Onan Microlite 4000 generator won't turn over

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ADunnDealRV

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Hello fellow RV'ers..... We have a 2006 Winnebago Minnie Winnie Chalet Class C (31 feet). Our onboard generator (Onan Microlite 4000) with about 2,200 hours on it won't turn over. The local RV mechanic thinks that the engine is seized up due to it running out of oil. The solenoid and starter seem to be fine. What are some resources (i.e. websites, forums, companies, etc.) to search for a new (or preferably used) generator? Or, is it worth trying to rebuild the existing generator?
 
2,200 hours out of an Onan KY 4000 is doing good, I would suggest replacement rather than rebuild at those hours.  As to sources, try craigslist, local junk yards with motorhomes, etc. The  big motorhome junkyards like Colaws, and Visone often have them, but their asking prices are high at around half of retail, I have seen low hour Onan 4000's go for under $900 fairly often on Craigslist and ebay, there are a lot of them out there, finding them is the only challenge.

p.s. being 2006 yours should be a Micro-Quiet 4000 not a Microlite, the major difference being the electronic controller with blink error codes.  For all practical purposes there has been no significant change in the design of the Onan KY generator since the switch to the blink code controller board / Micro-Quiet name in about 2001, the Newer ones will be marked Onan QG4000 and the case will look slightly different, but that change was mainly about bringing the naming inline for all the RV generators with gasoline models being QG, and diesels being QD, not the internal design.
 
If I'm not mistaken, your generator has an auto-cutoff switch for low oil pressure. It's designed to prevent the engine from being damaged by running it with low, or no oil pressure. You might want to verify that the engine has indeed siezed before you go to the expense of replacing it.

Kev
 
The Onan KY 4000's excluding the very earliest models (Spec A) do not have a low oil level switch, Onan found they were problematic, so removed them.  Also they have a splash lubricated not a pressurized oil system
 
Remove enough shrouding that you can access the flywheel and try turning it by hand before you write it off. Maybe the starter has seized or jammed in the ring gear.
 
Roy M said:
Remove enough shrouding that you can access the flywheel and try turning it by hand before you write it off. Maybe the starter has seized or jammed in the ring gear.
Click to expand...

I second this idea.  Turn the fly wheel by hand before doing anything.  If it doesn't turn it could be seized or the starter stuck engaged to the fly wheel.  This happened to me.  Sadly the fix is to remove the generator from the RV take off the cover and start to remove the starter.  When I did this I heard the starter dis-engage the flywheel.  Then I put it all back together.
 
soemtimes with mine it'll bump and then stop... an error code... other times just not turn at all when I hit the starter switch.  I have to press stop, sometimes press and hold it a bit, sometimes repeat a time or two...then I can get it to catch and it turns over like nothing happened and fires up. I think pressing stop serves to reset fault indications.

I've also found that if my house battery is a bit low it'll act like this and if I try the e start switch, or better yet fire up the chassis engine to let the bird connect to the alternator, then the genny is more happy.

Doesn't seem right to me but it's been that was since new, I just wonder if some of these reports we see posted all the time about them not turning over might be similar.

Have you tried something like this with the stop switch?...and are you sure your battery has a good charge?
 
It seems to me that this kind of no start happens on a low battery.  For me it happened while the RV was in storage.  I went to check on it and figured I will start the generator to exercise it, it was hot, and to charge the battery.

What I learned was that the battery has enough juice to engage the generator starter to the fly wheel but not enough to turn the fly wheel, and the starter gets stuck.  I replaced the solenoid, still same problem.  I brought it to a retired Onan guy who did work on the side.  He reached back to flywheel and tried to turn it.  No go, told me the starter was jammed and how to fix it.  He quoted a price and I said I would do it myself.  Paid him $20 for his time (5 minutes).

I created a new rule, for myself.  Start the chassis engine first to suppy 12v+ to everything, and as stated above the genny is much happier.  Never had a problem since. 

While camping if we lose power I start the genny once I verify it is a campground/area wide problem and not a temp outage.  The batteries are still fresh and it starts right up.  Had this happen while work camping in Washington state during fires nearby, and in Texas during a snow storm.
 
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