# ~12kw Portable Generator Convert to NG



## jasonjax (Mar 15, 2020)

Hi folks,

I live in Florida, and want to be prepared for hurricane season this time around. I've had a hard cutover installed for the electrical panel w/ 50A service installed outside by the garage. I will have the gas folks tee off the pool heater for fuel. I also had a hard-start installed on the AC unit to help with the compressor drawing too much power at start-up.

So my question: I've seen conversion kits from these folks: https://centuryfuelproducts.com/generators/conversion-kits and a lot of them say the frame needs to be cut, which I want to avoid if at all possible.

Anyone have some thoughts on the best generator for what I'm trying to accomplish? As usual, looking for the happy medium between cost and reliability/performance.

Thanks,
Jason


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## tabora (Sep 6, 2018)

The Duromax dual fuel XP12000EH would be a good candidate and is often available on sale for under $1K: https://www.duromaxpower.com/products/duromax-xp12000eh-dual-fuel-portable-gas-propane-generator
If you get a gas-only generator and need a conversion kit, the U.S. Carburetion kits do not require cutting the frame: https://www.motorsnorkel.com/


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## jasonjax (Mar 15, 2020)

thanks for the suggestion … do you know which kit would fit that model? I certainly like the price point compared to other options!


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## KRE (Nov 29, 2011)

Fully understand somethings are not as simple as they first seem. Teeing off may not be an option due to pressure an flow requirements of the gen set. Most I have installed will not run under much load plumed up that way. The other thing you need to check out, is talk to the engine mfg an see if a timing change has to be made if your converting an engine over to LP or Natural. Why? Because depending upon combustion chamber design or compression ratio a timing change may be required and on some engines it's not that simple at all. Engine sold that are designed for different fuel you'll have no issue with, however not all engines will convert an pull their max HP on that new fuel w/o a change or two.


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## Melson (Dec 8, 2019)

The OP states "NG", which I assume he is referring to natural gas.
The Doromax lists "dual fuel" as being gasoline or propane. 
My question: Is there a compatability problem between propane and natural gas? Are the two interchangeable?


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## KRE (Nov 29, 2011)

Yes, major difference between NG & LP depending engine RPM an design. 3600 rpm units that will run both fuels, normally have a wire that will change the timing between the two different fuels. If it does not have the wire, most will not even come close to pulling even a small load. The install/operation manual will have the info about how to change the timing if so equipped. Before buying any genset ask them about how the way your going to operate it, that way if there's an issue you can fall back on them vs spending a large chunk of money that is not what you want or need. Education is the key and is sorely lacking in the small EPG market most here talk about or are in.


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## drmerdp (Apr 10, 2018)

There are no portable generators out of the box compatible with natural gas. You will require a conversion kit. I highly recommend UScarburetion for an appropriate kit. Their “snorkel” eliminates the need for a bulky adapter. Don’t bother with a dual fuel generator save the money and buy a tri fuel kit. 

The question is, does your pool heaters gas line support the demand of a generator. We need to know from the meter the size of the pipes and length of that diameter pipe up to where you plan to tee in. It’s also important to understand that elbows need to be considered if your pipe is on the small side. 

A true 12k generator will have a 18hp engine requiring a minumum 180CFH (180,000btuh.) You need to be sure that your gas plumbing will support that. Also consider your meter is likely a 250CFH, so make sure you don’t run too many gas appliances at the same time as the generator. 

The duromax 12000 is a 9500watt continuous generator. It’s advertised 18hp is bogus. More like 14-15 sae hp. So in this case minumum a minimum 140CFH supply is needed. It’s also important to understand that you need to derate the 9500 watts by 20%. NG has a lower BTU per volume content as compared to gasoline and propane.


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## ToolLover (Jan 13, 2020)

To those of you that are considering a conversion to NG or propane you might be advised that two pressure regulators are necessary for proper operation.
Just like pre regulating propane.
The US Carburator kit must be seccondary to a pre regulator that lowers the pressure.
Failure to drop pressure will result in a damaged US carb unit and render it useless.
Take it from a guy that blew up a US carb unit.
Some more knowledgable about regulators might shed some light on this.


