4000i Dual Fuel Generator 4000i Dual Fuel Generator

  • Model #: 4L1-RV401
  • Barcode: 850041427119
Flex Power ®
In Stock . // Ready to ship.

Buy RVMP Flex Power® 4000i | 4000 Watt Dual-Fuel Installed RV Generator by RVMP: 4000i Dual Fuel Generator 4000i Dual Fuel Generator

  • Model #: 4L1-RV401
  • Barcode: 850041427119
Flex Power ®
In Stock // Ready to ship.

The next generation of RV generators. Designed for permanent installation. The RV Mobile Power® Flex Power® 4000i runs on a flexible and reliable single-cylinder 224cc OHV air-cooled engine with a digital governor.Is designed to be: compact, quiet, powerful, and efficient. Run your RV’s appliances directly or re-charge your battery bank for extended off-grid boondocking.

Price: $3,699.00
Recreational vehicle owners know the importance of having a backup generator. They are often critical to a fun and comfortable outdoor adventure, but they must be reliable and safe. The RVMP Flex Power Generator is manufactured with power, performance, and, most importantly, safety in mind. The generator’s compact design removes the traditional bulk of most generators, making it easier to fit within storage spaces or compartments. Not only is it lighter at 121 pounds (over 40 pounds lighter than comparable generators,) but it's also more versatile with the capability to run on both gasoline or propane. Dual fuel capacity allows for flexibility - gasoline provides a higher BTU, and propane runs cleaner and quieter. Travel with peace of mind knowing your generator can change fuel sources with the simple flip of a switch. The RVMP Flex Power generator also features smart start technology, removing the traditional starter, which may need to be replaced over time. Smart start technology uses a digitally produced three-phase waveform passed to the alternator's stator to rotate the engine and start more efficiently. Without a traditional starter and no spark from a commutator, the risk of igniting combustible fuels is largely removed, improving safety and offering peace of mind. Unlike generators of the past, the 4000 Watt Flex Power model is equipped with an integrated inverter forclean power production. A completely new exhaust and cooling system has been designed for maximum cooling while staying quiet. Your RV will be complete with the RVMP Flex Power Generator. When partnered with solar power, your setup will keep you running even in extended boondocking and dry camping environments. This new and innovative patent-pending design brings many upgrades over traditional generator models. Important Note: This generator is for RVs that are prepped for a permanent generator install location or have the adequate space and fuel supply (gasoline and propane) located in the area where the generator will be installed. Important Note: 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 which can be found HERE. Before using this generator, be sure to install a carbon monoxide detector inside the RV.
  • Better efficiency - On-demand power uses less fuel than other popular generator models both while running and at rest
  • Dual Fuel - 2 types applicable in one unit: Gasoline or Propane
  • Hassle-free electric start system with remote start lets you start the generator from inside the coach
  • Designed for reliable service with all total low harmonic distortion for use with sensitive electronics.
  • Emergency backup recoil start gives you further peace of mind when you are using the Flex Power 4000i – No other generator has this capability
  • Multi-pole PM brushless alternator incorporates a digital voltage regulator. The total harmonic distortion is only 3%, which makes it safer to power all types of electronic devices.
  • Offers stepped-up power-on-demand, eliminating issues of overload. The motor slows down when you reduce load and will speed up when you resume a higher load. High performance, low cost, quiet operations, and fuel efficiency make this RV generator the best in its class by every measure.
  • Compared to the competition: The Flex Power™ 4000i is lighter, more fuel efficient, lower in harmonic distortion, quieter, has a higher base load, and has many more features.
  • 100% replacement for Onan installed generators - Fits in the same space as Onan and other competitors.
  • Your safety is our concern, the Flex Power™ 4000i includes many safety features that go above and beyond industry standards. Including a digital valve controller that offers auto shut-off for fire prevention.
  • Consistent output - Less distortion (3% compared to 17% in competitive models) allows you to power sensitive devices like laptops, TVs, and gaming counsels, without worrying about overload
