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.
done that with a 2003 merc 90 2 stroke and a 2012 Yammi 70 4 stroke stored in unheated garage
so far that's been working for me
but have read reporting to the opposite, like was mention earlier, that also works
common denominator seems to be proper deployment of additives
reason I do the fill method is to mitigate water in the fuel tank from condensation ...
the Yammi has an additional fuel/water separating filter, which has to help, especially with ethanol fuels... that I avoid