Pappy's right! I see them all the time at work, and usually the same deal-cut it open and it's falling apart inside.
Those silver lines are what? $35? An OE Yamaha line is closer to $80 last time I looked.
You get what you pay for. For certain, the newer Yamaha fuel lines are top notch! They stay flexible, they don't fall apart inside, the bulb doesn't harden up, and the sunshine doesn't affect them NEARLY as much as them silver jubilee's. I haven't seen a better line (yet).
About 90% of the time when I tell a customer that their line is junk, they just go buy another one. They're usually back in a couple years (or less) as well.
As far as I know, Ethanol has nothing to do with the line and it's durability. Unless the line in question does not meet EPA low-permeation requirements, which wouldn't' surprise me especially if it says "made in China" on it, or the package that it comes in. Even then, I wouldn't say ethanol is THE culprit. We forget to remember that Ethanol in itself isn't the problem, it's the fuel itself that's the problem. Gasoline has been blended differently in the last decade and even ethanol free fuels will cause issues. Fuel can be labeled "no ethanol" if the content is below I think 3%. Fuel is labeled "up to 10% ethanol" if the Ethanol content is 7%-10%. The window between I think 3% and 7% doesn't have to be labeled anything. And it still might have some E content. How do ya know? Buy yourself a test strip kit. I bought one a while back and tested a bunch of different gas stations, the ones that were selling "no ethanol" fuels were typically 1-3%, sometimes greater. There was only ONE station that was under 2%, and the owner said he specifically asked the distributor not to blend the Ethanol into his gasoline. He was an independent full service station owner who also was part owner of the distributor. Y'all might want to research the laws about this, I may be off a little on the percentages as I'm going off of my not-so-great memory.
Or next time you have to get a new fuel line, get one of the Yamaha lines and put your own ends on it.