Lawn Mower Won't Start: Causes & Fixes
Mowing the lawn is an essential garden task — one that some gardeners enjoy and others find a chore. What nobody enjoys, however, is a lawn mower that won't start. Fortunately, the vast majority of mowers on the market have a straightforward design. This generally means you can carry out repairs yourself, rather than calling in a professional.
If your lawn mower won't start, first check whether there is enough fuel in the tank. If the tank is leaking, you will need a professional. In many cases, the wrong type of fuel is also to blame when the machine won't start. The majority of models on the market run on unleaded petrol. Others run on diesel.
It is also possible that an excess of fuel in the combustion chamber is flooding the engine. In that case, the spark plug needs to be dried out so the mower can start.
In general, most faults on the majority of mowers can be fixed by any competent home user. If all else fails, contact a professional.
Lawn Mower Drive Fault: Reasons Why Your Lawn Mower Won't Start
Possible causes include:
- Faulty spark plug
- Long period of storage
- Dirty air filter
- Blocked blades
- Clogged fuel filter
- Dirty carburettor
Faulty Spark Plug
There is fuel in the tank but your lawn mower still won't work? A dirty or corroded spark plug may be the culprit. Spark plugs do not last indefinitely, so remove the spark plug and inspect it carefully.
If you are unsure where the spark plug is located, consult the owner's manual for your mower. It will tell you where to find it, how to remove it, and how to clean it. In many cases, wiping the spark plug with a cloth is sufficient. Make sure there is no rust or dirt on the contacts in particular, as these need to be clean to allow the spark to jump.
If the mower still won't start, replace the spark plug with a new one. Make sure you purchase a spark plug that is compatible with your specific mower model.
Your Lawn Mower Has Been in Storage for a Long Time
Lawn mowers are often left unused over the winter months, which frequently causes starting problems come spring. After a prolonged period of storage, oil can settle and build up in the internal pipework. Pipes that are not properly lubricated often cause starting difficulties. We have compiled tips on how to winterise your lawn mower separately.
Ideally, the problem will resolve itself after several attempts to start the engine. Your owner's manual may also describe steps to remedy the issue.
Dirty Air Filter
Every lawn mower needs a clean air supply to start, and this is the job of the air filter. It prevents dust and dirt from entering the carburettor. The air filter cannot do its job properly if it becomes clogged with dirt — in which case the engine will cut out and the mower won't start.
A dirty air filter is perfectly normal. Over time, dust, oil, and debris will accumulate. It is therefore good practice to clean the filter regularly.
To remove the air filter correctly, refer to your owner's manual. If it is a paper filter, tap it gently to dislodge debris or clean it with compressed air. Foam filters can be washed with washing-up liquid and warm water. For a dual filter, it is advisable to replace the paper section when it becomes dirty. As a general rule, the mower should be cleaned regularly to prevent breakdowns.
After cleaning, allow the air filter to dry thoroughly before reassembling and refitting it.
Blocked Blades
You pull the starter cord and nothing happens. A likely cause is stones or twigs jamming the blade. This is often noticeable because the cord requires more effort than usual to pull. Now take a look underneath the mower — but first disconnect the spark plug lead or the mains cable. For a petrol-powered mower, make sure the fuel cap is closed. Remove any grass clippings, stones, and other debris blocking the blade. Ideally, wear gloves to protect yourself from the blade edges.
Replacing the blade is not a complicated job. We have outlined how to do this in our guide "How to Sharpen Lawn Mower Blades". It is also important to ensure you fit the correct blade for your mower. A blade that is not compatible can cause damage to the machine.
Clogged Fuel Filter
The fuel filter's job is to trap impurities in the fuel so they do not restrict the flow of petrol to the carburettor. This means that a dirty fuel filter will result in too little — or no — petrol reaching the carburettor, preventing the mower from starting.
To fix this, close the fuel tap and open the filter. Clean the filter element with compressed air or replace it. Close the filter and reattach the fuel line.
Dirty Carburettor
The carburettor is where petrol and air are mixed to create a combustible mixture. If the carburettor is dirty, the needle that regulates the fuel supply will not function correctly. This results in a mixture that can no longer ignite. A faulty or missing air filter or fuel filter is often the underlying cause.
The solution is to clean the filters mentioned above. Then open the carburettor and clean it with a brush before reassembling it correctly.
Electric Lawn Mower – Mower Won't Start
Electric lawn mowers often present similar problems to petrol-powered models. Issues such as running out of petrol, spark plug faults, and problems with the throttle cable do not apply, of course. Problems with electric mowers are more commonly caused by wear and tear, blockages, or cable damage. The same applies to axles and wheel bearings.
As diagnosing faults on an electric mower requires specialist knowledge and skill, repairs are best left to a qualified professional. Blockages and dirt can usually be cleared fairly easily.
If the mower won't start, it is often simply a case of the plug not being properly inserted into the socket, or a fault with the power cable. You should also check that the fuse has not blown.
For the sake of your own safety, do not attempt to repair damaged power cables yourself. Always contact a qualified electrician or specialist for this type of problem.
An important safety point with this type of mower: always disconnect it from the mains before carrying out any checks or cleaning. Failing to do so puts you at serious risk of injury.
