Onanistic Gas Generator

[Kencan18]

My Onan Gas Generator runs fine for about 5-10 minutes after start up then shuts off and won't restart. After a period of time it will restart and do the same thing? Any suggestions?
Ken

[allegro1x]

Have you checked the oil level? Can either have to much or not enough. Dave

[Jamie65]

Change both fuel filters, the one inside the Gen and the extra inline filter between the Gen and fuel feed line. Pull out the gen and crawl underneath the RV and follow the fuel line from the Gen back and look for the extra add on in line filter that is usually there. Generac replacement from NAPA or most other auto parts stores. Primary NAPA 3031, Secondary NAPA 3063. Then push the prime button on the Gen panel a few times to purge the air out of the lines.

[gorwig]

It may be a partially clogged carb. When the generator first starts, the choke is partially closed to provide a rich fuel mixture. As the generator engine warms up, the choke opens. If the carb is partially clogged up with fuel gum deposits the mixture becomes too lean. Usually you will hear a backfire or two. This slows the generator and the throttle opens to compensate. The open throttle makes the lean condition much worse and the engine dies.

Since it still starts when cold you might be able to run carb cleaner through the fuel line to clean out the gum deposits. The trick is to get the carb cleaner into the fuel line! This can be dangerous work because often times the fuel line is "down hill" from the main gas tank and disconnecting the fuel line will result in a gush of gasoline. I know from experience with my previous motorhome.

Also, my Onan (maybe all gas Onans) had a sealed carb and no repair kits are available. I finally had to replace the carb and that fixed the problem.

Now I put fuel stabilizer in the main tank any time I fill it before storage and I run that generator every month to get some fresh fuel through the carb.