How to Drain Gas from a Briggs & Stratton Lawnmower, the best three methods


It’s the start of the season, and you take your winterized Briggs & Stratton lawnmower out. If you notice your engine not starting after not using it for an extended time, it’s a high possibility that the fuel stored in it has gone stale. As a result, deposits have formed inside the carburetor, and the engine doesn’t produce enough power. The solution to this is to drain the old fuel completely from your lawnmower, clean the carburetor and add fresh gas. Besides bad fuel, there can be other reasons you need to drain the tank’s gas. This blog post helps you with some of the best and easiest methods to drain the gas from a Briggs & Stratton lawnmower.

How to drain gas from a Briggs and Stratton lawnmower, the best three methods:

  • Method 1: Use a siphon pump to empty the fuel tank. The pump’s top hose goes into the tank, whereas the bottom hose carries fuel to a storage container.
  • Method 2: Disconnect the fuel line leading to the carburetor and collect the fuel coming out of it until the tank is emptied.
  • Method 3: For lighter walk-behind mowers, the machine can be tilted with the air filter upwards to catch the tank’s fuel.
How to Drain Gas from a Briggs & Stratton Lawnmower, the best three methods 1

For almost all small engines, gasoline is used as fuel. The gasoline quality doesn’t remain the same over time. It generally degrades, thus forming deposits. Typically, gasoline compounds react with oxygen to form sticky residues that can clog your filters and jets. As a result, the fuel isn’t able to reach the engine for combustion to initiate. To solve this problem, you need to replenish the gasoline in the tank.

This article will look into the above-mentioned methods in more detail.

The best ways to drain gas from a Briggs and Stratton lawnmower:

There are several ways to remove gas from your Briggs and Stratton lawnmower. We shall explore these methods one by one.

● Equipment needed:

It’s always better to know what tools you would need before starting any repair work. Luckily, this task doesn’t need sophisticated equipment. If you choose the siphon pump method, you need one, of course. Additionally, you need a pair of nose pliers, a screwdriver, a rag to catch spills, and a plastic container/bottle for this job. Before you start, park the Briggs and Stratton lawnmower at a location that can deal with some gas spillage.

● Method 1: Using a siphon pump:

A siphon pump is the cleanest and easiest way of removing bad gasoline from the Briggs and Stratton fuel tank. It can be used on both riding lawnmowers and walk-behind lawnmowers. You can purchase a siphon pump quite easily by visiting a car parts store for as low as 10$.

– For riding lawnmowers:

In riding Briggs and Stratton lawnmowers, the gas tank is situated just underneath the seat or under the hood. For some models, you might need to lift the seat to access the fuel cap.

  • Step 1: To drain the fuel, open the cap and insert the siphon pump’s top hose to fully immersed into the tank. For your information, a siphon pump comes with two hoses. The top one is inserted from where the fuel has to be drained. In contrast, the bottom hose carries the drained fuel into a secondary container.
  • Step 2: Manage any plastic cylinder or a plastic bottle to store the gasoline removed from the tank. Avoid using any metal can since the flow of gas can induce static charge, which may produce a spark in the presence of metal.
  • Step 3: Pump the siphon with your hand to draw the gasoline from the tank and transfer it into the plastic container. Remove any kinks or curls in the siphon hose to allow easy drainage. Keep pumping the gas until the fuel tank is empty.

– For walk-behind lawnmowers:

For walk-behind Briggs and Stratton lawnmowers, the methodology is entirely the same except that the gas tank is easier to find as it is present on the top. Remove its cap and insert the siphon hose to drain the fuel.

● Method 2: Disconnecting the fuel line:

If a siphon pump isn’t available, you can disconnect the fuel line. This method is somewhat more complex but is still quite convenient to drain the Briggs and Stratton fuel tank. It can be applied to both riding and walk-behind lawnmowers.

– Riding lawnmowers:

In riding lawnmowers, the first thing you need to do is locate the fuel line that transports the fuel from the tank into the carburetor.

Step 1: To access the carburetor, you might need to lift the mower hood and detach the air filter assembly. This might seem not very easy, but once you gain access to the carburetor, it’s just a matter of a few minutes to drain the fuel entirely.

