Maintaining your generator

2800 MicroLite by Onan
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skater
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Posts: 2569
Joined: Thu Mar 08, 2007 1:00 am
B190 Year: 1991
WBCCI: 13270
Location: Annapolis, MD

Maintaining your generator

Post by skater »

Our Onan 2.8 generators are pretty good generators, made by the same company that makes huge industrial generators for large buildings. They should last a long time, but they have to be taken care of. You don't want to have to replace it-they run about $2100-and they're the only model that fits in the box (trust me, I looked).

I'm no expert on generators, but since my original generator died, I've learned a few things:

* The manual recommends you run the generator for at least four hours (continuously) each month, with a load. Turn on the A/C, or in the winter, turn on the heat strip if you have it, all the lights, fans, etc.
* When you're shutting the generator down, allow it to run a couple minutes to cool off; don't shut it down while it's at maximum load (and throttle). Doing so will make it hard to start again.
* The generator does not run very well when it's severely off level, and it seems to be more sensitive to side-to-side variations than front to back. I've actually had the new generator stall while climbing long hills on the road.
* Many people recommend using the generator and running the rooftop A/C instead of using the engine's A/C, especially if you're towing, so that the engine's power is available for moving the camper. I think it depends on what you're doing - if you're not towing anything and you're sitting in the front, then the engine A/C would be fine. I travel with my cat, so I want it cool in the camper even when I'm inside a restaurant eating lunch, so I use the generator to run the rooftop A/C. Plus my engine's A/C doesn't work. :)
* The air conditioner on the roof of our B190s is actually smaller than the generator can start and run. We have an 11,000 BTU A/C, but the generator can handle a 13,500 BTU A/C. The generator's manual states it can start and run a 13,500 BTU A/C plus an 800 watt base load. So, you might as well run the fridge on 110 volt while you're on the road if you're going to have the generator running the rooftop A/C anyway. (At 110 volt, the fridge will do better at getting and staying cold than it will at 12 volt; the 12 volt mode is intended for maintaining the temperature only. Don't use the gas mode while you're on the road.)
* If your generator is running strangely, get it looked at before it dies. It's likely they'll be able to diagnose the problem better and tell you what it'll cost to fix. For example, my original generator was surging at idle, but I ignored the problem. When it died, the service shops that looked at it both said I'd spend several hundred dollars getting it out of the camper, then it could be as much as $1000 to fix it. If it'd still been running (even poorly) they might have been able to figure out what the issue was and give me a better estimate on fixing it without removing it from the camper. In my case, it didn't make sense to dump $1000 into a 16-year-old generator that I could replace for $2000.
* Changing the oil - I haven't actually done this yet, but: Airstream didn't give us a way to drain the oil out of the generator short of removing it from the box (be careful if you try - it weighs 113 lbs, so be ready for that if you do remove it!). I think a better idea is to remove the old oil using a turkey baster. Probably not recommended by Onan, but what are you going to do? (Update 8/9/08: The turkey baster doesn't work - the angle is all wrong.) One member of the B190 mailing list said that someone had used a hole saw to drill a hole in the bottom of the access compartment to allow them to change the oil - but of course to do that you have to take it out once.
* The hour meter in the panel of my '91 doesn't work with the new generator.

Here are some useful links for the Onan Microlite 2800:

* Service Manual
* Onan's website
* Fact sheet from Onan for the Microlite 2800 (PDF format)
1991 Airstream B190 - bought, 2005; sold, 2011; bought 2017
1995 Airstream Excella 30' trailer

WBCCI #13270, Washington, DC Unit
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