A petrol lawn mower comes in handy. With it you can effortlessly reach every piece of the lawn without dragging an annoying cable. Sometime in late autumn, the last round of the mooring is due. After that, the lawn hardly grows and the lawnmower is allowed to take a break. At his winter storage location, he shouldn’t take any petrol leftovers in the tank. Why is that and how do we get it completely empty? In this guide you will learn how to properly drain the gasoline from a lawn mower.

Gasoline is a chemical mixture. It can react with substances that are in its immediate vicinity. For example with the oxygen in the tank. This changes it and with it its quality. From a chemical point of view, the following reactions take place – unnoticed by our eyes:

·        Light hydrocarbons volatilize

·        Other ingredients oxidize with oxygen

·        As a result, they clump together

·        So-called oxidation inhibitors cannot stop the process entirely

·        The component ethanol absorbs moisture from the environment

·        From a certain degree of saturation it sinks to the bottom of the tank

·        There it has a strong rust-promoting effect

how to clean a lawn mower gas tank

The time factor determines how the chemical processes affect the typical properties of gasoline.

Note: The petrol tank should not only be empty over the winter. This also applies to any mowing break that lasts longer than four weeks. It doesn’t matter what time of year it is.

Adverse effects

We will feel the effects of the chemical processes listed above in the spring of the following year at the latest. The grass has grown quite a bit, and the first mowing of the year is due. But the large walk behind mower just won’t start. The gasoline has lost its ignitability. This cannot be restored with such a modified fuel. The hastily refilled “fresh” gasoline will not bring the expected result. The newly created mixture still does not have sufficient ignitability. After all, the “deficient” gasoline is still in the lawnmower’s tank.

The rust formation in the tank will also become noticeable at some point. Even if not immediately in the following year.

Why empty the tank?

With an empty tank in winter, chemical reactions and thus starting difficulties in spring should be completely prevented. The free space in a tank that is not full is filled with air. In turn, there is oxygen in the air, with which the fuel enters into a chemical reaction. As soon as oxygen is withdrawn from the amount of air in the tank, this imbalance is balanced out again by the ambient air. This keeps the chemical process going. There is enough time until spring to make the petrol unusable. A half full tank is therefore not a good idea in the long run.

how to clean a lawn mower gas tank

Dangers when emptying

The improper and careless handling of gasoline poses some health risks for people. These are based on the rising gasoline vapors. They can easily be inhaled into the lungs and cause damage there. All sorts of instructions for emptying the tank are circulating on the Internet that virtually conjure up these dangers.

In particular, steer clear of tips if you have to suck in fuel by mouth. Also draining gasoline into buckets, bowls, etc. is not advisable. All too easily these can be knocked over. The liquid would seep into the ground, spreading its toxic fumes. More suitable emptying methods are described in more detail below.

Instructions for the most convenient variant

Start the engine and let the petrol of the best lawn mower idle until all the fuel is used up. This method cannot be called environmentally friendly. But compared to the exhaust gases that come out of the exhausts of cars every day, the amount is small. They can also help ensure that the idle lasts only for a short time. At the end of the mowing season, only add small amounts of fuel, if necessary.

how to clean a lawn mower gas tank

Instructions for a suction pump

You can also drain the gasoline using a special oil suction pump. It sucks in the fuel liquid, and gravity takes over the continued flow. Such pumps are available in different designs. The cheapest copy costs around 10 euros. It can be used multiple times. Below are the instructions for draining gasoline from a lawn mower with such a pump.

1.     Read the instructions for use from the pump manufacturer. Handling can vary from model to model. In addition to pumps that can be operated manually, there are also fully automatic pumps.

2.     Obtain a large enough gasoline can.

3.     First, clean the petrol lawn mower from grass and earth debris. This prevents the pump from becoming dirty. When doing this, follow the manufacturer’s instructions so that the lawn mower cannot start unexpectedly and injure you.

4.     Move the lawn mower to a location that is convenient for draining.

5.     Place the lawn mower in an elevated position. The petrol tank should be higher than the petrol can, otherwise the fuel will not flow out. How you bring about this increase is the same? However, it should be strong enough to support the weight of the lawn mower.

6.     Open the cap on the petrol tank and the petrol can.

7.     Insert one end of the hose deep enough into the tank. The other end into the open gasoline can. Warning: this must not happen indiscriminately. Make sure beforehand which hose end goes where.

8.     Start the suction mechanism.

9.     Wait for the fuel to drain from the petrol lawn mower.

10. First pull the hose out of the lawn mower. Hold it up so that it is completely emptied into the petrol can.

11. Close the gas tank and gas can tightly.

Fill up instead of emptying?

The purpose of draining gasoline from a lawn mower is to prevent its chemical change. With the aim that the petrol lawn mower starts up again in the spring without any problems. Just like emptying, filling the tank should also be able to do this. When the entire volume of the tank is filled with gasoline, there is no more room for oxygen. This means that oxidation processes are not possible. That sounds plausible so far. This is why this method is also recommended by some manufacturers. In addition, a commercially available fuel stabilizer should be used.

Read what the manufacturer of your lawn mower recommends in the owner’s manual or on their website. There is no harm in sticking to it.

how to clean a lawn mower gas tank

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Riding Mower offers expert mowing tips and tricks for keeping your garden or yard healthy. Find out the reviews, comparisons, and buying guides for all kinds of electric, gas, or riding lawn mowers.

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