Why Won’t Your String Trimmer Turn On When It’s Hot?

You were able to get your string trimmer going and use it for a time, but it eventually stopped off and won’t restart.

A hot string trimmer won’t start if the engine is flooded, the choke is set incorrectly, the carburetor is clogged, the spark plug is dirty, the ignition coil is broken, the fuel tank vent is plugged, or vapor lock has occurred.

Please observe all of the string trimmer’s safety instructions. Before making any repairs, the spark plug wire must always be removed.

String Trimmer

When troubleshooting, repairing, or using a piece of equipment, be sure to first read and follow any safety recommendations found in the manual.If you don’t feel confident in your ability to conduct the repair safely due to a lack of experience, training, or health, it’s best to call in an expert.

Ignition Problem with Hot String Trimmer

Flooded Engine/Incorrect Ignition Sequence

When starting a cold engine, the choke lever is only used to limit airflow and make the gasoline run rich. When the engine is at operating temperature, this is unnecessary.

If the engine is already warm and you try to start it with the choke lever closed, nothing will happen.

Position of the choke to initiate string trimming:

  • When starting a cold engine, close the choke by moving the lever or knob to the closed position.
  • The engine should be warm before starting, and the choke should be open.

The flood in the string trimmer’s engine:

You may have flooded the engine while trying to start it, rendering it inoperable. Here are a few typical methods of flooding the engine:

  • Too many times were spent pulling the starter rope and closing the choke.
  • The power switch is disabled and the pull cord is cycled several times.
  • Too many times are spent pressing the priming bulb. You need just press the priming bulb a few times before you can see fuel entering the bulb. The light bulb can be empty.

There’s no need to panic; just pick one of the solutions from the list below.

Avoid using the choke if the engine is already warm before starting it. If you let too much gas into the cylinders, the engine will overflow.

Fixing a String Trimmer’s Overheated Engine (Option 1)

  • Flip the switch to the “on” position.
  • Adjust the choke so that it is fully open, or in the “run” position.
  • While repeatedly drawing the starter rope, you should press the throttle lockout and squeeze the trigger. Pulling this can take anywhere from 5-15 tries until it begins. First, the motor on your string trimmer will start to splutter. If you keep pulling, it should turn over after another pull or two.

Repairing a String Trimmer’s Overheated Engine (Option 2)

  • Turn off the switch completely.
  • Taking off the spark plug to be cleaned
  • Grab the starter rope and yank it 6–8 times.
  • Replace the spark plug with a fresh, dry one.
  • The light must be switched to the on position.
  • The string trimmer’s choke should be removed and the machine set to open/run before you turn it on.

The String Trimmer’s Unclean Carburetor

The carburetor controls how much gas is blended with air to get your string trimmer going and keeps it going.

It’s possible for the string trimmer to stop working due to clogged passages or malfunctioning tiny parts.

A carburetor’s inability to function is often caused by the use of stale fuel.

You might try cleaning or rebuilding the carburetor to see if it helps. If this does not fix the problem, you will need to replace the carburetor.

The String Trimmer’s Flawed Spark Plug

If the spark plug in your string trimmer is dirty or broken, you won’t get the reliable spark you need to get the machine started and running. It could be providing an intermittent spark that prevents the saw from starting while it is hot.

Check the spark plug’s tip for damage. If the spark plug is particularly black in color, or if you see any signs of damage to the porcelain or the electrode, you should replace it.

Spark plugs can be cleaned with a wire brush and reused if they are just slightly soiled. I’d rather just get a new one.

It’s vital to the effective operation of your string trimmer and must be present for it to start. It’s a low-cost component that can be used for upkeep.

Check that the spark plug wire is properly attached and that the space between the electrodes is correct. If you need to make further repairs, remove the spark plug first.

String Trimmer With a Bad Ignition Coil

Once you’ve established that the spark plug is in good shape, it’s time to move on to the ignition coil.

In order to start and maintain operation of your string trimmer, electrical current must be supplied from the coil to the spark plug in the form of a spark.

The coil’s winding can come unwound and cause a short when it becomes too hot. When there is a weak or nonexistent spark, your string trimmer will not start.

The spark plug will not receive enough electricity from an ineffective ignition coil.

If there is a break in continuity, the ignition coil must be tested and maybe replaced.

String Trimmer with Blocked Fuel Tank Vent

String trimmers’ fuel tanks need vents to let air in while the machine is running.

Before adding fuel, make sure the vent is open so that air may escape the tank. When the fuel level in the tank drops, it’s also important that air be able to enter the container.

If the tank can’t vent, a vacuum will create, blocking the fuel from reaching the carburetor. Until the fuel tank can acquire air, the string trimmer will stop working.

Find your string trimmer’s fuel vent and clean it out if it’s clogged. It’s a tiny circular attachment that goes on the top of the tank.

String Trimmer with a Vapor Lock

String trimmers have a gasoline mixture that, when heated, can evaporate and form bubbles, preventing fuel from reaching the engine. It could be too hot to start the string trimmer.

Let the string trimmer cool down. Always use fresh fuel and air-cooled engine oil to lessen the likelihood of vapor lock problems.

When operating the saw in extremely hot temperatures for long periods of time, vapor lock is more prone to occur.

Be careful when you’re opening the gas tank. If the gasoline tank is pressurized and the cap is removed while fuel is still within, petrol may spray out.

String Trimmer’s Plugged Spark Arrestor

Spark arrestors are standard equipment on string trimmers. This is a little screen that can be attached to the muffler to prevent hot exhaust from escaping.

The purpose of this screen is twofold: to shield the operator from flying debris and to stop the fire hazard posed by the material’s high temperature.

Filth and soot on the screen might trap hot exhaust air within the trimmer. Your string trimmer may stall out and refuse to start as a result of this.

The problem can be fixed by removing the spark plug boot. Do not drive with a hot engine. The engine cover and the exhaust cover must be removed.

To get rid of the soot, take off the spark arrestor and scrub it with a wire brush. If the spark arrestor screen has a hole, is broken, or cannot be cleaned properly, it must be replaced.

Does Starting Your String Trimmer Require Additional Assistance?

Be sure the fuel is of good quality. The engine may not obtain the gasoline it needs if it is fed old fuel due to fuel limits or component failure.

Start-up issues with your string trimmer? Learn more about gasoline, fuel limits, and other potential causes.

Is Your String Trimmer Still Giving You Trouble?

There will be times as a string trimmer owner when you have difficulties. All trimmers suffer from this flaw.

I’ve compiled a helpful reference guide to assist you in determining the source of the issue and the best course of action for resolving it. There’s advice for when the string trimmer jams, won’t start, or stops working altogether.