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Flex Power Mini Onboard RV Generator - 4,000 Watts - Dual Fuel and Inverter - Fixed Mount
Flex Power

Flex Power Mini Onboard RV Generator - 4,000 Watts - Dual Fuel and Inverter - Fixed Mount

Part Number: FP86FR
$4,644.00
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Trying to run AC and electronics off-grid but your generator will not fit or handle mixed loads is a common issue. This 4000W onboard unit uses inverter output with dual fuel in a compact 22" frame, so appliances and devices keep running. 1-800-940-8924 to order Flex Power generators part number FP86FR or order online at etrailer.com. Free expert support on all Flex Power products. Great prices and Fastest Shipping for Flex Power Mini Onboard RV Generator - 4,000 Watts - Dual Fuel and Inverter - Fixed Mount. Generators reviews from real customers.
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Flex Power Generators - FP86FR

  • Inverter
  • Gas
  • Gas and Propane
  • Propane
  • Onboard Generator
  • Flex Power
  • 3001 - 4000 Watts
  • 120V Output
  • Electric Start
  • Electronic Fuel Injection

Trying to run AC and electronics off-grid but your generator will not fit or handle mixed loads is a common issue. This 4000W onboard unit uses inverter output with dual fuel in a compact 22" frame, so appliances and devices keep running.


Highlights

  • Onboard Power Away From Hookups: 4,000 watts and 33.3 amps run RV power needs off-grid.
  • Power for Sensitive Electronics: Built-in inverter output supplies stable electricity for TVs and laptops.
  • Fuel Choice for Longer Stays: Gasoline or propane operation gives you two fuel options off-grid.
  • Quieter Camp Power: Variable-speed operation avoids loud rev cycles during changing loads.
  • Compact Installed Fit: 22" long x 16-7/8" wide x 13-3/8" tall frame fits tight spaces.
  • Service Timing You Can Track: Digital hour meter records run time for maintenance planning.

Features to know about

Camp Where the Hookups Stop


push button start

You pull into a quiet off-grid spot, then the power math starts with appliances, chargers, and electronics still needing to run. This fixed-mount generator supplies 4,000 watts, 33.3 amps, and 117-120 volts of onboard power. You can stay parked and keep the trip moving without setting up a separate portable generator. The push-button start makes it easy to power your rig, and an optional remote start panel (sold separately) lets you stay dry on rainy days.

Safe Power for Plugged-In Gear

It's one thing to run basic RV loads, but laptops and TVs need stable electricity when they're plugged in. Built-in inverter output delivers clean, stable electricity safe for sensitive electronics. Your devices keep working while the generator carries the RV's power demand.

Fuel Options for Longer Stops

Long stays get stressful when your only fuel source starts running low and town isn't close. This generator runs on gasoline or propane, giving you two confirmed fuel options at camp. Use the fuel you have available and keep power flowing through the stop.

Quiet Power That Doesn't Take Over the Campsite

Some onboard generators constantly rev up and down, making it hard to relax outside or even hold a conversation nearby. This generator uses inverter technology and a softer sound profile to keep noise levels more controlled as power demand changes. That means you can run the A/C, charge devices, or watch TV without the generator becoming the loudest part of camp. It also makes late nights, early mornings, and crowded campgrounds a lot less stressful for you and the people parked nearby.

A Mounting Path for Tight Installs


generator on mounting frame

Some install plans fall apart when the available space doesn't match a standard platform setup. This generator includes a mounting frame, giving you the choice of a hanging install or installation on an existing platform. You get a clearer path to installed power when space under the RV is limited.

Service Timing You Can See

After weekend trips, off-season runs, and quick overnight stops, it's easy to lose track of runtime. The digital hour meter records run time directly on the unit, tying maintenance to actual use. Check the meter, handle the service, and head into the next trip with the generator kept on schedule.

Notes:

  • This generator produces hot exhaust gases which must be piped out of the RV. The exhaust outlet is on the bottom of the generator. Please be sure to use the proper exhaust connections, hangers, and clamps. Before using this generator, be sure to install a carbon monoxide detector inside the RV.
  • Per manufacturer guidelines, the generator should be run for 2 hours each month under load to maintain proper operation and prevent fuel system issues.
  • CARB (California Air Resource Board), EPA, and National Park Approved.

