Do you empty the fuel line on your outboard

[Piotr]

I suspect that it is not the evaporation of ethanol because that would solve your problem. The problem with ethanol is that it absorbs water from the atmosphere. The more ethanol in the bowl the more water, and water is the one that reacts with the aluminum in the bowl.

Ditto

 

[shemandr]

And, if you have an oil injected 2 stroke outboard (Not a sailboat), can you disconnect the fuel line. Or would that cause the oil injection system to go kabooli.

 

[Doc_holiday]

I have a mercury 9.9 2 stroke and I always pull the fuel lime off, partly to clear the car and partly because someone stole my stop button. (Its a remote control motor but the remote is gone)