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## drmerdp (Apr 10, 2018)

ToolLover said:


> To those of you that are considering a conversion to NG or propane you might be advised that two pressure regulators are necessary for proper operation.
> Just like pre regulating propane.
> The US Carburator kit must be seccondary to a pre regulator that lowers the pressure.
> Failure to drop pressure will result in a damaged US carb unit and render it useless.
> ...


The KN demand regulators use a max of 11” water column (< 1/2psi. ) 

If running off a propane cylinder 20, 30, 40 100lb tanks, a low pressure single stage regulator is required. 

I have a 500gallon tank that feeds my house. It uses a high pressure regulator to drop tank pressure to 10psi which feeds a low pressure regulator before entering the house at about 9” water column.

Most natural gas systems operate at 7” water column.


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## tabora (Sep 6, 2018)

Melson said:


> The OP states "NG", which I assume he is referring to natural gas.
> The Doromax lists "dual fuel" as being gasoline or propane.
> My question: Is there a compatability problem between propane and natural gas? Are the two interchangeable?


You would likely need a separate regulator to run it on natural gas. Many have used the U.S. Carburetion kit: 



 As @drmerdp mentions, there are other considerations, as well. If you didn't want to start with a hybrid unit, they also have gas-only units:
XP12000E: https://www.duromaxpower.com/collec...2000e-12000-watt-18-hp-portable-gas-generator
XP13000E: https://www.duromaxpower.com/collec...00-watt-portable-gas-electric-start-generator
XP15000E: https://www.duromaxpower.com/collec...gas-powered-electric-start-portable-generator


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## KRE (Nov 29, 2011)

drmerdp said:


> It uses a high pressure regulator to drop tank pressure to 15psi which feeds a low pressure regulator before entering the house at about 9” water column.


That is interesting as most first stage regulators are adjusted to output 10psi max. The second stage that is used with a first stage has a normal input of 10 psi without put between 7"-11" h2o. If you over pressure a second stage regulator many of them will not operate properly. A two stage regulator combines operations both at the tank if the piping run is short. LP regulators can be used on NG but most of the time you will not have the correct spring to convert one unless your in the industry, an even then you have to know the color that goes with that mfg's reg. On some models the demand reg is operated w/o the spring on LP, but on NG the spring has to be installed with the tulip up an output pressure has to de adjusted to 5" h2O positive pressure, vs a negative when using LP. Most NG meters can be quickly changed at the panel from 7-11" H2O output to 2psi output. Then the down stream has to have 2psi to 7-11" h2O regs installed when adding gen sets over 5-8KW depending piping run an size. Bottom line read the mfgs manual or talk to their service people before/when installing, designing, or trying to repair anything. Gas systems are very safe but only if installed properly. Many stories out there of what can go wrong when installed improperly, an many lives have been lost as well.


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## ToolLover (Jan 13, 2020)

About pressure regulators:
First off I have no formal training on pressure regulators.
Inches of water column is greek to me.
Like KRE says there is a regulator at the input line of the NG.
My Generac has a regulator in the line that feeds it.
I decided that the more gas the better my ES 6500 would run.
So, I bypassed the Generac regulator and connected my US Carb directly to the House gas line for the Honda supply.
Boom! No more US Carb regulator. Destroyed.
Had to replace it at $50.
I do not mess with regulators as they are above my level of knowledge.


