How to Replace the Chain Adjustment Bolt on an Echo Chainsaw

The chain/bar adjustment bolt works with the adjuster gears and the adjustment pin, allowing you to adjust the tension on the cutting chain. The bolt is rotated by the gears. As it rotates, it pulls the adjustment pin along, which moves the bar. The threads on the bolt can strip, either after years of use, or more quickly if the chain is over-tensioned.

Let's get started.

REMOVING THE ADJUSTMENT BOLT   1. Remove the chain brake.

a. Use a wrench to loosen the two bar nuts.

b. Use a screwdriver to rotate the chain adjustment screw counterclockwise to reduce tension from the chain.

c. Remove the two bar nuts.

d. Remove the chain brake assembly from the saw.

  2. Remove the bar and chain.

a. Carefully remove the chain from the front of the bar.

b. Remove the chain from the rear sprocket.

c. Remove the bar from the saw.

  3. Remove the adjuster assembly.

a. Lay the chain brake assembly on your workbench so that the metal brake band faces up.

b. Remove the two screws securing the metal cover plate to the tensioner assembly.

c. Remove the metal cover plate.

d. Remove the adjuster assembly from the brake housing.

  4. Remove the adjustment bolt.

a. Separate the bevel gear and collar from the adjustment bolt and tensioner pin.

b. Unthread and remove the chain tensioner pin from the adjustment bolt.

d. Discard the old adjustment bolt.

INSTALLING THE NEW ADJUSTMENT BOLT

  5. Install the adjustment bolt.

a. Thread the chain tensioner pin onto the new adjustment bolt (approximately half-way onto the new bolt).

b. Thread the new adjustment bolt (with the chain tensioner) through the plastic collar and through the center of the bevel gear.

REASSEMBLING THE UNIT

  6. Reinstall the adjuster assembly.

a. Install the adjuster assembly into the chain brake housing. The plastic collar should fit snugly into the channel on the housing and the tensioner pin should face away from the workbench.

b. Install the metal cover plate onto the chain brake housing.

c. Secure the metal cover plate with the two screws.

  7. Reinstall the bar and chain.

a. Install the bar onto the bar studs.

b. Slide the bar toward the rear of the saw.

c. Carefully install the rear portion of the chain around the sprocket and drum.

d. Install the front portion of the chain onto the bar, ensuring that the chain aligns with the groove along the top of the bar, as well as the sprocket at the tip of the bar.

e. Slide the bar toward the front of the saw until the chain seats snugly onto the bar.

  8. Reinstall the chain brake assembly.

a. Install the chain brake assembly onto the saw (the bar studs should align with the openings on the housing).

b. Use a screwdriver to rotate the tensioner screw (as-needed) until the chain brake assembly seats (snaps) securely in place.

c. Install (but do not fully tighten) the bar nuts onto the bar studs.

  9. Tension the chain.

a. Grasp and raise the distant end of the bar and chain assembly (opposite the engine).

b. While holding the bar in a raised position, use a screwdriver to rotate the tensioner screw until the chain begins to tighten against the bar.

c. Lift the chain away from the bar assembly and inspect the gap between the two components.

d. The chain is tensioned correctly when you are able to raise the chain slightly away from the bar without creating a visible gap between the guide links and the top of the bar.

e. Once the chain is properly adjusted, tighten the bar nuts to secure the assembly.