Generator Oil Change

In a perfect world you would change the oil both spring and fall.

In my imperfect world I consider fall the correct time. As any engine operates it accumulates acids and contaminants in the oil. It is generally recommended to store an engine with clean oil rather than with the contaminated oil.

For the lowest cost of ownership and reliability -that Onan needs to be run under a moderate to full load at least monthly. Running the unit like this will keep moisture out of the oil, keep the generator end slip rings from corroding, and keep your carb from gumming up. I am a strong believer in ethanol free fuel for small engines. If you have to use ethanol fuel -stabilize it to prevent phase shifting(fuel component separating) and the related corrosion that happens from this condition. I always keep my fuel tank full and the fuel treated with a mixture of Stabil and SeaFoam. Startron is also a good product.

(condensation doesn't collect in the oil?

WoW this is interesting:Link copied and pasted below.
http://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/How_Does_Water_Get_in_Motor_Oil.aspx

Water can get into the oil two ways. You generally don't have to worry about one of the ways if you drive your car enough to burn off the water during normal driving. This drives off the moisture that simply comes from your engine breathing when it is not being used (cold air enters a hot engine and water condenses) and from combustion by-products. The second more destructive route is through a coolant.


I live a mile from the beach we to get a lot of condensation this time of year it's nothing to worry about!

Ive actually gone a couple years on my genset without changing the oil...and this year changed it and the oil appeared good. As long as its run monthly and to temp there should be no problem changing it now. I think the biggest issue would be fuel. I had some problems last year with genset and part of it was because I didnt run it religiously. So this year, some fresh premium fuel and a dose of STABIL..and a reminder set on my phone to run the genset. Also a friend told me and have been doing it...run the fuel station pump to keep it lubricated and healthy. Just pump it back into the tank.

Worry about the gas, not the oil. Run your gen once a month to cycle the gas through the carb and the lines.

While not an expert in oil I’ll pass along some hints, tricks, and concerns I learned (heard) over the years.

1)You should run your engine at operating temperature for a period of time, not just bring it up to temperature and shut it off. This allows the extended heat exposures to evaporate any moisture in the oil before changing. This is why short driving trips are harder on an engine than longer commutes

2)You should not let any oil sit for long periods of time once the oil has been run, even for short periods of time, as it develops acids and other heat related changes that can damage bearing surfaces and other metals. This can be seen as pitting of machined metal surfaces. Once you’ve identified the end of your season you should change the oil before storage. If you continue to run the gen on a regular bases (at least every 2-3 months) then change the oil at the recommended intervals.

3)Always change oil and filter to remove any particles of worn metals and the acids contained in the oil.

4)Additives and supplemental are your call.

Hap

As he said, its best to run it every so often. Helps keep fresh (well, fresher than whats sitting in the bowl) fuel going through it, keeps parts lubricated and on some models/types of generators it will keep the rotor from losing its residual magnetism. If you ever have a portable generator that has set along time and it wont put out, plug an electric drill motor into it, hold the drill switch on and spin the drill chuck by hand, it may excite the rotor and start output.

I would think once a year is plenty for most users. I think it is more important to let it get up to full temp when using it after a break (approx 1/2 hr under a good load) That will burn off/remove any moisture that has made it's way in. Just pick a month and stick with it. If i lived in a moist climate i would do it in the spring.

I replace the oil (I use synthetic) yearly in our Onan and have done it both at the end and beginning of the camping season with no noticeable affect on lubrication performance or longevity either way. In fact I was planning to do mine this past week and decided to wait until Spring since oil appears OK for the few times I will exercise the genny during the off season.