Replacing Blue Max Chainsaw Fuel Line: A Step-By-Step Guide

If your Blue Max chainsaw is not starting, it may be time to replace the fuel line. This is a common issue with chainsaws, as the fuel lines that carry fuel from the tank to the carburettor can clog, crimp or crack over time. Damaged fuel lines restrict fuel flow and prevent the engine from starting. To replace the fuel line, you will need to remove the fuel cap and empty the fuel tank into an approved storage container, remove the cylinder shield, disconnect the spark plug wire and remove the air filter, remove the fuel filter, remove the carburettor, pull out the old fuel lines, and install the new fuel lines. You should wear work gloves and carry out the task in a well-ventilated area.

Clearing clogs and checking for cracks or crimps in the fuel line

To clear clogs in the fuel line, you will need to remove the fuel filter. First, empty the fuel tank into an approved storage container. Then, straighten a coat hanger and bend a hook at the end. Feed this through the mouth of the tank and fish out the cylindrical fuel filter. Cut the fuel line to remove the filter.

To check for cracks or crimps in the fuel line, you will need to remove the fuel lines from the carburetor and primer bulb using needle-nose pliers. Pay close attention to the connections and junctions where leaks are more likely. Look out for any signs of wear and tear, rust, or damage.

If you identify any clogs, cracks, or crimps, you will need to replace the fuel lines with manufacturer-approved parts.

Replacing the carburetor

To replace the carburetor on a Blue Max chainsaw, you will need to:

• Work in a well-ventilated area and remove the fuel cap, emptying the fuel tank into an approved storage container.
• Remove the cylinder shield using an Allen wrench to take out the screws holding it to the engine.
• Disconnect the spark plug wire and remove the air filter.
• Remove the carburetor using a 7/16-inch socket driver to loosen the two mounting nuts that secure the carburetor to the engine.
• Pull the air filter housing off the carburetor and carefully slide the carburetor off the engine block, being careful not to bend the throttle linkage or damage the gas lines.
• Reinstall the new carburetor, ensuring you do not crimp the fuel lines.
• Reattach the air filter cover and connect the spark plug.
• Reinstall the cylinder shield.
• Refill the fuel tank.

Note: It is important to wear work gloves and use the proper tools and safety equipment when performing any chainsaw repairs.

Checking the spark plug

To check the spark plug of your chainsaw, you will need to first remove the top cover to expose the spark plug. Then, remove the spark plug itself.

There are three methods you can use to check the spark plug:

First Method

• Place the spark plug wire onto the spark plug, but do not install the spark plug into the cylinder. Instead, leave it dangling loose.
• Hold the boot on the end of the spark plug wire with your hand and place the electrode tip of the spark plug onto a metal surface on the saw (e.g. the cylinder). Ensure that the spark plug remains in the spark plug boot.
• Using your other hand, pull the starter cord quickly.
• If your ignition works, you should see blue sparks where the plug is being grounded on the metal surface. Make sure that your ignition switch is in the "on" position.

Second Method

• Attach one end of an alligator clip wire to the spark plug boot, ensuring that the clip contacts the metal conducting surface inside the boot.
• Attach the other end of the alligator clip wire to the hot end of a digital multimeter.
• Touch a good metal surface ground with your ground probe on the multimeter.
• Set the multimeter to 20v DC.
• Pull the saw over and look for the multimeter to react. Fluctuating readings indicate that the ignition works, while no action means that it does not.

Third Method

• Place the spark plug wire onto the spark plug, but do not install the spark plug into the cylinder. Leave it dangling loose.
• Hold the metal threaded part of the spark plug in one hand and pull the saw over with the other.
• If you feel a shock, the ignition works. This method can be particularly useful in high-light situations where it may be difficult to see the spark directly.

If your chainsaw is not starting, a damaged spark plug may be the reason. Other potential reasons include stale gasoline, cracked fuel lines, a dirty carburetor, worn piston rings, and insufficient compression.

Checking the impulse hose

To check the impulse hose on a Blue Max chainsaw, follow these steps:

Firstly, it is important to understand the function of the impulse hose. The impulse hose is responsible for sending signals from the engine to the carburetor through pressure pulses, which in turn drives the diaphragm pump to deliver fuel to the combustion chamber.

Now, to check the impulse hose:

• Remove the spark plug: This will allow you to access the impulse hole and perform the necessary checks without the engine running.
• Cover the impulse hole with grease: Use a small amount of grease, such as Moly grease, and cover the impulse hole completely.
• Block the manifold: Use your thumb or another suitable object to block the manifold.
• Pull the starter cord: With the impulse hole covered in grease and the manifold blocked, pull the starter cord several times quickly.
• Observe the grease: If the impulse hose is functioning correctly, the grease should either be sucked into the impulse hole or expelled out. This indicates that the hose is intact and able to transmit pressure changes.
• Observe the engine: If the engine is not running, it may be due to a lack of fuel being pumped to the cylinder. This could be caused by a blocked or cracked impulse hose, a clogged fuel filter, or air leaks in the engine.
• Inspect the impulse hose: Remove the handle and inspect the impulse hose for any signs of damage, cracks, or blockages. A cracked or blocked impulse hose will need to be replaced.
• Check the intake manifold boot: Ensure that the intake manifold boot is intact and not torn, as this could also affect the engine's performance.
• Consult a specialist: If you are unable to identify the issue, it is recommended to consult a qualified technician or seek advice from a forum dedicated to chainsaw repair and maintenance.

By following these steps, you can effectively check the impulse hose on your Blue Max chainsaw and identify any potential issues affecting its performance.

Checking the piston

To check the piston of your Blue Max chainsaw, you will first need to disassemble the engine. This will involve removing the muffler and taking out the cylinder.

Once you have removed the cylinder, you can inspect the piston for any signs of damage. Look for vertical lines or streaks on the piston, which could indicate that it has been scored. If the piston is scored, it may need to be replaced.

You should also check the piston rings. Make sure they are free to move in the groove and can expand to make a seal with the cylinder wall. If the rings are damaged or stuck, they will need to be replaced.

Additionally, examine the cylinder for any scratches or grooves. If the cylinder is damaged, it may need to be honed or bored to restore it to a usable condition.

It is important to identify the cause of any piston damage to prevent it from occurring again. Common causes of piston damage include air leaks, lean fuel mixtures, debris in the air intake, and bearing failure.

If you are unsure about the condition of your piston or how to replace it, it is recommended to consult a qualified technician for assistance.

Frequently asked questions