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Common Lawnmower Problems and How to Fix Them

Maintaining a pristine lawn is a source of pride for many homeowners, and a reliable lawnmower is an essential tool in this endeavour. However, lawnmowers can encounter problems that disrupt their performance like all machinery. Whether you use a petrol, electric, cordless, or robotic lawnmower, understanding common issues and their solutions can save you time and frustration. In this blog, we will explore typical lawnmower problems and provide practical advice on how to resolve them, ensuring your lawn remains immaculate.


What to do When You’re Lawnmower Won’t Start

One of the most frequent complaints about lawnmowers, especially petrol models, is that they refuse to start. This can be due to several reasons:


  • Empty Fuel Tank: Ensure your fuel tank has enough petrol. If it’s empty, refill it with fresh petrol.
  • Old Fuel: Stale petrol can prevent your mower from starting. If the petrol in your tank is more than 30 days old, drain it and add fresh fuel.
  • Spark Plug Issues: A dirty or damaged spark plug can also be the culprit. Inspect the spark plug and clean or replace it if necessary.
  • Clogged Carburettor: A clogged carburettor can restrict fuel flow. Clean the carburettor or use a carburettor cleaner to clear any blockages.

The Stihl RM253 T Petrol Lawn Mower has been designed with these issues in mind. It features an EVC 205 engine that is easy to start, making it ideal for entry-level users looking to maintain small to medium-sized lawns at home. With its reliable starting mechanism, you can effortlessly get to work without the common starting hassles.

Electric and cordless lawnmowers also face their starting issues. For electric mowers, ensure that the power supply is functioning and that the mower is properly plugged in. Cordless mowers rely on their batteries, so check that the battery is charged. Many electric mowers also feature a safety switch that must be engaged before starting. Ensuring this switch is in the correct position is a simple yet often overlooked step.

An image of the Stihl RM253 lawnmower

Is Your Lawnmower Engine Running Rough?

A lawnmower engine that runs unevenly can be frustrating and can lead to poor cutting performance. For petrol lawnmowers, a dirty air filter is a common cause. A clogged filter restricts airflow, causing the engine to struggle. Regularly cleaning or replacing the air filter can prevent this issue. Additionally, the carburettor might need adjustment to ensure the correct fuel-air mixture. Refer to your mower’s manual for guidance on this process.

Electric and cordless mowers might experience motor issues. Inspecting for loose connections or debris that could be affecting the motor's performance can often identify the problem.

Lawnmower Isn’t Cutting Evenly

An uneven cut can leave your lawn looking patchy and untidy. This issue is often due to dull blades. Blades that have lost their sharpness tear the grass rather than cutting it cleanly. Regularly sharpening the blades or replacing them when they become excessively worn can ensure a smooth cut.

Additionally, check that all the mower's wheels are set to the same height. Uneven wheel settings can cause an uneven cut. Cleaning the mower deck to remove any grass clippings or debris that might obstruct the blades can also help maintain a neat lawn.

This Milwaukee self-propelled lawnmower offers exceptional user control with its active speed management paddle. It features a High Lift Mode that allows the machine to switch between continuous peak power for superior cut quality and automatic blade speed adjustment for optimal efficiency. This ensures a consistently even cut every time.

Image of the Milwaukee M18 Fuel Dual Battery Self-Propelled Lawn Mower

My Lawnmower is Stalling

Lawnmowers stalling during use can disrupt your mowing session. For petrol lawnmowers, fuel flow issues are a common cause. Inspecting the fuel line for obstructions or checking the fuel filter for clogs can address this. Overheating is another issue that can cause stalling. Ensuring the engine cooling fins are clean and unobstructed can prevent overheating.

Cordless mowers might stall due to an overloaded battery. Allowing the battery to cool down and avoiding cutting too much grass at once can mitigate this problem.

With the Stihl RMI422 iMOW® Robotic Lawnmower , stalling is no longer a major concern. Designed for efficiency, the iMOW® mows your garden quickly, giving you more time to enjoy it. Fully automated, once installed, it handles mowing, charging, and scheduling independently. If the battery runs low or it starts to rain, the RMI 422 returns to its docking station, deciding whether to charge quickly or slowly based on how much lawn remains to be cut, thereby conserving power and ensuring optimal performance.

Image of the Stihl RMI1422 iMOW Robotic Lawnmower

Problems With Robotic Lawnmower Navigation

Robotic lawnmowers offer convenience but can sometimes encounter navigation problems:


  • Boundary Wire Issues: Ensure the boundary wire is properly installed and not damaged. The mower relies on this wire to navigate the lawn.
  • Sensor Obstruction: Clean the sensors on your robotic mower regularly. Dirt or debris on the sensors can interfere with its ability to navigate.
  • Software Updates: Check for any software updates for your robotic mower. Manufacturers often release updates to improve performance and fix bugs.

Excessive Vibration or Emitting Smoke?

Excessive vibration can make mowing uncomfortable and can damage your mower over time. This issue is often caused by imbalanced blades. Balancing the blades or replacing damaged ones can reduce vibration. Inspecting the mower for loose parts and tightening any that are found can also help mitigate this issue.

Seeing smoke from your lawnmower can be alarming. For petrol lawnmowers, this is often due to oil issues. Overfilling the oil or using the wrong type of oil can cause smoke. Checking the oil level and ensuring you are using the correct type can resolve this. A clogged air filter can also cause the engine to burn oil, leading to smoke. Cleaning or replacing the air filter can address this problem.

What to do When You’re Lawnmower Won’t Start

To keep your lawnmower in top condition, regular maintenance is crucial:


  • Regular Cleaning: Clean your mower after each use to prevent a build-up of grass and debris.
  • Scheduled Servicing: Follow the manufacturer’s recommended servicing schedule for your mower.
  • Proper Storage: Store your lawnmower in a dry, sheltered place to protect it from the elements.

By addressing these common lawnmower problems and performing regular maintenance, you can ensure your lawnmower operates efficiently and extends its lifespan. Whether you own a petrol, electric, cordless, or robotic lawnmower, keeping it in good working order will make lawn care a breeze and keep your garden looking its best.

At Highland Industrial Supplies, we offer an extensive selection of gardening tools and equipment, including top brands of lawnmowers. Each of our lawnmowers comes with an excellent warranty and detailed maintenance instructions to ensure you get the best use out of them. Our team is always ready to assist with any unlikely issues you may encounter and can provide advice about which mower is right for you. Visit us in-store or shop online today.