Reliable engine, regular maintenance: our key tips to avoid engine overheating

When the weather is warm and sunny, few things are better than spending a productive day outside – getting your mowing duties done while at the same time taking in the beautiful, green landscape.

However, when temperatures rise, both operators and machines suffer. Our human cooling system is activated and we begin to sweat… but what about our trusted lawn mowers?

With longer summers and hot spells occurring even in October in Europe – Madrid hit a high of 33°C on the 8th of October in 2023 – high temperatures are a concern for much of the year.

In intense heat, the resistance of our tools might be seriously tested – especially when it comes to the powerhouse, the engine. How can you be sure it won’t let you down? And what precautions can you take to prevent a failure?

Read on to find out and discover the best strategies to deal with and avoid an engine overheating.

Choose an engine famous for reliability

Prevention is the best cure. And by choosing an engine that is famous for reliability, you won’t have to worry about downtime because of engine overheating.

The most effective way to prevent technical issues like overheating is to rely on the best tools and parts you can find on the market. Kawasaki strives to deliver that quality thanks to a tireless R&D effort and a meticulous focus on quality at our manufacturing plants.

Kawasaki engines are tested in extreme conditions to make sure they can withstand significant heat stress, so you can minimise downtime and power through commercial workloads with ease. The durability and reliability of our engines is important to us, which is why every engine is started and test run before it leaves the factory.

To give professionals complete peace of mind on their investment, we offer a three year, unlimited hours warranty on all lawn mower engines for Commercial and Private use. Kawasaki engines are extremely durable – our warranty is a product of our confidence in this.

The tell-tale signs of an overheating engine

Kawasaki engines are designed to handle extreme conditions and long working hours, precisely so problems like overheating won’t impact a professional’s busy schedule. If not properly maintained, however, issues can arise in even the most durable engines.

Maintenance is vital for your engine’s health – failing to stick to a regular schedule or using aftermarket parts can impact performance, and leave it more vulnerable in extreme weather. Prevention is best, but it’s worth being aware of the signs of overheating just in case.

A seasoned professional knows when their lawn mower engine is not performing at its best. But when you’re working in heat and losing concentration, you might miss some of the more subtle signs.

In hot weather, you should always pay careful and close attention to your machine, as well as your own health. There are a few unmistakable symptoms that will indicate if something is going wrong – which can vary depending on your engine's cooling system.

Air-cooled mowers force air to the metal fins around the engine cylinder to dissipate internal heat, while their less common liquid-cooled counterparts have a radiator and a water pump. The pump distributes the liquid coolant to the engine block through hoses, and the heat from the engine is transferred to the coolant.

Typically, professional lawnmowers will be air-cooled, but some larger commercial mowers such as diesel ride-ons will be liquid-cooled. Kawasaki lawn mower engines are currently all air-cooled, so this is where we will focus our guide to overheating.

Here are a few things to consider to monitor your air-cooled engine's health.

An increasingly hot cowling

A little heat is perfectly normal, but if you notice your lawn mower's top is scorching hot, the engine might be suffering. If you feel heat radiating from the cowling, let your machine cool for a while.

Unusual noises

By now, you've certainly come to recognise the healthy noise of your engine – each model is slightly unique. When this auditory clue changes, it's usually a hint that something is not running smoothly.

In particular, a persistent sputtering sound might indicate an anomaly in the system and that the engine could be prone to overheating.

Alternatively, clunking sounds might be a sign that the oil's temperature is too high. When this happens, the liquid loses some of its lubricating properties and you might hear components in your engine grind with increasing friction.

A burning smell

When the temperature in your engine is high enough to burn the oil, you'll start smelling it. Worse, the plastic components in your engine might melt, emanating unpleasant fumes.

Any unusual odours should be cause for concern and call for an immediate resolution.

Reduced power

While it can potentially occur for a multitude of reasons, power loss is a common phenomenon when an engine overheats. This is because, as the pistons expand, the additional friction decreases the amount of power they're able to generate.

So, if you see that your lawn mower's performance is affected all of a sudden, make sure to stay alert to catch any of the anomalies described above.

Best strategies to deal with an overheated engine

Once you're fairly sure your engine is overheating, you should do everything you can to safely keep that temperature down. However, in most cases, the best strategy is to avoid the problem in the first place.

To help you in both scenarios, here are a few things you can do to cool your engine or prevent it from ever getting too hot.

Ensure your machine's cooling system is working smoothly

Intuitively, if you see that the engine is overheating, the cooling system will be the usual suspect. If it's not doing its job well, the machine is bound to run hot.

This is why you should make sure to regularly check that everything works perfectly and that the cooling fins aren't blocked by debris – a consistent approach to maintenance and daily checks are essential.

Avoid working in high temperatures

Is the warm weather making you feel the need to seek out shade and a refreshing glass of cold water? Your machine might have different needs to you, but it can be just as affected by the heat.

The best you can do to keep your lawn mower cool is to store it in a safe place protected from the sun when you're not using it and leave it in the shade between cuts.

If that's not enough and the weather is still causing overheating issues, you might want to start earlier and avoid cutting during the hottest hours of the day, especially the period between 14:00 and 16:00. It’s better for your health as well as the lawn mower engine!

Don't skip your oil changes

A low level of oil might also lead to overheating problems. When moving parts in your engine aren't lubricated enough, the increased internal friction will eventually cause higher temperatures that might damage the engine.

To make sure this scenario doesn't happen, remember to regularly check your oil levels.

Make sure the air filters are clean

Blocked air filters are another possible culprit when it comes to an overheated engine.

When the filter is clogged (either partially or completely), the vital air flow that is meant to cool the engine cannot perform its function and the internal heat may increase drastically.

In addition, the ensuing lack of oxygen can cause an imbalance affecting the optimal air-fuel mix ratio, which might also raise the temperature of your engine.

Use genuine parts

The difference in quality between aftermarket parts and Kawasaki Genuine Parts often becomes even clearer when they are tested in a more extreme environment, such as in high temperatures.

When using aftermarket parts, you run the risk of causing significant damage to your engine. Purchasing genuine parts removes all doubt. You know you have the best part for your engine available, designed and tested to maximise performance and handle difficult conditions. With aftermarket parts, cost savings come with risk – can you trust the part to handle high temperatures and the most testing conditions?

Filters are the parts most often replaced and are a vital part of an engine’s cooling system. The differences can be subtle between aftermarket and genuine parts, but in high temperatures or over a longer period of time, the gap in quality is likely to become very clear.

A Kawasaki oil filter is more effective due to its low micron rating, meaning that it can trap a wider range of contaminants and improve the overall oil quality. Using non-genuine parts could potentially reduce the engine’s lifespan as contaminants are burnt during combustion.

For air filters, the problem is similar. A low micron rating and more folds in a Kawasaki genuine part enhances air quality and flow within the engine. Aftermarket filters instead might let dirt particles into the engine causing the premature wear of internal components, and negatively impact the air flow that is designed to cool off the engine, exacerbating the heat issues we examined above.

Year-round reliability: Kawasaki engines

Whether it's to prevent overheating or other reliability issues, choosing quality pays long-term – without even considering the damage that downtime can do to businesses.