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## drmerdp (Apr 10, 2018)

KRE said:


> That is interesting as most first stage regulators are adjusted to output 10psi max. The second stage that is used with a first stage has a normal input of 10 psi without put between 7"-11" h2o. If you over pressure a second stage regulator many of them will not operate properly. A two stage regulator combines operations both at the tank if the piping run is short. LP regulators can be used on NG but most of the time you will not have the correct spring to convert one unless your in the industry, an even then you have to know the color that goes with that mfg's reg. On some models the demand reg is operated w/o the spring on LP, but on NG the spring has to be installed with the tulip up an output pressure has to de adjusted to 5" h2O positive pressure, vs a negative when using LP. Most NG meters can be quickly changed at the panel from 7-11" H2O output to 2psi output. Then the down stream has to have 2psi to 7-11" h2O regs installed when adding gen sets over 5-8KW depending piping run an size. Bottom line read the mfgs manual or talk to their service people before/when installing, designing, or trying to repair anything. Gas systems are very safe but only if installed properly. Many stories out there of what can go wrong when installed improperly, an many lives have been lost as well.


My mistake it is 10psi.


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## email4eric (Dec 23, 2018)

Lots of good advice here. You're certainly going to need some serious supply for that engine involving a larger-than-normal house meter and then dedicated piping of substantial size (I'm thinking at least 1-1/4") to supply that. You should be able to take NG off of the meter with the appropriate kit installed like a Motorsnorkle. 



I converted my Honda 6500 to NG at my last home and it required 1 inch piping for supply. And, it maxed out my meter.


I'm now using LP from a 500 gal tank and that runs to a step down regulator that I plug my 1" supply hose into. 



There are calculators out there for the piping. Also, you can contact US Carboration with questions on how to prep and size...


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## KRE (Nov 29, 2011)

My home set is a 25KW unit. I had the gas company change the meter to 2psi output, it's a simple screw turn on most meters. I then split the discharge piping an placed a 7-11" H2O reg to fed the home, but ran the 2psi to the gen set. Piping run was 30' with 4 90*'s. The pipe is 1" an is over kill for this gen-set. I went with 1" as I may remove the 25kw an install a 40KW for larger machinery operation should I decide to up grade. 2 PSI of N/G will support way more than most any home gen-set requires. The thing most gas company's forget is a gen-set has to have the correct pressure an flow, on demand. I can not tell you how many installs I have been to where front money was wasted due to lack of education. That goes for units that have been installed an never ran right for years upon years as well. One install cost the home owner over $25K to install everything. It would not preform to design. We were called in an the whole system had to be corrected to the tune of over $30K more. It was no where near your average setup granted, but the bottom line all the front money was mostly for not. Do it right the first time, an be done with it.


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## mlonas (Apr 4, 2020)

I recently picked up a DuroMax XP12000EH at Lowe's. It is an upgraded model with a secondary regulator that looks like the one used in the Century Fuel Products DJ156F Dual Fuel (LP/NG) conversion Kit. I got excited thinking that I might be able to use natural gas and called DuroMax to ask about it. They told me that they had not tested this unit's carb with NG and that operating it with NG would void the warranty. The max inlet pressure of the secondary regulator is .5PSI which leads me to believe that NG would work satisfactorily but might require a mixture adjustment to maintain 3600RPM. I am tempted to give it a try. I would appreciate any advice. Any members out there that may have tried this with this unit? Thanks much.


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## jasonjax (Mar 15, 2020)

Interesting. I literally just ordered the conversion kit from U.S. Carburation a few minutes ago. I plan to pickup the XP13000EH when it is back in stock.


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## drmerdp (Apr 10, 2018)

OEM dual fuel generators are a bit lackluster. Its worth buying and installing a quality Tri-fuel kit. Although you might be able to reconfigure the equipment to work with natural gas, I personally wouldn't.


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## jasonjax (Mar 15, 2020)

What makes them lackluster?

I was planning on this guy's technique seems a lot cleaner to simply swap out the regulator and not mess with a snorkel or carb swap.


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## iowagold (Jan 22, 2020)

the after market demand regulator unit like us carb work fine.
get the load block like on the top of this regulator..
for natural gas use an iridum spark plug set to 0.020 inches.
and start with the 3/8 inch load block set to 10 turns out.


