Mower Dies When Brake Released: 7 Causes and Fixes Explained

In a lawnmower, when you release the brake, the engine will begin to run again and the blades will begin to turn. This allows the lawnmower to move forward and cut the grass.

But sometimes, the lawnmower loses power when the brake is released.

The possible causes range from a clogged air filter to a faulty ignition module, with seat switch being the most prominent one. A clogged carburetor or fuel filter and spark plug are also causes.

This article investigates the reasons of mower dies when brake released and solutions from an expert’s PoV.

Common Problems and Solutions of Mower Dies When Brake Released

Here are the detailed explanations why does your mower die when brake is released, and their ultimate fixes:

1. Seat Switch

The seat switch is a safety feature on mowers that disables the engine when no one is sitting on the seat. Whenthe seat switch is the problem, it stops signaling the engine that someone is seated. So the engine is likely to shut off when the brake is released.

Remove the cover or plastic guard over the switch. Check the switch for any signs of damage such as corrosion, broken wires, or loose connections. Use a

multimeter to test the switch.

Consider bypassing the safety switch for testing purposes only to see if your mower works.

The Fix

If any damage is found, replace the switch. Also, when the seat switch does not stall with the bypassed switch, you know that you need to replace it.

Here’s how to replace the seat switch:

Disconnect the spark plug and locate the switch. It is typically located under the seat. Then remove the wiring with pliers or a screwdriver. Disconnect the wiring from the switch.
Now, remove the old switch. Take out the bolts with a wrench. Carefully remove the switch and set it aside.
Finally, install the new switch. Secure the bolts and reconnect the wiring. Make sure to connect the spark plug.

2. Proper Fuel Ratio and Delivery

To inspect the fuel delivery in a lawnmower, begin by checking the fuel lines for any signs of wear.

If the spark plug is wet, this indicates that the fuel mixture is too rich. If the spark plug is dry and covered in soot, this indicates that the fuel mixture is too lean.

The Fix

Make sure there is enough fuel in the tank and that the fuel filter is not clogged. If the fuel is old or contaminated, it can cause the engine to shut off.

If the fuel ratio is not correct, you can adjust it using the carburetor. To do this, you will need to adjust the air and fuel screws.

3. Spark Plug

Check the ends of the spark plug for any signs of carbon buildup. Also, check for oil.

Check the gap of the spark plug. If the gap of the plug is too wide, the spark may not be able to easily jump the gap.

The Fix

Clean the spark plug. In case of damage, replace it.

Related Post: 5 Lawn Mower Bad Spark Plug Symptoms to Look Out For!

4. Air Filter

Remove the air filter from the lawnmower and inspect it closely. If it is saturated with oil or covered in dirt and debris, it is clogged.

The Fix

Clean the air filter using a shop vacuum or compressed air. In case of signs of wear and tear, replace the filter. If the filter is too old, replace it.

5. Carburetor

If the carburetor is clogged, it will be filled with dirt, dust, or other debris that has been collected over time. A kinked or clogged fuel line can cause the carburetor to become clogged.

If there is a vacuum leak, it can cause the carburetor to become clogged. Inspect the vacuum hoses.

The Fix

Clean the carburetor using carburetor cleaner and a small brush or compressed air. Replace the fuel line or vacuum hoses if it is worn or damaged.

Related Post: 8 Common Lawn Mower Carburetor Problems (Fixes Included)

6. Throttle

Inspect the throttle cable for any signs of wear and tear. Check the carburetor linkage to make sure that it is connected correctly and that the throttle plate is opening and closing correctly.

Make sure that the choke is working correctly. A faulty choke can also cause the engine to run unevenly and affect the throttle response.

The Fix

Make sure the throttle cable is properly connected to the throttle lever and that there is no kink or damage to the cable. Ensure that the throttle lever is moving freely and that the return spring is functioning correctly.

7. Governor

Check the governor linkage and spring for any wear or damage or improper functionality. Inspect the governor arm.

Listen to the engine when it is running. If the engine is running too fast or too slow, this can be an indication that the governor is not functioning properly.

The Fix

Make sure all screws and nuts are tight and the linkage moves freely.

Adjust the governor linkage so that it is properly connected to the carburetor and the governor arm. Make sure the governor arm moves freely and the linkage is tight.

Once the governor parts are clean, adjust the governor spring tension so that it is tight but not too tight. You should be able to move the governor arm with your hand.

Maintenance Tips for Avoiding Seat Switch Issues in the Future

The seat switch is the biggest and most common reason for mower dying when brake is released. So it is very important that you maintain the switch properly. This will prevent the need for a seat switch replacement frequently.

Following are some tips to avoid future seat Switch Issues in your lawn mower:

Clean the seat switch regularly. Dirt and debris can accumulate on the switch, causing it to malfunction. Cleaning the switch with a cloth or brush is ideal.
Make sure the wiring connecting the seat switch is securely connected. Adjust it in such a way that it doesn’t shear or tear easily. Avoid any kinks in adjustment.
Regularly test the switch to make sure it is functioning properly. Observe the performance of your mower when the switch is turned on.
Don’t use the mower for activities other than mowing. Your mower is not a tool to push around heavy objects.
While storing the mower, make sure it is in a dry, protected area. Avoid storing it in very high or very low temperatures. This is very damaging to the seat switch.

Frequently Asked Questions (FAQs)

Why does my lawnmower run for 10 minutes and then die?

This happens due to a vacuum leak.

How frequently should you clean the carburetor?

At least a few times a year.

What to do if the seat switch wiring is damaged?

Disconnect the seat switch. Replace the wiring immediately.

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Mower Dies When Brake Released: 7 Causes and Fixes Explained