Generator surging Under NO load

Old 02-21-15, 07:14 PM
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Generator surging Under NO load

So back ground.. I bought a sportsman GEN7000 genny last summer.
Prepped per directions, run with gas in summer and late Fall for about 30 min each time with gas and stabil. Each time was put away by turning fuel off letting carb run dry and siphoning out old gas. ( gas never sat in it for more than a day)

Last week Electrician put in a transfer panel, we hooked up the genny to it to ensure proper connection etc etc..
The genny was outside all day in about 4 degree weather.
It started fine (not connected to the transfer panel) with choke closed, then ran for another 30 seconds and choke slowly opened. Even after 30 min i couldnt open choke all the way, it only went to open 70% before the genny rhytmically surged but never turned off. Yuo could see the governor working back and forth in rhythym with the engine surging

We connected to the panel with the choke open and the genny surging and it outputted steady 240 volts but you could see lights in the house dim in rhythym with the genny surging noise. I cant remember if the light s dimmed steadily or output was steady with the choke only open 70% and no steady rhythmic surging.

I figured the carb just got clogged with fuel and was ready to tear it apart. but reading the manual it said that the air and gas flow ratio needs to be reset if the genny doesnt run. Turn the screw till it bottoms out then turn it out 2 1/2 turns out.

So today I went out in 12 degrees, genny turns on easily, ( again NO LOAD) and open choke to 70% before i see the same surging symptoms. I bottom the screw out and the surging dissapears and I open the choke full open. I start to turn the screw out 2 1/2 turns out but the surging returns after only a 1/4 turn out.

What gives? Should I turn the screw out under load only? (I didnt do that today as family was over, it was prohibitive) And more for just my knowledge why did it run fine in summer and fall but now now? Colder/ denser air? ethanol in gas? Tomorrow I'll run it with choke 70% open just before it surges. Then hook it up to the transfer pan and get a load on it and open choke all the way and ill hear the surging. Then Ill play around with that screw and i'm assuming i'll hit the magical screw turn.. right?
Old 02-21-15, 11:01 PM
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I don't think adjusting the screw is going to solve it. The gas, even though you only left it there for a day, still the small amount left in the carb turned to varnish. I'd get some carb cleaner and remove the bowl and shoot it up through the main jet and remove the mixture screw and spray through it too and see if it does better. If not, a more thorough cleaning might be required.
Old 02-22-15, 12:38 PM
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Bad gas can certainly be the problem. Even stabilized fuel doesn't last forever. If it's old gas, drain it completely. Put the old gas in your car.

It might also just be do to the temperature too. Colder air is more dense so the air fuel ratio is likely a bit leaner than during the summer. You'll note that most snow blowers have heated carb boxes as well.
Old 02-22-15, 01:01 PM
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surging under no load

Try adjusting the screw out 3 turns. Engine is running lean.

Old 02-24-15, 10:10 AM
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So i put a call into the manufacturer, I'd like to avoid cleaning out the carb if its Just a simple adjustment i do under load vs the no load i've done before.

The cold air thoery makes sense, as does varnish in the carb which annoys me as sitting for only 3 months and shutting it off per mfr recommended steps still results in this surging doesn't make me feel good usign this in a emergency use
I'll fiddle some more this sat when we are above 38 degrees and everyone doesn't freak out about no electricity. i'll put it under load and try 3 turns out since people said it is running lean ( however that was the setting before when it was surging, perhaps i'll go further out. maybe ill go further out)

If it is the carb issue i will more than likely clean it, sell it and buy a tri fuel generator or a tri fuel conversion kit.

but back to my original question.. right now the screw is only a 1/4 turn out. runnign the generator under load under that setting( if I truly need it to run), will it have negative effects , if so what?
Old 02-24-15, 03:11 PM
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Rather than tri-fuel why not a conversion to just gaseous fuel? My generator is set up for natural gas but I can go to propane with one simple adjustment. I have never had a problem with the gaseous fuels.

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