Emptying Gas from your Lawn Mower

The following is a recommendation from the Conservation Committee on how to dispose gas from your lawn mower.

With the leaves changing colors, it is time, almost, to put the gas-powered lawn mowers to rest for another winter. Prior to storing the lawn mower, it is a good idea to remove the remaining fuel from the fuel tank and dispose of it properly. Old gas will form “varnish” and other organic compounds that over time will clog the fuel filter and valves in the engines of modern mowers. There are a few ways to remove the fuel from the tank.

The time-honored method of our ancestors for performing this task is to turn on the lawn mower and let it run until the gas is spent, essentially, burning off the gas and in the process taking a good deal of time while generating a lot of toxic fumes. Emissions from this process are a nuisance to neighbors and generally awful for the environment, with an impact many times greater than that of an idling vehicle. Fortunately, alternatives exist that consume less time, are less expensive, and are more environmentally friendly. One way to remove the gas is to use either a hose to siphon off the gas or a baster/pipette to remove the gas from the lawn mower gas tank to a gas can. Alternatively, the fuel line connecting the fuel tank to the carburetor can be disconnected at the carburetor and fuel emptied into a gas can.

The choice of which method to use could depend on the design of the mower’s fuel system. On some mowers with Briggs and Stratton engines, the carburetor sits on and connects directly to the fuel tank. Since there is no fuel line, the gas should be removed from the tank using a siphon or baster. Honda mowers have fuel lines, which, when disconnected, can be used to drain the fuel tank.

By next spring, the gas will be too old to be used in the lawn mower. So, following removal from the fuel tank, gas should be disposed of properly. This also goes for gas left over in the gas storage tank. There are several ways to dispose of gas:

  • Since most modern lawn mowers have 4-stroke engines, the unused gas can be added to a car’s gas tank or other gas-powered engines gas tank, for example, a snow ( shiver !) blower. Oil may have to be added to the gas at the proper ratio for 2-stroke engines.
  • The gas can be taken to the appropriate gas recycling location. Milwaukee Metropolitan
  • Sewerage District (MMSD) has such a facility. MMSD also has a mobile disposal unit that appears at different locations in Milwaukee County on a monthly basis during Spring-Fall.

Similarly, gas from other gas-powered yard equipment (e.g. snow blowers) can be disposed of in the same manner.

Better Yet, Ditch Your Mower . . .

If all of this is just too much fuss, just get rid of the gas mower and go electric. The technology for battery-powered and corded mowers has improved considerably over the years. These mowers are quiet, odor free, and cut just as well as traditional gas-powered powers. Since most Shorewood yards are on the small side anyway, many neighbors have long relied on people-powered reel mowers. It’s good exercise, emissions free, and will free you of all the seasonal maintenance worries and inputs of engine-based lawn equipment.