Usage Guidelines:


What Size Onboard Generator Chat GPT


Wattage Usage Graphic Chat GPT

Specs

Electrical:

  • Watts: 4,000
  • Amps: 33.3
  • Volts: 117-120
  • RPM: variable 2,600 - 3,600
  • Frequency: 60 Hz

Dimensions and Weight:

  • Dimensions: 22" long x 16-7/8" wide x 13-3/8" tall
  • Weight: 87 lbs

Noise:

  • Sound level: 48 dB(A) @ 10 ft at half load
  • Meets National Park Service requirements of max 60 dB(A) @ 50 ft

Warranty:

  • 2-Year warranty


4L1-RV401-EFI (EM) RVMP Flex Power Mini 4000e - 4,000W Onboard RV Generator - Dual Fuel - Inverter - Installed Generator

Installation Details FP86FR Installation instructionsAlternate Instructions FP86FR Installation instructions



Video of Flex Power Mini Onboard RV Generator - 4,000 Watts - Dual Fuel and Inverter - Fixed Mount

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Review of Flex Power Generators - 4000 Watt Fixed Mount Dual Fuel Mini Onboard RV Generator - FP86FR

Hi everybody. Andy here with etrailer. Let's take a quick look at this Flex Power 4,000 watt fixed mount dual fuel mini onboard RV generator. This generator is designed to be efficient, flexible, and pretty easy to live with, especially if you're using this for an RV with sensitive electronics. This is gonna be ideal for RV owners or campers who want a quiet fuel efficient and versatile power source that, again, is gonna be safe for those sensitive electronics. Now, in terms of performance, this is going to deliver 4,000 watts of power and it's gonna run at variable speeds between 2,600 to 3,600 RPM.

This is gonna give you a standard 117 to 120 volt and it's gonna use a brushless system for reliability. Now one of the biggest advantages is its fuel efficiency. This does use on-demand power, which means it only works as hard as it needs to, so it's gonna burn less fuel compared to a lot of traditional generators, both while running and even when idling. And this also is a dual fuel, as I mentioned at the beginning of our time together, so you're gonna be able to run it on either gasoline or propane. I opened up the panel here real quick just to give you a view of the inside right here.

You're gonna be able to switch between propane and gas, and those hookups are at the back of this unit. So you're gonna be able to have options here depending on what's available to you or what fuel source you prefer. If you do use propane, as you probably know, it's gonna be a lot cleaner producing up to 10 times fewer emissions. Another standout feature is how clean and consistent the power is thanks to the built-in inverter. It has only about 3% distortion compared to around 17% on many other generators.

So in practical terms, that means it's gonna be safe to run your laptops, your TVs, your gaming systems, all without worrying about damaging them. And because of the steady output, this is gonna be quieter. You're not going to get those loud rubbing cycles that a lot of generators have. This is gonna run smoother with less noise overall. From a safety and convenience standpoint, it's well thought out.

It includes a digital valve controller that's gonna automatically shut things down if there's a risk, heat sensor to prevent over heating and over revving. And an overall design that's focused on reducing fire risk. I just wanted to show you this panel here. Hopefully you have a good view of it there. You got a reset button, gas primer button, your on/off, and then you have your push button, electronic start as well. And some indicator lights here for low oil overload and output ready. So you got a clear view there. I did notice that when you have the panel on, you've got a little view here, a little window if you wanna call it. So you can see those lights they light up. You got your oil here as well. And I mentioned where you can switch between the fuel sources there. So again, it's really laid out well. Easy to access tools are included here as well. You got your spark plug wrench, screwdriver, and it has either Phillips or Flathead, oil fuddle as well. So the essential things that you're gonna need to maintain this and keep it running for you, that also has a little sleeve here to keep your tools in. Now this does support remote start capability, which is gonna be especially useful for RV setup. So you can wire it in. So you can start it from the inside if you prefer. And just some measurements to give you a good idea of the size. Talking about just the generator first. The overall length is gonna be about 22 inches. If you add the bracket, that's gonna be about 35 and five-eighths inches. Then the overall width is gonna be about 16 and seven-eighths inches. If you add the bracket, about 19 and three-quarters inches wide. The overall height of just the generator itself, about 13 and three-eighths inches. And then again, if you add that bracket, about 14 and a half inches tall. Overall, this weighs a little under 90 pounds. ID did need some help getting it on my table safely, but this is gonna be certified by organizations like USDA, EPA and CSA. So it's gonna meet all those solid safety and environmental standards. Instructions are gonna be included with this as well. If you have any other questions, don't hesitate to reach out. We do wanna make sure that you're getting exactly what you need. If you need help with installation, we got you covered in that regard as well. On this product page, underneath the photo section, we have a link that will take you to our installer locator. Click that link, answer the questions that it has for you, and that locator will find an installer in your area that etrailer has partnered with to do the installation for you. But I think it's gonna wrap up our look today. I do hope that it was helpful for you. Again, my name's Andy. Thank you for joining me.

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See what our Experts say about this Flex Power Generators


Info for this part was:

Employee Mary K
Edited by:
Mary K
Employee Daron K
Updated by:
Daron K
Employee Dawn Z
Updated by:
Dawn Z
Employee Alex H
Written by:
Alex H
Employee Andy C
Installed by:
Andy C

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