This guide explains the correct starting procedure for a petrol strimmer or brush cutter.

Before starting, ensure that you are using the correct fuel mixture for your machine.

Table of Contents

1. Cold Start Procedure
2. Warm Start Procedure

   
   

Cold Start Procedure

Step 1 – Position the Machine

Place the machine on a flat, clear surface free from grass, debris, or other obstructions.

Rest the machine on the engine housing and safety guard.

Step 2 – Set the Start/Stop Switch

Move the Start/Stop switch to the START position.

Step 3 – Prime the Fuel System

Press the primer bulb approximately 7 times, or until no air bubbles are visible.

This fills the carburettor with fuel and prepares the engine for starting.

Step 4 – Apply Full Choke

Move the choke lever fully down to the Full Choke position.

Indicator: Horizontal line

This reduces airflow and enriches the fuel mixture for cold starting.

Step 5 – Pull the Starter Cord

1. Hold the machine securely using the rear handle.
2. Pull the starter cord slowly until resistance is felt.
3. Pull firmly and quickly 3–4 times.

The engine should begin to fire or briefly tick over.

Step 6 – Move to Half Choke

Once the engine begins to fire:

• Move the choke lever to the Half Choke position.

Indicator: Diagonal line

This allows additional airflow while the engine continues warming up.

Step 7 – Start the Engine

Pull the starter cord firmly again until the engine starts and runs continuously.

Step 8 – Warm Up the Engine

Allow the engine to run for approximately 30 seconds before operating the throttle.

When the throttle trigger is pressed, the choke will automatically move to the Run position.

Warm Start Procedure

If the engine has recently been running:

Step 1 – Set the Start/Stop Switch

Move the Start/Stop switch to the START position.

Step 2 – Set the Choke to Run

Move the choke lever to the RUN position.

Indicator: Vertical line

This allows maximum airflow into the engine.

Step 3 – Start the Engine

Pull the starter cord firmly until the engine starts and runs normally.

This guide covers a number of basic checks you can perform if your petrol strimmer or brush cutter is difficult to start, runs poorly, or will not run at all.

Tools Required

• Spark plug spanner

Contents

• Removing the Spark Plug
• Checking the Condition of the Spark Plug
• Testing the Spark Plug for a Spark
• Testing with a Different Spark Plug
• Reinstalling the Spark Plug

Removing the Spark Plug

1. Remove the spark plug cap (the thick black rubber lead attached to the spark plug, also known as the high-tension lead).
2. Using the spark plug spanner, turn the spark plug anti-clockwise to remove it.
3. Some resistance is normal and moderate force may be required.

Checking the Condition of the Spark Plug

Inspect the spark plug for signs of dirt, carbon build-up, or damage.

A spark plug covered in carbon deposits may not produce a strong spark, which can affect engine performance or prevent the engine from starting.

If the spark plug is dirty:

1. Clean the electrode end using a wire brush where possible.
2. Alternatively, wipe it carefully with a cloth lightly dampened with petrol.
3. Allow it to dry completely before testing or reinstalling.

Testing the Spark Plug for a Spark

Note: This test is easier and safer with two people.

1. Remove the spark plug as described above.
2. Ensure the spark plug is clean.
3. Reconnect the spark plug to the spark plug cap.
4. Position the metal body of the spark plug against a clean metal part of the machine to create an earth connection.
5. Ensure the Start/Stop switch is set to START.
6. Move to a shaded area where the spark is easier to see.
7. Pull the starter cord firmly while observing the tip of the spark plug.
8. Look for a small white or blue spark.

Results

• A visible spark indicates the spark plug is functioning correctly.
• No spark may indicate a faulty spark plug or an issue with the ignition system.

⚠️ Warning: Keep hands clear of the spark plug electrode during testing to avoid electric shock.

Testing with a Different Spark Plug

If you have access to another working petrol machine:

1. Remove the spark plug from the working machine.
2. Connect it to your machine's spark plug cap.
3. Repeat the spark test described above.

Results

• If the replacement spark plug produces a spark, your original spark plug is likely faulty and should be replaced.
• If neither spark plug produces a spark, there may be a fault with the ignition system, such as the ignition coil.

Reinstalling the Spark Plug

1. Carefully screw the spark plug into the engine by hand first to avoid cross-threading.
2. Once finger-tight, use the spark plug spanner to tighten securely.
3. Refit the spark plug cap, ensuring it is pushed fully into place.

