Echo Chain Saw CS4910 2020 Oiler System Replacement

Make sure you have the ignition switch turned off before starting your repair.

Use your fingers to loosen the air filter cover knob.

Remove the air filter cover.

Remove the air filter

Use your fingers to pull up and disconnect the spark plug boot.

Use a 13 mm wrench to loosen and remove the two nuts securing the sprocket guard.

Pull the sprocket guard straight off its two pegs and remove it.

Pull the saw chain away from the tip of the guide bar to unclip it.

Push the guide bar towards the back of the device to unclip the rest of the saw chain.

Pull the guide bar away from the device to separate the saw chain from the clutch drum.

Remove the guide bar and the saw chain.

Use a T25 Torx driver to remove the two 17 mm-long screws securing the bumper spike.

Pull the bumper spike away from the chassis and remove it.

Remove the two screws securing the inner guide plate:

Use a Phillips driver to remove the 8 mm-long screw.

Use a T25 Torx driver to remove the 33 mm-long screw.

Pull the inner guide plate straight off its two pegs and remove it.

Use a 2.5 mm hex key to remove the three 14 mm-long screws securing the brake cover.

Pull the brake cover straight off the chassis and remove it.

Make sure the chain brake is in the disengaged position before continuing.

Use a 4 mm hex key to remove the two screws securing the chain brake handle:

One 19 mm-long screw

One 23 mm-long screw

Rotate the chain brake handle towards the guide bar recess to unhook the brake lever.

Pull the handle away from the chassis to completely remove it.

Use a Phillips driver to remove the 8 mm-long screw securing the chain brake assembly.

While holding the spring with one hand, slowly push the brake lever out of its recess until the spring is fully extended.

Remove the chain brake assembly.

Pull the retaining off the chassis and remove it.

Pull the torsion spring off the chassis and remove it.

Use a flathead screwdriver to pry the collar out of its recess.

Remove the collar.

Use a flathead screwdriver, or a 3 mm hex key, to remove the three 18 mm screws securing the engine cover.

Pull the engine cover straight up off the engine.

Remove the engine cover.

Use a spark plug socket to loosen the spark plug.

Remove the spark plug.

Insert a piston stopping cord or rope through the cylinder head into the combustion chamber until the crankshaft can no longer turn over.

Use a 13 mm wrench to loosen and remove the clutch drum nut.

Remove the washer.

Remove the rim sprocket.

Pull the clutch drum straight off the clutch assembly to remove it.

Use a clutch removal tool to loosen the clutch assembly.

Remove the clutch assembly.

Pull the worm gear assembly off of the crankshaft and remove it.

Use a 3 mm hex key to remove the 18 mm-long screw securing the oiler cover.

Use a pick tool to remove the oiler cover from its recess.

Use a 3 mm hex key to remove the two 18 mm-long screws securing the auto-oiler assembly.

Use tweezers, or your fingers, to remove the auto-oiler assembly from the chassis.

Use a pick tool to pull the oil filter assembly through its hole in the chassis until you can grip it with your fingers.

Use your fingers to remove the rest of the oil filter assembly.