Question About Cummins-Ona 2.8 Generator

[Ron J. Moore]

I am going to change the oil in my '15 RT 210, and it looks like it takes about 20.1 ounces of oil, or am I reading something wrong. I had an '05 that I used a quart in - so the difference I figure I better ask advice on. Ron

[JohnnyFry]

The manual says that it takes one quart, that is what I used.

[Ron J. Moore]

Thanks John..I was reading someone's comment - hope they don't go that route! Ron

[BBQ]

.

IIRC

The new Onan takes less than one quart.

If you pour more than what it requires,
it will spit out in various places,
and the end result won't be pretty.

You better triple check.

[Ron J. Moore]

BBQ...you can bet I will know before pulling the plug to drain. I wonder what is different in the '05 era gens to the, in my case, the '15 models. If the high temps ever go down, then I will be under there. Ron

[BBQ]

.

The new Onan has a lower profile. It can fit under the chassis frame.

.

[JohnnyFry]

Clearly the route to go is to follow the manual. Of course check that the manual you have matches the genny model!

[Capt Ron]

Add it very slow and check it as you go. It takes little more than half quart(.63). It will blow out any excess and it will be on your parking area.

[avanti]

Originally Posted by Capt Ron

Add it very slow and check it as you go. It takes little more than half quart. It will blow out any excess and it will be on your parking area.

Are you certain this is safe? I know nothing about these engines, but in some designs over-filling the oil can be dangerous, due to oil in the sump touching moving parts and getting churned up. This introduces air into the oil and reduces the effectiveness of the lubrication. Don't know if this applies here.

[Capt Ron]

Read your book on it, mine is a 2.8 and that is what it says . 0.63 quart.

[AZ ADVenturist]

What model (series) genset are we referenceing? Ours is KV series in 2013 R/T. Operator Manual date: 02-2012. Calls for 1qt (0.95L). We use recommended 15w-40 Rotella T (heavy duty diesel) oil SG, SJ/CH4 performance class. You gotta read back label of oil bottle! And change oil twice yr. Spring & late fall. Most run time on ours is monthly exercise about 1 hr+/-. Especially winter months. Use it or lose it!

[avanti]

Originally Posted by AZ ADVenturist

Most run time on ours is monthly exercise about 1 hr+/-. Especially winter months. Use it or lose it!

Many of us believe that the importance of frequent "exercise" of propane gensets is greatly exaggerated. That is certainly my experience.

Gasoline units may be a different matter. I've never owned one.

[booster]

Originally Posted by avanti

Many of us believe that the importance of frequent "exercise" of propane gensets is greatly exaggerated. That is certainly my experience.

Gasoline units may be a different matter. I've never owned one.

I think this is an interesting point, although I think it is a highly variable need that is based on the conditions the generator sees. The exercise for a propane unit is primarily to keep the slip rings clean of tarnish and corrosion that will hurt performance and eventually need to be cleaned. Secondarily, it can be for getting rid of any moisture in the windings, or in the engine itself. The gas units have the much more common, and faster happening, carb plugging issues to deal with besides.

If your van and generator sit inside a climate controlled storage area, so it doesn't see big swings in temperature and/or humidity, I would totally agree with what Avanti stated. As long as none of the parts see conditions that will cause condensation on them, you are pretty safe, but there are also a lot of conditions that will cause the condensation. Condensation inside the generator will tarnish the slip rings quickly, it appears.

A very common example is if the van sits outside in many parts of the country. If it gets cooler at night and van and generator cool off to a point that is lower than the dewpoint the next day, before the parts warm up, you got condensation. It can be really bad if it sits over snowy areas, that will keep it cold under the van while surrounding areas warmer and carry in moisture in the air. All you need to do is look at any car or other piece of equipment that sat outside for a while over dirt especially. The bottom will always be rustier than the top, even though it wouldn't get wet from rain. When the classic car and muscle car folks take the vehicles to storage for the winter, usually an unheated pole barn, a large % of them put plastic down under the car to prevent moisture coming up and condensing on the undercarriage. Some do it on concrete, also.

