How do I change the fuel lines on my Petrol Chainsaw

Quick Answer

If your petrol chainsaw is difficult to start, leaking fuel, or running inconsistently, the fuel lines may need replacing. When fitting new fuel lines, it is important to route them correctly and ensure they are securely connected to prevent fuel leaks and maintain reliable engine performance.

⚠️ Safety Notice

Before carrying out any maintenance:

• Switch off the chainsaw and allow the engine to cool completely.
• Remove the spark plug cap to prevent accidental starting.
• Empty the fuel tank before removing the fuel lines.
• Work in a well-ventilated area away from open flames, sparks, or other ignition sources.
• Wear suitable protective gloves and eye protection.

When Do the Fuel Lines Need Replacing?

You may need to replace the fuel lines if:

• The chainsaw is difficult to start.
• Fuel is leaking from the machine.
• The engine runs unevenly or cuts out.
• The fuel lines are cracked, brittle, split, or damaged.
• The fuel lines have become loose or disconnected.

Before You Begin

Fuel line routing can vary between chainsaw models.

Always refer to the parts diagram or user manual for your specific model to ensure the fuel lines are routed correctly and connected to the appropriate components.

Replacing the Fuel Lines

1. Drain any remaining fuel from the fuel tank into a suitable container.
2. Remove any covers necessary to access the fuel tank and carburettor.
3. Carefully remove the existing fuel lines, noting their routing and connection points.
4. Compare the new fuel lines with the originals to ensure they are the correct length and diameter.
5. Fit the new fuel lines, following the routing shown for your model.
6. Ensure each fuel line is fully seated on its connection and is not twisted, kinked, or trapped.
7. Refit any components or covers removed during the replacement.
8. Refill the fuel tank with the correct fuel mixture.

Before Starting the Chainsaw

Before testing the machine:

• Check all fuel line connections are secure.
• Inspect for any signs of fuel leaks.
• Press the primer bulb (if fitted) until fuel flows through the lines.
• Start the chainsaw and allow it to idle.
• Check again for leaks while the engine is running.

Important Tip

Correct fuel line routing is essential for reliable operation.

If the fuel lines are connected incorrectly, the chainsaw may:

• Fail to start.
• Stall shortly after starting.
• Run poorly or lose power.
• Leak fuel.

If you are unsure of the correct routing, refer to the model-specific parts diagram before operating the chainsaw.

If the Problem Persists

If the chainsaw still does not run correctly after replacing the fuel lines:

• Check that all fuel line connections are secure.
• Ensure the fuel filter is fitted correctly inside the tank.
• Inspect the carburettor and primer bulb for damage or blockages.

Frequently Asked Questions

Why do fuel lines need replacing?

Fuel lines naturally deteriorate over time and can become hard, cracked, or split, leading to fuel leaks and poor engine performance.

Can I reuse the old fuel lines?

No. If the fuel lines are damaged or have become brittle, they should always be replaced.

Why won't my chainsaw start after replacing the fuel lines?

The fuel lines may be routed incorrectly, not fully connected, or contain air. Check the routing, ensure all connections are secure, and prime the fuel system before attempting to start the engine.

How do I know if a fuel line is leaking?

Signs of a leaking fuel line include the smell of petrol, visible fuel around the machine, or damp fuel lines and connections.