Common Lawn Mower Problems

If your lawnmower is having difficulty starting up then we might just be able to help you repair the fault yourself.

 

My (Petrol & Electric) Lawnmower Won't Start

A lawnmower that won’t start is a common problem – particularly after the long winter months, when they’re rarely in use.

A little routine maintenance is often all it takes to prevent issues. However, if you do experience a breakdown, these troubleshooting tips should help you get up and running again.

Petrol Lawnmowers

First Things First – Check You Have Petrol

This might sound silly, but it can be easy to overlook the fact that you’ve run out of petrol. Double-check that you’ve filled up and replace any old petrol, as this can cause problems too.

Faulty Spark Plug

The most common cause of a lawnmower that won’t start is a faulty spark plug. First, try cleaning any debris off the plug – if this doesn’t work, it will need to be replaced.

Dirty Air Filter

The problem could be caused by something as simple as a clogged air filter. Try cleaning the filter to remove any blockages – if you can’t remove all of the dirt, the filter will need to be replaced.

Fuel Not Reaching the Engine

In some cases, the fuel filter or carburetor may become clogged, preventing fuel from reaching the engine. Old/bad fuel in in the float bowl (often a problem after the winter months) can also be the culprit.

To fix the problem, drain the old fuel from the float bowl and thoroughly clean the carburetor. If this doesn’t work, the carburetor may need replacing.

Start Switch May Be Defective

A defective start switch could be stopping your lawnmower from turning on. First, try testing the switch for continuity with an ohmmeter. If the switch is working intermittently or is difficult to turn, it will need to be replaced.

Electric Lawnmowers

First Things First – Check the Power Supply is Connected

Again, this might sound silly, but we’ve all overlooked it at some point! Double-check the lawnmower is connected to a working power supply.

Blown Fuses or Tripped Breakers

A blown fuse or tripped breaker could be the simple explanation. You can test the outlet by plugging in a small lamp – if it won’t switch on, fuses and breakers may need resetting or replacing.

Full Cuttings Bag

The lawnmower won’t start if it detects the cuttings bag is full. Simply disconnect and empty the bag.

Grass and Other Debris Clogging Up the Blades

A build-up of grass and other debris can prevent the mower’s blades from turning. To fix the problem, carefully clean the blades.

Faulty On/Off Switch

As with petrol mowers, a faulty on/off switch could be the root of the problem. Simply replace the switch to fix the issue.

Activated Thermal Cut-Out

The thermal cut-out may be activated if your lawnmower’s blades become jammed or the motor is overloaded. If this is the case, ensure the blades are free and reset, or wait a few minutes for automatic reset to occur.

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My (Petrol & Electric) Lawnmower Starts Then Stops

A lawnmower that starts and then stops is a frustrating problem – and there are a number of possible causes.

Whether you own a petrol or electric mower, the trouble-shooting tips below should help you to identify and fix the issue.

Petrol Lawnmowers

Fuel Not Reaching the Engine Properly

If the carburetor has become clogged or there is bad/old fuel in the float bowl, not enough fuel will be able to reach the engine, which could cause the problem.

To solve this, drain the old fuel from the float bowl and carefully clean the carburetor. If this doesn’t work, the carburetor may need replacing.

Defective Petrol Cap

A problem with the petrol cap is a common cause of a lawnmower that starts and then stops. Petrol caps have a small vent to allow air back into the tank, which can become blocked or be defective.

Try loosening the petrol cap – if this results in the engine staying running, it may need to be replaced. In some cases, it is also possible to clean the petrol cap.

Defective Spark Plug

A defective spark plug is also a common cause of an engine that starts and stops. To fix the problem, try thoroughly cleaning the plug. If this doesn’t work, it will need to be replaced.

Electric Lawnmowers

Grass and Other Debris Obstructing the Blades

Lawnmower’s blades can become obstructed by grass and debris, preventing them from turning properly – and this often results in the engine cutting out.

To fix the problem, carefully clean the lawnmower’s blades.

Blown Fuses and Tripped Breakers

A blown fuse or tripped breaker could cause the lawnmower to cut-out. Try testing the outlet using a lamp – if it won’t switch on, you may need to reset or replace fuses and breakers.

Damaged Lawnmower Cable

A damaged cable could prevent power from reaching the lawnmower, as well as having the potential to be a serious risk. In this case, replace the cable immediately. 

Activated Thermal Cut-Out

If your lawnmower’s blades become jammed or the motor is overloaded, the thermal cut-out may be activated. First, ensure the blades are free, and then either reset or wait a few minutes for the automatic reset to kick in.

By Lee Gilbert

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