Riding Lawn Mower Hit Something and Stopped

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Running or hitting over something with your riding lawn mower may damage the flywheel key, blades, or crankshaft causing your mower to stop. Also, it can make restarting it difficult.

In this article, we share 6 reasons why your riding lawn may stop after hitting something, and how to fix it and get it back working promptly.

Ready? Let’s dive right into it:

6 Reasons Why Your Riding Lawn Mower May Stop After Hitting Something


1. Locked or Jammed Blades

If the blades of the riding mower get jammed or locked, it may stop the mower from working. This will affect your mowing operation because the blades won’t get activated.

Fix: You need to turn your riding mower over and remove the blades to check why it isn’t turning over.

 Ensure that you clean the underside of the mower and remove anything that is stuck in the blade.

2. Damaged Flywheel Key


Your flywheel key might get damaged after hitting objects such as a hose or rocks. This will make the machine stop operating.

Fix: To fix this issue, replace or repair the mower’s flywheel key.

3. Loose Belt

An individual using a Husqvarna riding mower complained that his machine stopped after “running over the metal gutter on the ground from his house”. 

He noticed that the belt got loose. Loose belts can make your riding lawn mower stop working after you hit something.

Fix: Make sure that you tighten the tension of your belt. Furthermore, ensure that the belt is in the right place.

4. Safety Switch

If your mower stops after hitting an object, the problem may be linked to the safety switch. The safety switch is located under the mower’s seat.

You may have tripped on it, making it shut off automatically when you hit the object. This will affect the mower’s operation because you may need to reset it before it can start working again.

Fix: You need to remove the mower seat to check the safety switch. All you need to do is to reset the switch and start the mower again.

5. Jammed Crankshaft

The mower’s crankshaft can get jammed if you hit the machine on stumps. As a result of this, the jammed crankshaft will prevent it from turning the flywheel.

Fix: Ensure that you check the crankshaft for damage. It is advisable to contact a professional to solve this.

6. Bent Blades


Bent blades can make the riding mower stop if it hits an object while mowing. It is important to fix this to prevent further issues.

Fix: To solve this problem, you need to replace the faulty blade with a new one. Here are the tips to fixing a new blade:

  • Tilt the mower to inspect if the blades are bent.
  • If they are bent, get a good socket wrench to take off the blade.
  • Replace the bent one with a new one. Make sure that the blade is the correct length for your lawn mower model.

What Happens if a Lawn Mower Hits a Rock?

Homeowners are often instructed to check their lawns for rocks and obstacles before they start mowing. This is to avoid accidents, large repair bills or mower damage. 

Below is an extensive discussion of what can happen if your riding mower hits a rock:

  • Mower Damage

Hitting a rock with your lawn mower can result in dent and bent parts. It can get damaged depending on how large the rock is and how the mower hits it.

The blades are very vulnerable to such occurrences, but you can still bend some parts like crankshafts and flywheel keys.

  • Unintentional Catapult

If the mower hits a rock, it can accidentally throw the rock up with force to hit other people, resulting in injuries.

How to Tell If Your Lawn Mower Crankshaft is Bent

The lawn mower’s crankshaft can get bent as a result of a collision with objects such as rock, stump or metal pipe.

In this case, you have to start shopping for another one. Here are some tips that will enable you to know if the crankshaft is bent:

  • Disconnect Spark Plug and Remove It

The first step to take is to disconnect the spark plug to prevent any possibility of starting. To take off the spark plug, make sure that the engine does not have any compression.

  • Tie the Brake Handle Down

The brake is another component of the machine that can prevent the engine and crankshaft from spinning freely. You need to tie the brake down with ropes or clamps.

  • Tilt the Lawn Mower

The next step is to tilt the mower. To do this, you can tip the back on its back wheels. You can also tip it on its side but make sure that you tip it on the right side.  Ensure that the air filter and carburetor are on the side that is facing the upward position.

  • Spin the Blade

This is a real test to know if the crankshaft is bent. It is important to use a leather glove while trying this. Push the blade on the back edge to enable it to spin around it.

Ensure that you quickly remove your hand once you have pushed it. The blade can spin freely because you have tied down the brake and removed the spark plug.

  • Inspect the Center Bolt

Take a look at the center bolt. You will hardly observe the center bolt moving if the crankshaft is okay. If you spin the blade and you discover that the center bolt is wobbling, then it means that the crankshaft is bent.