[JimD]

The stabilizer is mainly to absorb moisture in alchohol. That occurs immediately so I would add it even though you will burn the gas soon.

It is not worth the risk but I have let gas go all winter in my boat tank with stabilizer and without. I prefer to use it but sometimes I forget or get lazy. I just use the pink stuff they sell at Walmart and auto parts stores. Either with or without I have not had problems. But 2 cycle boat motors are pretty simple burning oil in their gas so they may be less sensitve than modern car engines. I never put stabil in the lawn mower but it's motor is even simpler.

Jim