Trimmer head keeps spinning

Trimmer head keeps spinning. String trimmers and chainsaws have similar systems designed to stop the blade or string from spinning when they’re not supposed to be doing so, causing potential harm and damage.

When the vehicle is idling, first check that the speed needs adjusting – this can usually be done at the base of the device near your feet – and then check whether there’s a problem with the clutch. It’s very important to check your weed eater thoroughly before using it.

This is because when you’re working with string trimmers, even something as simple as accidentally re-starting the blower without having the shaft drive gear engaged might cause something terrifying to happen.

In this article, we mentioned some solutions if your string trimmer head continuously spinning.

Trimmer head keeps spinningwh trimmer head keeps spinning

The problem with the spinning of the string trimmer will happen more often to those who are new to using this tool.

Instances, when something like this occurs, can be extremely frustrating, and in some cases, people may even feel like they want to give up on their new trimmer altogether.

By identifying this common problem and finding a solution for it, you’ll be able to ensure that your weed eating is nearing completion without any problems or worries.

For information regarding specific solutions for your tool’s model, consult your user’s manual.


The clutch manages how the spinning head and drive shaft move together. If the clutch is defective, it might engage the head directly to the shaft without a break, making the head spin without any interruption.

When this happens, there will be continued friction even if you are not cutting grass actively.

If your string trimmer performs as if it has no clutch, even though there is an actual functioning handle to control the speed of the head, then you will need to repair/replace the defective part in order for your device to be fully functional again.

Engine Idle Adjustment

Before disassembling the trimmer in order to diagnose a clutch problem, it’s a good idea to first check whether your engine is inevitably spinning too fast for this function to even be possible.

If so, then adjusting the idle speed will be beneficial since you’ll also save gas and improve engine performance. This way, you should be able to figure out if your problem lies in your clutch or idling problem or vice versa.

Should trimmer head spin at idle?

A trimmer, sometimes also known as a weed whacker or grass trimmer, makes use of a clutch just like a chainsaw to prevent the working part of the tool from spinning when the engine is idling.

If this clutch doesn’t work properly and your string won’t stop turning, then it can pull hard enough to damage something or even hurt you.

How do I know if my trimmer clutch is bad?

If the clutch springs have worn out, the trimmer head will start spinning as soon as you start the engine. This can cause great damage to both the head and anyone in its way if it starts violently spinning – let alone if you happen to be holding it at that time.

The shoes and heads may even slip against one another, causing very erratic or no spin at all when you engage the throttle.

Why is my trimmer vibrating?

Trimmers can also vibrate when the connection between the flex shaft and the trimmer head is loose or worn. When this happens, it could be from a poor connection.

Many users find that using a star-shaped connector to secure the two parts together can provide for a better fit, which in turn reduces vibration in the motor because it has something stationary to connect to as opposed to moving freely at all times.

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