I have read about Outboard engines. Including the results of tests run by Mercury Outboards. And heard of other small (lawn mower type) engine issues.
Here is my experience
IN June 2014 I drove to GA for the birth of my grandson (#1 Grandchild) A month and a birth later I left, Intending to fill up when I got to a gas station......... The engine blew due to oil issues caused by a road hazard (insurance paid)
I estimated the amount of fuel in the tank and added Seafoam
IN March of this year (3 years later) I called the tow truck... IN the interm I did run the Genrator roughly once a month for the requisite 1/2 hour or more under load. (Usually more) and I had to add Gasoline from time to time since I only had a half tank at Blewie.
But The ONLY generator issue turned out to be a stuck choke and pre-dates Blewie. (Found about it 3 weeks ago when I had the oil changed. FIrst time I PAID to have it changed and he spotted the stuck chock been sticking for years.. Works, just takes a bit to open)
Main engine... We got the 2005 engine out and lifted in an 2004 with a few 2005 parts attached.
Took 3 tries to start (Not unexpected) and very loud valve clatter (likewise) and one other noise I could not hear over the valve caltter
Found the other noise and fixed it (2nd fire up)
Fired it up to confirm fixed and PURRRRRRRRR
Has been PURRRRRRR ever sincem, save when it's ROAR (And an 8.1 can really ROAR under load)
Side story: Old man parked long term in the RF park where I was broke down.. He was went to hospital and then to extended care and the word is not returning to RV... Family called and ask it be moved to storage. Batteries FLAT and I mean FLAT, might as well not even be there. Between myself and two helpers we got the slides in, And the Park owner got a new chassis battery.. I installed it and he ask me to move it. This rig has not moved in at least 5 years.
Fired right up. Just like showroom, Drove nicely.. Oh yes there were a few "long term parked" issues (One jack did not want to retract had to help it up) but no fuel related issues.
Again though it's the 8.1 Workhorse Did not try the generator.