Let fuel sit in a carb bowl for five days -- very hard start

You should feel lucky that you have a petcock! On my Honda, I have to manually drain the carb after running it. Not a big deal, but not effortless, either. Some clever folks have installed aftermarket petcocks on their Hondas. I have thought about doing that, but I have enough trouble just looking after my pet dog. ;)

My 2KW Honda would sometimes be hard to start after sitting for three or four months in my garage. Then I started keeping it secured in the tailgate corner of my covered truck bed and it now starts on first or second pull of the cord. I guess the constant sloshing around of the fuel keeps all the crud cleaned up somewhat...

I too keep some Seafoam in my 5-gallon gas tank for the mowers and portable genset...

Roy Ken

gas siting for five daysnot the problem but thats just my opinion, gas sits in my boats ,three motors for weeks at a time and fire right up.

Not sure which generator you are having issues with but our Onan has been 100% problem free, even has the original fuel filter although I have a couple of spares. I use the cheapest gas I can find as with all my motorized equipment (including vehicles) and have never run any of them dry. Both my onboard Onan and Champion 3100 inverter genny are just turned off and on as needed, never a carb issue with the Onan going on 10 years using 85/86 octane ethanol gas. I know many have had issues using such gas, my experience indicates this isn't related to just cheap fuel.

For the Onan I always add a bit of Stabil when refueling and maybe couple times a year a can of Seafoam. With the Champion since the fuel tank is pretty small I don't add Stabil but I do add a small amount of Seafoam to the 5 gallon gas can I use. Our rig goes pretty much unused for 4 months during the winter season and never an issue with the old stale gas, just prime the Onan for 30 seconds and she cranks up fine. In fact that reminds me to go out there and give her a little exercise while I'm thinking about it. Hope whatever is plaguing your genny is minor.

I have a 1996 Southwind with the original Onan 5500 generator.
It does not have a peacock to shut off the fuel.

I run the generator every 4-6 weeks under a load. It always starts without a problem. I don't think it is necessary to install a shut of on the fuel line.

If this were my unit (an Onan 4000) I know from experience it would be because the choke was stuck in full open.