Start up your mower, and let it run until it no longer starts back up, and the fuel lines are empty. [substeps] Keeping fuel inside the mower is also a fire hazard.
[header] How to store a lawn mower [title] Run your mower out of fuel. [step] Condensation inside the fuel tank can seriously damage the mower's engine: if moisture develops, it can cause corrosion, clogs, and other problems. Having an empty tank before your mower is put into storage lowers the risk of condensation forming.