Lawn Mower Overheating Symptoms and Solutions

Lawn mower overheating: In this article, we're tackling the reasons your mower's overheating and how to set things right.

Overheating in lawn mowers can shorten the lifespan of your mower, so lets get right to it.

Lawn Mower Overheating

Why a Lawn Mower Overheats (General)

A lawn mower can overheat when its engine works excessively, leading to an increase in temperature.

Common reasons for this overheating include issues with the cutting height, blade condition, and clogged components like air vents or the cutting deck.

Additionally, in gas-powered mowers, fuel quality and using the right kind of oil can help engine performance and prevent overheating.

Proper maintenance and addressing these issues promptly can help prevent lawn mower overheating and keep your mower running smoothly.

Specific Causes of Mower Overheating, With Solutions

The following causes of, and solutions for, mower overheating apply to gas-powered and electric-powered lawn mower types.

Additional causes and solutions specific to gas mowers are listed after the universal causes and solutions.

Dull Blades

One common cause of lawn mower overheating is dull blades.

When your mower's blades are dull, it forces the engine to work harder, resulting in overheating.

To address this issue, regularly sharpen your mower blades, or replace them as needed.

Additional tip for gas mowers: For any blade related troubleshooting you will first need to tilt the mower properly to be able to see the blades.

If you tip it the mower the wrong way you may cause engine oil to leak through an open valve into the air filter.

The result will be a lawn mower than burns a lot of oil and billows a bluish smoke the next time you run it.

Lawn mower overheated and is blowing smoke in a backyard

Dirty Air Filters

Clogged air filters are another culprit behind overheating.

When air filters become clogged, they restrict airflow, causing the engine to overheat.

To prevent this, make sure to check and clean or replace the air filter regularly to ensure proper airflow.

Grass Buildup

Accumulation of debris and grass around the engine can hinder cooling airflow, leading to overheating.

To address this issue, periodically clean the engine and surrounding areas to remove grass clippings and debris.

Pay special attention to debris in the cooling fins of a gas engine because, when clogged, the engine can overheat quickly.

Cutting Height Trouble

Lowering the cutting height too much can make the engine work harder, which can result in overheating.

To avoid this, consider slightly raising the cutting height and avoid cutting too much grass at once.

Blade Problems

Loose or bent blades can put extra strain on the engine, cause excessive vibrations, and lead to overheating.

To prevent this, ensure that the blades are kept tight and properly aligned for smoother mowing.

Gas-Powered Lawn Mower

Overheating Issues Specific to Gas Mowers

Fuel Quality

Poor-quality fuel is another potential cause of engine problems and overheating.

To avoid this issue, always use high-quality fuel with the correct octane rating and avoid using old or stale gasoline.

Ignition Issues

Lastly, faulty ignition systems and coils can disrupt engine performance and lead to overheating.

To address this, inspect and replace spark plugs and ignition components as needed to maintain proper ignition.

Low Oil Level

In gas-powered movers, oil reduces heat by preventing friction inside the engine.

If your lawn mower is low on oil, or has poor quality oil, the engine will overheat.

It's a good idea to check the oil level of your mower before you start a mowing session, while the mower is still cool.

If the oil level is low it's OK to top it up, but remember, it's time for an oil change at your next earliest convenience.

IMPORTANT: Never over-fill a lawn mower by adding too much oil. A small engine with too much oil in it will run poorly, burn oil, and eventually break.

Fuel/Oil Mix in 2-stroke engines

For lawn mowers with 2-stroke engines a mixture of oil with fuel is needed.

This is because 2-stroke engines don't have an oil reservoire, they minimize friction by having a proper oil mix in their gasoline.

Summary and Additional Resources

While diagnosing an overheating condition in a lawn mower is fairly simple and straight forward, sometimes the solution isn't obvious.

For additional help in finging the problem and knowing what to do, consult the Lawn Mower Engine Troubleshooting guide. It covers all kinds of mower problems in-depth.

The guide also offers tips about safety, techniques, and required repair tools for each job.