Onan micro lite 4000 stalls under load

[Biggyniner]

Hey everyone,

Picked up a new to me 94 minnie winnie in really good shape. The Genet will start up and usually idle pretty well, however when a big load is placed on it (a/c micro etc) it starts running very very rough and sometimes stalls.

Any tips? Was planning on doing a standard tune up, Genet has 75 hours on it.

[Biggyniner]

jvkaveman wrote:
This happened to me as well and I just replaced the carb with a new one. Ebay is a good place to find one a little cheaper. It is important to use fuel stabilizer in your last tank of fuel for the year before storing the RV and then run that fuel through the generator to help prevent this problem. It could also help to put an inline fuel shut off valve on the fuel line to the generator so you can run the carb dry prior to storage as well. Today's gasoline is really bad and damages all small engine carb's if you are not using a quality fuel stabilizer. Running the carb's dry is the best prevention you can do.

This is a great idea, and there is a valve. Like I said this is a new to me rig so I will definitely up the maintenance game since I own it now and I am a maintenance freak..

[jvkaveman]

This happened to me as well and I just replaced the carb with a new one. Ebay is a good place to find one a little cheaper. It is important to use fuel stabilizer in your last tank of fuel for the year before storing the RV and then run that fuel through the generator to help prevent this problem. It could also help to put an inline fuel shut off valve on the fuel line to the generator so you can run the carb dry prior to storage as well. Today's gasoline is really bad and damages all small engine carb's if you are not using a quality fuel stabilizer. Running the carb's dry is the best prevention you can do.

[mlts22]

Seafoam is definitely cheaper than 200-300 bones for a new carb. Wish the newer Onan carbs were rebuildable. Onan would make a mint selling rebuild kits.

[quingus]

X2 on the seafoam. I put three bottles in my tank and run the genny everyday under load for one hour. This is two weeks out from my trip at the end of this week. She runs nicey nice. No high/low surge, no stall when initial A/C load is activated. BTW I got that info from the folks here. It's nice to be able to assist other folks with questions like the ones I have. Hope that hells. BTW I dump that product in engine, tranny and fuel tank any chance I get. Put a little in my coffee, really helps with the hard starts and joints. Cheers.

[Biggyniner]

darsben wrote:
The usual reason is a gummed up carb. Seafoam will usually cure it
If it is an ONAN a troubleshooting guide is at;
http://www.flightsystems.com/pdf/onan-rv-troubleshooing-guide.pdf

Boom.. so I ran some b12 Chem tool carb cleaner through it and she's running mostly great under load now... cuts out very intermittently under load but sooooooo much better.

Thanks for thay tip.

[darsben]

The usual reason is a gummed up carb. Seafoam will usually cure it
If it is an ONAN a troubleshooting guide is at;
http://www.flightsystems.com/pdf/onan-rv-troubleshooing-guide.pdf