How to Remove an Echo CS-305 Sprocket

The sprocket on an Echo CS-305 chain saw transfers movement and power from the clutch to the saw. Revolving continuously under constant stress, the sprocket wears out after two or three chains. Worn-out sprockets will transfer that roughness to the chain and cause chains to wear out more quickly. After each cleaning and sharpening, before replacing any chains, check the condition of the sprocket. Remove and replace the sprocket if you notice heavy wear on the teeth or the rim of the sprocket.

Combination bar tool
Leather work gloves
Piston stopper
Allen wrench

Instructions

- 1
  Pull the safety brake handle backward to disengage the chain brake. Shut the Echo's engine off and wait for the chain to stop spinning. Set the Echo chain saw on a workbench.
- 2
  Loosen the two bar nuts on the bar cover, using the wrench end of the combination bar tool. Loosen the bar adjustment screw, on the inside of the power head near the muffler on the CS-305, using the screwdriver end of the combination bar tool. Unscrew the bar nuts fully using your fingers. Pull off the bar cover.
- 3
  Pull the bar off the two bar posts, lifting up on the nose. Take the bar and chain off the Echo chain saw. Pull off the spark plug's lead wire from the end of the spark plug, near the rear handle. Unscrew the spark plug and take it out of the cylinder.
- 4
  Insert the piston stopper slowly into the cylinder hole. Rotate the clutch with your hand until the piston hits the stopper and can't move. Unscrew the center bolt clockwise on the clutch hub, using the Allen wrench. Slide the clutch assembly off the crankshaft stub.
- 5
  Pull off the sprocket and clutch drum from under the clutch assembly. Separate the parts and inspect them for damage. Replace the sprocket if it's worn below .5 mm. Reassemble the parts in reverse order. Lift out the piston stopper slowly when unblocking the cylinder.

Why Won't My Brand New Mower Start?

How to Install a 42 Troy-Bilt Mower Deck

Garden Tools & Supplies