How to drain gas from a lawnmower without a siphon, step by step


When packing the mower at the end of the season, it is good to vacant the mower gas tank. EIt inhibits sediment formation and clogging in the fuel system. It also prevents any major issues like rusting or leaking in the lines. Moreover, keep in mind that the fuel is also present inside the carburetor and the fuel lines. If your lawnmower refuses to start after it has not been used for some time, bad gasoline may be the cause. Preferable empty the gas tank before winterizing, and check the tank’s condition regularly. In case you don’t have a siphon pump to suck out the fuel, don’t worry as we take you through the steps to drain the tank using simple tools at home.

How to drain gas from lawnmower without siphon, step by step:

  • Step 1: Collect the required tools
  • Step 2: Park your mower and disconnect the spark plug
  • Step 3: Set the plastic tubes/hoses properly
  • Step 4: Drain the gas tank
  • Step 5: Disconnect the connections with the carburetor and open the drain tube if any
  • Step 6: Run the mower for a while

For a lot of lawnmowers, gas provides power to the engine. Suppose you notice problems starting or sputtering after the winter season old or bad gas will probably the cause. That is why you should not leave the lawnmower unused for an extended time with fuel in its tank. Draining gas is not a difficult job. It should take you around 30 minutes. This blog will explain how to drain gas from a lawnmower without a siphon with just some simple tubes and generate a pressure difference.

Step-by-step Guide

Draining gas from your lawnmower tank without using a siphon basically consists out of two parts. A good connection between fuel in the tank and an outside collecting can. And a pressure that pushes the fuel through the tube to the collection can. The following steps describe the entire procedure.

● Step 1: Collect the required tools

The first tool you need for draining gas is a gas resisted drain container. You can use a drain pan if you do not have an empty can. The drain pan is a small metal pan with raised edges to collect the old gas and handle it. Next, you will need a drain tube. It would be best if you had two simple plastic tubes/hoses, which can be found at many stores that sell lawnmower supplies. Also, have some cloth (rag/towel) at hand.

● Step 2: Park your mower and disconnect the spark plug

Park the mower on a flat stable location. Use the parking brakes to stop it from moving. As a safety step, it is good to disconnect the spark plug cables. That will ensure that the engine does not unintentionally start. Turn the ignition off and open the fuel cap.

● Step 3: Set all plastic tubes/hoses properly.

Without a siphon, you will need 2 pieces of plastic tubing/hose. They should preferably be transparent. Ensure that the length is enough to reach the gas tank from the container, the other one can be shorter. Place the empty drain container next to the gas tank of the mower on the ground. Ensure that the empty can collecting the gas is lower than the gas tank’s bottom for perfect siphoning to happen. Feed the longer tube or hose deep enough into the mower gas tank such that it is submerged entirely in the petrol. The is best if it reaches the lowest part of the tank. You can get a feel that the tube is touching the tank base.

Next, place the opposite end of the longer tube into the drain can. Place the shorter hose some inches into the gas tank such that the two tubes lay side-by-side.  However, the shorter tube should not touch the fuel inside the tank. Its purpose is mainly to develop an air channel between the tank and the atmosphere.

After that, the next step is to seal the fuel cap through which the tubes were inserted. The aim is that air flows inside only through the shorter tube. This will help develop an air pressure gradient that pushes out the liquid fuel. You can use a piece of an old wet rag or towel to seal the connection. The wet cloth is used as it sticks properly and better closes the inlet.

● Step 4: Drain the gas tank properly.

Now you are all set up for the draining task. You need to develop a propulsive force to thrust the liquid fuel out. On the open end of the shorter tube, blow hard to push air in the tank. If you have access to an air pump or compressor, the task becomes even easier. Use it to blow air in the tank, but make sure that you cover the tank opening with some cloth. Make sure that you do not inhale any fuel fumes while blowing in the tank. You will notice that fuel starts coming out of the tank from the other tube after some blows. When the flow gets continuous, you can stop blowing. Gravity and pressure difference do the rest. Almost all the gasoline will be drained out.

Pro-Tip: If you want to stop the draining at any stage, raise the container or the hose to a level higher than the gas level in the tank.

● Step 5: Disconnect the connections with the carburetor and open the drain tube if any

To remove the remaining fuel from the mower, you have two options. Drain it from the carburetor, or run the mower until it has used all the fuel (so step 5 or 6).

To drain the carburetor’s gas, detach the fuel line connecting the carburetor and the fuel tank. Some fuel always resides in it. Let it drain out in a drain pan placed beneath the tank. Some lawnmowers have a drain tube present at the tank’s base, while some mowers have the tube connecting it with the carburetor as a drain plug. You can also remove the fuel by opening it and letting the fuel drip into a pan placed beneath.

● Step 6: Run a lawnmower to get rid of any left gasoline.

Now, take out the tubes from the opening and close the tank. Close the can as well because gasoline is very volatile. Preserve it for later use. You will notice that there is always a small quantity of fuel left in the tank. If you are storing the mower for a more extended period, like the winter, it is still a good idea to empty the gas tank. Reattach the spark plug and turn the ignition on. Take the lawnmower outside and run the engine until it runs out of gas and dies out. You will now have fully drained all the gas.

Additional concerns:

Always keep in mind some preventive measures.

1. Work in a Ventilated area: Never use a lawnmower in a closed environment. The carbon monoxide gas, which resides in exhaust fumes, is odorless, colorless but poisonous, toxic, and can cause detrimental health issues. Ideally, it is suggested to run a lawnmower outdoors when you are doing its testing. Suppose you start the lawnmower in a garage or workshop. In that case, it must only be operated for a short duration of time, and you should ensure proper ventilation while performing any function.

2. Keep away any ignition source: You should always remove all sources that can give a spark and ignition away when dealing with gas. Something as minor as cigarette ash can ignite the fuel. It can get very dangerous depending on the amount of fuel you are dealing with.

Frequently asked questions:

1. How frequently do I need to drain the gas from my lawnmower?

As a rule of thumb, you should drain the riding lawnmower gas before storing it for a period longer than around two months. A more extended time with gas in the tank can lead to bad gas and will give problems starting. Another solution to keep the gas ok for such a time is using a fuel stabilizer. You add it to the gas, and there is no need to drain it when you store it for an extended period.

2. What if I inhale the gasoline fumes?

Gasoline is a volatile fuel, so it will always have fumes. When blowing into the tubes, avoid inhaling the petrol smell. In case you do inhale it, there is no big worry as it is not life-threatening. If you have difficulty in breathing, go out and breathe some fresh air.

3. Can I use the drained fuel?

Yes, you can reuse the fuel. But keep in mind that storing it for an extended time will make the gas bad. Your lawnmower should use some fresh gas or add fuel stabilizers to the gas you have drained. This will help the engine to keep running smooth and optimal. Of course, you can use the drained fuel for other purposes.

Final remarks:

All lawnmower owners have to store their mowers when the cutting season ends. Also, if their machines require tuning, they will always come across the problem of siphoning the gas out of the mower tank. If you do not have a siphon pump on you, you need a pair of tubes, a can, and a piece of cloth, along with some technical knowledge. This article has given you the step-by-step procedure to easily drain the gas tank without any siphon pump for the most common lawnmowers, including John Deere lawnmowers, Honda lawnmowers, and Briggs and Stratton lawnmowers.

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