At the worst possible time, your lawn mower won't start? This is no reason to panic. Fortunately, most devices are designed so that you can figure out and fix the problem yourself. This guide tells you the most common causes and gives tried-and-tested tips for immediate relief measures.
Why won't my lawnmower start?
If the lawnmower won't start, it could be due to empty fuel, a clogged air filter, a dirty spark plug, a blocked blade bar or a dirty carburettor. Check and clean these components or add gasoline to resolve the problem.
Cause: No fuel or electricity
Surveys among the largest lawn mower manufacturers revealed this. If the mower won't start, an empty tank is one of the top three most common causes. Therefore, first check the amount of fuel available in order to fill in fresh petrol if necessary. If the engine has become hot as a result of repeated starting attempts, wait until it has cooled down before filling.
The electric lawn mower cannot run out of fuel. However, an electric mower will not respond if the plug is not properly connected to the socket. If you can rule out this cause, check the fuse box to see whether the associated fuse has blown out. In most cases, a defective power cable caused the short circuit and must be completely replaced.
Cause: Spark plug dirty or defective
If the igniting spark does not jump, the lawn mower will not make any sound. Take a close look at the spark plug because this is where one of the most common causes of the engine not starting is hidden. If you are not familiar with the position of the spark plug, the operating instructions provide detailed information. How to get rid of the problem:
- Trigger the spark plug according to the manual
- Take a dry cloth
- Wipe the spark plug and contacts carefully
- Do not use water or other liquids
Reinstall the clean spark plug. If the lawn mower still does not start, the spark plug is defective and should be replaced with a new one.
Cause: Air filter clogged
The engine of your lawnmower is equipped with an air filter to prevent dirt particles from clogging the carburettor or entering the engine. The filter should be cleaned at fixed intervals of 25 operating hours. If maintenance is not carried out, the air filter becomes so clogged that the engine no longer starts. Most filter elements are made of foam or paper. How to get your lawnmower running again:
- Remove the air filter according to the instructions in the manual
- Tap out the paper filter or clean it with compressed air
- Never use compressed air in the immediate vicinity of the engine
- Clean the foam filter with hot water or dishwashing liquid (not a solvent)
- Rub dry with a cloth
Reassemble the clean air filter and install it according to the instructions for use. Various manufacturers use dual air filters, consisting of an upstream foam element and a paper filter. You can dispose of this paper filter when it is completely dirty. Foam air filters, on the other hand, are designed for around 100 hours of operation and also work without paper, so cleaning with water and a grease-dissolving agent is worthwhile.
Cause: Blade bar blocked
There is a close connection between the blade bar and the engine on the lawn mower, which only becomes apparent at second glance. If the starter cable is activated when the cutter bar is blocked, the engine cannot start. This problem often occurs when wet lawns have been previously cut. Clumps of grass form that get stuck between the blades. But stones or branches can also get caught. How to get your lawn mower running:
- Important: first pull out the ignition plug on a petrol mower or power plug on an electric mower
- Tilt the lawnmower backwards
- Alternatively, tilt the device with the air filter upwards
- Put on gloves
- Remove grass residue, branches and other contaminants
- Clean the housing with a hard brush
Before starting cleaning, please double check whether the engine is reliably prevented from starting accidentally. For safety reasons, we recommend fixing the spark plug cable on petrol lawn mowers so that it is at a sufficient distance from the spark plug.
Cause: Carburetor dirty
Regular contact of the motor with grass, leaves, twigs and soil can lead to deposits. It is not uncommon for accumulated impurities in the carburetor to hopelessly clog the fuel and air supply lines. Eventually the lawnmower won't start at all. This is how you approach the problem professionally:
- Remove spark plug cable and spark plug
- Add a teaspoon of fuel immediately into the cylinder
- Reinstall cable and spark plug
Start the engine. If it starts for a short time and then goes off again, the carburettor should be cleaned. It is often not necessary to remove the carburettor. You can purchase carburettor cleaning agents (€8.00 on Amazon) as a spray from specialist retailers, which can be used to remove dirt from the outside.
Tip
Does the lawnmower start and then stop again after a short while? Then the fuel is most likely too old. If the gasoline in the tank is older than a month, important components can become gummed up and the ability to start cold will gradually decrease. Replace the fuel, refill with fresh gasoline or spray a little jump starter spray onto the intake manifold (operating instructions).
