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Narflack · 05-13-2015, 07:38 AM

Had problems last year which required replacement of carburetor and control board. Was running fine but quit and wont restart. Fuel pump is working and have spark. Prime, attempt to start and hits maybe once or twice but wont run. No flashing code lights on switch after attempting to start just blinking while cranking.

Any advice appreciated.

okcnewbie · 05-13-2015, 01:46 PM

Flight systems has a good troubleshooting chart on their website; Onan Generator Voltage Regulator and Control Board Parts

Have you been running the genset with a load for an hour or so a month?

The folks over at Smokstak might be able to help as well.

Good luck!

DD788Snipe · 05-14-2015, 07:24 PM

Voltage regulator possibly. Happened to mine several years ago and wiped out the stator. Cost to repair was $1200. That's was 12 years ago and I was fontunate I new someone who only charged me $100 labor and $1100 for parts. Reason not excerising the unit monthly.

Narflack · 07-07-2015, 06:12 PM

I'm back. Problem still exists looking for more advice. Took RV to Northside RV in Lexington Ky, big mistake don't go there I can explain if interested. At any rate was told after initial "diagnosis" at cost of $140.00 unit would have to be remove with 3 to 7 hours of labor??? To determine if control unit was bad. I replaced it last year in less than an hour as well as carburetor and fuel filter with generator still mounted in unit. Anyone have any suggestions or recommendation for reputable generator mechanic in Lexington area?

IdahoSRT10 · 07-07-2015, 06:23 PM

Do an Onan 4000 search... Also please fill out your profile stats so we can help you diagnose the problem.
I'm thinking you need to add a 'push fuel pump' right after your main fuel tank. This fuel pump cured my issues. http://www.summitracing.com/parts/atx-e8012s/overview/

note: I replaced the OEM fuel pump and it ran for 8 hours in the heat then stopped. I have 73 hours on my gen.

mgscott4 · 07-08-2015, 06:05 AM

Do a quick test first, Get a few feet of fuel line and some starting fluid and your lawnmower gas can. drop the fuel line into the gas can and connect it directly to to the fuel pump. Remove the air cleaner and squirt starting fluid into the carb. See if it starts.

If it doesn't start it is not a fuel problem. I would start looking something electrical.

If it only starts for a few seconds you have a fuel pump or filter or carb problem.

If it starts and runs on your fuel can, the problem is toward your fuel tank.

Narflack · 07-08-2015, 06:09 AM

Thanks to both. It doesn't start at all, turns over fine I don't get any flashing code lights either as I did when circuit board was bad

mgscott4 · 07-08-2015, 06:14 AM

Use the switch at the generator and push down to prime and listen for the fuel pump to turn on. you should hear it. Prime for 5-10 seconds.

Just because the prime light comes on, does not necessarily mean it is priming, you need to actually hear the pump come on.

Waiter21 · 07-08-2015, 07:00 AM

OkcNewbie. Thats a good document you refereed to. I downloaded it, printed it, and stuck it in my books. Keep in mind, not all the discussion applies to the KY series. This document will turn anyone into a Onan Expert. (almost)

I also have a 4000 Microlite (KY).

I've never had problems with mine, but have read through most of the posts (in case I ever do) and also read thru the FlightSystems document.

There is a good troubleshooting section and it has pinouts of the controller boards for the various Onan generators.

George Schweikle · 07-08-2015, 07:09 AM

We also had a lot of trouble with a 1999 Onan Microlite 4000. First, went to Northside RV in Lexington, then to the Cummins Onan service center in Louisville. Some satsfaction in both locations, then more trouble during a trip to Canada. Cummins Onan in Michigan replaced a solid state spark box, and the thing worked until we got home. I then got a diagnostic scheme from Generator Parts, Generac, Onan, Kohler, Hotstart, Dynagen, Dinosaur, Newage, Leroy, Basler and a shorted stator / rotor seemed likely. At this point, dealer repair cost was close enough to a new generator that I just bought a new Microlite. It was cheaper to do this through Northside than drive the motorhome to Louisville.

Bottom line: I'm pretty happy with Northside for parts, but Onan in Louisville has better technicians.

Here's an example of how difficult things can be: after returning to Louisville the second time after waiting for parts, the genny began acting up, not running, etc. The tech tried and tried, and finally suggested considering a new genny since this one was eating money at a fast rate. I went in the MH for a while, then heard the generator running properly. Me: "What did you do?". Tech: "I can't say". Me: "I gotta know". Well, I had put in a new spark plug, and the tech put in another new plug. Then, after the third spark plug, the thing ran!. What's the likelhood of two consecutive spark plugs going bad?. To their credit, Onan took a lot of diagnostic hours off of my bill.

If Honda ever starts making generators for installation in Motorhomes, Onan might be in trouble.

Quote:

Originally Posted by Narflack

I'm back. Problem still exists looking for more advice. Took RV to Northside RV in Lexington Ky, big mistake don't go there I can explain if interested. At any rate was told after initial "diagnosis" at cost of $140.00 unit would have to be remove with 3 to 7 hours of labor??? To determine if control unit was bad. I replaced it last year in less than an hour as well as carburetor and fuel filter with generator still mounted in unit. Anyone have any suggestions or recommendation for reputable generator mechanic in Lexington area?