If the engine is running fast (revving high):

1. Please check the throttle cable, making sure there are no kinks found in it.
2. Also, make sure that the choke is disengaged and the throttle hold has been reset by pressing the trigger.

This article covers the basic checks and adjustments that can be performed if your petrol strimmer or brush cutter starts but cuts out when the throttle trigger is released.

Contents

• Preliminary Checks
• Carburettor Adjustment – L Screw Focus
• Unable to Perform This Procedure?

Preliminary Checks

If the engine is not running at idle speed and cuts out when you release the throttle trigger, please carry out the following checks:

Fuel

Ensure the fuel is fresh and mixed correctly according to the manufacturer's recommendations. Old or incorrectly mixed fuel can cause poor engine performance and affect idling.

Air Filter

Check that the air filter is clean and free from dirt or debris. A blocked air filter can restrict airflow and prevent the engine from idling correctly.

Fuel Cap

Ensure the fuel cap is fitted securely and is hand-tight. Avoid overtightening or leaving it too loose, as this may affect fuel tank ventilation.

Carburettor

If the above checks do not resolve the issue, the carburettor settings may require adjustment.

Carburettor Adjustment – L Screw Focus

It is possible that the carburettor settings require adjustment to restore a stable idle speed.

Important: This procedure requires a good level of mechanical knowledge. Incorrect adjustment may worsen engine performance or cause starting and running issues. If you are unsure, please contact our support team for assistance.

Tools Required

• Carburettor adjustment ("Pacman") tool

Adjustment Procedure

1. Start the machine and allow it to warm up fully.
2. Locate the two adjustment screws on the carburettor:
   • L = Low-speed adjustment
   • H = High-speed adjustment
3. Slowly adjust the L screw until the engine idles smoothly without stalling and without the cutting head rotating.
4. To adjust the H screw, run the machine at full throttle.
5. Turn the H screw anti-clockwise until the engine begins to struggle to reach maximum RPM.
6. Slowly turn the screw clockwise until the engine returns to maximum RPM and runs smoothly.
7. Once the engine accelerates cleanly and idles correctly, the adjustment is complete.

This article covers the basic checks and adjustments that can be performed if your petrol strimmer or brush cutter starts but will not reach higher engine speeds, bogs down under throttle, or cuts out before reaching full revs.

Contents

• Preliminary Checks
• Carburettor Adjustment – H Screw Focus
• Unable to Perform This Procedure?

Preliminary Checks

If the engine is not revving up properly and cuts out before reaching higher RPM, please carry out the following checks before adjusting the carburettor:

Fuel

Ensure the fuel is fresh and mixed correctly according to the manufacturer's recommendations. Old or incorrectly mixed fuel can cause poor engine performance and hesitation under throttle.

Air Filter

Check that the air filter is clean and free from dirt or debris. A blocked air filter can restrict airflow and prevent the engine from reaching full speed.

Fuel Cap

Ensure the fuel cap is fitted securely and is hand-tight. A loose fuel cap may affect fuel delivery, while an overtightened cap can sometimes restrict tank ventilation.

Carburettor

If the above checks do not resolve the issue, the carburettor settings may require adjustment.

Carburettor Adjustment – H Screw Focus

It is possible that the carburettor settings require adjustment to restore proper engine performance at higher RPM.

Important: This procedure requires a good level of mechanical knowledge. Incorrect adjustment may worsen engine performance or cause starting and running issues. If you are unsure, please contact our support team for assistance.

Tools Required

• Carburettor adjustment ("Pacman") tool

Adjustment Procedure

1. Start the machine and allow it to warm up fully.
2. Locate the two adjustment screws on the carburettor:
   • L = Low-speed adjustment
   • H = High-speed adjustment
3. Check the low-speed setting first by adjusting the L screw until the engine idles smoothly without stalling and without the cutting head rotating.
4. To adjust the H screw, run the machine at full throttle.
5. Slowly turn the H screw anti-clockwise until the engine begins to struggle to reach maximum RPM.
6. Gradually turn the screw clockwise until the engine returns to maximum RPM and runs smoothly.
7. Once the engine accelerates cleanly and reaches full speed without hesitation, the adjustment is complete.

Unable to Perform This Procedure?

If you are unable or uncomfortable carrying out this procedure, you have the following options:

• Order a replacement carburettor.
• Contact our support team for further guidance.
• If your machine is still within its warranty period, arrange for collection and repair by our workshop technicians.

Please note that carburettor adjustments should only be carried out using the correct tools and with appropriate mechanical knowledge, as incorrect settings can lead to further performance issues.

