Originally Posted by wayne and sherry
Anyone know what oil and filter the generator should use. I want to change the oil and filter in it next weekend
LOL I guess you can hijack your own thread.
Onan 4000's come with 15w-40 from the factory. You can use other grades depending on the ambient temps you run your genset at. Since I run only in the summer, I use a straight 30w. Use only API certified oil.(Starburst)
Oil filter: You got no stinking oil filter.
It takes about 1.5 Qts. 100hrs between changes. I do about 75 cause it runs hot. You will need a T-30 bit to get the cover plate (green) off. I think the drain plug is 7/16". Refil SLOWLY or you will spill. Have a rag under the fill spout in the pan.