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## drmerdp (Apr 10, 2018)

I’ve seen a few regulators fail, hoses routed poorly and kink as they age, hoses dry rot to the point of cracking or disintegrating. This may not be representative of all dual fuel generators, but ive seen my fair share of issues. 

The gaseous fuel inlet on the carb is nice through. Being cast into the body of the carb at the venturi without having the snorkel partially obstructing some airflow through the throat of the carb is a nice feature. 

Im just saying why waste the extra 100bucks on the dual fuel version just to replace the regulator anyway... the KN demand regulator he used was from UScarb. I like their load block better then others. 

Also the hose he used is interesting. You have to be careful with selecting the best hose for this application. Typically those gray hoses are not the best option. They usually use a flare fitting at 1 or both ends which is a flow restriction over NPT ends. Uscarb sells the best hoses for the job. Lastly, he is using a small bore gas valve and not a FULL bore Valve. Thats a big red flag. On NG fuel flow and volume very important. One good thing is he tapped into his gas line right after the meter. 

With a 457cc engine you'll likely want to upgrade to 1" hose depending on where in your NG system you are tapping into.


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## iowagold (Jan 22, 2020)

amen on the small feed lines and fittings on NG systems!!
yup watch all of the fittings for full flow!! like he stated and the shut off valves!!
lol a ball bearing works great for checking those ball valve dia where they are clear back in!
that go / no go thing!! lol
with 460cc watch the feed line length and dia real close!!
lots of ng btu required to feed that gen..


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## Ron Wagner (Dec 15, 2020)

jasonjax said:


> Interesting. I literally just ordered the conversion kit from U.S. Carburation a few minutes ago. I plan to pickup the XP13000EH when it is back in stock.


I just picked up a XP13000EH and wanted to convert to NG. Did you ever get around to it? If so, what parts did it require?


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## iowagold (Jan 22, 2020)

Ron Wagner said:


> I just picked up a XP13000EH and wanted to convert to NG. Did you ever get around to it? If so, what parts did it require?


pretty basic parts on a ng conversion kit
plan on 500.00 usd and up depending on how far you need to run any gas lines and hoses.
most bare kits run 300 bucks plus hoses and fittings
*click here for us carb oem site*
or call them
*1-800-553-5608 *
their email address is on the us carb site.

so maybe basic parts to expect;
carb adapter
load block
demand regulator
quick couplers
3/8 to 1/2 id hose from the demand regulator to the carb adapter depending on the cfm of the engine.
3/4 id hose from the demand regulator to the NG feed line
1 inch ball valve for feed line and for most small gens at short runs a 1 inch feed line works.
lots of msc couplers and adapters maybe mounting brackets for the demand regulator.


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## iowagold (Jan 22, 2020)

for ng hoses check out this site
click here for lp and ng hoses
they are out of TX and custom make hoses as well.
I like the mb sturgis quick couplers. 
they hold up well.
and at the bottom of that page is a hose size chart by HP.


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## dmark1867 (Feb 28, 2021)

jasonjax said:


> Interesting. I literally just ordered the conversion kit from U.S. Carburation a few minutes ago. I plan to pickup the XP13000EH when it is back in stock.


jasonjax did you pickup and convert the XP1300EH to Natural Gas? I would be interested in hearing what you ended up doing and how it went. Thanks


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## Ekrekel (Apr 20, 2021)

mlonas said:


> I recently picked up a DuroMax XP12000EH at Lowe's. It is an upgraded model with a secondary regulator that looks like the one used in the Century Fuel Products DJ156F Dual Fuel (LP/NG) conversion Kit. I got excited thinking that I might be able to use natural gas and called DuroMax to ask about it. They told me that they had not tested this unit's carb with NG and that operating it with NG would void the warranty. The max inlet pressure of the secondary regulator is .5PSI which leads me to believe that NG would work satisfactorily but might require a mixture adjustment to maintain 3600RPM. I am tempted to give it a try. I would appreciate any advice. Any members out there that may have tried this with this unit? Thanks much.
> View attachment 7783


Did you wind up trying NG directly on this?