This article covers the basic checks you can perform if the strimmer head or brush cutter blade is not rotating when the engine is running.

Contents

• Check the Head or Blade Installation
• Check the Shaft Connection
• Inspect the Drive Shaft

Check the Head or Blade Installation

Before carrying out any further checks, ensure that the strimmer head or brush cutter blade has been installed correctly.

If you have recently changed between a strimmer head and a brush cutter blade, refer to the relevant installation guide and confirm that all components have been fitted and secured correctly.

Check the Shaft Connection

If the cutting attachment is installed correctly but still does not rotate, check that the upper and lower shaft sections are properly connected.

A loose or incorrectly assembled shaft connection can prevent drive from being transferred from the engine to the cutting head.

Inspect the Drive Shaft

The most effective way to diagnose the issue is to check whether the internal drive shaft is damaged, bent, twisted, or disconnected.

Step 1 – Separate the Shaft Sections

Carefully disconnect the upper and lower shaft sections according to the instructions in your user manual.

Step 2 – Check the Lower Shaft

1. Rotate the strimmer head or brush cutter blade by hand.
2. While doing so, look down the lower shaft tube.
3. The internal drive shaft should rotate smoothly and consistently.

Result:

• If the drive shaft does not rotate smoothly, the lower shaft assembly is likely damaged and may need replacing.
• If it rotates correctly, proceed to the next step.

Step 3 – Check the Upper Shaft

⚠️ Warning: Take extra care when carrying out this check. Keep hands, clothing, and loose objects clear of any moving parts.

1. Start the engine.
2. Look down the upper shaft tube.
3. Gently apply throttle while observing the drive shaft.

Result:

• If the drive shaft rotates smoothly, the issue may lie elsewhere in the drive system.
• If the drive shaft does not rotate, the upper shaft assembly or drive mechanism may have failed and require replacement.

1. This article covers the basic checks you can perform if your petrol strimmer or brush cutter is vibrating excessively during operation.

   Contents

   • Identify the Source of the Vibration
   • Vibration from the Engine Housing
   • Vibration from the Shaft

2. ---

   Identify the Source of the Vibration

   The first step is to determine where the vibration is originating from. Excessive vibration will typically come from either:

   • The engine housing
   • The drive shaft assembly

3. Identifying the source of the vibration will help determine the appropriate corrective action.

   ---

   Vibration from the Engine Housing

   If the vibration appears to be coming from the engine housing:

   1. Stop the engine and allow it to cool completely.
   2. Inspect all visible screws, bolts, and fasteners.
   3. Ensure they are secure and correctly tightened.

4. If all fasteners are secure and the vibration persists, there may be an internal engine fault that requires further investigation.

   Possible causes include:

   • Damaged engine components
   • Excessive engine wear
   • Internal mechanical failure

5. In these cases, the engine should be inspected by a qualified technician.

   ---

   Vibration from the Shaft

   If the vibration is coming from the shaft assembly, the internal drive cable may be bent, twisted, worn, or damaged.

   Step 1 – Separate the Shaft Sections

   Disconnect the upper and lower shaft sections according to the instructions in your user manual.

   Step 2 – Check the Lower Shaft

   1. Rotate the strimmer head or brush cutter blade by hand.
   2. While rotating it, look down the lower shaft tube.
   3. Observe whether the internal drive cable rotates smoothly.

6. Step 3 – Check the Upper Shaft

   ⚠️ Warning: Keep hands, clothing, and loose objects clear of moving parts during this check.

   1. Start the engine.
   2. Look down the upper shaft tube.
   3. Gently apply throttle while observing the internal drive cable.

7. Results

   • If vibration or irregular movement is observed in the lower shaft, the lower shaft assembly may require replacement.
   • If vibration or irregular movement is observed in the upper shaft, the upper shaft assembly may require replacement.

My Petrol Strimmer/Brush Cutter Pull Cord Is Faulty

This guide covers the basic checks and repair options if your pull cord is not working correctly.

Common Pull Cord Faults

If your pull cord:

• Will not pull out properly
• Is stuck
• Feels loose
• Does not retract correctly

you will usually need to replace the Starter Assembly.

Please note that replacing the starter assembly on this machine is a complex repair because it involves removing the clutch assembly, which requires specialist tools and mechanical experience.

If you are not confident carrying out this repair, we recommend contacting our Warranty & Technical Support team to discuss a possible collection and repair. Alternatively, a qualified mechanic or technician may be able to carry out the work for you.

Replacement starter assemblies are available through our website or via our Spares Helpline.

