Did you know your fuel can become stale within 30 days of being pumped?? It could even be sooner if it wasn't fresh when it was pumped.
There are a few ways to tell if your fuel has gone stale. When starting your engine, if it sputters, dies or refuses to catch, then your fuel may be stale. However, this may also be caused from a worn out spark plug.
A better way would be to take a sample of your fuel in a clear glass and compare it to a freshly pumped sample. You will notice the older fuel will be darker, however this is caused by oxidation which occurs after fuel has been pumped. If there is any sediment at the bottom of the glass, or you see water separation, then you have bad fuel.
Once your fuel has turned bad, you will need to drain the fuel tank, clean the tank and start fresh. You may also need to clean your carburetor as the old fuel may have gummed and clogged up.
For additional storage tips for the winter months, please follow the link: https://www.smallenginewarehouse.com.au/blogs/tips/winter-storage-tips-for-your-lawn-mower
It is also important to use a fuel stabilizer or treatment year round to keep your fuel fresh and protect your engine. The fuel stabilizer can be added to your gas at the pump when you fill up.