6 Best Dual Fuel Kits for Generator Options for Gas and Propane (2026)

By Miles Sinclair

Updated November 2026

Shoppers looking for a dual fuel kit for generator use usually want one thing: the ability to run a gasoline engine on propane or natural gas when gasoline is stale, scarce, or hard to store. A dual fuel kit replaces or supplements the carburetor so the engine can burn LPG or NG, often extending run time and keeping fuel fresher during long outages. This list was built from manufacturer specifications, fitment information on each listing, brand reputation, and patterns that owners commonly report about installation and performance. We did not run these kits ourselves. The selection criteria were engine compatibility, carburetor design, included hardware, and how clearly each listing states what it fits.

Our Top Picks

Quick Comparison

HND1.2CD Dual System Extended Run Generator Fuel Kit for Honda EU1000i, EU2000i, EU2200i, Polaris P1000i, Champion 2000, Generac and Kipor Generators (Without Fuel Tank)

HND1.2CD Dual System Extended Run Generator Fuel Kit for Honda EU1000i, EU2000i, EU2200i, Polaris P1000i, Champion 2000, Generac and Kipor Generators (Without Fuel Tank)

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Best for: Small inverter-style generators that need extended run time and a dual gasoline and propane setup.

This kit suits owners of compact inverter generators who want to keep gasoline as the primary fuel while adding a propane or natural gas supply. It is designed around the fuel-system architecture of smaller Honda-type and similar units rather than large-displacement industrial engines.

Key specs:

• Listed fitment: Honda EU1000i, EU2000i, EU2200i and similar models
• Dual system design for gasoline and gaseous fuel
• Sold without a fuel tank

Pros:

• Clear fitment list for common small inverter models
• Supports extended run time on a separate fuel source
• Broad brand compatibility in the listing

Cons:

• Requires a separate tank for the gaseous fuel supply
• Not suited to large Predator or GX390 engines

Bottom line: A strong fit for owners of small inverter generators who want a dual system with clearly listed compatibility.

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AUTOKAY Dual Fuel Carburetor LPG NG Conversion Kit for Gasoline Generator 4.5-5.5KW GX390 188F Carburetor with Air Filter and Spacer Insulator

AUTOKAY Dual Fuel Carburetor LPG NG Conversion Kit for Gasoline Generator 4.5-5.5KW GX390 188F Carburetor with Air Filter and Spacer Insulator

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Best for: 4.5–5.5kW gasoline generators built around the GX390/188F engine family.

Owners of mid-size portable generators with GX390-style engines who want a complete carburetor-based conversion, including the air filter and spacer, will find this kit a practical match.

Key specs:

• Designed for 4.5–5.5kW gasoline generators
• GX390 / 188F carburetor fitment
• Includes air filter and spacer insulator

Pros:

• Includes the air filter and spacer, reducing extra parts
• Specific engine-size match in the listing
• Covers both LPG and natural gas

Cons:

• Installation requires carburetor work and careful fuel-line routing
• Not intended for smaller or larger engine families

Bottom line: A good choice for 4.5–5.5kW owners who want an all-in-one carburetor kit with the filter and spacer included.

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Generac Champion 163cc 196cc 212cc 224cc Generator Natural gas Gasoline Propane LPG Conversion Kit Dual Tri Fuel Carburetor for Predator 4000 4375 Honda GX160

for Generac Champion 163cc 196cc 212cc 224cc Generator Natural gas Gasoline Propane LPG Conversion Kit Dual Tri Fuel Carburetor for Predator 4000 4375 Honda GX160

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Best for: Predator 4000-class and GX160-size engines that need gasoline, propane and natural gas options.

This tri-fuel carburetor kit targets smaller air-cooled engines in the 163cc to 224cc range. It suits owners who want flexibility across three fuel types on a single carburetor.

Key specs:

• Engine range: 163cc, 196cc, 212cc and 224cc
• Fuels: gasoline, natural gas and LPG
• Listed fitment includes Predator 4000 and 4375 and Honda GX160

Pros:

• Three-fuel compatibility in one carburetor
• Wide displacement range in the listing
• Clear model references for Predator and GX160 engines

Cons:

• Tuning may be needed to hold steady idle on some engines
• Smaller engine focus means limited use on high-output units

Bottom line: Best for owners of smaller air-cooled engines who want a tri-fuel carburetor covering the most common fuel options.

