bardo said:as someone who rebuilds 20-30 carbs a week, sometimes ones sitting for years, the ethanol stuff is mostly a myth. Rust and plain old gunk 99% of the time. When you do get the green bowl of death you actually find less dirt/grime but sometimes what looks like lime scale.
Sorry, no.
The rust you see is because ethanol fuel is hygroscopic.
Vented gasoline fuel tanks allow air in, and the moisture is absorbed into the fuel, and the volatiles evaporate too, thickening the fuel. Where do you think that rust and gunk (sludge) is coming from?
Why would you even have to rebuild 20-30 a week if the poor grade, stagnant fuel was not plugging them up?
The resulting sludge and rust plugs up the small jets in the carburetors of small engines.
Not myth. Fact.