How do I replace the oil pump on my Petrol Chainsaw

Quick Answer

If your petrol chainsaw is no longer lubricating the chain and the oil pump has been identified as the cause, it will need to be replaced. This repair involves removing the clutch assembly to gain access to the oil pump and should only be carried out by someone with good mechanical knowledge and the correct tools.

⚠️ Safety Notice

This is a complex repair that requires specialist tools and mechanical experience.

Before you begin:

• Switch off the chainsaw and allow the engine to cool completely.
• Disconnect the spark plug cap to prevent accidental starting.
• Empty the fuel and chain oil tanks where possible to reduce the risk of spills.
• Wear suitable protective gloves and eye protection.
• Work on a clean, stable surface.

If you are unsure at any stage, please contact our Technical Support Team before continuing.

Tools Required

You will need:

• Clutch removal tool
• Piston stop
• T20 Torx bit
• 13 mm socket
• Replacement oil pump

Before You Begin

The oil pump is located behind the clutch assembly. To access it, the clutch and surrounding components must first be removed.

Take note of the position of all components during disassembly to ensure they are reassembled correctly.

Oil Pump Replacement Procedure

Step 1: Remove the Chain Brake Assembly

1. Remove the chain brake assembly by undoing the two 13 mm retaining nuts.
2. Remove the guide bar and chain if they have not already been removed.

Step 2: Remove the Clutch

1. Remove the spark plug and fit a piston stop into the cylinder.
2. Using the clutch removal tool, rotate the clutch clockwise (towards OFF) to loosen it.
3. The clutch may be tight initially before it begins to unscrew.
4. Continue until the clutch has been completely removed.

Step 3: Access the Oil Pump

1. Using a T20 Torx bit, remove the two upper screws securing the black cover behind the clutch.
2. Remove the cover to expose the oil pump.

Step 4: Remove the Oil Pump

1. Remove the two Torx screws securing the oil pump.
2. Take care when removing the upper right-hand screw, as it also secures the earth cable.
3. Disconnect the oil pipes from the pump and remove the oil pump.

Step 5: Install the New Oil Pump

1. Position the replacement oil pump.
2. Reconnect the oil pipes.
3. Refit the earth cable in its original position.
4. Tighten both retaining screws securely.

Step 6: Reassemble the Chainsaw

1. Refit the black cover and secure it with the two Torx screws.
2. Reinstall the clutch using the clutch removal tool.
3. Tighten the clutch by turning it anti-clockwise until secure.

Important: Do not overtighten the clutch. Check that it rotates freely and that all components are correctly seated.

Step 7: Refit the Cutting Components

1. Refit the guide bar and chain.
2. Reinstall the chain brake assembly.
3. Adjust the chain tension in accordance with the user manual.

Step 8: Final Checks

Before using the chainsaw:

• Ensure all screws and fixings are secure.
• Check that the chain moves freely.
• Fill the chain oil reservoir.
• Start the chainsaw and confirm that oil is being delivered to the guide bar and chain.

If You Are Unsure

If you are not confident carrying out this repair, or if the chainsaw still does not lubricate the chain after replacing the oil pump, please contact our Technical Support Team for further assistance.

Frequently Asked Questions

How do I know if the oil pump needs replacing?

If the oil tank is full, the oil ports are clear, and the chain still is not receiving oil, the oil pump may be faulty.

Do I need to remove the clutch to replace the oil pump?

Yes. The oil pump is located behind the clutch assembly and cannot be accessed without first removing the clutch.

Why is a piston stop required?

The piston stop prevents the engine from turning while the clutch is being removed and refitted.

Should I test the chainsaw after replacing the oil pump?

Yes. Refill the chain oil reservoir and check that oil is being delivered to the guide bar before using the chainsaw for cutting.