  • Softer sound - Consistent output allows for a quieter run without loud rev cycles
  • Significantly fewer emissions when run with propane - up to 10x less output
  • Digital hour reading – Easily measure running time for maintenance
  • Safer design -Engineered and built to mitigate fire risk
  • Digital valve controller - Auto shutoff monitoring for fire prevention
  • Remote start capability – wiring harness for connecting to controls within the RV for remote starting
  • Heat sensor - Built-in protection from overheating and over-revving
  • Patent-pending technology – See RVMP Patents for more information
  • Exceeds U.S. Forest Services (USFS), CSA, RVIA, and EPA emission requirements.
  • Original equipment for Forrest River, NeXus RV, and Thor Industry.
  • Backed by our guarantee to provide you the best customer support and a 3-year limited warranty.
  • AC/DC Excitation: Brushless PM
  • Amps: 33.3
  • Design: Multi Pole PM
  • Dimensions: 29.5" L x 19.25" W x 13.5" H
  • Frequency: 60
  • Fuel: Gasoline/LP
  • RPM: Variable 2200-3600
  • Voltage Regulation: Digital
  • Volts: 117-120
  • Watts: 4000
  • Weight: 121 lb. (54.88 kg)
  • Owner's manual
  • Installation guide
  • Oil funnel
  • Spark plug toolkit
  • Screwdriver
Comparable titles
Flex Power ® RVMP Flex Power 4.0kW Dual Fuel Installed Generator
3 Years Limited , 4000i Dual Fuel Generator has Warranty
3 Years Limited
EPA Emissions Durability
500 Hours , 4000i Dual Fuel Generator has EPA Emissions Durability
500 Hours
Electrical Specifications
4000/3800 , 4000i Dual Fuel Generator has Watts
60 , 4000i Dual Fuel Generator has Frequency
54 - 60
117 - 120 , 4000i Dual Fuel Generator has Volts
112 - 120
33.3 , 4000i Dual Fuel Generator has Amps
Alternator Specification
Multi Pole PM , 4000i Dual Fuel Generator has Design
2 Pole
AC Excitation
Brushless PM , 4000i Dual Fuel Generator has AC Excitation
DC Excitation
Brushless PM , 4000i Dual Fuel Generator has DC Excitation
Voltage Regulation
Digital , 4000i Dual Fuel Generator has Voltage Regulation
Voltage Regulation
120-117 volts , 4000i Dual Fuel Generator has Voltage Regulation
Frequency Regulation
59-61 Hz , 4000i Dual Fuel Generator has Frequency Regulation
60 +/- 2.5%
Total Harmonic Distortion
3% , 4000i Dual Fuel Generator has Total Harmonic Distortion
Ambient Temperature Rating
48C , 4000i Dual Fuel Generator has Ambient Temperature Rating
Bonded , 4000i Dual Fuel Generator has Neutral
Regulatory Approvals
Yes, 4000i Dual Fuel Generator has RVIA
Yes, 4000i Dual Fuel Generator has EPA
Yes, 4000i Dual Fuel Generator has CARB
CSA 22.2 No. 100-14 , 4000i Dual Fuel Generator has CSA
CSA Electrical Bulletin 946Does NOT conform to the most recent CSA22.2-100 standard
Yes, 4000i Dual Fuel Generator has USDA
Mechanical Specifications
Gasoline/LPFlex Power™ Generator can switch between fuels while running on fly. , 4000i Dual Fuel Generator has Fuel
Variable 2200-3600 , 4000i Dual Fuel Generator has RPM
121 lb. , 4000i Dual Fuel Generator has Weight
172 lb.
Set Dimensions (LxWxH)
29.5 X 19.25 X 13.5 , 4000i Dual Fuel Generator has Set Dimensions (LxWxH)
30.0 x 19.7 x 14.4 In
Engine Detail
No. Cylinder/Type
1/OHV , 4000i Dual Fuel Generator has No. Cylinder/Type
13.7 in3 (224cc) , 4000i Dual Fuel Generator has Displacement
18.5 in3 (304cc)
Compression Ratio
8.5:1 , 4000i Dual Fuel Generator has Compression Ratio
Cooling System Type
Air , 4000i Dual Fuel Generator has Cooling System Type
Digital , 4000i Dual Fuel Generator has Govener
Automatic Digital , 4000i Dual Fuel Generator has Choke
Oil Capacity
1.7 qt (1.6L) , 4000i Dual Fuel Generator has Oil Capacity
1.6 qt (1.5L)
Splash , 4000i Dual Fuel Generator has Lubrication
Emergency Starting
Recoil Start for Emergency , 4000i Dual Fuel Generator has Emergency Starting
Average Fuel Consumption
No Load
.12 Gal/hr /.79 lb/hrApproximately 50% more efficient at no load , 4000i Dual Fuel Generator has No Load
0.3 Gal/h / 1.5 lb/hr
Half Load
.30 Gal/hr /2.2 lb/hrApproximately 40% more efficient at half load , 4000i Dual Fuel Generator has Half Load
0.5 Gal/h / 2.4 lb/hr
Full Load
.6 Gal/hr / 3.3 lb/hrApproximately 15% more efficient at full load , 4000i Dual Fuel Generator has Full Load
0.7 Gal/h / 3.1 lb/hr
Performance @100F/38C and 500 ft./152.4 m altitude
Air Conditioner (BTU)
One 15,000 , 4000i Dual Fuel Generator has Air Conditioner (BTU)
One 15,000
Additional Watts
2300 (Base Load)Will reliably start the AC with base load at 55C , 4000i Dual Fuel Generator has Additional Watts
1000 (700)
Battery Charger
600 , 4000i Dual Fuel Generator has Battery Charger
Sound Level @ 10ft. (3M) in dB(A)
At Half Load
48Approximately 30% less noise , 4000i Dual Fuel Generator has At Half Load

