# Homemade Natural Gas Conversion and Dual Fuel Conversion



## Danny LA (Oct 30, 2021)

In 2016 I made my natural gas adapters out of 3/8" OD stainless steel tubing for my double throat carburetor. I bent two 90's and installed them after the air filter (in the plastic between the carburetor and air filter) and sealed them in with JB weld. It just ran 24/7 for 9 days after hurricane Ida. I only shut it down every 4 days for an oil change. After hurricane Ida I made an adapter for my son's 5000 watt generator out of 1/4" ID reinforced rubber hose. I striped 2" of the reinforcement off one end of the hose and drilled through the air filter housing and the air filter. The hose goes 1" into the throat of the carburetor. I made a clamp to screw it in place with some strapping, hose clamp and screws. It runs great on natural gas or gasoline. I just tried a KN regulator on a dual fuel generator to run it on natural gas using the hose on it for the LP fuel. It also run great. All 3 use a KN low pressure natural gas regulator and I make a adjustable gas valve out of brass fittings. I get everything from EBay. I tried attaching pictures of them to this post, but was unsuccessful.


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## drmerdp (Apr 10, 2018)

You might need a certain amount of posts before being allowed to attach pictures. I’m interested in seeing your contraption.


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## oldcodger (Sep 13, 2021)

What happens if the motor quits? Will the gas supply be shut of automatically or will it just continue to flow? The device which appears to be a regulator on dual fuel generators is really a safety vacuum actuated demand controller. If the engine dies and it no longer sees vacuum demand it closes and prevents the flow of gas.


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## OrlyP (Oct 19, 2021)

oldcodger said:


> What happens if the motor quits? Will the gas supply be shut of automatically or will it just continue to flow? The device which appears to be a regulator on dual fuel generators is really a safety vacuum actuated demand controller. If the engine dies and it no longer sees vacuum demand it closes and prevents the flow of gas.


The "KN regulator" mentioned _is_ the demand regulator (Garretson Model KN).

It works in conjunction with an upstream low-pressure regulator.


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## oldcodger (Sep 13, 2021)

Good. Your wording calling it a low pressure regulator made me think it was simply a second stage regulator.


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## Danny LA (Oct 30, 2021)

oldcodger said:


> What happens if the motor quits? Will the gas supply be shut of automatically or will it just continue to flow? The device which appears to be a regulator on dual fuel generators is really a safety vacuum actuated demand controller. If the engine dies and it no longer sees vacuum demand it closes and prevents the flow of gas.


The regulator has to see a vacuum to let the gas flow. The intake is sucking vacuum when the engine is turning. If the engine stops turning the gas flow stops.


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## Danny LA (Oct 30, 2021)

Danny LA said:


> In 2016 I made my natural gas adapters out of 3/8" OD stainless steel tubing for my double throat carburetor. I bent two 90's and installed them after the air filter (in the plastic between the carburetor and air filter) and sealed them in with JB weld. It just ran 24/7 for 9 days after hurricane Ida. I only shut it down every 4 days for an oil change. After hurricane Ida I made an adapter for my son's 5000 watt generator out of 1/4" ID reinforced rubber hose. I striped 2" of the reinforcement off one end of the hose and drilled through the air filter housing and the air filter. The hose goes 1" into the throat of the carburetor. I made a clamp to screw it in place with some strapping, hose clamp and screws. It runs great on natural gas or gasoline. I just tried a KN regulator on a dual fuel generator to run it on natural gas using the hose on it for the LP fuel. It also run great. All 3 use a KN low pressure natural gas regulator and I make a adjustable gas valve out of brass fittings. I get everything from EBay. I tried attaching pictures of them to this post, but was unsuccessful.


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## Danny LA (Oct 30, 2021)

drmerdp said:


> You might need a certain amount of posts before being allowed to attach pictures. I’m interested in seeing your contraption.


Did you notice I was able to attach pictures?


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## iowagold (Jan 22, 2020)

make sure to change out the hose for rated for vapor gas as LP and NG hose.

i do question on all of the setups the air flow interference of the extra tube in the air flow stream...
i would think it would be part of the reason for lower power....
as lower air flow...
just a question.
in reality i have yet to see a small disturbance to be an issue.

now if the oem mfg's would get a good setup for efi with LP and NG then they will have something!
the cost per unit is the big thing...
and the demand for a unit with 2 sets of efi on board for tri fuel.

or even just a trade off system as a choice of mono fuel as efi gasoline or efi LP and NG
that they should be able to keep the retail price close to what we have now on gen sets like the eu7000is.

one of the things i have noticed as an issue is the vibration of the gen running with the demand regulator attached to the frame direct...
over time the demand regulator will develop issues from internal wear.
i have relocated the demand regulator to not attached to the gens for this reason.
and as long as the hose run from the demand regulator is short (under 6 feet) and is proper sized for the flow demand you are still ok on load response.

and to danny la
it looks like a good setup!
not bad for a home build!
just change out the hose to a rated for LP/ NG is all i see as bad.

and you might be able to make a frame mod out of bendable emt pipe for the yellow gen.


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## sdowney717 (12 mo ago)

iowagold said:


> make sure to change out the hose for rated for vapor gas as LP and NG hose.
> 
> i do question on all of the setups the air flow interference of the extra tube in the air flow stream...
> i would think it would be part of the reason for lower power....
> ...


That is interesting keeping the demand regulator away from the generator frame. I might just do that too. As well as wear issues, It solves mounting issues onto the gen frame which I had figured out. I am going to try 1/2 inch copper water pipe with 5/8 heater hose to run to another short piece of 1/2 inch copper water pipe fit into the metal air housing with tube end sitting at the carb inlet, not into the carb inlet. I see kits online some use 3/8, some are 1/2. I simply have all the pieces free for using a 5/8 heater hose to the carb from the regulator. Otherwise, I can go with actual 1/2" heater hose all the way to carb and use smaller copper water pipe meant for compression rings. It is a good bit smaller diameter than hard copper 1/2 sweated soldered pipes. Gen for this experimenting is a 8000w Troy Bilt.


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