Hmmm-

Use Diesel?

Maybe 87 octane?

Alcohol?

ORRR-

The solution to pollution is....



Dilution.

Use the garden hose?

I had 10 year old gas that wasn't jelled. But I'm in AZ. Maybe 10 gals each tank.
First I PUMPED them out. Fk siphoning.
Added 5 gals fresh.
Pumped it to the right tank, then back to the left. then right, then left again.
CHANGED both spin on fuel filters .
Finally put the spent 5 gals. in my dually, (carb'd 454) and filled it full, both boat and dually.

Dually ran like chit on that tank. 3-5 mpg instead of the usual 9.

Boat ran fine.

Dan'l