I bought one off eBay for my Onan 4000. About $40 and it works perfect, way easier than doing the clean. I keep the one Onan carb though.
I never use amazon site bc they are the devil, but eBay has everything, and any online store or site will probably be the same stuff.
Agree with all about ethanol gas, ethanol is the devil too.
Run the last minutes off 100% gas or at least use a fuel stabilizer in the ethanol gas, and always leave carb empty for storage. You can starve the running gen of gas and that will get enough out typically, or you can drain the carb somehow after engine cools off.