If your petrol hedge trimmer is revving too fast

Quick Answer

If your petrol hedge trimmer is revving too fast while idling, the most common causes are the choke not being fully disengaged, the throttle hold (fast-idle) function remaining engaged, or a sticking throttle cable. Follow the checks below to help identify the cause.

⚠️ Safety Notice

Before carrying out any checks:

• Switch off the hedge trimmer and allow the engine to cool if necessary.
• Keep hands, clothing, and loose objects away from the cutting blades.
• Place the hedge trimmer on a flat, stable surface.

Do not use the hedge trimmer if the engine continues to race or the blades move unexpectedly at idle.

Check the Choke Position

After the engine has started, ensure the choke lever has been moved fully to the Run position.

If the choke remains partially or fully engaged:

• The engine may run unevenly.
• Engine speed may increase unexpectedly.
• The engine may produce excessive exhaust smoke or run poorly.

Move the choke fully to the Run position and allow the engine to stabilise.

Reset the Throttle Hold

Some petrol hedge trimmers have a throttle hold or fast-idle function to assist with starting.

To disengage it:

1. Hold the hedge trimmer securely.
2. Press and release the throttle trigger.
3. Check whether the engine returns to its normal idle speed.

If the engine speed returns to normal, the throttle hold has been successfully released.

Inspect the Throttle Cable

A sticking or damaged throttle cable can prevent the throttle from returning to the idle position.

Visually inspect the cable for:

• Kinks or bends
• Signs of wear or damage
• Obstructions preventing free movement

If the throttle trigger does not move freely or fails to return to its resting position, discontinue use of the hedge trimmer.

Important: Accessing or adjusting the throttle cable usually requires partial disassembly of the machine. This should not be attempted, as it may invalidate your warranty.

If the Problem Persists

If the engine continues to rev too fast after completing the checks above:

• Stop using the hedge trimmer immediately.
• Do not attempt to adjust the carburettor unless instructed by the manufacturer.
• Contact our Technical Support Team for further assistance.

Further inspection may be required to identify a fault with the throttle mechanism, carburettor, or engine.

Frequently Asked Questions

Why is my petrol hedge trimmer revving too fast?

The most common causes are the choke remaining engaged, the throttle hold still being activated, or a sticking throttle cable.

How do I release the throttle hold?

Press and release the throttle trigger after the engine has started. This should return the engine to its normal idle speed.

Is it safe to use the hedge trimmer if it is revving too fast?

No. If the engine is racing or the blades continue moving unexpectedly at idle, stop using the machine until the fault has been resolved.

Can I adjust the throttle cable myself?

No. Accessing or adjusting the throttle cable generally requires disassembly of the hedge trimmer and may invalidate your warranty.

What should I do if the engine speed does not return to normal?

Stop using the hedge trimmer and contact our Technical Support Team for further advice.