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Fit for Predator 188F 190F 8500 8750 7000 9000 Generator Replace for Honda GX340 GX420 11HP 13HP 15HP 4.5KW-6.5KW GX390 LPG/NG Generator Carburetor Dual Fuel Conversion Kit

Fit for Predator 188F 190F 8500 8750 7000 9000 Generator Replace for Honda GX340 GX420 11HP 13HP 15HP 4.5KW-6.5KW GX390 LPG/NG Generator Carburetor Dual Fuel Conversion Kit

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Best for: Predator 7000–9000 and GX340/GX420 engine swaps across the 4.5–6.5kW range.

Owners of larger Predator-branded or Honda-clone generators in the 11–15HP range will find this kit covers the widest set of engine references among these six listings.

Key specs:

• Listed fitment: Predator 188F, 190F, 7000, 8500, 8750 and 9000
• Also lists GX340, GX390 and GX420 compatibility
• Rated range in the listing: 4.5kW–6.5kW

Pros:

• Broad list of compatible engine models
• Covers LPG and natural gas
• Useful for swapping across several engine families

Cons:

• Broad fitment claims mean you must confirm your exact engine code
• Carburetor adjustment may be needed after installation

Bottom line: A good match for owners of 7000–9000 Predator-type units who want a broadly listed LPG/NG carburetor.

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Replacement for Harbor Freight Predator 5500 6500 7000 8750 generator, Replacement for Honda GX390 188F 190F generator engine Carburetor Dual Fuel Carb Conversion Kits (Style2)

Replacement for Harbor Freight Predator 5500 6500 7000 8750 generator, Replacement for Honda GX390 188F 190F generator engine GX390 188F 190F Carburetor Dual Fuel Carb Conversion Kits (Style2)

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Best for: Harbor Freight Predator 5500–8750 owners who want a replacement-style carburetor.

This kit is aimed at owners of Harbor Freight Predator units and Honda GX390 clones who want a drop-in style replacement instead of a full retrofit.

Key specs:

• Listed for Harbor Freight Predator 5500, 6500, 7000 and 8750
• Also references Honda GX390 and 188F/190F engines
• Style2 replacement carburetor design

Pros:

• Specific Harbor Freight model references
• Replacement-style fit reduces modification work
• Covers common GX390-family engines

Cons:

• Style2 designation means you should verify the exact part against your carburetor
• Limited to the listed model families

Bottom line: A focused option for Harbor Freight Predator owners who want a replacement carburetor rather than a general-purpose kit.

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Dual Fuel Carburetor with LPG/CNG Conversion Kit for Honda GX390 188F 13-14HP 4.5-5.5KW Generator Engine, for predator 7250/9000 Watts

Dual Fuel Carburetor with LPG/CNG Conversion Kit for Honda GX390 188F 13-14HP 4.5-5.5KW Generator Engine, for predator 7250/9000 Watts

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Best for: 7250–9000W Predator and 13–14HP GX390 engines on a tighter budget.

This kit suits owners who want LPG/CNG capability on 13–14HP generators and are comfortable doing their own carburetor work.

Key specs:

• Listed for Honda GX390 188F, 13–14HP and 4.5–5.5kW
• Also listed for Predator 7250 and 9000-watt units
• LPG and CNG conversion capability

Pros:

• Covers both LPG and CNG
• Specific wattage and horsepower references
• Good match for 7250–9000W Predator owners

Cons:

• Installation requires working knowledge of carburetor and fuel-line work
• Owner feedback patterns suggest careful jetting checks are wise

Bottom line: A practical choice for 13–14HP GX390 and 7250–9000W Predator owners who want LPG/CNG at a lower-cost entry point.

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Buying Guide

Engine compatibility and carburetor type

Check your engine family and model code before anything else. GX390, 188F/190F, GX340/GX420 and Predator 4000-class engines use different carburetor bodies. A kit that fits one may not seat correctly on another. Look for explicit engine model references in the listing rather than generic “fits most” claims.

Good picks for this: Fit for Predator 188F LPG/NG Carburetor Dual Fuel Conversion Kit, Dual Fuel Carburetor with LPG/CNG Conversion Kit

Fuel types supported

Most kits in this category cover LPG (propane) and natural gas (NG). Some also list CNG. Confirm which fuels the kit supports and whether your local supply matches. Tri-fuel designs add gasoline as a third option, which can help during supply interruptions.

Good picks for this: Generac Champion Dual Tri Fuel Carburetor Conversion Kit, AUTOKAY Dual Fuel Carburetor LPG NG Conversion Kit

Displacement and output rating

Match the kit to your generator’s displacement (cc) and rated kilowatt output. A 4.5–5.5kW kit will not suit a 7000-watt unit well, and vice versa. Manufacturers usually state the rated range in the listing title, so check it against your nameplate.