Frequently Asked Questions for buying 4000i Dual Fuel Generator

Do you have an Auto Generator Start System?

We will have this ready by the end of 4th quarter 2022. Our generator will work with any auto start feature that has a dry pin connection for starting the generator. The pin out chart within the installation manual will show you which wire to connect your AutoStart system to. We cannot advise as to specific AutoStart systems, as there are too many, but generally speaking this is the process to connect.

Will my existing exhaust system work when doing an install?

Should I operate my generator without an onboard properly functioning carbon monoxide detector?

ABSOLUTELY NOT!!! Failure to adhere to this requirement could result in death.

Should I check all exhaust connections regularly for leaks and tighten them as necessary?

Absolutely exhaust gas is deadly! Do not operate the generator with a faulty exhaust system. Your tailpipe MUST ALWAYS extend beyond the bottom edge of the vehicle sidewall.

I bottomed out on a driveway, what should I do?

Make sure you inspect the unit for damage, paying particular attention to the exhaust pipe that is extending beyond the bottom edge of the vehicle sidewall. If this is damaged be sure to seek service immediately, as this damage could result in inhalation of exhaust gas which is deadly.

Can I store gas, oil, or other flammable materials in the generator compartment?

NO! Do not store anything inside the generator enclosure. This area must always be kept free from debris.

Can I service the generator while it is running?

NO! You must perform on maintenance and service while the generator is off, and the negative battery cable is disconnected. Moving parts can cause injury and or death, and live wires could cause fatal electrocution.

Can I use my RV generator as back-up power in my home or business?

No! Backfeed to utility systems can cause serious risks to life or property. Never connect the generator to an external electrical system except through an approved transfer switch.

Can I use an exhaust extension kit on my generator?

RVMP advises against and does not like to endorse any kits for the following reasons and will impact the FLEX POWER™ Limited Warranty:

  1. Back Pressure: this may increase the back pressure on the engine and reduce engine performance, or cause the engine to fail to meet regulated exhaust standards.
  2. Heat: could cause burns to anybody coming in contact.
  3. Fit: to be effective these connections must be gas-tight. This cannot be guaranteed after each installation.
  4. Direct of Exhaust: because these units are exhausting along the roof line, there is a higher probability that roof mounted vents and air-conditioners could intake the exhaust and circulate throughout the unit. Circulation of exhaust inside the unit could result in carbon monoxide poisoning.
  5. Weight: improper installation can result in reasonable stress on the existing exhaust system. The factory installed exhaust is not designed to carry this additional weight, and as a result any damage to the exhaust system could be detrimental to the life and well-being of the occupants of the vehicle.

