Why is My Weed Eater Overheating? 6 Causes and 4 Solutions

Weed eaters are designed to shred through grass, shrubs, and everything in between. However, improper usage can cause overheating and clogs. The good news is that you can take care of the problem in a handful of simple steps that you’ll learn today.

A weed eater overheats because the cooling system is clogged, the air passage is dirty, or there’s an improper fuel mixture. Other common overheating causes include low-quality batteries, overworked motors, and incorrect power supplies. Proper storage and cleaning can prevent all of these problems.

Throughout this article, you’ll also find out the following info about why your weed eater is overheating:

• Six reasons that weed whackers run hot, smoke, or sputter
• Four quick solutions to repair and maintain a weed trimmer
• A list of probable issues associated with overworked motors

Quick Recommendation: Perhaps the most common cause of an overheated weed eater is an improper fuel mixture. Coagulated, dried oil can wreak havoc on a motor. Consider reviewing the best weed eater fuel on Amazon. You’ll be able to get the most out of your tools without overheating them.

Here’s What Makes Your String Trimmer Run Hot

Getting a high-quality trimmer will limit the issues that you encounter.

A Clogged Cooling System Could Be the Cause

The cooling system of a weed eater helps heat to escape to avoid overheating. It operates by pulling in cool air through the flywheel while radiating heat outwards.

Most weed eaters have cooling fins within the engine cylinder that aid in the removal of hot air. The cooling system in most weed trimmers is accessible through the removal of the drive shaft.

It’s important to keep the starter system, flywheel, and the cylinder cover on top of the engine clean to prevent trapped particles from blocking the air supply.

Fuel-Related Issues in Petrol Engines

The fuel used to power a weed trimmer with a 2-stroke engine is usually pre-mixed fuel. The fuel mix should be in the correct ratios so that it can burn correctly.

Fuel combines with the engine oil to keep the crankcase and piston adequately lubricated. The reason your weed trimmer is overheating is that there’s too much petrol in the mixture that makes the fuel burn at a higher temperature.

To find out if the fuel mixture is the problem, put on ear and eye protection, and start the weed eater and let it run to warm up. Proceed to press the throttle and inspect the weed eater’s engine for smoke or oil dripping from the exhaust. It’s an indicator that there’s too much oil.

If the oil is less than required, the engine will get damaged fast as there isn’t enough lubrication. It’s also advisable to change the fuel as it tends to separate and go bad after 30 days.

There Might Be Dirty Air Passages

Every string trimmer features air passages that regulate the breathing function of the engine. The air passages comprise of the air filter and the muffler. The air filter allows clean, cool air used in combustion into the engine, and the muffler assists heated gasses in the engine to be emitted. According to Hunker, when air passages are dirty or blocked, the engine overheats since the circulation of air is hindered.

Check the Carburetor

All petrol weed eaters require carburetor adjustments at some point. Petrol and air mix in the carburetor before being ignited by the spark plug. There are three adjustable screws in the carburetor of most weed eater lawn trimmers used to regulate the amount of gas at a given engine speed.

The engine speeds up and overheats if there’s too much gas used. It’s advisable to call a professional to readjust your carburetor if you have cleaned the air and cooling system and checked the fuel supply, and your equipment is still running hot.

Don’t Use a Battery-Powered String Trimmer for Large Workloads

Battery-powered weed eaters tend to overheat when overworked. Clearing thick and overgrown garden areas may overwork battery-powered weed eaters as they are not as powerful as petrol ones. To avoid this, use battery-powered string trimmers to clear weed and grass and petrol ones for thickets.

Incorrect Power Supply for Corded Weed Eaters

Compared to petrol engines, electrical string trimmers experience fewer mechanical issues. For corded string trimmers, overheating may be caused by using a voltage supply that is too high. For instance, a voltage supply of 210-volt on a 110-volt machine will cause it to overheat or even damage it. Follow the instructions outlined in the user manual regarding the amount of voltage required for your string trimmer to prevent overheating or damage.

How to Fix an Overheated Weed Eater

1. Start by cleaning the cooling system. Cleaning the cooling system of a weed eater allows heat to escape easily. It’s through getting rid of any trapped vegetation or debris that blocks the air supply. The cooling fins can be cleaned using an old toothbrush. Check the user manual to understand how to access your weed eater’s cooling fins as you have to remove any covers to get to them.
2. Check your fuel. Proper ratios of gas to oil mixture are necessary for keeping the piston lubricated. The fuel and oil mixture should be pre-mixed before pouring into the tank so that they blend evenly. To achieve this, you shake the container with the oil and gas mixture before each use. Ensure the right measurements and instructions are followed, as indicated in the owner’s manual. Engine oil replacement should be regular after every 30 days as the oil usually goes “bad” and may cause loss of power in your weed eater. Learn more about fuel mixtures from SF Gate.
3. Clean the air passages. To clean the air passages, remove the air filter pads and wash them in soapy water, rinse in cool water and let them dry. The mufflers and spark plug arrestors are cleaned using a wire brush. Clean air passages ensure that your engine regulates incoming and outgoing air efficiently.
4. Adjust the carburetor if you need to. Adjust your string trimmer’s carburetor by following the instruction manual details on how to access the carburetor. Then, tighten the screws that are used to control the amount of fuel fed into the engine. Seek the help of a professional to avoid damaging your equipment if you’re unsure how to adjust it.

Some of the steps are similar to dealing with lawn mower problems. Read my quick guide to tackle the most common mower issues if you have a few spare minutes.

What Can Happen if It Gets Too Hot?

The weed eater may stop functioning if it gets too hot. The reason is that heat isn’t dispelled correctly, and it will cause it to overheat. If the weed eater gets too hot and it’s not readily corrected, it will result in the following:

• It will damage the cooling fins, and the engine will lose its ability to cool. Gardeners Yards explains that this is one of the most common issues.
• The weed eater’s gasket will get damaged, and it will allow in air and interfere with the fuel-air mixture.
• It will lead to the spark plugs not firing correctly because of the dirt clogging the tips. Alternatively, it will damage the spark arrester.
• The muffler will get damaged, and the string in the weed eater will burnout.
• The cutting head at the end of the shaft might melt along with the cords rendering it useless. It’s because the head will stop spinning.
• The string trimmer will keep stalling every time it overheats. It will inconvenience you, and you will have to keep pulling the cords to fire it up. If it starts to smoke, follow this guide.

Final Thoughts

Weed eaters are an irreplaceable tool in the lawn care industry. If you want bushes, weeds, and grass trimmed to an ideal level, you have to rely on your weed whacker. The good news is that you now know how to treat an overheated motor.

Here’s a rundown of what you should’ve learned:

• Weed whackers overheat from clogs, dirty parts, and bad fuel.
• Always replace the oil and gas after long-term storage.
• Never overwork a battery-powered weed eater for too long.