If the lawnmower has no shut off valve on the line, consider installing one, otherwise drain the tank and run the engine until it uses all the before storing. At of the lawn mower season if your lawmnower has a shut-off valve on the line, turn off the valve and run the engine until it quits. This assure all the is used up in the carburetor before storing. Also use a shut off valve as a safety feature during the season when storing equipment in a garage or storage building between mowings. It helps with leaks due to a bad needle valve or leaking carburetor., Weight: 0.32187490252 Pounds, Manufacturer: tiyao