How do I check that the start-stop cable is tensioned correctly on my Petrol Lawnmower

This guide explains how to check and adjust the start–stop (engine brake) cable tension on your petrol lawnmower. If this cable is incorrectly adjusted, the engine may fail to start or may not stop correctly.

Table of Contents

1. What the Start–Stop Cable Does
2. Signs of Incorrect Cable Tension
3. Tools Required
4. Checking Cable Tension
5. Adjusting the Cable
6. Final Checks

What the Start–Stop Cable Does

The start–stop cable runs from the control lever on the handle down to the engine.

Its function is to:

• Engage and disengage the engine brake
• Allow the engine to start when the lever is held
• Stop the engine when the lever is released

If the cable is not correctly adjusted, the engine may not operate as expected.

Signs of Incorrect Cable Tension

The cable may need adjustment if:

• The engine will not start
• The start lever feels too loose or unresponsive
• The engine does not stop correctly when the lever is released
• There is excessive slack in the cable

Tools Required

Depending on your model, you may need:

• 8mm and 10mm spanner
• or 10mm and 12mm spanner

Checking Cable Tension

Step 1 – Inspect Cable Slack

Check the amount of free movement in the cable.

If there is more than 5–10mm of play, the cable will need adjustment.

Step 2 – Locate the Adjuster

Find the silver barrel adjuster located approximately halfway along the cable.

This is the adjustment point for tensioning.

Adjusting the Cable

Step 1 – Loosen Locking Nut

• Use the correct spanner to loosen the locking nut at the top of the barrel adjuster
• Do not fully remove the nut

Step 2 – Adjust Cable Tension

• Turn the barrel adjuster to reduce cable slack
• Aim for approximately 5–10mm of free play in the cable

Adjust gradually and recheck movement as you go.

Step 3 – Secure the Adjustment

Once correct tension is achieved:

• Tighten the locking nut
• Fully secure the barrel using the appropriate spanners

Ensure nothing moves once tightened.

Final Checks

After adjustment:

1. Pull the start lever to confirm smooth operation
2. Check that the cable returns correctly when released
3. Attempt to start the mower to confirm correct function

Safety Information

Always ensure the engine is switched off before adjusting the cable.

Keep hands clear of moving parts, and ensure the mower is on a stable surface before carrying out any maintenance.