Damaged Pull Handle Only

If only the plastic pull handle is damaged and the cord is still retracting correctly into the machine, you may only need to replace the Starter Grip rather than the complete starter assembly.

Starter grips are available through our website or via our Spares Helpline.

Replacing the Starter Assembly

⚠️ Warning: This procedure is complex, requires specialist tools, and can be dangerous if performed incorrectly.

Tools Required

• Torx bit (T25/T27)
• Piston stop
• Precision pliers
• Clutch removal tool

Parts Required

• Starter Assembly

Removal Procedure

1. Using a T25/T27 Torx bit, remove the four screws securing the cone to the starter assembly.
2. Carefully separate the cone from the starter assembly.
3. Remove the spark plug and install a piston stop.
4. Remove the retaining bolt located in the centre of the clutch housing.
5. Remove the retaining circlip from the top of the clutch.
6. Using a clutch removal tool, rotate the clutch anti-clockwise and remove both the clutch and the backing plate.
7. Remove the four screws securing the starter assembly.
8. Remove the two screws located on the rear engine cover (black plastic cover).
9. Ensure the retaining clip on the right-hand side connecting the two covers is unclipped.
10. Remove the starter assembly and replace it with the new unit.

Reassembly

Reassemble the machine by following the above steps in reverse order.

During reassembly:

• Ensure the clutch is tightened correctly.
• Ensure the retaining circlip is refitted securely.
• When reconnecting the upper shaft to the clutch housing, make sure the main drive shaft engages correctly in the drive slot.

⚠️ If the drive shaft is not seated correctly in the slot, the engine will run but no drive will be transmitted to the cutting attachment.

This guide explains how to change your petrol brush cutter from a grass trimmer head to a brush cutter blade, and how to convert it back again.

Please follow the instructions for your specific model.

Changing from Grass Trimmer to Brush Cutter

Step 1 – Lock the Gear Head

1. Align the slot in the flanged washer with the slot in the gear head.
2. Insert the supplied hex wrench through both slots to lock the gear head and prevent it from rotating.

Step 2 – Remove the Trimmer Head

1. Unscrew the grass trimmer head assembly by turning it clockwise.
2. Remove the cupped washer and flanged washer.
3. Retain these parts for installing the brush cutter blade.

Step 3 – Install the Brush Cutter Blade

1. Place the flanged washer onto the gear head shaft with the hollow side facing the gear head.
2. Position the brush cutter blade onto the flanged washer.
3. Ensure the raised centre of the washer passes through the hole in the blade and that the blade sits flat.

Step 4 – Fit the Retaining Hardware

1. Install the cupped washer with the raised centre facing away from the blade.
2. Fit the blade nut onto the gear head shaft.

Step 5 – Secure the Blade

1. Insert the hex wrench through the locking slots again to prevent rotation.
2. Tighten the blade nut by turning it anti-clockwise (left-hand thread).
3. Use the supplied wrench to tighten the nut securely.

Changing Back to Grass Trimmer

To convert back to a grass trimmer:

1. Remove the blade nut, cupped washer, and blade.
2. Refit the flanged washer.
3. Screw the trimmer head back onto the shaft by turning it anti-clockwise.
4. Tighten securely before use.

Follow the installation steps above in reverse order.

Changing from Brush Cutter to Grass Trimmer

Step 1 – Remove the Brush Cutter Blade

1. Hold the flange in place using an Allen key.
2. Unscrew the retaining nut by turning it clockwise.
3. Remove the blade.
4. Remove the shield washer(s) and retain them for reassembly.

Step 2 – Fit the Trimmer Head

1. Continue holding the flange with the Allen key.
2. Screw the trimmer head onto the shaft by turning it anti-clockwise.
3. Tighten until fully seated.
4. Remove the Allen key.

Refitting the Brush Cutter Blade

To reinstall the blade:

1. Remove the trimmer head.
2. Refit the shield washers in the same order they were removed.
3. Position the blade correctly on the shaft.
4. Hold the flange with the Allen key.
5. Install and tighten the retaining nut by turning it anti-clockwise.
6. Ensure the blade is secure before operating the machine.

Important: Keep the upper flange locked with the Allen key while tightening the blade nut.

This guide explains how to fit and replace the strimmer line on your petrol strimmer.

Table of Contents

• Removing the Spool
• Fitting New Strimmer Line
• Refitting the Spool
• Reinstalling the Cover
• Adjusting the Line Length

Removing the Spool

1. Remove the spool cover/bolt cap.
2. Carefully remove the cover and set aside the spring. Take care not to lose it.

       3.Remove the spool and discard any remaining strimmer line.

