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sharp3's avatar
sharp3
Explorer
May 15, 2013

Running generator on Natural Gas

I need some advise from some one who knows about LPG/NG conversions.
A while ago I bought a small 1.2 KVA gasoline generator and had it converted to run on LPG/Natural Gas by a mechanic. He drilled a hole in the carburetor midway between the existing gasoline inlet and carburetor's filter end (where choke is located), inserted and sealed a small metallic tube in the hole and then connected it to a demand regulator. This way he said that i will be able to run it on both gasoline and NG/LPG. He also gave it a test run in the workshop on LPG and it started and ran fine for a while.
After that i brought it home and tried to ran it on Natural Gas but it never starts (runs fine on gasoline though). They only thing i can do is start it on gasoline, turn off the gasoline knob and then when it start to die, turn on the gas. This way it continues to run on NG but keeps hunting and surging. With trial and error i figured out that when i move the choke almost halfway it stabilizes. Still, it only runs under very light load (say 10-20%). As soon as i increase the load further it dies.
My concerns are following:
1- Is there something wrong with the Demand Regulator?
2- Is there something wrong with the conversion mechanic did?
3- Are there any adjustments on the generator or carb that needs to be fine tuned?
4- Any other problem.
Is there any way i can run it smoothly on NG? I hope some one could help me out with this issue.

25 Replies

  • I have had a tri-fuel gen for years and have run on all three fuels.

    You should have a load block adjusment. If the load block is set for propane it will not even start on natural gas unless you enrichen the mixture with the load block adjustment. Natural gas doesn't have as many BTUs at propane, so it needs more gas.

    Do you have instructions for the conversion? If you do read them please.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    You said he modified it to run on LP and tested it on LP but you are trying to run it on NG and it's not working, Nor would I expect it too.

    This is not even close to accurate but it is a bit like trying to run a gasoline engine on diesel.. Won't work.

    The part he inserted into the air flow near the choke is simply the wrong part, You should have specified NATURAL GAS as your fuel, not LP, the orifice size is quite a bit different.
  • My Yamaha generators run on gasoline/ LP/ Nat Gas. They are equipped with a load block in addition to the regulator with prime button. I don't think you can get a gas model to run efficiently on LP without a load block which allows for the air/ fuel mixture when running on LP.
  • I have two home generators converted over to run, gasoline, LPG or natural gas. On the last one I converted the demand regulator has a primer button on the back. I push it in for a for a few seconds and hit the starter. It fires right up I have never used NG but the directions that came with the conversion kit said to open up the regulator screw to allow more gas to get to the engine than when using propane. My adjustment screw sets on top of my demand regulator where the line to the engine starts from.

    The first generator I converted doesn't have the primer button and often I will start it on gasoline and then switch it to propane. I have a RPM gauge on mine and once I have it warmed up and a load on it, I will adjust the adjustment screw to get 3,600 RPMs on the gauge. This gives me close to correct voltage.

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