Generator maintenance question

[Bluecal]

I have an Onan 4000 gasoline generator on my winterized RV in the damp Pacific NW. I exercise it monthly and I have Stabil in my gas tank. I have been advised by 2 knowledgeable people with opposite recommendations. One says to always keep the carburetor bowl empty except when exercising because water will form and ruin the carb. The other says don't do it because the seals and gaskets will dry out and be ruined. What's the answer?

[abjbrtd]

Originally Posted by Bluecal

I have an Onan 4000 gasoline generator on my winterized RV in the damp Pacific NW. I exercise it monthly and I have Stabil in my gas tank. I have been advised by 2 knowledgeable people with opposite recommendations. One says to always keep the carburetor bowl empty except when exercising because water will form and ruin the carb. The other says don't do it because the seals and gaskets will dry out and be ruined. What's the answer?

How does he "keep the carburetor bowl empty"?
I know how I do it.

[ducksface]

Neither.
The dry Bowl is old school bad Gas cure when varnish was an issue...but I do it when able. The wet Bowl is for organic gaskets from decades ago.
I'm not sure varnish can form in the presence of alcohol...but something is different.

My 15 year sitting-in-the-weather ford lawn tractor fired up with a 15 year dry carb without a leak, and my John Deere fired off with a 15 month wet carb without a leak.

Ive rethought a bit and the only carb I drain out of everything on the place is the concrete mixer. It sits for a year, I run a tank through it until it's empty, sits AGAIN for a year....i haven't even drained the chainsaws.

Edit:
You reminded me it was time to run the generator.
It's now outside its house purring away.
I wont drain the carb when it comes back inside.
Thanks.

[Bluecal]

I was shown how to open up drain screw. Gas comes out until the bowl is empty. Close the drain screw. Next month press the primer until the gas fills the bowl and then start it up.

[Bluecal]

Thanks for the info, DF. The guy who recommended emptying the carb bowl was actually a generator mechanic who happened to be at my home doing annual maintenance on my house standby generator. He was not so concerned about the varnish issue as how moisture ends up in the gas in this part of the country. It's plausible, I guess, and I'm new to this area so I tend to listen to the locals. He said he's seen several cases of water damaging the carburetors. The part about old organic gaskets makes sense. Since I couldn't decide, one month I drained it and one month I didn't! I think in March I'll just get in it and go drive around for a month. That's what it's for anyway.

[Lt Keefer]

Do a search on youTube looking for videos about old power equipment being bought back to life. In most of them, the new fuels that have alcohol have caused a small amount of corrosion in the carbs. In the ones with old style gasoline, the lack of alcohol has caused the carbs to have a certain amount of varnish. To me, the real question is which do you want to deal with, corrosion in the carb or varnish. I never drain the carbs in my power equipment and the only ones I have had trouble with were the two strokers. But to be honest, I have replaced all the two stroke engines with lithium power and use stabil in the others.

[dkoldman]

If you exercise it every month for at least 1 hour, why worry about doing anything else?

Just follow the Onan manual. It says nothing of emptying carburetor bowl. I know fuel stabilizer is good, but somewhere I read to never add to fuel additives. Maybe it was just focused on methanol?

I run my genset whenever I think about it. I have never had to use the prime feature. Easy start 1st time every time.

My manual has instructions for long term storage if you cannot exercise, but as I read it, if you exercise regularly there is nothing else to do but change oil and filters.

[rbykid]

I say keep it wet and run it once a month.

I have a Yamaha 4 wheeler that I ran the carb dry and it sat for 2 years. That ethanol gas residue cemented the needle and seat together like Gorilla Glue. I now leave my carbs wet and use fuel stabilizer.

[Pete'sMH]

I’m in the leave it wet and run it for an hour or more under load at least monthly. I use a space heater in the winter and the AC in the summer. If I can find a nice day I try to drive it for 20 or 30 miles at the same time. I believe pretty much every machine will benefit from regular use.

