Here’s Why Your Briggs & Stratton Engine Won’t Start

You’ve checked to make sure there is plenty of gas in your lawnmower, but for some reason it still isn’t running. Extreme lethargy, to the point where I worried it was dying, characterizes its behavior.

When the fuel filter is clogged, the fuel line is clogged, the fuel pump is broken, the carburetor is dirty, or the gas cap is broken, a Briggs and Stratton engine isn’t getting gas and won’t start.

Working with the fuel system requires extreme care. Take care to ensure that the space you are working in has adequate ventilation. Wear protective equipment such as goggles and gloves, and disconnect the spark plug wire, before beginning maintenance.

Briggs, Stratton Engine
Briggs, Stratton Engine

Before diagnosing, repairing, or operating, make sure you’ve read and understood all of the safety instructions in the equipment’s operator’s manual. If you lack the knowledge, experience, or physical ability to complete the repair safely, you should seek the advice of a professional.

A Briggs and Stratton Engine Is Not Getting Fuel Because of These 6 Common Problems

Briggs and Stratton Lawn Mower Leaking Old Gas

The fuel in your Briggs and Stratton mower should always be fresh. You should use the gas you buy within 30 days, as after that point it may begin to degrade.

In some cases, using old fuel can prevent the engine from starting altogether. Varnish and gummy deposits left behind by old gas can restrict fuel flow and shorten the lifespan of components.

To mitigate the long-term damage caused by depleted fuel reserves. If you want to keep your new fuel from going bad, you can use an additive like Sea Foam or STA-BIL.

SOLUTION: When this happens, the fuel tank must be drained into a safe container. Put in new gas that has a fuel additive like Sea Foam to clean the fuel and dry it out.

Find out why adding Sea Foam to your fuel is a good idea.

Fuel Filter Clogged on a Briggs and Stratton Lawnmower

It is recommended that the fuel filter be changed once a year as preventative maintenance. The fuel filter can become clogged if it is not replaced regularly, reducing the fuel flow.

SOLUTION: Use a new Briggs and Stratton fuel filter to unclog the old one. Take note of the arrow imprinted on the plastic housing’s side. This arrow indicates the proper orientation of the filter during installation, which is in the fuel flow direction.

Briggs and Stratton Lawnmower Fuel Lines Get Clogged

If dirt or old fuel have made their way into the fuel system, they may have left behind gummy deposits that have the potential to clog the fuel lines. Because of these obstructions, fuel flow to the Briggs and Stratton may be reduced or the line may become completely blocked.

SOLUTION: Checking the fuel flow in a small section of the line using the fuel shut-off valve or pinch-off pliers.

Locate the blockage in the fuel line and clear it:

  • To halt fuel flow, use the fuel shut-off valve or pinch-off pliers.
  • Take out the fuel line’s end that is farthest from the tank and set it aside. If you want the fuel to drain away from the tank, set the container lower than the tank.
  • Turn on the gas again.
  • If fuel is not flowing freely into the storage tank, the limitation in the fuel line must be fixed. To do this, disconnect the fuel line from your mower and shut off the fuel valve.
  • Use carburetor cleaner sprayed into the hose and compressed air to clear the line. Keep trying until the fuel line is free of obstructions.
  • Replace the mower’s gas line.
  • If the fuel line cannot be cleared to allow unrestricted fuel flow, a new fuel line must be installed. If the fuel line is dry and has cracks, you should replace it before it leaks.

Briggs and Stratton Lawnmower Fuel Pump Failure

When the fuel tank is lower than the carburetor, a plastic or metal fuel pump will be installed on the lawn mower. By drawing pressure from the engine’s crankcase, a vacuum fuel pump creates a vacuum in the fuel tank. The fuel is forced upward into the carburetor by this pressure.

Fuel pumps need to be replaced when they develop cracks, become damaged, or begin leaking.

SOLUTION: If the fuel pump is not visibly broken or leaking, it is time to perform some diagnostics to make sure it is functioning properly.

Verify fuel flow to the pump to ensure it is receiving fuel and is thus able to function. It’s possible that you looked for blockages in the fuel lines in the previous step, in which case you can skip this one.

Once you’ve confirmed a healthy flow into the fuel pump’s inlet port, you can disconnect the fuel line from the carburetor and set it aside.

Turn on the mower and listen for the sound of fuel dripping or pulsing into the storage tank. You should replace the fuel pump if the flow rate is low.

If the fuel pump is broken or not producing fuel pressure, you should replace it.

Briggs and Stratton Lawnmower with a Filthy Carburetor

The carburetor controls how much air and fuel are mixed together and injected into the cylinder. The carburetor on your engine is attached to the top or side of the block. It’s typically situated either beneath or behind the air filter.

Your Briggs and Stratton engine may not get fuel if the carburetor is dirty, which can clog or jam the fuel jet.

SOLUTION: Spritz some carburetor cleaner into the intake air after removing the air filter. Get the car going to see if it still runs. Your lawnmower’s carburetor may need to be removed, disassembled, and cleaned if it starts but then dies.

Read this article for detailed steps on how to clean the carburetor on your lawn mower.

Broken Gas Cap for Briggs and Stratton

The fuel cap provides this necessary venting for the gas tank. When the fuel cap vent stops working, the tank becomes pressurized. Because of the vacuum, fuel won’t be able to reach the engine.

SOLUTION: Run the mower with and without the fuel cap to determine if you have a faulty fuel cap.

If the engine starts and runs smoothly when the fuel cap is not loosened or removed, but stalls or stops after being run for a while with the cap back on, the fuel cap may be at fault.

An old gas cap needs to be changed.