Can I buy spare parts for my generator?

Yes, all of the following name brand parts are available for Flex Power generators:

  1. Spark Plug: 100729763
  2. Air Filter: 100730618
  3. Carburetor: 100753507
  4. Fuel Pump: 100729673
  5. Gas Regulator: 100729675
  6. Electric Fan: 100729684
  7. Hour Meter/Control Gauge: 100729698
  8. Power Regulator: 100729714

Should I turn off the air conditioners and large electrical loads in my vehicle before starting the generator?

Yes, this is good practice and will keep your generator running optimally.

Should I really follow the breaking procedures?

Yes, following these guidelines in the RVMP Owner’s Manual, will decrease oil consumption and improve long-term power characteristics. The braking process usually involves running the generator at about 50% load for two hours, then 75% load for two hours, then letting it cool down and starting over again. This process is good practice and will pay dividends for the reliability of your generator.

Do I really have to "exercise" my generator?

Yes, it is recommended to run your generator a minimum of 50% capacity for two hours once every month. This prevents the fuel from coming up with varnish, fuel varnishing results in hard starting and surging. Monthly exercising of your unit will keep your generator running well.

What is an AMP?

An amp is the amount of current flowing in a wire or a conductor. Typically RVs have two different categories of amperage: 30 amp or 50 amp. Make sure you know the difference.

What is a volt?

A volt is the amount of electrical potential present, specifically for an RV this is 120 VAC when running on “shore power” (your generator is plugged into the power grid) or when running on generator power. When operating solely on batteries the voltage is 12 VDC.

What is a watt?

Wattage is the representation of power. You calculate wattage by multiplying voltage x amps: 120 VAC x 30 AMPS = 3,600 WATTS. If you look at each item running in your vehicle you can calculate the wattage required versus your wattage available to compare demand on system and capacities.

30 AMP versus 50 AMP

Today all RVs are wired for either 30 or 50 AMP shore power. A 30 AMP electrical cable cored is rated at 120 VAC, and the 50 AMP is rated at 240 VAC. A quick analysis shows a 50 AMP shore cord has close to three times the power potential than a 30 AMP system.

What are the biggest loads in my RV on the generator?

The largest single demand on any generator will be powering the cooling systems. This could be one, two, or even three roof mounted air conditioners. Also, the battery charger demands significant power output from your generator. Understanding and managing these loads is very important to optimizing generator performance.

What are some common loads on the generator in an RV:

Common loads on the generator in an RV:

  • Air Conditioner: 1,200-2,400 W and 7.5-15 AMPS
  • Battery Charger: 3000 W and 7-24 AMPS
  • Blender: 450-700 W and 3-6 AMPS
  • Entertainment System: 85-120 W and 1-3 AMPS
  • Coffee Pot: 1,000-1,300 W and 8-11 AMPS
  • Laptop: 20-100 W and .25-1 AMPS
  • Microwave: 800-1,600 W and 7-14 AMPS
  • Refrigerator: 500-1,200 W and 4-8 AMPS
  • Toaster: 1,000-1,500 W and 7-12 AMPS

What is an air conditioner "short-cycling"?

When an air conditioner is running normally pressure is created in the refrigerant. When shut off the system requires at least five minutes for the pressure to equalize. If the air conditioner is started before the pressure equalizes this is called “short-cycling.” This can cause the AC to trip the circuit breaker, overload the generator, and make the AC shut off due to thermal overload. The only way to address this is to allow sufficient time for the AC to equalize pressure and temperature. To prevent this make sure the AC is not blowing directly on the thermostat.

What is worse high altitude or high temperature on generator performace?

Both can cause the generator to lose power and performance. Altitude results in a power decrease of approximately 3% for every 1,000 feet above 500 feet. Temperature results in a 1% loss of operations for each 10℉ above 80℉. In some cases, it may be required to manually adjust the carburetor to overcome some of these performance issues. Please see the Owner’s Manual.