Good picks for this: AUTOKAY Dual Fuel Carburetor LPG NG Conversion Kit, Replacement for Harbor Freight Predator Carb Conversion Kit (Style2)

Included hardware

Some kits include an air filter, spacer insulator, gaskets or fuel-line fittings. Others are carburetor only. Missing parts add time and sometimes require a trip to a parts store mid-installation. Compare what each listing actually includes.

Good picks for this: AUTOKAY Dual Fuel Carburetor LPG NG Conversion Kit, HND1.2CD Dual System Extended Run Generator Fuel Kit

Dual system versus carburetor replacement

Two approaches exist. A dual system adds a second fuel feed while keeping the gasoline carburetor, often using a separate tank. A carburetor replacement swaps the carb for a gas-capable unit. Decide which fits your setup, since the wiring, plumbing and maintenance differ.

Good picks for this: HND1.2CD Dual System Extended Run Generator Fuel Kit, Dual Fuel Carburetor with LPG/CNG Conversion Kit

Installation difficulty and skill level

Carburetor swaps involve fuel lines, jets and sometimes idle adjustment. If you have not done carburetor work before, budget extra time and read the install guide closely. Owners often report that a careful, slow install prevents most problems. When in doubt, consult a qualified small-engine technician.

Good picks for this: Generac Champion Dual Tri Fuel Carburetor Conversion Kit, Fit for Predator 188F LPG/NG Carburetor Dual Fuel Conversion Kit

Durability and fuel-system care

Gaseous fuel runs cleaner than gasoline, but it still requires regular checks of hoses, regulators and fittings for leaks. Gas leaks are a serious safety hazard. Test fittings with a soapy-water solution, never with an open flame, and keep the generator outdoors and away from openings.

Good picks for this: Replacement for Harbor Freight Predator Carb Conversion Kit (Style2), HND1.2CD Dual System Extended Run Generator Fuel Kit

FAQ

Can any generator use a dual fuel kit?

No. A dual fuel kit only works with engines that match the carburetor type and displacement the kit is designed for. Check the listed engine models, such as GX390, 188F or Predator 4000-class, before buying.

Do I need a separate propane tank?

Usually yes, for a dual system or a propane-fed carburetor. Some kits require a regulator and a fuel line rated for LPG. Follow the manufacturer’s specifications for fuel pressure and hose type.

Will running on propane reduce power output?

Often, yes. Gaseous fuels typically produce somewhat less power than gasoline at the same engine size. Manufacturers usually state a derating figure. Confirm the expected output before relying on the generator for heavy loads.

Is natural gas safer than gasoline for generators?

Natural gas and propane are less prone to spoiling than gasoline, which helps with long storage. They are still flammable gases, so leaks must be checked and the unit must run in a ventilated area away from doors and windows.

Can I install a dual fuel kit myself?

Some owners do, especially with a basic mechanical background. Carburetor work and gas-line connections carry risk. If you are unsure, have a qualified small-engine technician or licensed installer handle the work.

Does a dual fuel kit affect warranty coverage?

It can. Modifying the fuel system may void part of the manufacturer’s warranty. Check your generator’s warranty terms before installing any conversion kit.

Conclusion

For most buyers, the right dual fuel kit for generator use depends on engine family first and fuel preference second. Owners of small inverter-style units will look at the HND1.2CD dual system. Those with GX390 or 4.5–5.5kW engines should consider the AUTOKAY carburetor kit. Predator 4000-class owners may prefer the Generac tri-fuel option, while 7000–9000W Predator owners have two carburetor-replacement choices to compare. Verify fitment against your exact engine model before buying, and follow installation and gas-safety guidance closely.

Sources

• Background on propane and natural gas as alternative fuels and their handling characteristics (energy.gov)
• Carbon monoxide and generator safety guidance for home and outdoor use (cpsc.gov)
• Workplace guidance on compressed and liquefied gas handling and ventilation (osha.gov)

Related reading

• Dual Fuel Conversion Kit for Generator: Step-by-Step Install and Safety Guide
• Why Does My Dual Fuel Generator Carb Keep Clogging? Causes and Fixes
• What Is a 240V Dual Fuel Generator and Is It Right for Home Backup?
• Westinghouse WGen9500DF Dual Fuel Portable Generator Review (2026)
• Westinghouse Dual Fuel Generator: Setup, Quieting and Fuel Tips (2026)
• WEN 6800 Dual Fuel Inverter Generator Review: Is It Worth It?

About Miles Sinclair

Miles Sinclair is part of our editorial team and reviews and edits our generators & noise guides, checking product details against manufacturer specifications and owner feedback.