To fill or not to fill?
I always winterize my own boat and use the pink Stabil stabilizer. I used to fill my tank full believe in then there is less room for condensation. For the pat few years, I have filled my tank before my last outing, stabilized that gas, used what ever amount of gas that I used typically abotu 1/2 tank, then fill it up in the spring before I go out. Have not had any issues either way.
By the way I used 87 Octane gas with Ethanol in my motor.
1997 60hp Mariner. Owned it since '01.
Bottom line: Avoid the ethanol gas if you can.....in everything!
On another boat I own that does not get used much I opted to go with the run it down put in additive then fresh gas in the spring. This boat has not run quite right all season and is currently in the shop getting the injectors cleaned and gas drained.
Moral of the story is I will be winterizing with with premium on my guide boat and I will be only running premium in the boat that does not get used as much. I am also now storing all my mowers, ice augers and other engines that do not get used as much with premium to prevent any issues with bad gas.