavier generators, is relatively quiet, and it started with the first pull of the cord. It has a 30 amp input, which is perfect to use it to power my travel trailer, but it does require an adaptor to connect them. ... show more
Reviewed in the United States on May 21, 2024 by Jeff Mullen
    • Small and Powerful
Review Image by MNA Warehouse MNA Warehouse
The media could not be loaded. These are great little generators. I work with a non-profit that does disaster response and the other small generators that we have used for years are no longer being manufactured. When we started looking for replacements, I wanted something with a good brand name behind it, small and compact, powerful, and easy to transport and maintain. These are usually used when there are disasters and people need them to provide temporary power for their homes. I ordered one of these to test it and then ordered nine more once I determined this was what we wanted. These are compact and have the frame all the way around them for ease in carrying and for protection. They are super easy to start and run smoothly and efficiently. One great thing about these is that they come with everything you need to get started (sans gas) in that there is a funnel and a bottle of oil that contains the exact amount you need. I wish there was somewhere to store the funnel and tools that come with it, but I'll likely tie a mesh or other bag to them. I'm very pleased so far and will use these for our next disaster. One tiny little thing that could improve these is if they would include holes for your hands in the box so they would be easier to grasp and move. That's a very small thing but when you are moving lots of these just a little handhold on each side would be so helpful. ... show more
Reviewed in the United States on February 20, 2024 by MNA Warehouse MNA Warehouse
    • quiet and fuel stingy.
Only have a couple hours on it. Not very noisy and is stingy on the gas. I have an old Onan that has less capacity that drinks twice the gas.
Reviewed in the United States on January 15, 2024 by TheWad
    • Generac 3500iO
We’ve owned this generator for 4 years now and I can easily say it was a great purchase. Works well and provides the claimed wattage of 3000 constant watts and 3500 start up watts.
Reviewed in the United States on March 9, 2025 by Lane Vines
    • Reliable, easy to use and quiet
We've used this generator for a few weeks now on several outings. Left it running overnight and most of the day while camping. It's extremely fuel efficient and quiet for it's size. The only way you're going to find a quieter generator is if you get a smaller briefcase style one. There are no break in instructions with it.but in my opinion, you should do a break in procedure just to protect your investment anyway. I ran it for an hour with no load then changed the oil. After the unit completely cooled I ran it for another hour at half load and changed the oil. Very small amount of metal contamination in the oil but nothing of concern. Seems like a well built unit. ... show more
Reviewed in the United States on October 8, 2021 by Valerie Haas
    • Finally clean power
I have a much larger 7800 Watt generator that is much much louder and produced very dirty power. I didn't know about clean power until some of my electronics started to break. Electric components in my refrigerator started to fail after having it connected to the larger 7800 Watt generator but it was not until a few months after. I do not have any direct proof that the dirty power killed it but sensitive electronics just do not work run running off the 7800. So for this purchase I specifically wanted an inverter generator and boy is there a difference. I now feel comfortable running TVs, computers, refrigerators, off this generator. My old 7800 must have been over 200 lbs and two of us could not lift it. This generator is much quieter, lighter, and has clean power. Granted it's not a 7800 Watt but I would much rather have the clean power. ... show more
Reviewed in the United States on October 27, 2020 by Joeyi
    • Do not buy
Review Image by Joe S. Joe S.
Review Image by Joe S. Joe S.
Review Image by Joe S. Joe S.
Update- it broke, the oil sensor failed theres no way to fix without replacing the motor. Its at a local shop been there for a month and generac is not taking care of me. I could of bought 2 craftsman generators for the price of this one. Do no buy. Its nice when its running So after over a month of waiting on generac they offered to send me a replacement generator. Its a DR Horton generator. Generac don't even make small generators. So they bought out DR. And put thier name on it. DO NOT BUY. its not a reliable generator. And its over priced ... show more
Reviewed in the United States on January 15, 2020 by Joe S. Joe S.

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