Onan MicroLite 2.5 LP series L

it has a low oil level sensor. I bought a toy hauler that had a 2800 gas gen it did the same thing. Oil level was good but when it got hot the oil was so thin it thought it was out of oil. Changed the oil and all was well. When I drained it the oil was as thin as gas. The oil was either old or the wrong wgt. Kept it for a few yrs and sold it. Never had another problem. Sold it to a friend who had it for another 5 yrs and it was still running good. I change the oil every spring no matter how many hrs are on it. Just a guess.

Have you disconnected the low oil pressure sensor wire? Onan oil sensor is usually open circuit when OK.

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Rebel1 wrote:
Hello! Newbie needs help! Does anyone have a copy of the SERVICE manual for a Onan MicroLite 2.5 KV, LP (propane) Series L generator that I can download? I have a problem that after running 20 minutes the generator loses spark for a second or two and the generator hesitates, backfires and sometimes will die. Doesn't matter if it is under load, or not. The Onan dealer thinks it may be the ignition controller or an intermittent low oil sensor. I would like to do the diagnoses myself but do not have wiring diagrams, module testing procedures, etc.
Thank You!

This?
2500 / 2800 Onan service manual

If yours is a Spec L. You don't have a low oil sensor. They stopped using them on Spec K models. Can you post the full model and serial number.

The model number is 2.5KVFA26120L and the serial number is G050807230.

marcsbigfoo20b27: Thanks for the link but it doesn't really show tests to check the coil, mag or controller. I'm not sure the wiring diagrams are the same for the 2.5 LP, spec L since mine may not have the oil level sensor. I sure do appreciate the response.
Any one have any ideas?
Thanks

Okay, I've checked the grounds and cleaned them. Pulled the wire off the small spade terminal at the coil and checked it and cleaned it. Seems fine with good tension. I replaced the spark plug yesterday with an original plug from Cummins/Onan dealer. I pulled the 12 terminal plug apart that goes to (I think) the voltage regulator. It looked fine but spread the terminals slightly to increase tension. It has been running for 20 minutes and started the same old thing. It's like it gets hot and losses ignition for a second and then picks it up and will run for a few minutes before it does it again. Sometimes it will cut out and backfire and then MAY die.
ANY ideas? I hate to just start throwing parts at it and the Cummins/Onan dealer doesn't have a clue. They want me to pull the entire unit out and bring it to them. Plus they are a hundred miles away. I would really like to figure this out.
Thanks

Take a look at this one. 981-0518E
981-0518E kv service manual

Did a little snooping your looking for diagram 610-0388 it is in 981-0518E service manual says begin spec f.
981-0238 issue 21 kv parts manual
There's a table in the parts manual that tells the wiring diagram you need.

Thanks for the replies and the manuals. I'll do more pinpoint tests next week.