Is it the integrated inverter that allows you to power more sensitive electronics, such as laptops and gaming consoles?

Yes, this allows for variable speed and a more controlled and pure electricity output.

On the digital hour reading, what does that monitor? Frequency? Voltage? Run time? And is there a common name for it or just “digital hour reading”?

Hours of operation, voltage, and various codes. ex P25 oil change at 25 hours. P50 Clean air filter @ 50 hours, P100 replace the fuel and air filters and change engine oil.

What component allows it to run quieter?

The overall assembly. The engine is 30% smaller than Onan with improved output.

Will the low oil indicator flash/illuminate before to alert you of low oil? Or will it automatically shut the engine off if the oil level is too low for safe use and then flash/illuminate?

Yes. It will shut down and/or prevent the unit from starting.

Is this an accurate description for the overload indicator?

In the event your generator is becoming overloaded, the indicator light will begin to flash. If the generator is overloaded and shuts down, simply unplug one or more devices, and push the “restart” button to power the generator back up. Yes. Under normal operating conditions 90F and below 2000 feet above sea level based on user’s current configuration.

What does the output ready indicator entail?

The unit is ready to output power and the unit is operating normally.

What allows it to emit few emissions? What is green machine?

Smaller engine and improved efficiency.

Could you explain what the digital valve controller does?

This is a proprietary feature that allows for seamless operations between propane and gasoline. It also allows for the implementation of a safety feature that allows for the shutdown of fuel in the event of a fire. (Onan does not have this feature.)

Upgrading from an Cummin Onan’s Generator

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Customer Reviews

Based on 12 reviews
Gregory Kuneman

I used a motorcycle lift to remove old generator and install RVMP generator. Worked very well. Didn’t need included 12volt negative wire as all my old wires mounted to new generator without any alteration including fuel line. This was installed in Phoenix Cruiser 2551. The most difficult part was pulling 110 wires through existing conduit. Recommend doing with two people, one pushing and one pulling string left in conduit when removing old wires. Transfer switch was just inside so it was just a matter of cutting wires to length and connecting. If you know what you’re doing, the install can be done in a couple of hours. Reconnecting exhaust was a puzzle to solve since I don’t own a pipe bender and it seems these days, motorcycle shops and muffler shop don’t bend pipe anymore. I squared it off and made a pipe insert for connecting using existing exhaust pipe. Break in of engine went without any issues. I’ll see how things work out on upcoming Quartzsite trip.

Steve Schumaker
Solid unit.. good price

Really like the quality of the unit.. install instructions could use some additions for donit yourself installers.. better drawings of fuel lines .. i orginally thought the 2 fuel lines one was a return to the fuel tank but found out later it was a vaper exhaust hose.. and 12 volt Install.. also a note that the unit does not recharge the battery attached to it.. otherwise.. still breaking in.. the footprint size of the unit is great .. looking forward to long life use of it..

James Blanton

I replaced a 16 year old onan with the 4000 rvmp. I have a 30 foot Winnebago 2007. Its like new only 38000 miles at purchase. I can run everything in the coach with no worries. It is amazing. The support from Bryan and Jimmy Conroy is A1. I am a mechanical person so I did it myself. The instructions were clear. Just make sure to check oil before initial startup. Don't prime it hit start it will do it on its own.if your an onan owner these don't crank like that. No starter its a motor generator. Think of a golf cart. I'm very satisfied with the performance and the support from the manufacturer. Call onan you'll get a menu. Call rvmp and the CEO answers the phone, even when he's on vacation. Ill be upgrading with all of the products they offer as time goes on. On a side note if you don't have step just buy a filter to plug in the hose to keep the bugs out tie wrap it vertical and forget about it. Do not plug it. By far the best generator on the market.

Joshua Penn
So far so good

Happy so far fit right where the onan was under my class c.

Kenneth Smith
Extremely excited

Was time to replace the generator in my 1999 thor hurricane. Was able to save a lot of money going this route and also feel really good about my connection with Jimmy and Brian. They speak incredibly highly of tyler’s skill set too. Very excited about future products!

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