When we had a gas Onan, it was always inside in a heated garage, so itdidn't see any condensation conditions, so as long as I had treated fuel in it, I would let it go 3-4 months between runs without worrying. When I sold it after 7 years, I had it hooked up on test to show perspective buyers it ran and made spec, and it actually produced above rated output by about 5%, so the slip rings were in great shape.

If we had a propane genny stored the way ours was, I would not be worried by longer periods of non exercise. If it sat outside here in Minnesota, I would run it every month , except in the nice summer weather.

[BBQ]

.

The problem is not so much in the generator,
but the residue gasoline left in the carburetor.

When the gasoline evaporates,
it leaves behind the wax and varnish,
which gums up the carburetor.

If you periodically add some carburetor cleaner in your fuel,
it will help alleviate the problem.

[Ron J. Moore]

What got me asking was I couldn't locate my RT Manual...now I found them - right where I didn't look!

My gen is 2.8 Gas, Model HGJBB(Spec A) and it takes 0.6L/.63qt/20oz.

Like I said, the '05 RT190 took a quart...and when I read somewhere it was 20ounces, I really got curious. Ron

[avanti]

Originally Posted by BBQ

.

The problem is not so much in the generator,
but the residue gasoline left in the carburetor.

When the gasoline evaporates,
it leaves behind the wax and varnish,
which gums up the carburetor.

Yes, exactly. That is why I exempted gasoline gensets from my comments. I have rebuilt enough old motorcycle carbs to take this seriously. On my bikes (and my snow blower), I always run the carbs dry before long periods of storage. I do not know if there is a practical way to do this with a gasoline genset, but if there is, I would do it religiously.

As for moisture issues, I believe that the concern is largely theoretical more than practical. Yes, of course, moisture in the air can condense on ANY unprotected metal surface. The ferrous components of a genset are no better or worse than any other similar machine in this regard. The question is whether in practice this makes any important difference. Typically, it does not. In most cases a microscopic layer of oxidation forms, which seals the surface from further oxidation. Absent salts or other rust promoters, nothing bad happens and the parts are shiny again after the first couple of revolutions in the spring. Not desirable, but no big deal either. Balancing this is the fact that every time you start the engine, new moisture is drawn into the system, and more is produced by the combustion process. This also is no big deal, unless the user fails to bring the engine fully up to temperature, in which case real damage can be done. With many years of experience with collector cars, motorcycles, small utility engines, and RVs, I have a LOT of data on this topic. I NEVER "exercise" them--I let them sleep through the winter (and sometimes MUCH longer). I have never, ever had an issue, except when I foolishly allowed gasoline to sit for long periods in carbs. Even then, it takes a LONG time to do any damage.

IMO, there are far more constructive ways to use your precious time than digging a path through the snow to run your genset for an hour in the dead of winter.

[booster]

I think the biggest differentiation is copper vs other metals. Copper will build up oxidation thicker and thicker over time. Look at the copper plumbing in your house or the statue of liberty. The oxidation is also non conductive, and moisture greatly increases the speed of the buildup. Even power plants and stationary power system generators have exercise and slip ring maintenance and inspection criteria. How often it is needed in an RV certainly is up for grabs and opinions, but there have been many, many, folks who bought low hour RVs and the low generators in them, that found they needed to be pulled and the slip rings cleaned.

[avanti]

I totally agree that going for years without ever running them is a bad idea. I just believe that "monthly for at least an hour" is bonkers.

[InterBlog]

Ours is a 2500, not 2800, but many of the principles (and challenges) are similar. I changed our oil two days ago. Blog post with pics and a few pointers here, FYI.

[BBQ]

.

Valvoline makes a small hand pump for changing oil in difficult to access places.
The pump fits on the oil bottle.
It costs less than $10.