Fitting New Strimmer Line

1. Create a small bend or nick in the centre of the new line.
2. Hook the centre of the line into the slot located in the middle of the spool.
3. Wind the line evenly onto both sides of the spool, following the direction indicated by the arrows on the spool.

1. Ensure the line is wound neatly and evenly to prevent tangling during operation.

Refitting the Spool

1. Secure both ends of the line in the retaining slots on the spool.
2. Feed the line ends through the eyelets in the spool housing.
3. Carefully insert the spool and spring back into the housing.
4. Pull both line ends through the eyelets while pushing the spool into place.
5. Press the spool down and turn it clockwise until it reaches the stop.
6. While holding the spool in position, turn it back slightly to ensure it locks securely.

Reinstalling the Cover

1. Refit the spool cover/bolt cap.
2. Tighten the cover by hand only. Do not overtighten.

Adjusting the Line Length

1. Press the underside of the spool by hand.
2. Pull both line ends until they extend slightly beyond the edge of the safety guard.
3. Check that the line feeds freely and is evenly positioned on both sides.
4. The strimmer head is now ready for use.

This guide explains how to replace the fuel lines on your petrol strimmer.

Note: These instructions are based on the CDB models but should be applicable to most petrol strimmer and brush cutter models with a similar fuel system, always check instruction manuals

Replacing the Fuel Lines

Step 1 – Feed the Fuel Line Through the Tank

1. Locate the fuel line opening in the fuel tank.
2. From the outside of the tank, feed the new fuel line through the hole.
3. Continue pulling the line through until a small section protrudes from the fuel filler opening.

Step 2 – Fit the Fuel Filter      

1. Through the fuel filler opening, locate the end of the fuel line.
   
2. Gently pull enough of the line through to provide access.
3. Attach the fuel filter securely to the end of the fuel line.
4. Once fitted, pull the fuel line back into position so that the filter sits freely inside the fuel tank.
5. Then pull the fuel line back from the outside and attach it to the carburettor inlet:
    

Step 3 – Check the Installation

1. Ensure the fuel line is seated securely in the tank opening.
2. Check that the fuel filter can move freely within the tank and reach the fuel during operation.
3. Verify that there are no kinks, twists, or damage to the fuel line.
4. Inspect all connections to ensure they are secure and fuel-tight.

Final Checks

Before starting the machine:

• Check for any signs of fuel leakage.
• Ensure all fuel lines are correctly routed.
• Confirm the fuel filter remains attached and positioned inside the tank.
• Refill with the correct fuel mixture if required.

Your petrol strimmer should now be ready for use.

Tip: If you are replacing multiple fuel lines, it can be helpful to take a photograph of the original routing before removal to ensure the new lines are installed correctly.

           This video is for the CDB30 grass trimmer, however it still applies in principle to other 2-stroke engines.

Proper winter storage helps prevent fuel-related issues and ensures your petrol strimmer is ready for use when the season starts again.

Note: The accompanying video demonstrates the procedure on a CDB30 grass trimmer. While the machine shown may differ from your model, the same principles apply to most 2-stroke petrol strimmers and brush cutters.

• Winter Storage Procedure

Step 1: Empty the Fuel Tank

Drain any remaining fuel from the fuel tank.

Leaving fuel in the tank over winter can lead to the formation of deposits and residues, particularly if condensation occurs. These deposits can cause starting and performance issues when the machine is next used.

Step 2: Empty the Carburettor

Start the engine and allow it to run until it stops naturally.

This ensures that any fuel remaining in the carburettor is used up before storage.

Step 3: Clear Any Remaining Fuel

Press the primer bulb several times to move any remaining fuel through the fuel system.

Attempt to start the machine again. If the engine does not start, the fuel system is sufficiently empty for storage.

Step 4: Store the Machine

Store the strimmer or brush cutter in a clean, dry location away from moisture and extreme temperatures.

Where possible:

• Keep the machine out of direct sunlight.
• Store it in a well-ventilated area.
• Protect it from damp conditions that could cause corrosion.

• Before Using the Machine Again

  At the start of the next season:

  1. Inspect the machine for any signs of wear or damage.
  2. Fill the tank with fresh 2-stroke fuel mixture prepared according to the manufacturer's recommendations.
  3. Prime and start the machine as normal.

• Following these simple steps will help keep your petrol strimmer in good condition and reduce the likelihood of fuel-related problems after long-term storage.