Can you run a natural gas generator on [propane

Not sure about the Kohler demand regulator but on my Generac it's a simple jet change to go from one to the other.

The instruction manaul should tell you for sure, if you don't have one it's probably available on the net.

H.

The hole in the gas orifice is much larger for natural gas. You will need a different orifice, but they should be available and cheap. The first place to find out should be Kohler.

You can, for just a test, just feed propane into the carb's throat from a hose from the propane tank's regulator but you will need an adjustable valve on the propane hose to get the volume of propane correct so it runs smoothly.

MikeB

That's what, about a 20 horse engine? I'd probably stuff the hose from my turkey cooker into the intake, turn on the gas and see if it fires off. I've used a nozzleless propane torch to do the honors when starting a balky car engine, too, easier on the innards than ether. Just don't expect long run times with either, you'll probably get a few revs under power before the mixture in the manifold gets too lean.

Now if you want to convert it, that's another story. Don't really know much about smaller engines and propane power, but the larger ones need a vaporizer that's usually tapped into the oil system to vaporize the LP as it comes from the tank. A natural gas system won't need that or have that. Larger engines will pull more gas than ambient heat can vaporize, the tank would freeze up. A vaporizer setup with the LP carb might be available as an option on that particular engine or generator model, though. Probably would cost a bit for the conversion and be a bit fiddly to get going. If you want/need LP power, sell the current one and get one. Plenty of demand for NG backup power. No cold weather starting problems and the tank never runs dry.

As far as I know, a forklift tank uses the same POL fitting that barbeque bottles do, the difference is that the forklift tank has a siphon tube to pass liquid, not gas, see above about the vaporizer. So no regulator in that application, the vaporizer does the honors in combination with the LP carb/mixer. I don't know if you could get just gas out of the thing standing it on it's head and using a barbeque regulator, it'd be inconvenient, though. If you're using it on an engine, you'll want liquid and won't need a regulator.

Stan

To answer your subject line question: The answer is yes. If you can locate the proper carburetor metering orifice for propane.

The selection of regulator depends on the fuel flow rate. Someone can do a conversion from kiloWatts to BTU/H and you can find one that meets your requirements. Also, check the output pressure. Mostly specified in inches of water, many regulators are fixed.

I don't know about forklifts, but as you get to larger engines (I had a propane powered pickup truck) they switch from gas (vapor) tank pickup to liquid. That changes the type of regulator needed completely.

For higher flow rates, liquid propane is taken from the bottom of the tank (rather than the top vapor) and run through the regulator where it changes to a gas. Since this phase change occurs in the regulator (which is physically small compared to a tank), some heat input must be provided or it will freeze. In vehicular use, the engine coolant is usually circulated through a jacket in the regulator.

I dunno what would be practical about using a forklift LP tank.. as Paul and Stan suggest, you can use LP vapor (not liquid) for testing purposes.

AKA, the widely used Propane Enrichment Test for 4-cycle engines (even gasoline engines).. for small engines, a simple common propane torch is sufficient for testing. For larger engines, a larger supply/feed of LP vapor may be required, again.. for testing, not normal operation.

A propane vapor/gas stream, directed into the open air intake (air cleaner or other enclosure removed) will often provide enough fuel to meet a crude mix of air/fuel ratio to run an engine for testing purposes.

The LP gas supply should have an OH SHIT self-shutoff device to prevent a small problem from turning into a 911 call training event.

First things first - not last.. have a known good, operational fire extinguisher within reach.

All safety precautions need to be followed as required when dealing with any fuel gas.. no stray potential ignition sources from old cracked spark plug/coil wires arcing to ground, loose electrical connections, or carelessness resulting in a cloud of vapor taking place around an operating engine (often of questionable operating condition, timing issues, backfiring etc).. and with regard to the engine vibrations when it is running (no jumper leads with alligator clips used for temporary electrical connections which may shake off).

If you are keeping the generator, get the proper orifice for the metering body ("carburetor") and you'll probably need a Gasifier also

- like a Forklift, you can't draw off vapor fast enough from a small bottle, the bottle will frost over. From a 500-gallon tank this isn't that big a deal.

HINT: The Gasifier needs a hot liquid to vaporize enough Propane to run an engine, preferably hot engine coolant - but there's no rule saying it can't be the Motor Oil from an air-cooled engine... (I have seen Propane Corvairs.) Goes a lot easier if the engine has a pressure lubricating system, tap into the line for the Oil Filter with a Remote Mount kit. Bonus, it acts as an oil cooler.

If you plan to sell the generator once you prove it runs properly, you might just want to take it somewhere that has natural gas available and test it there.

You can improvise the hoses for the hookup, since the gas pressure is under 1 PSI anything that will hold pressure and not leak will do - Garden Hose being the obvious one.

