# Modifying a dual fuel generator to also use natural gas?



## brownnugen

I was thinking about getting a portable generator for my house. The Firman dual fuel generator appeals to me because it gives me the option to run on either gasoline or propane. https://www.costco.com/Firman-7500W-Running--9400W-Peak-Dual-Fuel-Generator.product.100417697.html

After looking at how my house is set up and location of the natural gas line to the house, I was thinking it may be worth considering natural gas as my primary fuel so I wouldn't have to worry about running out of fuel during a hurricane

My question is; how would I go about making the dual fuel generator run on natural gas? I've seen dual fuel generator conversion kits for about $40 https://www.amazon.com/HIPA-Generator-Carburetor-Conversion-4-5-5-5KW/dp/B019RLSJQ4/ref=sr_1_2?keywords=natural+gas+generator&qid=1570494453&refinements=p_36%3A2661613011&rnid=2661611011&sr=8-2 I was thinking that kit would be applicable if the generator was gasoline only, but since it is dual fuel, this wouldn't be applicable. 

In this case, would it be better to just buy a gasoline only generator and then add the conversion kit (I guess that would mean I wouldn't have propane as an option)?


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## tabora

On a dual-fuel unit, you would likely need to adjust the metering on the secondary regulator, assuming the natural gas was supplied at sufficient pressure. 

As an example, a 20KW generator fully-loaded on propane will consume 122 cubic feet of gas an hour. That same generator fueled on natural gas will consume 245 cubic feet of gas an hour. It’s twice the amount of fuel in cubic feet an hour on natural gas than on propane. Plus there is a 15 percent reduction in the power output of the generator on natural gas vs propane.


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## brownnugen

tabora said:


> On a dual-fuel unit, you would likely need to adjust the metering on the secondary regulator, assuming the natural gas was supplied at sufficient pressure.
> 
> As an example, a 20KW generator fully-loaded on propane will consume 122 cubic feet of gas an hour. That same generator fueled on natural gas will consume 245 cubic feet of gas an hour. It’s twice the amount of fuel in cubic feet an hour on natural gas than on propane. Plus there is a 15 percent reduction in the power output of the generator on natural gas vs propane.


Thank you for the response. I am new to all of this so please forgive my lack of the proper terminology; is the secondary regulator already built in the generator from the factory or is that something I would need to purchase separately? 

Also, what is the best way to meter the amount of natural gas going into the generator? I think there should be sufficient pressure since I would tapping directly from the pipe coming into the house. Is that a safe assumption?


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## tabora

brownnugen said:


> Thank you for the response. I am new to all of this so please forgive my lack of the proper terminology; is the secondary regulator already built in the generator from the factory or is that something I would need to purchase separately?


The secondary regulator is already installed on a dual fuel unit. Look for the propane inlet; the regulator should be right behind the panel.


brownnugen said:


> Also, what is the best way to meter the amount of natural gas going into the generator? I think there should be sufficient pressure since I would tapping directly from the pipe coming into the house. Is that a safe assumption?


There is usually an adjustment valve (load-block) on the secondary regulator output side. You'll need to check what pressure is coming off your primary natural gas regulator. Here's a link to a chart that will help you determine if you can run on natural gas: Natural Gas Generator Pipe Size Chart


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## tabora

Having looked at the Firman unit further, I would not recommend it if your goal is to run primarily on natural gas, which is my understanding. The purpose in setting up a natural gas generator is generally ease-of-use and long-run capability. Something like the Generac 7.5Kw which includes a weather housing and a 50A Load Center for under $2000 would probably make you happier in the long run: https://www.norwall.com/products/7-...ential-Backup-Power-with-50A-Load-Center-ATS/ Briggs & Stratton and Champion also have similar offerings...


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## brownnugen

I am looking for a portable generator because I would like the ability to take the generator with us when we go camping or for the occasions that I need a portable source of energy when it is not feasible to run an extension cord. For those times, having a portable generator that I can operate on gasoline or propane would be nice. 

When using the generator to power the house when power is off for a couple of days (hurricane season in coastal South Carolina), using natural gas would be a nice option, but I wouldn't want to be beholden to natural gas if there was ever a problem with the gas lines. 

I guess I am looking for the one size fits all situations magic bullet. Hope that makes sense


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## tabora

You don't want the Firman if you're camping. That's a LOUD unit. Maybe a 
Westinghouse iGen4500DF Dual Fuel Inverter Generator - 3700 Rated Watts & 4500 Peak Watts would better suit your needs:* 



*


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## brownnugen

tabora said:


> You don't want the Firman if you're camping. That's a LOUD unit. Maybe a
> Westinghouse iGen4500DF Dual Fuel Inverter Generator - 3700 Rated Watts & 4500 Peak Watts would better suit your needs:* https://www.amazon.com/Westinghouse...r-Generator/dp/B078V6V965?ref_=fsclp_pl_dp_11
> *


Even if I got a more quiet generator like the Westinghouse or any other brand, I would still be in the same situation; wanting to have the option and convenience of using natural gas.


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## speedy2019

brownnugen said:


> I am looking for a portable generator because I would like the ability to take the generator with us when we go camping or for the occasions that I need a portable source of energy when it is not feasible to run an extension cord. For those times, having a portable generator that I can operate on gasoline or propane would be nice.
> 
> When using the generator to power the house when power is off for a couple of days (hurricane season in coastal South Carolina), using natural gas would be a nice option, but I wouldn't want to be beholden to natural gas if there was ever a problem with the gas lines.
> 
> I guess I am looking for the one size fits all situations magic bullet. Hope that makes sense



And you want a 7000watt for camping? a 7000watt will be quite loud:tango_face_surprise


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## brownnugen

I am looking for the portable generator primarily for times when we lose power so we can comfortably remain in the house. It would be nice to use it for other purposes when/if needed so I am looking for it be versatile for those situations and to be able to use different fuels (propane, natural gas, and gasoline). 

That's why I started this thread, to see if it is possible and if so, how to adapt a dual fuel or a normal gasoline generator to be tri-fuel capable.


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## tabora

brownnugen said:


> That's why I started this thread, to see if it is possible and if so, how to adapt a dual fuel or a normal gasoline generator to be tri-fuel capable.


 Go to US Carburetion (they are cited in prior links given). https://www.uscarburetion.com/
They have tri-fuel motor snorkel kits for most portable gas generators. I used one of their dual-fuel kits on my PowerMate.


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## Robh

I called them once when investigating a tri-fuel setup for a generator. They informed me that they prefer to NOT use existing dual-fuel generator designs. The motor snorkel would interfere.


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## tabora

Robh said:


> I called them once when investigating a tri-fuel setup for a generator. They informed me that they prefer to NOT use existing dual-fuel generator designs. The motor snorkel would interfere.


Correct, their kits are for gasoline generators to add propane or propane/NG as additional fuel sources. Mine works great.


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## email4eric

I would suggest getting a gasoline generator rated for your home use and converting using a tri-fuel conversion from US Carburetion as mentioned earlier. No need to get a duel fuel and then try to get it converted for a third fuel type.


I have that setup on a Honda EU6500is running from piped propane and previous to that, natural gas. Works beautifully. I have quick disconnect dedicated 1 inch hose.


Then, perhaps get a second, size- appropriate generator for those other duties as lugging a 7000W generator around will be a bear...


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## speedy2019

Over here in the united kingdom, their have been talks about getting rid of gas and maybe oil due to pollution and rubbish and they expect to heat our homes with electric, it would cost us a fortune. I cant see it working.


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## Retrocop

tabora said:


> Having looked at the Firman unit further, I would not recommend it if your goal is to run primarily on natural gas, which is my understanding. The purpose in setting up a natural gas generator is generally ease-of-use and long-run capability. Something like the Generac 7.5Kw which includes a weather housing and a 50A Load Center for under $2000 would probably make you happier in the long run: 7.5kW Generac 69981 Backup Generator + 8 Circuit ATS—Norwall PowerSystems Briggs & Stratton and Champion also have similar offerings...


YOu might want to read the sole review on the link you gave. DISASTER!!!


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## tabora

Retrocop said:


> YOu might want to read the sole review on the link you gave. DISASTER!!!


You might not want to base decisions on a single review out of many thousands of units sold. 

Although Generac is not the same company they once were...


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## ricarhimel

Actually, I have tried to do that back in the day, and I have actually destroyed the freaking generator! It got broken because I did not adjust the metering on the secondary regulator, assuming the natural gas was supplied at sufficient pressure. The worst part of it is that even if you do it all correctly, the generator will consume waaaay more natural gas than it used to consume propane or something else. That is exactly why I even have a dual fuel tariff at home, as it is the cheapest and most effective way of receiving energy supply. Actually, I decided to get this tariff only after reading a particular article about it on simplyswitch.com. The author of that article has explained why we should choose this tariff and what is so great about it, and I can say that all the benefits listed by him are real.


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## Browse Deweb

The MotorSnorkel.com (US Carb) MSK7000 kit works great with the Honda EU7000is for natural gas. A few of us on the forum have this setup. The only negative is that this isn't cheap...you're looking at about $6k with an interlock, breaker, cable, input box, genny, NG hose, quick disconnects and conversion kit. Super quiet though.


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## ajnuzzi

I used century fuels natural gas conversion kit on two different generators. A duromax 12000 and a westinghouse 9500 (basically the same engine). They both run perfect on natural gas, although for my specific set up, they do not run great on gasoline or propane now due to the carb/intake being modified BUT it only takes 5 minutes or so to put it back to stock in case I need to revert to gasoline and/or propane. If you end up having to install one of these kits I highly recommend the century kit - most of these are basically the same but century uses the largest hoses/venturi allowing for more natural gas flow. When doing these conversions the biggest problem you run into is that Natural gas is not as energy dense as propane or gasoline, so you need a significantly higher volume of fuel than the other two. If you need any help with the install just message me


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