Step 2: Once the Briggs and Stratton carburetor is visible, locate the fuel line that carries the tank’s fuel. You need to use a pair of nose pliers to squeeze the hose and remove it from the connector’s hold. Or you can loosen the connector with a screwdriver.

Step 3: When the hose is detached, fuel starts coming out of it. You need to arrange an open container to catch the fuel coming from the tank. Lower the hose downwards and allow all the fuel to be drained entirely into the container. Keep doing this until the tank has been emptied.

– Walk-behind lawnmowers:

This procedure is comparatively easy in Briggs and Stratton walk-behind mowers as the fuel line is normally visible from the outside. Furthermore, the mower deck acts as a fuel-catching container and can catch gas spills.

Before draining the fuel, don’t forget to clean the fuel lines from dirt with a rag.

● Method 3: Tilting the mower over:

The last method sounds easy but is often more challenging than you think. It can better be performed with two people. It is limited to walk-behind Briggs and Stratton mowers as they can be tilted easily. Before starting, make sure you follow the steps below:

  • Step 1: Before tilting, make sure that the spark plug wire is disconnected so that there is no risk of your Briggs and Stratton engine starting accidentally. Also, take care that the air filter assembly needs be pointing upwards when tilting the mower. This step is done so that the engine oil does not flow into the fuel tank.
  • Step 2: Arrange a plastic container to catch the fuel and place it under the fuel cap. Open the fuel cap and allow the fuel to be entirely drained into the container.
  • Step 3: Once the container is empty, dispose of the fuel removed and close the fuel cap. Reconnect the spark plug wire.

● Additional Steps:

Note that whatever method you follow for draining the fuel, there are some additional steps that you should follow for completely removing the fuel remnants from your mower.

– Run the engine for a while:

After the Briggs and Stratton fuel tank is empty, some fuel might still be left in the carburetor and fuel lines. To empty this leftover fuel, start your lawnmower engine and allow it to run for a while. When the engine has stopped after some time, your device is devoid of any fuel now.

– Clean the carburetor:

When removing old fuel, it is always good to clean the carburetor from old fuel deposits. To do this, open the bowl nut of your carburetor and remove both the nut and bowl. Spray some carburetor cleaner liquid on the nut, which is the main jet, to dislodge any debris. Also, clean the bowl and spray some cleaner inside the carburetor. This guarantees a smooth Briggs and Stratton engine performance once you start it after fresh fuel addition.

Related Questions:

1. What is the best lawnmower gas?

The best gas for a lawnmower is the one with the following characteristics:

  • It should be fresh and clean.
  • If you are working at high altitudes, you should have at least an octane number of 87.
  • 10 percent of ethanol or up to 15 percent of MTBE
  • A canned fuel option such as Briggs & Stratton Advanced Formula Ethanol-Free Fuel can also be used.

2.  Should I be using a fuel stabilizer?

A fuel stabilizer is a way to safeguard the gas in the lawnmower. It is generally made from petroleum products and is combined with gasoline to prevent evaporation. This prevents the gasoline from forming sticky deposits stuck in the carburetor and can restrict the flow.

Fuel stabilizers are not recommended for the daily use of vehicles. However, it is highly recommended for seasonal equipment such as lawnmowers to use a fuel stabilizer to avoid gasoline evaporation.

3. Can you clean a lawnmower fuel filter?

Cleaning a fuel filter occasionally prevents deposits in the carburetor and guarantees a smooth engine operation. To clean the fuel filter, detach the fuel line leaving the fuel tank for the carburetor. The filter is present in this fuel line.

After removing the filter, clean it using a solvent cleaner. Let it dry for some time and reinstall it back into the fuel line. Note that your fuel tank should be emptied while doing this, and fresh addition of fuel should be carried out.

Final Remarks:

The gasoline drainage should be carried out in an environment isolated from electrical connections, sparks, or even smoke. Since gasoline is highly combustible, you should be proactive in this regard. Try doing this in your driveaway away from electrical cables. Moreover, If the fuel in your Briggs and Stratton gas tank is stale, dump it appropriately by taking it to an auto parts dealer. It is advised that you should always add a fuel stabilizer to your gas tank to preserve its quality for longer intervals.

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