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livesound · 08-25-2013, 12:11 PM

It must x

livesound · 08-25-2013, 02:55 PM

It must be the heat, got going for about 90 minutes and shut off. Stopped an hour later fired right up, ran about 30 and shut off. So here a bit later I can run it while stopped for a few hours. I'll post what happens when parked,
Thanks again for all the input

livesound · 08-25-2013, 03:51 PM

Also I finally got Internet, and the oil I used was 10 30 mobile 1 synthetic. The manual says above 100 10w40. That could be it?

sswilson · 08-25-2013, 04:03 PM

I am unsure whether that will make the difference, BUT, there is one way to find out

really can't tell whether it is an engine problem or a generator problem (safety switches). Have you tried to contact Onan?

clyon51 · 08-25-2013, 04:43 PM

Quote:

Originally Posted by livesound

Also I finally got Internet, and the oil I used was 10 30 mobile 1 synthetic. The manual says above 100 10w40. That could be it?

No.

rgreen45 · 08-25-2013, 05:56 PM

Sounds like fuel pump heating up and shutting down.

Synthetic oil viscosity will usually measure the full spectrum at any temperature so rule it out. The only real reason it's labeled at all is to meet manufacturers specs. Who else but Mobil1 have a 5w-50 oil (Corvette).

livesound · 08-25-2013, 10:39 PM

So update, got to parking kit an ran for 5 hours no problem, that's what I thought about synthetic, one of the many reason I use it for all my motors. When I did the front brakes I did notice that the dirt dobbers, have a had a field day, it's a new to me rig so I haven't been all over just yet. I have done tires all fluids, except differential. While we are talking I got the fuel filter for the geni, it's threaded in one end but I couldn't find one on the unit?

rgreen45 · 08-26-2013, 05:34 AM

Quote:

Originally Posted by livesound

While we are talking I got the fuel filter for the geni, it's threaded in one end but I couldn't find one on the unit?

On that unit I think it's gonna be on the inlet end of the fuel pump. Where your rubber line comes from the gas tank ..... it should connect to the FF which is screwed into the FP.

clyon51 · 08-26-2013, 07:05 AM

Quote:

Originally Posted by rgreen45

On that unit I think it's gonna be on the inlet end of the fuel pump. Where your rubber line comes from the gas tank ..... it should connect to the FF which is screwed into the FP.

I agree this is the most common setup. In any event, following the fuel line from the tank area, the fuel filter should be the first encountered. If all is still stock, it should screw into the pump.

While we're on the fuel system and your apparent overeating issue, gennys do have internal overheat sensors. Also, if the fuel gets too hot, you experience vapor lock and an overheated fuel pump can quit working too, as rgreen pointed out.

It would be prudent to inspect the fuel line run to make sure it is not routed close to any heat sources such as an exaust pipe, muffler or cooling air exaust from the genny. Many have solved this problem by wrapping/insulating as much of the fuel line as possible.

Just as info, genny mfgrs bench test their air cooled units in 125 degree temps. The problem comes in when MH mfgrs enclose them in a bay, behind the heat generating engine and transmission.

tom77hmstd · 08-26-2013, 07:16 AM

Quote:

Originally Posted by livesound

It must be the heat, got going for about 90 minutes and shut off. Stopped an hour later fired right up, ran about 30 and shut off. So here a bit later I can run it while stopped for a few hours. I'll post what happens when parked,
Thanks again for all the input

Don't think oil is your problem I think heat is. I had a 5.5 in a class c that would do the heat shutdown. The problem was the cooling system is maxed out with all coach running and the radiator had some junk on it closing off partial air flow, I know the rad is blocked from view with the shrouding pull it back and take a look. Also you can take a fan and force air into the opening when parked and see if that keeps it running.

livesound · 09-03-2013, 07:51 PM

Just an update. replaced the fuel pump, all new fuel lines. runs like a champ.

clyon51 · 09-03-2013, 08:07 PM

Quote:

Originally Posted by livesound

Just an update. replaced the fuel pump, all new fuel lines. runs like a champ.

Any idea which one corrected the problem? In other words, did you do one at a time then test, or just did them both first.

wildbill001 · 09-04-2013, 08:47 AM

One other possibility. You mentioned dirt-dobber nests. Possibly had some in/around the cooling fins, under the sheet-metal housing. If, after you did the work, you noticed dirt under the genny, that may have also contributed to the issue.

Bill W

wa8yxm · 09-04-2013, 06:59 PM

Many Onans are chatty... If you press the proper button the light flashes in a pattern,, Write down the pattern and let us know what it is (example. Just now my car sends 0455, but that is a car, not a generator so the code would mean nothing to you).

In either case... I suspect what happened to you was vapor lock. Though changes in how fuel is delivered to an gasoline engine have all but eliminated vapor lock on the big engine (In fact I do not think a real vapor lock is possible) the Generator still uses an older delivery system.

ONE cure for a vapor lock is... Let it cool off.