On a regular house or small business, you can tap off at the "Gas Company Use Only" testing valve or tee and plug AFTER the regulator and meter for a temporary source - just have to put it back when you are done.

If you have a 3/4" (or larger) tee and plug, that's where they put a temporary gas feed when they go to change the meter when nobodys home. They have a special bag and nozzle gidge where they loosen up the plug to finger-tight and put a bag over the tee. Then they remove the plug inside the bag (now at 6" WC gas pressure) and stick the nozzle into the tee and the pipe to the house - now their portable bottle is running the house, and they can change out your gas meter.

You can rig the same thing with a big plastic bag wrapped around the end of the tee and taped closed - loosen the plug to finger tight, put pipe dope on the valve, put the valve in the bag and the bag over the tee, pull the plug and put in the ball valve to finger-tight. Bada-Bing!

If you were running an industrial plant like a big Bakery or a Glass Foundry where you can't just shut down mid-batch if the Natural Gas ever fails... Or you wanted the same generator to switch between NG and Propane easily... There IS a way to substitute Propane for Natural Gas without changing anything in the plant. They have a metering device that mixes Propane and low pressure Compressed Air (from a ring blower) to get the same BTU content, then they pipe it on into the plant to keep it running.

The same thing could be done on a small scale, but it would be far too expensive to mess with building or buying one unless you plan to do it every day. I'm just mentioning it so you know it exists.

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I remember hearing that forklift tanks have a flexible dip tube, so they feed liquid propane regardless of the tank position. Definitely need a gassifier.

Christopher A. Young Learn more about Jesus

If you are keeping the generator, get the proper orifice for the metering body ("carburetor") and you'll probably need a Gasifier also

- like a Forklift, you can't draw off vapor fast enough from a small bottle, the bottle will frost over. From a 500-gallon tank this isn't that big a deal.

HINT: The Gasifier needs a hot liquid to vaporize enough Propane to run an engine, preferably hot engine coolant - but there's no rule saying it can't be the Motor Oil from an air-cooled engine... (I have seen Propane Corvairs.) Goes a lot easier if the engine has a pressure lubricating system, tap into the line for the Oil Filter with a Remote Mount kit. Bonus, it acts as an oil cooler.

If you plan to sell the generator once you prove it runs properly, you might just want to take it somewhere that has natural gas available and test it there.

You can improvise the hoses for the hookup, since the gas pressure is under 1 PSI anything that will hold pressure and not leak will do - Garden Hose being the obvious one.

On a regular house or small business, you can tap off at the "Gas Company Use Only" testing valve or tee and plug AFTER the regulator and meter for a temporary source - just have to put it back when you are done.

If you have a 3/4" (or larger) tee and plug, that's where they put a temporary gas feed when they go to change the meter when nobodys home. They have a special bag and nozzle gidge where they loosen up the plug to finger-tight and put a bag over the tee. Then they remove the plug inside the bag (now at 6" WC gas pressure) and stick the nozzle into the tee and the pipe to the house - now their portable bottle is running the house, and they can change out your gas meter.

You can rig the same thing with a big plastic bag wrapped around the end of the tee and taped closed - loosen the plug to finger tight, put pipe dope on the valve, put the valve in the bag and the bag over the tee, pull the plug and put in the ball valve to finger-tight. Bada-Bing!

If you were running an industrial plant like a big Bakery or a Glass Foundry where you can't just shut down mid-batch if the Natural Gas ever fails... Or you wanted the same generator to switch between NG and Propane easily... There IS a way to substitute Propane for Natural Gas without changing anything in the plant. They have a metering device that mixes Propane and low pressure Compressed Air (from a ring blower) to get the same BTU content, then they pipe it on into the plant to keep it running.

The same thing could be done on a small scale, but it would be far too expensive to mess with building or buying one unless you plan to do it every day. I'm just mentioning it so you know it exists.

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Oh yeah, I almost forgot: Propane regulators designed for engine use have an interesting safety feature not found on barbecue or similar regulators. They are designed to supply gas at a slightly negative pressure relative to atmospheric. Instead of providing a positive fraction of an inch of water pressure, they require a negative pressure. That way, a running engine has to provide a slight vacuum to draw gas from the system. If the engine stalls, the gas flow stops.

What are the stories behind the two guys who got burned? What did they do wrong?

RWL

AND that's why they need electric start.. you gotta crank away & get some intake vacuum to draw in propane.

I think some of the gas carbs for hand-cranked engines have a button to add a shot of gas while starting.

The hardware is more or less the same. The orifice is smaller with propane and larger with Natural Gas. More energy in propane.

I've had it done to ranges, hot water heaters, ovens and furnaces.

When you live in a propane home you get to know the unique needs. Now, out of that house into an all electric. Wish we had Natural gas.

Mart> David Lesher wrote: