wnjj wrote:
Maybe in a carburetor where there are small quantities exposed to air but completely not an issue in a large fuel tank that is before the filter anyway.
I rope started a snowmobile that had 5 year old gas in it. Just added some fresh after it started and all was well.
Surprised you use ethanol gasoline in your snowmobile.
One of the reasons people put STA-BIL in fuel is varnish build up. I’ve experienced it.
https://www.goldeagle.com/product/sta-bil-fuel-stabilizer/ is what they say about it. Of course, they sell a product, so you may/may not believe them.
I don’t know if your 5 year old fuel had STA-BIL, ethanol, or either.