How To Drain Gas From Your Lawn Mower (And Why You Should)

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Ethanol blended gasoline can cause a lot of problems for people as they pull their lawn mowers from storage in the spring. The problems arise after parking a mower after its last use in the fall, then neglecting to perform any end-of-season maintenance. This task could be as easy as adding a fuel stabilizer to your engine by pouring in the correct amount for the size of your gas tank, topping it off with fresh gasoline, and allowing the engine to run for a few minutes to circulate the treated fuel throughout the system, particularly the carburetor.

However, if you didn't know or forgot, and now your lawn mower won't start, won't idle, or runs terribly, then you should drain the gas from your lawn mower and start with a fresh tank of gasoline. Long term storage of your lawn mower (more than the winter months) or the need to store it inside or under the same roof as your living space are other reasons you may need to drain the gas from your lawn mower.

Draining the gas from your lawn mower is a simple DIY task, but you'll need to do it in an area with adequate ventilation, such as outside or in a garage with the doors open at the very least. In addition to a cheap mechanic tool set, you'll want to purchase a fuel transfer pump, like this portable battery powered version from Amazon priced at $29.99. The alternatives include sucking on a hose to siphon the gas from the tank, which we strongly do not recommend, turning your mower upside down to pour gasoline out of the tank, or removing the fuel supply line from the carburetor and letting it drain, slowly.

Once the gas tank is empty, if you're trying to clear out last year's gasoline, you'll have to remove the fuel supply line from the bottom of the carburetor to drain it if you haven't already. If you're simply draining the gas to store your mower you can leave the supply line attached, or re-attach it, and start the mower, letting it run until it runs out of gas, ensuring that all the fuel is removed from the system. If you're trying to recover from last year's stale fuel, reconnect the fuel supply line and put some fresh gas, along with a fuel additive, like Sea Foam, in the tank.

If it starts, let it run until the engine is warm. If it runs smoothly, congratulations, if not, it may need to sit with the treated fuel for a few hours or overnight, or it may need the carburetor disassembled and cleaned out.