Generac generator (natural gas) starts but won't stay running

It will only run for about 8sec's then stops. It does it 4 or 5 times then shuts down.
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On 09/06/2013 02:44 PM, TOM wrote:

Maybe it is sensing low oil pressure and shutting down?
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On 9/6/2013 2:40 PM, Jack Goff wrote:

I had to replace a lot of defective oil pressure sensors on Generac gensets for that reason. I had forgotten until you brought it up. I tested for that by disconnecting the terminal from the post on the oil pressure switch and making sure there was sufficient oil in the crankcase started the generator. If the engine ran with the oil pressure switch disconnected then stopped when the wire was shorted to ground, that indicated a problem. The switch shorted the connection to ground when oil pressure was lost. There is a time delay allowing oil pressure to build up and open the connection when proper oil pressure is reached. With the engine running, use an ohmmeter set to the lowest scale, the switch should test open with the engine running. I found that the big old oil pressure switches meant for older automobile oil pressure lights worked better than the OEM replacement available from Generac which was a cheap dinky little switch and it was a very common failure point on their gensets. ^_^
TDD
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On Friday, September 6, 2013 1:44:01 PM UTC-5, TOM wrote:

n shuts down. -- posted from http://www.homeownershub.com/maintenance/gener ac-generator-natural-gas-starts-but-won-t-stay-runnin-762399-.htm using Hom eOwnersHub's Web, RSS and Social Media Interface to home and garden related groups
Are you sure the gas supply can keep up with the needs of the generator? H ow old is the unit, when did it last run satisfactorily, etc, etc.
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On Fri, 06 Sep 2013 18:44:01 +0000, TOM

Check the low oil shutdown switch (and the oil level)
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On Friday, September 6, 2013 5:46:31 PM UTC-4, snipped-for-privacy@snyder.on.ca wrote:

Could be something simple like that. Or it could be more serious. I went through diagnosing one last year that also started up, ran for some number of seconds, maybe 10 - 15 secs or so, then shut off. As I recall, a few things happen around that time. One is that upon starting, the ignition voltage is supplied by the battery, but then after starting, it switches to being supplied by one generator winding that serves that purpose. If that winding or associated circuit is bad, it loses ignition. Also, as I recall, the generator control looks for normal voltage after start-up. If it doesn't see it, then it will shut it down.
In the generator I had, it was a bad rotor for sure, and possibly a bad stator too. I took a look at all the complaints on Amazon about similar Generacs and concluded it wasn't worth fixing. That had also been the conclusion of the service guy who diagnosed it for the neighbor I got it from. Being that it was only about 5 years old, I thought I might get lucky and be able to fix it, but it didn't pan out.
I found the Generac service manual online which had good detail on the various test procedures.
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On Friday, September 6, 2013 6:22:19 PM UTC-4, snipped-for-privacy@optonline.net wrote:

Also, the unit here had a couple of fuses that were accessible right at the control panel. Checking them is quick and easy. As another simple test, if you're comfortable working with AC, put a test meter on the generator output. If you have 240V during the time it's running, then you know the generator section is working. If not, then you know you have bigger problems.
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