When you take your new chainsaw out of the box for the first time, you may be surprised to find there is some assembly required. New chainsaws are shipped with the guide bar and chain unattached. Correctly mounting the bar and chain is important to the saw's operation as well as your safety. Instructions can vary slightly with different models. Your chainsaw may have a safety brake or a different bolt configuration for the sprocket cover. The basic directions for chain installation is the same for almost all models.
Unscrew the nuts on the sprocket cover with a wrench. The sprocket cover is located on the right side of the motor housing in front of the handle.
Remove the sprocket cover, and set it aside.
Loosen the tensioning screw by turning it counterclockwise until the tensioning tab meets the end of the guide slot furthest from the tip of the guide bar.
Mount the guide bar over the studs for the sprocket cover. The adjusting tab must fit into the adjusting slot on the guide bar. Properly installed, the end of the guide bar lies flat against the body of the saw.
Put on a pair of leather gloves before handling the chain.
Lay the chain out in a flat loop. The drive and guide teeth are on the inside of the loop with the cutting teeth facing out.
Place the chain over the teeth on the saw's drive sprocket. Fit the remaining portion of the chain's guide teeth into the groove on the guide bar.
Remove most of the slack in the chain by turning the tensioning screw clockwise.
Replace the sprocket cover. Replace the nuts that retain the cover. Tighten them with your fingers only at this time.
Set the saw upright. Lift the tip of the guide bar with one hand. Turn the tensioning screw clockwise until the chain fits snugly against the bottom of the guide bar.
Tighten the nuts on the sprocket cover firmly with a wrench.
Refer to your owner's manual for the exact location of your tensioning screw. If your saw is equipped with a chain brake, pull the brake lever toward the handle before attaching the chain. When replacing a chain, match the drive teeth of the new blade carefully with the existing chain. Drive teeth with improper spacing can damage the drive socket or cause the chain to jump off the bar.
Do not start or operate the saw until you secure all attachments. Operating a chainsaw with too much slack in the chain can cause serious injury. Check the tension often while using a new chain. Always wear gloves when handling the chain on your saw. The cutting edges on the chain are sharp and dangerous even when the saw is not operating.