I have an older generator with a Briggs and Stratton 10 hp engine. We have only needed to use it a few times but the issue with gasoline fueled generators is when things go sideways gasoline becomes difficult to find. So I decided to convert my existing gen set to propane or natural gas. The good thing about propane is it can be stored for long periods without it deteriorating like gasoline. Natural gas is the same but during a power outage it is seldom interrupted.
There are lots of kits available to do the conversions usually costing between $150 and $200. I chose to save a few bucks and source the parts needed and do a DIY conversion. Basic parts needed are a regulator, some way to regulate the fuel flow to the engine and some way to introduce the gas to the engine intake.
The regulator is called a demand regulator. There must be a slight vacuum on the outlet side to get it to open and flow gas. This is a safety device so that if the generator stops the gas stops also. The regulators commonly used in this application are Garrison. I bought this one from Century fuels.
I made the gas flow device using a 3/8" brass pipe tee. It has a 3/8" X 1/8" pipe bushing in one side with the bushing drilled and tapped for 1/2-20 threads. A 1/2-20 bolt is used to regulate the flow. There is a jam nut on the bolt to keep it in place when the gen is running. This is where you tune the air/gas mixture to get the best performance. Switching from propane to natural gas will require an adjustment. A ball valve or globe valve would probably work as well.
To inject the gas into the engine intake I made a 3/4" thick donut that fits between the carb and the air filter. There is a 1/8" pipe thread in the side with a 1/8" NPT x 3/8" hose adapter. The bore is slightly smaller than the carb bore so there is some pressure drop to operate the regulator. The carb studs need to be extended to account for the thickness of the donut. On my Briggs engine the studs are 1/4-20 thread so all thread works. Had it been metric I would be looking for some long metric bolts.
The regulator is mounted to the gen frame and needs to be mounted vertically. The regulator is supplied with two red plastic plugs that vent the atmospheric side of the diaphragm. Make sure you remove these plugs. Probably not a bad idea to re-install the plugs for storage. Dirt daubers love places like this to nest and the regulator does not work unless vented. I added a voltage and frequency meter from Amazon to complete the conversion.
Then the question becomes did I save any money over ordering a kit. the confirmed answer is maybe. The regulator was $70 delivered. There are probably another $20 in pipe fittings and hose to get to the materials in the kits. In addition to the materials in the kits I set up my gas supply with quick connects so that was additional. I bought a 12 ft propane hose with quick connects from Amazon that was $40.
Happy to answer any questions.
There are lots of kits available to do the conversions usually costing between $150 and $200. I chose to save a few bucks and source the parts needed and do a DIY conversion. Basic parts needed are a regulator, some way to regulate the fuel flow to the engine and some way to introduce the gas to the engine intake.
The regulator is called a demand regulator. There must be a slight vacuum on the outlet side to get it to open and flow gas. This is a safety device so that if the generator stops the gas stops also. The regulators commonly used in this application are Garrison. I bought this one from Century fuels.
I made the gas flow device using a 3/8" brass pipe tee. It has a 3/8" X 1/8" pipe bushing in one side with the bushing drilled and tapped for 1/2-20 threads. A 1/2-20 bolt is used to regulate the flow. There is a jam nut on the bolt to keep it in place when the gen is running. This is where you tune the air/gas mixture to get the best performance. Switching from propane to natural gas will require an adjustment. A ball valve or globe valve would probably work as well.
To inject the gas into the engine intake I made a 3/4" thick donut that fits between the carb and the air filter. There is a 1/8" pipe thread in the side with a 1/8" NPT x 3/8" hose adapter. The bore is slightly smaller than the carb bore so there is some pressure drop to operate the regulator. The carb studs need to be extended to account for the thickness of the donut. On my Briggs engine the studs are 1/4-20 thread so all thread works. Had it been metric I would be looking for some long metric bolts.
The regulator is mounted to the gen frame and needs to be mounted vertically. The regulator is supplied with two red plastic plugs that vent the atmospheric side of the diaphragm. Make sure you remove these plugs. Probably not a bad idea to re-install the plugs for storage. Dirt daubers love places like this to nest and the regulator does not work unless vented. I added a voltage and frequency meter from Amazon to complete the conversion.
Then the question becomes did I save any money over ordering a kit. the confirmed answer is maybe. The regulator was $70 delivered. There are probably another $20 in pipe fittings and hose to get to the materials in the kits. In addition to the materials in the kits I set up my gas supply with quick connects so that was additional. I bought a 12 ft propane hose with quick connects from Amazon that was $40.
Happy to answer any questions.
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