My Lawnmower Won't Start - Petrol & Electric

In this article we'll look at the common faults that can cause your lawnmower to not start.

Petrol Lawnmower – Check You Have Petrol

A basic check, 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.

Petrol Lawnmower - Defective Fuel 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.

Petrol Lawnmower - 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.

Petrol Lawnmower - 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.

Petrol Lawnmower - 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.

Petrol Lawnmower - 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 Lawnmower – 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.

Electric Lawnmower - 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.

Electric Lawnmower - Full Grass Collection Box or Bag

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

Electric Lawnmower - Grass 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.

Electric Lawnmower - 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.

Electric Lawnmower - 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.