[Roadsters] What is in todays fuel that makes everything gum up?

[David Boerst]

I don't call todays fuel gasoline. When I grew up gasoline was copper/gold in color. The only thing todays fuel has in common with the color is the price. My 1600 and Amy's 1966 1600 keep gumming up choke piston wise. Is there any treatment/additive or polishing of piston to make the choke system stop from sticking?