When your lawn mower sits for 4-6 months, that is a question that comes to mind before you pour what could be bad gas into your lawn mower.
Today’s gasoline begins to deteriorate in 90 days and its condition only worsens from there. If you put fuel stabilizer in the gasoline, then it will be good for us to 5 years! Gasoline is expensive, so you don’t want to waste it.
To test your gasoline, you can smell it first and if it has a sour odor to it, more than likely it is bad. You can also pour a small sample into a glass jar. If it doesn’t appear to be very clear with a slight yellowish tint, then it is going bad. As gasoline ages, it begins to turn darker in color. Sitting in a carburetor, it will begin to evaporate and leave a crusty residue behind that will plug up the idle and main jets of that carburetor.
If your gas can doesn’t have a cap on the nozzle, it can also attract moisture because of the ethanol in the gas. Ethanol is a form of alcohol and that will pull the moisture and be absorbed into the gasoline. This is why it is so important for the use of fuel stabilizers today.