To Exercise or Not Exercise My Onan ... That is the Question

[avanti]

Originally Posted by RTRanger

It’s your choice to exercise or not.

I agree.

I exercise mine and it starts with just a couple cranks.

That's good. The only problem is that both of mine also started with just a couple of cranks--for a total of 17 years, so...

Hard to prove a negative.

[jjrbus]

Originally Posted by avanti

I agree.



That's good. The only problem is that both of mine also started with just a couple of cranks--for a total of 17 years, so...

Hard to prove a negative.

I have been on internet forums since they started and have seen thousands and upon thousands of posts that start, my generator will not start or starts and runs for a bit and then dies. Unknowing people who do not mention if it cranks or any details all they know is it won't start. Once talked through it they go to the dealer and spend over $1000 up to $2000 to get fixed, so

Then there are the thousands of ones that the electronics were corroded from not being exercised, so

Maybe they were all trolls?

[avanti]

Originally Posted by jjrbus

thousands and upon thousands of posts

Thousands upon thousands? Uh, OK.

[@Michael]

Originally Posted by avanti

Seriously, though, although occasional "exercise" of an Onan genset is a good idea, my experience is that the the whole issue is greatly exaggerated, and the "every month" thing that Onan recommends is mostly CYA. Admittedly, though, my experience has been limited to propane units, so...

Originally Posted by avanti

OTOH, I have LOTS of experience with motorcycles and snow blowers. In those cases, I was always careful to run the engine dry before storage by shutting down the fuel supply, thus presumably emptying the carbs. This has always appeared to be effective, even with long-term storage and crappy gas. I wonder if that is a viable option with gas gensets?

As you've indicated, propane is a completely different beast than gasoline, and lessons learned on propane engines are generally not relevant to gasoline-fired engines.

This winter, after spending days last fall trying to get my gasoline fired Onan to run reliably, pulling and cleaning the carb multiple times, and running for hours on concentrated seafoam-gasoline mix, I decided to run for an hour from seafoam-loaded gasoline, then run the carb dry and leave it until spring. I'll know in a couple of months if that made a difference.

[avanti]

Originally Posted by @Michael

As you've indicated, propane is a completely different beast than gasoline, and lessons learned on propane engines are generally not relevant to gasoline-fired engines.

This winter, after spending days last fall trying to get my gasoline fired Onan to run reliably, pulling and cleaning the carb multiple times, and running for hours on concentrated seafoam-gasoline mix, I decided to run for an hour from seafoam-loaded gasoline, then run the carb dry and leave it until spring. I'll know in a couple of months if that made a difference.

Completely agree.

My experience is that almost all problems with long-term storage of conventional gas small engines are due to shellac buildup due to letting stale gas sit in carbs for long periods of time. You have to get that old gas out at least a few times a year, one way or another. You also need to get the surface oxidation off of the commutator surface of the generator. It is just that it doesn't take two hours/month to accomplish either task.

Let us know how your "run dry" experiment goes. It makes a lot of sense to me.

[booster]

Originally Posted by @Michael

As you've indicated, propane is a completely different beast than gasoline, and lessons learned on propane engines are generally not relevant to gasoline-fired engines.

This winter, after spending days last fall trying to get my gasoline fired Onan to run reliably, pulling and cleaning the carb multiple times, and running for hours on concentrated seafoam-gasoline mix, I decided to run for an hour from seafoam-loaded gasoline, then run the carb dry and leave it until spring. I'll know in a couple of months if that made a difference.

We had the same kind of fits when we first got our van and Onan had allegedly cleaned the carb out so would not surge. Lasted about a week and it was surging again.


We also tried running with Seafoam which helped some, but when I switched to a 20 minute run with seafoam and then sit overnight, repeat, repeat it got better much more quickly. After a half dozen cycles ran well and did right up until we sold it years later.

[jjrbus]

Originally Posted by avanti

Thousands upon thousands? Uh, OK.