Common causes of cable damage on electric lawn mowers include:
• Damage caused by the cutting blade,
• Damage caused by animals,
• Cable breakage due to incorrect winding,
• Damage caused by adverse mechanical force.
Prevention – Keeping Your Lawn Mower Starting Reliably
To ensure your lawn mower always starts when you need it, it makes sense to have it serviced regularly or carry out routine maintenance yourself. This involves checking all the essential components on a regular basis and resolving any issues before they become serious problems. You can of course take this into your own hands and give your mower a thorough check-over each year before putting it away for winter. Alternatively, you can do this in spring — ideally carrying out an oil change at the same time. You can also rely on the intelligent technology offered by FUXTEC: the Auto-Choke system. This is a quick-start feature for petrol lawn mowers. It ensures you can start your petrol mower reliably under all conditions, as there is no need to operate a primer pump. This significantly reduces the risk of your mower failing to start.
Time for a fresh cut?
Discover the powerful FUXTEC lawn mowers for optimal lawn care.
Häufige Fragen: Rasenmäher springt nicht an
Hier findest Du kompakte Antworten zu Startproblemen bei Benzin-, Elektro- und Akku-Rasenmähern sowie zu Kraftstoff, Zündkerze, Luftfilter und Vergaser.
Ein Benzin-Rasenmäher springt häufig wegen fehlendem oder altem Kraftstoff, einer verschmutzten Zündkerze, einem verstopften Luftfilter oder Problemen mit der Kraftstoffzufuhr nicht an. Prüfe zuerst den Tankinhalt und verwende den für Dein Modell vorgeschriebenen frischen Kraftstoff. Kontrolliere danach Zündkerze, Luftfilter, Benzinfilter und Vergaser. Stelle außerdem sicher, dass der Motorbrems- oder Sicherheitsbügel beim Starten korrekt betätigt wird.
Springt ein Rasenmäher nach dem Winter nicht an, ist überalterter Kraftstoff eine der naheliegenden Ursachen. Benzin kann während einer längeren Standzeit seine Eigenschaften verändern und Ablagerungen im Kraftstoffsystem verursachen. Leere alten Kraftstoff entsprechend der Bedienungsanleitung, kontrolliere den Vergaser und fülle frischen, für das Modell geeigneten Kraftstoff ein. Prüfe zusätzlich Zündkerze, Luftfilter und Sicherheitsbügel.
Eine verschmutzte oder defekte Zündkerze kann dazu führen, dass der Rasenmäher schlecht startet, unruhig läuft oder gar nicht anspringt. Entferne den Zündkerzenstecker erst, nachdem der Motor vollständig abgekühlt ist. Prüfe die Zündkerze auf starke Ablagerungen, Rost, beschädigte Elektroden und einen falschen Elektrodenabstand. Reinige oder ersetze sie ausschließlich nach den Vorgaben der Bedienungsanleitung.
Ein stark verschmutzter Luftfilter kann verhindern, dass der Motor genügend Luft erhält und der Benzin-Rasenmäher zuverlässig startet. Kontrolliere den Filter auf Staub, Öl und Grasreste. Papierfilter werden je nach Zustand vorsichtig ausgeklopft oder ersetzt, während Schaumstofffilter nur entsprechend der Herstellervorgabe gereinigt werden dürfen. Starte den Motor nicht dauerhaft ohne eingesetzten Luftfilter.
Ist ein Benzin-Rasenmäher abgesoffen, befindet sich zu viel Kraftstoff im Brennraum und die Zündkerze kann nass sein. Beende weitere Startversuche und lasse den Motor abkühlen. Baue die Zündkerze nach der Bedienungsanleitung aus, lasse sie vollständig trocknen oder ersetze sie bei Bedarf und setze sie anschließend korrekt wieder ein. Wiederholt sich das Problem, solltest Du Kraftstoffzufuhr, Vergaser und Startvorgang überprüfen.
Ein Elektro- oder Akku-Rasenmäher startet nicht, wenn die Stromversorgung unterbrochen, der Akku leer oder eine Sicherheitssperre nicht korrekt gelöst ist. Prüfe bei einem Elektrorasenmäher Steckdose, Verlängerungskabel, Stecker, Sicherung und Sicherheitsbügel. Bei einem Akku-Rasenmäher kontrollierst Du Ladezustand, korrekten Sitz des Akkus und einen eventuell vorhandenen Sicherheitsschlüssel. Beschädigte Kabel, Stecker oder Akkus dürfen nicht weiterverwendet werden.
Everything you need for a well-kept, healthy lawn – from a single source
Your complete package for lawn care
More lawn mower tips
Rasenmäher Radantrieb warten: Ursachen erkennen und Probleme selbst beheben
Rasenmäher-Radantrieb funktioniert nicht: Ursachen prüfen und Fehler beheben Ein Rasenmäher mit Radantrieb nimmt dir auf größeren Flächen, unebenem Boden und an leichten Steigungen viel Schubarbei...
How to Winterise Your Lawn Mower | Storage Tips
Die wichtigsten Infos in Kürze Reinigung vor dem Winter Benzin ablassen oder Akku entfernen trocken und frostfrei lagern
Lawn Mower Won't Start: Causes & Fixes
Mowing the lawn is an essential garden task — one that some gardeners enjoy and others find a chore. What nobody enjoys, however, is a lawn mower that won't start. Fortunately, the vast majority of...
