RG 022 / 22kw Liquid Cooled

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Capt Schmitty
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I have a 1 year old Generac RG 022 / 22kw liquid cooled with Mitsubishi 2.4L engine. It a runs on Propane Gas
I had the problem with sputtering a couple weeks ago and switched spark plugs to Champion RC9YC and that smoothed it out. It’s only run about 20 hours since then, now it’s sputtering again only worse and backfiring.
Could this be a fuel injector problem ?
Any help is greatly appreciated
Birken Vogt
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You should keep this to one thread. I had to search around for your other threads on this unit.

Close the gap on the plugs to .015 or so. If it runs better you have an ignition problem. Wires, coils, or both. Did you replace the wires already?
Capt Schmitty
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No I have not replaced wires or coil.
The gen is only a year old. The puzzling thing is when it starts sputter and backfire (15-20) hours in new plugs. I replace the plugs with new ones gapped at 42 per your advice. It runs perfectly for about 15-20 hours then gets rough and backfires / replace plugs runs fine
Chris
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Do the plugs look fouled? Could be that the fuel system isn't configured properly...
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grsthegreat
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were the fuel ports changed to propane.?
Birken Vogt
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Gapping the plugs at .015 is a diagnostic step of my own invention. Most vapor fuel engines will run fine on this gap and if the ignition system is the problem it will run much better. After that test you can start deciding what you want to do about it.
Capt Schmitty
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The plugs looked like they are burned after about 20 hours. The electrode edges are rounded off they are a light grey color. The gas has increased quite a bit from the wear. The fuel ports were switched to propane. I have a gas pressure meter and have checked that. It’s perfect. I also have two completely separate propane supply with manual cut over valves. 1 - 1000 gallon tank
And 4 - 100 gallon tanks it acts the same way in either supply. I have read in other places that these engines tend to run better on a smaller plug gap and some recommend platinum and iridium plugs. I have not tried them. Would you consider it reasonable to expect wear on the coil and or plugs wires in a unit so new and with low hours ? I’m crazy anal about maintenance and do it every 50 hours and was changing spark plugs every time. As I mentioned now by 15-20 hours it starts sputtering again and now backfiring. I’m definitely puzzled because new spark plugs make it all go away and she runs perfect for a while. I’ll follow your advice and reduce the gap in the plugs this morning. The generator gets about 9-12 hours of runtime every month in the summer. My home is all solar, totally off grid. When there is rainy cloudy weather (often in Florida) my battery bank can run the house for three days, the generator comes in automatically and fully charges the batteries in 2.5 - 3 hours.
Capt Schmitty
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I meant to say after 20 hours the spark plugs look very worn Definitely not fouled at all, the electrode is worn down and rounded off thus increasing the plug gap quite a bit
Birken Vogt
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I've seen spark plugs get rounded off when they have many thousands of hours on them. But not when they have 25. Almost seems impossible. Sounds like the engine might be running terribly lean for some reason.
Capt Schmitty
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Hm, is there a remedy for that ?
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