Champion 4000 Running 5000 Starting Watts Generators

Paid 500 per generator over 2 yrs don't know how to repair these or where to start but they did work then they didn't want to crank up so I drained oil out of most of them and put it in the shed 250 for 3 of these maybe the other 2 can be used for parts to fix one or you can fix all 3 and charge 250 a piece for them my lost your gain 500 for all 6 or 250 for 3 need gone need my truck fixed and travel money please be serious about buying and picking them up they come with 2 or 3yr factory warranty and one has a extended warranty but trying to get tractor supply or the ppl to fix them is a joke so here I am every 6 to 8 months I'm buying another due to needing it for camper they do have rv plug 30 and 50 amp as of may they are still available I have at least 8 gens champion and 1 Westinghouse they came with 3 yr manufacture warranty’s some should still have them and 1 I bought the extended warranty which you can’t use until the 3yrs are up