Petrol-powered Brushcutter support

A clean spark plug helps your Husqvarna grass trimmer or brushcutter start more easily, run smoothly and deliver full engine performance.

Over time carbon deposits can build up on the spark plug, reducing ignition performance. Regular inspection and cleaning help keep your engine running efficiently.

Quick answer

Check the spark plug if your product:

• Is difficult to start

• Runs unevenly at idle

• Loses power during use

• Won’t reach full throttle

Cleaning or replacing the spark plug often restores normal engine performance.

Watch: how to clean a spark plug

The video shows the complete cleaning process, from removing the spark plug to reinstalling it correctly.

Safety first:

Before inspecting the spark plug:

• Wear protective gloves

• Turn off the engine

• Disconnect the spark plug

• Allow the engine to cool completely

What you’ll need:

• Wire brush

• Spak plug wrench or combi spanner

• Clean cloth

• Replacement spark plug (if required)

Always use the spark plug type recommended for your model. An incorrect spark plug can damage the engine.

Step-by-step: clean the spark plug

Access the spark plug

Remove the engine cover (if fitted) and disconnect the spark plug cap.

Remove the spark plug

Use a spark plug wrench or combi spanner.

Turn the spark plug anticlockwise until it can be removed.

Inspect the spark plug

Check for:

• Carbon deposits

• Cracks in the ceramic insulator

• Burnt or worn electrode

• Corrosion

If the spark plug is damaged, replace it instead of cleaning it.

Clean the spark plug

Use a wire brush to remove carbon deposits from the electrode and contact surfaces.

Only reinstall the spark plug if it is clean and undamaged.

Reinstall the spark plug

Thread the spark plug in by hand first.

Tighten it securely using the correct tool, but do not overtighten.

Test the product

Start the grass trimmer or brushcutter and check that it:

• Starts easily

• Idles smoothly

• Accelerates normally

• Maintains power while cutting

When should you replace the spark plug

Replace the spark plug if:

• The ceramic insulator is cracked

• The electrode is badly worn

• Heavy carbon deposits cannot be removed

• Cleaning does not improve performance

Common mistakes to avoid

• Removing the spark plug without cleaning around it first

• Overtightening the spark plug

• Using the wrong spark plug type

• Reinstalling a damaged spark plug

When should you inspect the spark plug?

Inspect the spark plug:

• During routine maintenance

• If the engine becomes difficult to start

• If engine power decreases

• If the engine runs unevenly

A spark plug inspection is one of the quickest ways to identify ignition-related problems.