Onan generators are picky. We have a POS Micolite 2.8 in the Class C and one in pieces in a shed. I am not a fan of Onan. Level has nothing to do with it. You most likely have either too much oil or too little oil. Or the sensor is off. If the truck is "level enough to sleep in " (meaning that if you had a bed in there, you wouldn't fall out of the bed) then it's fine with the generator.
You can't have too much oil in them or they won't run right.
You can't have too little oil in them or they won't run right
You can use parts by other companies or they won't run right.
You can't use the "wrong" manufacturers oil or they won't run right. Did you use "ONAN" oil? If not, that could be your problem... or you have too much oil. Microlite 2.8KW
Choose Operators Manual to download a PDF file. should be a trouble shooting section in the back of the manual. I have two different manuals. One is an Install & the other is an Operators. I end up going thru both when trying to figure out problems. I think I ordered mine from Onan.
post edited by lornaschinske - 2012/06/09 13:34:01