Go to the Bus conversion forum, the Onan FB page, the Honda FB page, Toyota RV FB page, The Toyota RV forum, the class B forum, any one of the Roadtrek RV FB pages, the Good Sam community forum and over 20+ years yes thousands upon thousands.

[JonMN]

I do run my Onan 2800i about once a month or so. In the winter I apply a load of about 50% by using the Truma heater on the "1" electrical setting. I'm supposed to move the van anyway to prevent tire flat spots, so I combine the effort.

Just a couple comments: I bought our Beyond in the winter here in Minnesota. So when I tried to start the generator it barely started. Then I discovered the oil was about the consistency of honey. Must have shipped with single grade 30. I follow an oil forum (believe it or not) and changed all of my small engines years ago to Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil. Now my Onan starts no problem all winter.

In MN it's a hassle to track down ethanol free gas so I just quit trying. I add StaBil to any engine (sports car, RV, lawn mower) if it's going to be sitting all winter. Since I started doing this I have not had a carburetor problem in the last 10+ years. (I did have several small engine problems before using StaBil.)

[booster]

Originally Posted by JonMN

I do run my Onan 2800i about once a month or so. In the winter I apply a load of about 50% by using the Truma heater on the "1" electrical setting.

Just a couple comments: I bought our Beyond in the winter here in Minnesota. So when I tried to start the generator it barely started. Then I discovered the oil was about the consistency of honey. Must have shipped with single grade 30. I follow an oil forum (believe it or not) and changed all of my small engines years ago to Shell Rotella T6 Full Synthetic 5W-40 Diesel Engine Oil. Now my Onan starts no problem all winter.

In MN it's a hassle to track down ethanol free gas so I just quit trying. I add StaBil to any engine (sports car, RV, lawn mower) if it's going to be sitting all winter. Since I started doing this I have not had a carburetor problem in the last 10+ years. (I did have several small engine problems before using StaBil.)

Fun in Minnesota, all those warm weather folks just don't know what they are missing.


Be aware that some of the most recent diesel oils are no longer all that good for small engines. It has to do with them now getting zinc reduced for emissions and equipment issues. Rotella used to be the standard go to for getting around the reduced zinc engine oils, but I think at least some of them aren't appropriate any more. Some of the high end synthetic motorcycle oils are very good oils and work well in mulitgrade. I have been using Redline 10w40 in our 17hp Kawasaki powered lawn tractor for years and it doesn't even start to get dirty or darkened in the time that other oils do. Also be aware that Redline makes a general purpose SN rated oil also which is zinc reduced like all of the other SN oils.


For no ethanol fuel take a look at Kwiktrip stations as most them have it. It is 91 or 92 octane premium and is Toptier approved. Holiday also has it at some of it's stations but not nearly as many as Kwiktrip does. Around here (Andover) a Kwiktrip seems to be sprouting up on every other street corner.

[SteveJ]

Originally Posted by booster

For no ethanol fuel take a look at Kwiktrip stations as most them have it. It is 91 or 92 octane premium and is Toptier approved. Holiday also has it at some of it's stations but not nearly as many as Kwiktrip does. Around here (Andover) a Kwiktrip seems to be sprouting up on every other street corner.

Kwiktrip and Holiday are no longer on the Toptier list. BP also vanished some time ago.

https://www.toptiergas.com/gasoline-brands/

[jjrbus]

Originally Posted by RTRanger

Why would Onan know anything about how to maintain a generator?

Their customers told them?

[booster]

Originally Posted by SteveJ

Kwiktrip and Holiday are no longer on the Toptier list. BP also vanished some time ago.

https://www.toptiergas.com/gasoline-brands/

It looks like they got rid of it during covid days because the additives were hard to get and never put it back in. They have nice, easy in and out stations, so that is a shame. Of course there are a lot of naysayers on the internet saying it is all a scam, regardless of the fact the numerous major vehicle manufacturers say it is a necessity for their vehicle and people always love a good conspiracy so believe the anonymous internet troll instead of the lab tested data.


They have not answered my request for information on the topic either, so they must be getting at least some heat about not bringing Toptier back, like they said they would back when they discontinued it.

