Puddin' Man wrote:
I got this container of STA-BIL, maybe 6 years old, ...
....
I don't necessarily trust this stuff, but ...

Would you use it for small 4-stroke motors, 3-4 mos. winter storage?
....

Hardly worth the bother imo. For that short a time period unless it's
in a hot location (which wouldn't seem likely for winter storage ),
the loss of volatility in gasoline wouldn't be sufficient to matter much
if the container is tightly closed.

In my 60+ years I've never had an issue w/ any engine over the winter
simply closing the fuel line and running them dry so carb doesn't sit
full and leaving tank as is. Spring use a little fresh to refill carb
and they're fine.

As others said, highly unlikely it would hurt anything, probably would
have some effect but it really isn't of much need ime certainly for less
than 6-months.

--