[dkoldman]

Originally Posted by Pete'sMH

I’m in the leave it wet and run it for an hour or more under load at least monthly. I use a space heater in the winter and the AC in the summer. If I can find a nice day I try to drive it for 20 or 30 miles at the same time. I believe pretty much every machine will benefit from regular use.

When I was talking with Onan Engineering trying to get what I needed for my install of AGS, they made the point of running the Generator crystal clear. They stated that RV owners with AGS system that use them have a lot lower failure rate than regular owners without. They state a number of RV owners falsely think they are somehow increasing value of genset by having less hours.

Proof that they walk their talk, they increase the warranty to 3 years if you have AGS installed by authorized dealer. I do my portable the same way.

[ducksface]

I didnt know about the ags warranty increase.
I expect no problems but its nice to know.
My ags has been in the rv for 18 months ot so, and I've yet to program it.
Rv lives inside on shore power. Plenty of battery so no surprise dead stuff, big inverter...
One day I'll need it.

[dkoldman]

Originally Posted by ducksface

I didnt know about the ags warranty increase.
I expect no problems but its nice to know.
My ags has been in the rv for 18 months ot so, and I've yet to program it.
Rv lives inside on shore power. Plenty of battery so no surprise dead stuff, big inverter...
One day I'll need it.

I don't they market it. It is carrot they dangle for you to buy the AGS (EC-30) given you have Cummins Onan Genset without AGS.

I use mine all the time, but I admit the $200 more I paid to have them rewire Shorepower sense BEFORE ATS was just a luxury. It is only needed where you are actually on Shorepower but you want the genset to come on the instant shorepower is lost.

When I do use it, it is simply programmed for low batteries or hot temperatures inside the RV. I have gotten a little fancy exercising it by putting it on Auto when at home and just leave it along, eventually it will start itself up to charge the batteries. It has a log to tell you when it came on and why and when it shut itself down.

Our batteries have never been discharged. They are basic Group 24s but we can make it overnight 10PM to next morning at 7:00 AM without dropping below 12.2vdc Eventually I wish to double my AHs but it is not really a big deal right now.

But right now my AGS (EC-30) is my favorite toy in the entire RV. I get a big thrill every time it start itself or turn itself off. I think I feel this way, because being an advid boater, dead batteries was a big fear. The RV has a lot of things to worry about but low batteries is not one I worry about. I have zero interest in solar.

With Propane Fridge, Propane water heater, LED lights, we don't have much draw. We may have two TVs inside running, sound bar and 1 or two lights on. We have outdoor fridge that runs off inverter, but I only use it when driving on long trips, or plugged in at a campsite. If I was boondocking why have two Refrigerators

[KevinH]

An Onan/Cummins tech at the RV Basics course advised us to exercise the generator under load every month for 90-120 minutes. Prime by holding the start/stop button to STOP until the light goes out, run genny 2-3 minutes then start appliance for load (AC in summer, microwave, plug in room heater, etc). Turn load off 2-3 minutes prior to shutting genny down. He did not advise emptying the carb. By running the genny under load all varnish/carbon build up burned off.

[Shoreguy]

I place my gasoline RV in outside storage in late December and pull it out the 1st of March. Three months with the RV covered, all batteries removed and generator winterized as follows: I fill the RV tank with gas and fuel stabilizer and run the generator one hour under load to circulate the new stabilized fuel to the generator. I "fog" the carb, drain the bowl, pull the plug and fog the piston. I place a rag in the exhaust pipe for critters. Have never had a problem starting in the spring.

It may make sense to exercise the generator if the RV is stored in an enclosure but I think the above winterization process is better protection for three months.

[Marcia]

While our RV sat at the dealers getting repairs for 3 months, the gas in the Onan carb varnished very badly. Had to replace the carb. While we were at it we installed a pitcock valve to turn the gas off to the generator. Now we always turn off the gas to it and let it run dry. No more problems!