[JohnnyFry]

Some might disagree with me on this but: exercising the generator accomplishes 3 things: First, running it under load and varying the load insures that new gasoline goes through all portions of the carburetor: Second, Running under load heats up the windings in the generator and drives off any moisture (East coast and Florida, especially): and third, it polishes the slip rings and serves to stop corrosion and subsequent high resistance. High resistance can do in the voltage regulator. That's my 2 cents worth.

[avanti]

Originally Posted by JohnnyFry

Some might disagree with me on this but: exercising the generator accomplishes 3 things: First, running it under load and varying the load insures that new gasoline goes through all portions of the carburetor: Second, Running under load heats up the windings in the generator and drives off any moisture (East coast and Florida, especially): and third, it polishes the slip rings and serves to stop corrosion and subsequent high resistance. High resistance can do in the voltage regulator. That's my 2 cents worth.

All three of your points are correct. However, #1 and #3, though important, take minutes, not hours, and only need to be done a few times per year. Also note that the patina that forms on copper surfaces is actually protective of the underlying metal--the problem only arises when it accumulates to the point that makes starting difficult. Rust on ferrous metals is a different matter, but that isn't involved here, as far as I can see.

#2, though is a double-edged sword: Although running the engine will indeed dry it out, the effect on the windings and external parts of the engine is strictly ephemeral--they will return to ambient humidity in a matter of hours. Moreover, every time you start an engine, it sucks humid air into the carb, cylinder, and exhaust. This is mitigated to some extent by bringing the engine up to full operating temperature, but even so, the last of the moisture after a shutdown is unavoidably trapped in the engine, and whatever doesn't escape will condense forming liquid water. Thus, there is a real cost to frequent starts during storage, and is the reason why you should never start a stored engine without bringing it up to full operating temperature. Even here, though, this takes nowhere near two hours (although running at load may be important for achieving full temperature).

[booster]

My understanding of the darkess that is always found on armatures is more related to the transfer of the graphite from the brushes and is considered a good thing as it is conductive and a lubricant. The oxidation you commonly get on copper, AFAIK is non conductive. I think the is kind of similar to the brake pad transfer layer that is one the brake rotors and is also a good thing except there it is for friction not slip improvement.

[jjrbus]

[IMG][/IMG]

[jjrbus]

Plus maybe another $1200 to remove generator, remove and replace stator and generator. So $2000, might as well buy a new generator.
[IMG][/IMG]

[Sensfan]

Originally Posted by DaveBad

As Booster previously mentioned. "Splicing" in a line is a good option to get a good gas/seafoam mixture directly into the carb/genny. Here's what I did- First I installed a 2-way fuel valve. In position "1" the fuel goes from the vehicles’ fuel tank to the generator as normal. In position "2" the fuel is shut off completely to the generator. In position "3" I have a piece of fuel line that I can drop into a jar of seafom and gas mixture that will now go directly to the carb. I leave the extra fuel line connected but I plug the other end and stow it up in the frame with a tie wrap.
- The valve: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Thanks.
It is logical to conclude that both your and Booster's modification mitigates the known risk associated with burning ethanol gas in a generator. Was your modification very time consuming? My garage will be doing the mod.

[booster]

Originally Posted by Sensfan

Thanks.
It is logical to conclude that both your and Booster's modification mitigates the known risk associated with burning ethanol gas in a generator. Was your modification very time consuming? My garage will be doing the mod.

It is not too bad as many of the parts are available in the marine market for motor tank switching. You can use a barbed two way valve in the hose as mentioned and connect with outboard portable tank quick connect fittings for the temporary tank running off the tap line from the valve.

[Sensfan]

Originally Posted by booster

It is not too bad as many of the parts are available in the marine market for motor tank switching. You can use a barbed two way valve in the hose as mentioned and connect with outboard portable tank quick connect fittings for the temporary tank running off the tap line from the valve.

Thanks.
My Ranger is a 190, similar to yours. How easy or difficult was it to connect the outboard portable tank hose to your 190 Onan, e.g. did you reach under the chassis?