I do stabilize fuel for the winter, but then come spring I generally empty it out anyway and stick it in my truck, lol! And ya know, it never looks very good. I was using Seafoam and this year I'm using something called k100MG.Really? I have several carbureted bikes and have not noticed a problem. Have to put stabil in them when leaving them over winter, but otherwise no worries at all.
But, yeah, when I got my Sprint, my ex500 was ignored just a few weeks, and guess what? Gunk in the carbs, lol!
And when I went to do the major service on my Sprint, I hadn't ridden it for maybe 2.5 weeks due to high heat and that gas looked like crap already. And I bought it from a busy gas station in Toledo.
I think some areas of our country have better gas than others. It never used to be a big deal to let my tractors and what not sit over the winter, but now it is.
I worked on some carbs a few months ago for another member here that had already been "cleaned" at a bike shop for a cost of $300, but the guy who worked on them didn't do a very good job. There was gunk in the passage from the pilot screws to the pilot jets, and rust in the float bowls from before that member had lined the gas tank. It was like he didn't even take the float bowls off and look at them.
I've done a lot of lawn mowers and snow blowers this year for people as well as bikes.