Continual running of Onan microquiet 4000

i made an exhaust stack, similar to the genturi. works fine. 1 ft above roof line. All fan and AC on roof only expel air from RV. No smell to neighbors. CO2 units in RV regardless

One of the guys here, Handbasket I think, points out that a lot of the value in Monthly Exercise is to keep moisture from permeating the winding laminations in the generator end of the genset. A dry climate would help avoid that issue.
I can easily see where a microquiet could hang around a long time, just not a lot of hours on an extended basis.

The other couple we travel with have a poorly maintained 20 year old Onan 4K in their Class C that still starts up and runs fine. They do not have a bunch of hours on it - just short runs here and there down though the years.

I'm not sure exactly what the magic formula is for long life on a 3600 RPM splash-lubrication single cylinder Onan RV generator. Maybe the RV spending it's life in CA away from brutal winters is somehow the key?

I've gone over 1200 hours on my Yamaha in less than two years. Other than the issue of neglect which will kill any generator dead (even LP gas ones will have windings corrode), if reasonably maintained, I've not read about any major Onan horror stories.

MicroQuiet/MicroLite have 3600-RPM, single-cylinder, splash-lubed engines. This is a far cry from the pressure-lubed, twin-cylinder, 1800-RPM engines in other ONAN's like Emerald Series, and all the famous ONAN utility engines in welders, skid steers etc. etc. I don't want to say "Cheap" which I really don't think is true. They're better than that, but I don't think they have the pedigree to be called "Iconic."
I doubt many of us will ever wear one out in RV use.
Clean fuel, Clean Air Filter properly installed (can't breathe in dust), Clean OIL kept full and changed regularly.
And, make sure it hasn't sucked in things like grass clippings and bug nests in the air cooling passages.

Schooner wrote:
I asked a Onan guy once what the reasonable life of the 4K Microlite was and he said about 1200 hours.

That sounds a little low as a design target lifetime for them.

Assuming one maintains them correctly, I would hope it would be more like 12000 hours ... considering what those Onans cost new.

I asked a Onan guy once what the reasonable life of the 4K Microlite was and he said about 1200 hours.

I've run them for days at a time and had 750 hours on one.

I agree with the comments about CO detectors and checking the oil enough to get a idea of how often to shut it down. Mine used to trip the propane detector sometimes when I opened the roof vent. Never had a problem at neutral pressure.

Be aware of dry grass or such near the unit.

mlts22 wrote:
I wonder how useful a Gen-Turi would be as an alternative. One wouldn't want to have air sucked in from top, but instead, the generator's exhaust ends up being dispersed from a much higher point so it can't build up.

You still run the risk of exhaust creeping up into the RV from an exhaust leak. Also, the Genturi isn't a sealed system.

Pressurizing the RV from a fresh air source is a very good idea.

There are some better (than what RVs come with) CO detectors out there that actually will show CO levels. I put one in my RV to supplement the OE unit. ProTech is one brand.

I wonder how useful a Gen-Turi would be as an alternative. One wouldn't want to have air sucked in from top, but instead, the generator's exhaust ends up being dispersed from a much higher point so it can't build up.

With regards to running a built-in Onan RV generator for long time periods ... so far we've only run ours for about a 6 hour stretch in order to sleep in high-humidity heat. Whenever doing long run times like this we maintain air pressure inside the RV to ensure that no fumes can enter anywhere near the bottom 98% of the motorhome's structure.

We maintain air pressure in the RV's entire interior by closing EVERY opening except one. We then keep only the roof vent with the reversible variable speed fan in it open. We turn the fan to "air in" and turn it on it's lowest speed setting. Using just a very little air from way up high on the roof, the fan then pushes against the motorhome's interior air volume to maintain some pressure everywhere inside. This prevents any generator fumes from entering anywhere below the roof line.

P.S. We also use the same technique above to keep all dust out of the interior when traveling on unpaved dusty dirt/gravel roads in our Class C.

Everything I've read says Onan RV generators are engineered and built to run continuously in "any" outside ambient temperatures. Most of the noise from the Onan in our Class C is in fact due to the rushing air sound from it's tremendous cooling air flow. We have no fears in running our Onan as much as necessary to provide full 120 AC power if needed for long time periods. We camp some in the desert and use the Onan as necessary to provide great comfort during high outside temperatures.

For what the Onan generators cost, they HAD BETTER be pretty much indestructible if you maintain them. ;)