Anybody know what this is?

Washopay · Postby **Washopay** » August 21st, 2015, 12:39 pm

Hi boys,
I'm having a problem with my Onan Genny. I believe I've isolated it down to a fuel issue. Does any body know what this silver can on the right is? It is past the filter on the fuel line leading to the genny.

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bud37 · Postby **bud37** » August 21st, 2015, 4:49 pm

It is a fuel filter , just a different style.....

Postby **Viper** » August 23rd, 2015, 8:55 pm

Yes, in-line fuel filter. Not needed there though. In fact it may cause problems. What symptoms are you experiencing?

Washopay · Postby **Washopay** » August 24th, 2015, 4:19 pm

Viper wrote:Yes, in-line fuel filter. Not needed there though. In fact it may cause problems. What symptoms are you experiencing?

Beginning of the season, it sputtered to halt after 1/2 hour run time. Then 20 minutes. I'm down to about 5 now. I've put a thermal gun to it and it is not overheating (I think if it was a sensor grounding it would shut right off not sputter to a stop). I've replaced the sensor to be sure, and the oil pressure sensor (Level is good). Thermostat, strainer, impeller, all good.

It starts fine, runs fine then suddenly starts to sputter and fart and then just dies. I found that a new marina I have been buying gas from is providing fuel with 10% ethanol (arrrgh). I'm thinking this might be the source of my problem. Sooooo.... I'm going to replace the filters next and try. Then (I suppose), I have to check the tanks to see if there is water.

I'm wide open to other ideas! Thanks Viper and Bud37

bud37 · Postby **bud37** » August 24th, 2015, 7:17 pm

One thing about ethanol...it is a form of solvent which will clean your fuel system over time especially old tanks....the bad thing is that it puts the crap in suspension which passes thru filters and drops out in the carb while not in use.....you just may have a bad fuel pump there as well, may be worth a look....pretty simplistic answer as those gennies have many many things that screw them up, but that is all I know about ethanol fuel....

Low Flyer · Postby **Low Flyer** » August 25th, 2015, 2:01 am

Replace that fuel filter, take it out of the line or/and add fuel stabilizer to your fuel system.
You may just have a partially clogged fuel filter (inline filter that shouldn't be there) that is restricting the fuel flow.
A fuel stabilizer should be part of your re-fueling regime to help inhibit ethanol and water problems.

Washopay · Postby **Washopay** » August 27th, 2015, 10:54 pm

Thanks for the advice guys. After all the effort, changed filters and sensors etc. etc. etc. It turned out to be a clogged fuel vent that was creating a vacuum and starving the pump. Loosened the filler cap and she runs great. Anybody know how to clean the vent line or am I best to just replace it?

SplashyLady · Postby **SplashyLady** » January 5th, 2016, 3:36 pm

Does the vent have a screen in it? If not, then just push some wire down the hole to clear the vent line. Mud daubers often will clog these vents if they are unscreened. If your vent is screened, you will need to remove it to clean the line. Good luck! :down:

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