The need for carb replacement is 99.99999% due to old stale cheap gasoline that has sat in the carb bowl way too long, corroding the nozzle & jets.
Just for giggles, if by chance you had the avgas 100LL in it, the fuel lasts years instead of weeks.
Not suggesting using avgas 100LL, but the point is, use a high octane level gasoline, it lasts so much longer and the engine runs so much better.
Being an Onan dealer for the past 40 years, have seen many who try to out smart the system, they loose every time. Why carbs are a big seller.
Gasoline today is not the same as it was even 20 yrs ago.