100% or Ethanol Gas?

Just wondering what kind of gas you all run? I have been running 100% in my '68 Johnson and was wondering if the Ethanol would ruin it or not? I'd hate to run something through it and have to replace it later on...

The ethanol will eat your gaskets and fuel lines on that older motor....... so continue running ethanol free fuel. In a pinch you could run ethanol fuel through it but if you continue to do it then expect to replace fuel lines, gaskets and also you will be cleaning the carburetor to get the fuel line debri out of it.

How well does the marine sta-bil ethanol treatment work? Will running "up-to" 10% ethanol fuel with stabil be safe if ethanol-free is not available?

Unfortunately I don't have access to 100% I have always run the 10% with stabil. I run it in everything from saws, dirtbike, atv, boat, haven't had any issues. But I religiously use stabil

Newer motors and equipment handle ethanol better. So if you have to run the 10% E and your motor is pre 2000 or so then I would highly advise replacing all fuel lines and using a stabil. I believe 2005 is when they made some crap *** mandate to start using ethanol more widely?

I try to always use 100% and still run a hefty dose of Sta-Bil. Ethanol does a lot of crapy things in gas. It will eat your lines. It will clean any deposits out of your old gas tanks and run it into your motor. And it will a chemical reaction with any water in the bottom of your tank (even tiny amouts from condensation) called Phase Separation - https://fuelschool.blogspot.com/2009/02/phase-separation-in-ethanol-blended.html. Essentally you will end up running the water through you motor - which we all know is bad.