It is not so much the ethanol...we all want to place the blame there, but it's not the root cause of the problems. I see this stuff day in and day out. Most people know about 'ethanol problems' and most have compensated by buying 'non ethanol' fuel.
The government doesn't require fuel to be labeled 10% ethanol until it's 7% or more. IIRC if the content is below 5%, it can be labeled non ethanol. Not that it makes much difference.
The fuel itself...even without ethanol...has changed over the last 10 years or so. I'm seeing older stuff with shrunken o-rings, diaphragms, fuel lines falling apart, all the normal problems that are usually blamed on ethanol...but the problem is, those people that have those problems are telling me that they have been using non-ethanol fuel?
OE manufacturers have dealt with this stuff...at least Yamaha has. Their old fuel lines are NLA, if you replace a line, you get the new part number, which is about $100, but it does not get hard or deteriorate. I have one of the first ones and it's as soft today as it was when I bought it I think in 2007 or 8. The bulbs don't get hard. I replaced the lines from the motor connector to the fuel pump, and from the pump to the carb, and the new ones are of a different material. The bowl gasket is also a different material, and so are the pump diaphragm and gaskets. I don't know if Sierra and the others have changed their materials to cope with new fuel blends or not. That's all I have dealt with is Yamaha.
If there is absolutely no fuel in the carb, lines, and pump, then there is nothing to worry about, unless the lines are already old and starting to dry crack from the inside.
