Reply To: Newer Yamaha 50 HP 4-stroke question

[David Stanton]

He uses 10% ethanol fuel because that is what’s available near his house. When winter comes, he adds a can of Seafoam to his 20 gallon boat tank, which is vented to the atmosphere like most all boat tanks, but he doesn’t add any other stabilizer. I’m amazed this has worked for him in unheated storage in Minnesota. I would expect some phase separation when the temp drops. Maybe the Seafoam somehow keeps the ethanol from absorbing humidity from the air like Stabil-Marine does?

Dave