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## ggritter504 (Sep 6, 2021)

jasonjax said:


> Hi folks,
> 
> I live in Florida, and want to be prepared for hurricane season this time around. I've had a hard cutover installed for the electrical panel w/ 50A service installed outside by the garage. I will have the gas folks tee off the pool heater for fuel. I also had a hard-start installed on the AC unit to help with the compressor drawing too much power at start-up.
> 
> ...


Jason, i am working on a plan to do the same. Wondering why you chose to install hard-start on the AC instead of soft-start? what i've been reading suggests to install soft-start for this type power supply when utility power is not available. An AC installer i know also suggested soft-start. Also, i'm curious where to buy these AC components..?


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## drmerdp (Apr 10, 2018)

Soft start over hard start. Use the products selector to choose the appropriate model.









Leaders in Custom Marine & RV A/C Controls, Soft Starters & Displays


Micro-Air - Leaders in custom engineering & design of proven soft starters for single phase motors, control boards and displays in the Marine & RV industries.




www.microair.net


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## ajnuzzi (12 mo ago)

I'm not sure if you have already bought a generator and kit yet, I see this post is kinda old but I can give you real world advice as I have a duromax 12000eh. 
You have two routes to go for the conversion. 
1) remove the propane regulator and hose and replace it with a garretson kn style regulator and run it right to the propane inlet. This is the easiest solutions but will most likely result in you not getting enough fuel. I have heard from some people that this method has worked for them depending on your conditions and gas pressure. I tried this first and it worked under a load but I had to keep the chock 1/2 on to get it to run properly, was running lean. 
2) put the entire conversion kit in, including the venturi adapter between the air box and the carb. This method works easly and perfectly on the duromax 13000 but on our 12000 the engine is about an inch closer to the frame so it would require you to cut the frame to fit it in. I actually cut half of the airbox cover off to make it fit as opposed to the frame. If you haven't bought a generator yet get the 13000eh - the conversion kit will go in easily without major modification. Good luck and if you have any questions feel free to PM me


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## ajnuzzi (12 mo ago)

mlonas said:


> I recently picked up a DuroMax XP12000EH at Lowe's. It is an upgraded model with a secondary regulator that looks like the one used in the Century Fuel Products DJ156F Dual Fuel (LP/NG) conversion Kit. I got excited thinking that I might be able to use natural gas and called DuroMax to ask about it. They told me that they had not tested this unit's carb with NG and that operating it with NG would void the warranty. The max inlet pressure of the secondary regulator is .5PSI which leads me to believe that NG would work satisfactorily but might require a mixture adjustment to maintain 3600RPM. I am tempted to give it a try. I would appreciate any advice. Any members out there that may have tried this with this unit? Thanks much.
> View attachment 7783


I have the same generator and can tell you that regulator will not work with natural gas. You will need to put the adapter in between the airbox and the carb and modify either the frame or airbox to fit.


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## jsa307 (Oct 6, 2021)

can anyone recommend a store that sells and ships pre-modified portable natural gas generators? thank you


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## ajnuzzi (12 mo ago)

jsa307 said:


> can anyone recommend a store that sells and ships pre-modified portable natural gas generators? thank you


If you're in Texas Green's Blue flame in Houston will allow you to get your generator shipped directly to them where they will do the Tri Fuel conversion. I do not know if they will ship it after they convert it though you'd have to call and ask, I got a feeling at that point the only option would be to pick it up. I'm sure there are other places that do this is well that's just one I'm familiar with. I would suggest calling your local propane supplier.


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## ajnuzzi (12 mo ago)

jsa307 said:


> can anyone recommend a store that sells and ships pre-modified portable natural gas generators? thank you


On another note depending on what kind of generator you have the conversion is fairly simple. I am NOT a mechanically inclined person and I was able to convert a westinghouse wgen9500df as well as a duromax 12000eh. If you'd like to ask any questions about the conversion feel free to PM me.


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